European Cyclotron Progress Meeting 2012

9 May 2012, 08:00 → 12 May 2012, 22:00 Europe/Zurich

Auditorium (PSI)

Mike Seidel (Paul Scherrer Institut)

The European Cyclotron Progress Meeting ECPM XXXVIII was held at PSI from 9 until 12 May 2012.

The meeting will be devoted to:

• cyclotrons and their applications
• new projects and upgrades
• cyclotron subsystems and technical advancements
• medical and industrial applications
• general trends and future developments
• educational reviews

The ECPM will start on Wednesday evening, 9 May 2012, at 19:00, with a welcome reception (light meal) at the Auditorium. The Registration desk will be open from 18:00 - 20:00 in the same area.

A one-day educational session for students will be planned for 9 May 2012. Should you be interested to attend the educational session, please check this option in the registration form.

First announcement (pdf)

Circulars first_circular_ecpm2012.pdf second_circular_ecpm2012.pdf

Document

• anfahrt_psi_zurzach.pdf
• BusTimetables.pdf
• Exhibition_Form_ECPM2012.pdf

Picture Package ECPM2012.zip

Poster A3_ECPM2012.pdf

Wednesday, 9 May

09:00 → 09:05 Welcome Educational Session

Speaker: Marco Schippers (Paul Scherrer Institut)

09:05 → 10:45 Basic techniques and Physics:

Convener: Marco Schippers (Paul Scherrer Institut)

09:05 Basic beam dynamics

Speaker: Dr Frederic Chautard (CNRS)

Slides Cyclotrons_ECPM_2012-B.pdf

Video Beam_Dynamics_by_Frédéric_Chautard_PSI_logo.AVI

09:55 Central region/injection and extraction

Speaker: Dr Pauli Heikkinen (University of Jyväskylä, Department of Physics)

Slides Injection_cr_extraction.pdf

Video Injection,_central_region_and_extraction_by_Pauli_Heikkinen_PSI_logo_.AVI

10:45 → 11:15 Coffee Break

11:15 → 12:05 Basic techniques and Physics:

Convener: Marco Schippers (Paul Scherrer Institut)

11:15 Diagnostics in cyclotrons

Speaker: Rudolf Doelling (Paul Scherrer Institut)

Slides ECPM2012_lecture_Beam_Diagnostics_Doelling.pdf

Video Diagnostics_in_Cyclotrons_by_Rudolf_Dölling_PSI_logo.AVI

12:05 → 13:30 Lunch

13:30 → 14:20 Basic techniques and Physics:

Convener: Marco Schippers (Paul Scherrer Institut)

13:30 RF systems

Speaker: Mr Antonino CARUSO (INFN-LNS)

Slides Rf_systems_4_J.pdf

Video RF_Systems_by_Antonio_Caruso.AVI

14:20 → 16:00 Special topics and new Developments

Convener: Joachim Grillenberger (Paul Scherrer Institut)

14:20 Reliability and life-cycle of accelerators

Speaker: Mr Samuel Meyroneinc (Institut Curie - Centre de Protonthérapie)

Slides ECPM2012_-_Educ_Reliability_and_life-cycle_accelerator_SM.pdf

Video Reliability_and_Lifecycle_by_Samuel_Meyroneinc.AVI

15:10 High intensity and high power aspects of cyclotrons

Speaker: Mike Seidel (Paul Scherrer Institut)

Slides cyclotrons_highIntensity_Seidel.pdf

Video High_intensity_and_high_power_aspects_of_cyclotrons_by_Mike_Seidel.AVI

16:00 → 16:30 Coffee Break

16:30 → 17:20 Special topics and new Developments

Convener: Marco Schippers (Paul Scherrer Institut)

16:30 Physical issues at size reduction of cyclotrons

Speaker: Dr Willem Kleeven (IBA)

Slides ECPM2012-Physical_issues_at_size_reduction_of_cyclotrons.pdf

Video Physical_issues_at_size_reduction_of_cyclotrons_by_Willem_Kleeven_PSI_Logo.AVI

18:00 → 20:00 Registration

Conveners: Barbara Ajmo (Paul Scherrer Institut), Mrs Daniela Lerch (Paul Scherrer Institut)

19:00 → 21:00 Welcome Reception

Thursday, 10 May

09:00 → 18:00 Industrial Exhibition

09:00 → 09:25 Welcome ECPM - 2012

Conveners: Leonid Rivkin (Paul Scherrer Institut), Mike Seidel (Paul Scherrer Institut)

09:05 Opening Address

Speaker: Leonid Rivkin (Paul Scherrer Institut)

09:25 → 10:40 Projects and studies

Convener: Mike Seidel (Paul Scherrer Institut)

09:25 SPES Project: a Neutron Rich ISOL Facility for re-accelerated RIBs

SPES (Selective Production of Exotic Species) is an INFN project to develop a Radioactive Ion Beam (RIB) facility as an intermediate step toward EURISOL. The SPES Project is under realization at the INFN Legnaro National Laboratories site. SPES Project main goal is to provide an accelerator system to perform forefront research in nuclear physics by studying nuclei far from stability. SPES Project is concentrating on the production of neutron-rich radioactive nuclei with mass in the range 80-160. The final energy of the radioactive beams on target will range from few MeV/u up to 11 MeV/u for A=130. The SPES acceleration system will be presented, together with the facility realization status.

Speaker: Mr Leandro AC Piazza (INFN - LNL)

Slides 120510_lp_SPES_ECPM012.pdf

09:50 DAEdALUS Superconducting Ring Cyclotron To Deliver 10 mA Proton Beam at 800 MeV

An accelerator module based on a injector cyclotron and a Superconducting Ring Cyclotron (SRC) able to accelerate H2+ at energy of 800 MeV/amu and with peak current of 5 mA is presented. The use of a H2+ molecule beam has three main advantages: 1) it reduces the space charge effects, 2) because of the stripping extraction it simplifies the extraction process w.r.t. single turn extraction and 3) we can extract more than one beam out of one SRC. This module is forecasted for the DAEdALUS (Decay At rest Experiment for cp At Laboratory for Underground Science) experiment, which is a neutrino experiment proposed by groups from MIT and Columbia University. This experiment needs three accelerator modules able to deliver about 1.6 MW, each one, when operated with a duty cycle of 20%. Extensive beam dynamics studies have been carried out over the last two years and have proved the feasibility of the design. The superconducting magnetic sector of the SRC is calculated with the TOSCA module of OPERA3D. The main features and the beam dynamic along the SRC acceleration, without and with space charge effects, are presented.

Speaker: Mrs Alessandra Calanna (MIT)

Slides DAEdALUS_ECPM2012_calanna.pdf

10:15 Commissioning of the 72 MeV Transfer Line for the Buncher Based Beam Injection into the Ringcyclotron

In the last year, the extraction of a 2.4 mA proton beam became a well established operation mode of the 590 MeV Ringcyclotron. The enhancement of the beam power up to 1.42 MW at a relative loss level of 10-4 has evolved from modifications applied to the PSI high power proton facility, reported earlier. However, the layout of the 3rd harmonic cavity has reached its operation limits. To advance the extracted beam intensity towards 3 mA, a 500 MHz rebuncher has been installed in the 72 MeV transfer line between Injector 2 and the Ringcyclotron. To meet the needs of this buncher based injection, several investigations were performed. In particular a demanding control of the dispersion along the 72 MeV transfer line has been worked out, a more flexible algorithm to change the number of revolutions in the Ringcyclotron has been established, and an improvement of the matching has been found. Moreover, a precise modelling of the space charge effects in the injection region of the Ringcyclotron has been recognized as mandatory, since these have to be compensated by the installed flattop system.

Speaker: Mr Martin Humbel (Paul Scherrer Institut)

Slides Villigenakt.pdf

10:40 → 11:10 Coffee Break

11:10 → 12:25 Projects and studies

Convener: Dr Frederic Chautard (CNRS)

11:10 Boosting 250 MeV protons from a cyclotron to 350 MeV For Therapy and Radiography Applications

We propose to upgrade existing proton therapy facilities by adding a Linac, which boosts typical cyclotron beams of 230 or 250 MeV protons to 350 MeV. This energy allows proton radiography of all sites in the patients body (yielding improved dose calculations). Furthermore, the transversal penumbra of a 350 MeV proton is comparable to that of carbon ion beams. This can be used in stereotactic proton irradiations of small volumes or if a sharp dose gradient is needed. Based on work conducted by the TERA Foundation a design of a 3 GHz Cell Coupled Linac (CCL) has been made. The CCL-technology enables strong (20-25 MV/m) electric fields for the acceleration. This confines the total linac length to less than 7 m, which allows for upgrading existing proton therapy facilities. As the linac will be pulsed at 200 Hz repetition rate, we have modified the beam intensity control in the central region of the cyclotron to make a pulsed beam (pulse length 5 mus, rise/fall time 1 mus), to minimize beam losses between linac pulses. A first unit accelerating from 250 MeV to 275 MeV is planned to be built and inserted for tests in the existing beam line of the proton therapy facility at PSI.

Speaker: Marco Schippers (Paul Scherrer Institut)

Slides booster-ECPM2012-04-09-used.pdf

11:35 IBA Accelerator Group R&D Projects Overview

Since last ECPM, the IBA R&D Accelerator Group delivered several new Cyclotrons developments to customers. In the range of low energy machines, first Cyclone3 and Cyclone11 were studied, built and accepted by their users. Beside this, the Cyclone30 family grew up with a high current version completed on site and a multi-particle machine, the Cyclone 30xp, largely inspired by Cyclone70 and freshly factory tested. At higher energy, dedicated to ProtonTherapy, the development of the new superconducting synchro-cyclotron (S2C2) has been modeled, designed and is now being built in a joint effort of many team members and IBA partners. As an introduction to the various scientific communications presented during the 2012 ECPM, this presentation will give an overview of those projects. Main deliverables, facts and figures will be presented. Major risks, successes and issues will be highlighted too. Moreover, the way to handle such a bunch of projects with a limited team and within a short period of time will be detailed. It is indeed not a trivial question, as it impacts our scientific tools, internal R&D processes, knowledge management and knowledge acquisition strategy.

Speaker: Mr Thomas Servais (IBA)

Slides IBA_Accelerator_Group_R&D_projects_overview_pdf_version.pdf

12:00 The new Cyclotron Laboratory in Bern

A new cyclotron laboratory for radioisotope production and multi-disciplinary research in Bern has been constructed and will be fully operational in 2012. A commercial IBA 18 MeV proton cyclotron, equipped with a specifically conceived 6 m long external beam line, ending in a separate bunker, will provide beams for routine 18-F and other PET radioisotope production as well as for novel detector, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. The accelerator is embedded into a complex building which hosts two physics laboratories, four Good Manufacturing Practice (GMP) radiochemistry and radiopharmacy laboratories, offices and two floors for patient treatment and clinical research activities. This project is the result of a successful collaboration among the University Hospital in Bern (Inselspital), the University of Bern and private investors, aiming at the constitution of a combined medical and research center able to provide the most cutting-edge technologies in medical imaging and cancer radiation therapy. In this context, the establishment of a proton therapy center on the campus of the Inselspital is in the phase of advanced study.

Speaker: Dr Saverio Braccini (Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland)

Slides Braccini_ECPM_PSI_10-5-2012.pdf

12:25 → 13:30 Lunch

13:30 → 14:45 Projects and studies

Convener: Dr Pauli Heikkinen (University of Jyväskylä, Department of Physics)

13:30 Commissioning and Testing of Varian’s 250 MeV Superconducting ProBeam™ Cyclotrons for Proton Therapy

Varian Medical Systems Particle Therapy is facing the challenge of having to manufacture, test, deliver, and commission several ProBeam™ proton therapy systems within the next years. Our strategy to deliver high quality products is based on comprehensive integral factory testing of all critical system components, including beam operation of the 250 MeV superconducting cyclotrons. For that purpose, Varian is operating an integrated assembly and test facility near Cologne/Germany. We report on the factory commissioning of Varian’s 3rd SC cyclotron comprising of magnetic shimming, fast pulsed mode RF conditioning using a newly developed high power combined transistor amplifier, hw and sw system integration tests, and -finally- beam operation. This machine, together with all other technical equipment, has already been delivered to the customer’s site in the USA. The successful transportation and installation proved Varian’s concept of shipping the cyclotron essentially in its factory assembled and tested state. On-site verification tests are fulfilling our expectations for fast beam commissioning. Furthermore, the current manufacturing status of cyclotrons #4 and #5 will be presented.

Speaker: Dr Heinrich Röcken (Varian Medical Systems Particle Therapy)

Slides ECPM2012-Varian_PT_Superconducting_Cyclotron_Commissioning+Testing_publication.pdf

13:55 Development of the new IBA S2C2

In an effort to respond to market needs, the decision was taken in 2009 to start the development of a compact superconducting synchrocyclotron as an alternative source of protons. This new accelerator will be integrated to future small footprint proton therapy centers called Proteus One ®. This ambitious project, driven by a small dedicated team and run on a tight schedule and budget, is challenging in numerous aspects. Also, the S2C2 is a unique opportunity to start from a blank page, bring new technologies into the company, create new partnerships and incorporate novel ideas in the system architecture. Furthermore, other aspects affecting the competitivity of the future products have also been taken into account. For instance, on site deployment costs, operability and maintainability are key aspects in technological choices and design. This presentation covers the evolution of the project from initial requirements and sketches to the latest pictures of assembly and testing in our factory, describing all major sub-systems in detail and discussing a few of the difficulties encountered.

Speaker: Mr Patrick Verbruggen (IBA)

Slides ECPM2012_-_Development_of_the_new_IBA_S2C2.pdf

14:20 Beam sharing in cyclotron-based proton therapy facilities

In cyclotron based proton therapy facilities using volumetric scanning the beam energy beam is varied with a degrader and energy selection system (ESS) to control the beam quality. This system is located directly behind the cyclotron and is shared by all treatment rooms. Consequently the switching of the beam between rooms requires retuning of the ESS and the common beam line and a logical process to couple the ESS with another irradiation setup. This timeconsuming process reduces the treatment capacity of larger facilties. We propose an optimized layout with a separate ESS for each setup and a system for rapid switching or beam splitting, which increases patient throughput. Beam splitting allows simultaneous irradiations in all treatment rooms and gives the largest gain. The independent control of the beam intensity in the different treatment rooms is, however, a challenge. The rapid switching is in this respect straightforward. It allows quasi-simultaneous treatment: during field changes in one treatment room the beam can be used in another room. The fixed beam energy in the common beam line makes it possible to use permanent magnet quadrupoles in this line.

Speaker: Prof. Sytze Brandenburg (Kernfysisch Versneller Instituut, University of Groningen, the Netherlands)

Slides ECPM1205.pdf

14:45 → 15:15 Coffee Break

15:15 → 16:00 Technology

Convener: Dr Heinrich Röcken (Varian Medical Systems Particle Therapy)

15:15 Transmission for high intensity heavy ion beams in the AGOR cyclotron

Experiments with short-lived Ra nuclides require high intensity heavy ion beams such as 206Pb at 8.5 MeV/amu. During acceleration charge exchange with rest gas occurs. Charge exchanged particles eventually hit the walls of the cyclotron, leading to desorption, which in turn gives rise to vacuum degradation. This positive feedback process leads to a deterioration of the transmission, limiting the maximum extracted intensity. To define a mitigation strategy we investigated the beam loss dynamics. Charge exchange cross-sections are calculated using semi-empirical models. Orbit calculations were done to track lost ions. Simulations show for a single charge exchange near extraction, particles hit the perimeter at shallow angles of incidence. Remaining particles require multiple charge exchanges before they too hit the perimeter. Ion induced desorption was measured for different beams at an energy of 8 MeV/amu, incident on materials representative of the cyclotron interior. We will discuss simulation and experiment results, comparison of ion-induced desorption data with existing models, and a new model being developed.

Speaker: Mr Ayanangsha Sen (Kernfysisch Versneller Instituut)

Slides ECPM_ayan_1.pdf

16:00 → 17:30 Start of PSI tour

Friday, 11 May

09:00 → 18:00 Industrial Exhibition

09:00 → 10:40 Projects and studies

Convener: Marco Schippers (Paul Scherrer Institut)

09:00 The C70 ARRONAX cyclotron hands-on phase status

The C70 ARRONAX is a 350 E-6 A intensity and 70 MeV energy multi-particle cyclotron aiming at R&D on material and radiolysis, and production of radioisotopes. The machine began its hands-on phase in December 2010 and the operating and maintenance group is accumulating experience on this machine. A review of the machine status and present possibilities in terms of beam capacities is thus presented. The status of the beamlines adaptation undergone is given as well as the simulations updates. As beamlines adaptation, the energy degrader installation update and alpha pulsing results are detailed. This status includes the diagnostics in development.

Speaker: Dr freddy Poirier (Subatech - Arronax)

Slides fp_ecpm_2012_v0.3.pdf

09:25 The Compact Injector Cyclotron For DAEdALUS Experiment

The experiment DAEdALUS, proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector and of a booster ring cyclotron has been proposed. Due to the low duty cycle, the peak current to be accelerated is 5 mA. The problem related to the injection of a H2+ beam, delivered by a compact ion source, and to the space charge effects will be discussed. To reduce the cost a solution based on a compact cyclotron is proposed and this pose anlimit to the maximum energy of the H2+ beam. Two cyclotron model have been simulated one with a pole gap of 10 cm and another with 6 cm gap. For both the case the beam extraction is performed by electrostatic deflectors. The main characteristics of Daedalus injector cyclotron able to accelerate a H2+ molecule beam up to 60 MeV/n, the magnetic configuration, the isochronous magnetic field and beam dynamics during the acceleration, without and with space charge effects, and along the extraction path will be presented, too.

Speaker: Prof. Luciano Calabretta (INFN-LNS)

Slides DAEDALUS_Inj_ECPM.pdf

09:50 SPIRAL2 arrival consequences on the existing GANIL installation

Since the 1st of July 2005, a major evolution of the GANIL is under construction. After SPIRAL1, SPIRAL2 will continue to extent the panel of exotic beams available. The coupling of a new superconducting linear accelerator and the existing compact cyclotron CIME (SPIRAL1) and experimental area allows minimizing the building modifications. Nevertheless, the INB (Installation Nucléaire de Base) specificity attached to the site implies to reviews the capabilities of the exiting GANIL to run the new facility in term of radiological impacts, seism, etc… The presentation will review the modifications and new features of the installation.

Speaker: Dr Frederic Chautard (CNRS)

Slides Presentation_oral_ECPM12-Chautard.pdf

10:15 CC-1-3 cyclotron complex

The CC-1-3 cyclotron complex, to be used for analysis of materials, has been designed. The techniques of analysis of materials that will be implemented are RBS spectrometry, PES spectrometry, NRA, and PIXE spectroscopy. The complex is composed of a compact isochronous cyclotron and a particle beam preparation system with the chosen energy characteristics. The cyclotron enables the acceleration of negative hydrogen ions up to the energy range from 1 to 3 MeV, and the extraction of protons using a thin carbon stripping foil. The cyclotron magnet is of the closed type with the median plane in the horizontal position. The isochronous magnetic field is formed with a four-sector structure. A two-dee acceleration system is placed completely inside the magnet poles. The proton beam preparation system ensures that the width of the beam energy spectrum is below 0.1 %. The basic element of this system is a magnetic analyzer having the bending angle of 270 deg. The parts of the cyclotron complex are in the phase of fabrication. Its assembling and commissioning will be performed in the Vinca Institute of Nuclear Sciences by the end of 2012.

Speaker: Dr Nebojsa Neskovic (Vinca Institute of Nuclear Sciences)

Slides ECPM_2012_Neskovic_2.pdf

10:40 → 11:10 Coffee Break

11:10 → 12:30 Poster Session

11:10 A calculation study of H+ recapture in a synchrocyclotron using the IBA phase_motion code

One of the important concerns in the development of a synchrocyclotron for clinical use is the predictability and accuracy of the beam pulse. During studies of the longitudinal motion in the S2C2 we have observed that protons falling out of the RF bucket but not lost, may regain stable oscillations around a subsequent synchronous particle and hence be recaptured in a later beam pulse. Such a behavior must be quantified and suppressed in the stages of machine design to deliver a high quality treatment beam. It has been the purpose of this study to extend the 1-D phase_motion code for longitudinal motion to describe the case of particles recaptured after multiple turns without acceleration in a synchrocyclotron. The strong advantages of this 1-D approximation are i) rapid study of large numbers of particles over many thousands of turns and ii) associated optimization of the RF-frequency and voltage curves during the full acceleration up to the maximum radius in the cyclotron. In this communication the extensions to the phase_motion program are explained and the problem of H+ recapture in the S2C2 is studied.

Speakers: Dr Emma Pearson (IBA), Dr Willem Kleeven (IBA)

Slides P2-Poster-S2C2-HPLUS-RECAPTURE.pdf

11:10 A COMPACT SOLUTION FOR DDS-GENERATOR, TURN-ON AND PROTECTIONS IN RADIO FREQUENCY CYCLOTRON SYSTEMS

One single compact rack includes: Direct Digital Synthesizer generator, turn-on and protection system. The system synthesizes a high stable RF signal up to 120 MHz, turns the power on into the RF cavities through a step-ramp modulator, protects the RF system against mismatching, sparks and multipactoring. A first prototype has been designed, assembled and tested on the RF system of the k-800 superconducting cyclotron at Infn-Lns. The hardware, the software, and the preliminary test results, are shown in this paper. This solution is part of the new computer-based RF control system.

Speaker: Mr Antonino CARUSO (INFN-LNS)

Poster POSTER_ecpm2012_2.pdf

11:10 BEAM EXTACTION SYSTEM FROM DC110 CYCLOTRON

The heavy ion beams Ar,Kr and Xe with fixed energy 2.5 MeV/amu extracted from DC110 cyclotron. The beam extraction is performed by an electrostatic deflector placed in the valley. In order to compensate the radial beam defocusing caused by the high gradient of the frigging magnetic field passive magnetic channel, located in hill, are used. The parameters of extraction system elements (electrostatic deflector and focusing magnetic channel) and diagnostic elements are presented.

Speaker: Dr Oleg Borisov (JINR)

11:10 Fast computation of magnetic shimming in high field environment

During the development of the new S2C2 at IBA, it was found that the axial field harmonics may have an impcat on the machine performance. Due to the compactness of the machine, outside elements such as magnetic shielding (for cryo-coolers and rotco), the external beam line, and the yoke-lifting system, have an influence on the median plane field inside the synchrocyclotron itself. This is detailed in another communication. Shimming may be necessary to adjust these errors. In this communication a simulation method for shimming a first harmonic in a cyclotron is described. The shimming is done with multiple iron shims with rectangular or sector shape in the pole gap. It is assumed that these iron shims are completely and uniformly saturated by the external magnetic field. Analytical expressions are given for the magnetic field produced by a single shim. A program is described that calculates the magnetic field produced by multiple shims. As an example, the method is applied for shimming of the first harmonic field error due to the extraction system. The calculations are very fast and allow a quick convergence to a good final solution. Good agreement was found with OPERA3D.

Speaker: Dr Willem Kleeven (IBA)

Slides P4-s2c2_harmonic_shimming_poster.pdf

11:30 Cyclotron median plane errors due to asymmetric RF cavities

IBA is currently investigating asymmetric RF cavities for some of its PET cyclotrons. Those cavities will only occupy two upper pumping holes with dee-stems and outer cavity walls. The corresponding two lower pumping holes will be empty. The advantages of such a configuration are: i) The four oil diffusion pumps mounted underneath the cyclotron are more efficient, ii) the cavities become considerably shorter due to the almost twice higher effective dee-capacity per cavity and iii) the system becomes less expensive and more rigid. A possible disadvantage could be the vertical asymmetry of the structure which could distort the median plane An equation is derived for the electric median plane error as a function of position and RF phase. A CST Microwave Studio® cavity model was used to obtain the vertical median plane E-fields. Combining both results, the distorted median plane at any point in the cyclotron is calculated. For realistic values of the vertical betatron tune and for reasonable values of the RF phase, the median plane excursion remains below 0.1 mm. It is concluded that the vertical asymmetry of the cavity does not pose any problem with respect to the beam optics.

Speakers: Dr Michel Abs (IBA), Dr Willem Kleeven (IBA)

Slides P5-c18new_asymmetric_cavity_poster.pdf

11:30 Developments on the S2C2 mapping system

A new mapping system for the Super Conducting Synchro Cyclotron (S2C2) was developed at IBA. One of the major differences with existing mapping systems at IBA is the replacement of the Hall probe by a search coil. In the S2C2, the field ranges from 4.6 to 5.7 T and large field gradients exist in the extraction region (the regenerator). These gradients should be measured with high precision in order to ensure proper extraction from the machine. The search coil was tested and calibrated in the S2C2, which was equipped with resistive coils, resulting in a field range from 0.8 to 2.2 T. Due to the non-point like nature of the search coil, corrections have to be applied to the measured field profile. To assess the validity of these corrections, field profiles measured with a Hall probe (point-like) and the search coil were compared. In addition, field errors due to misalignment of the search coil with respect to the median plane were simulated. The mechanical layout of the mapping system will be described together with the measurement sequence. The latter aims at minimizing errors due to drifting integrator offsets which might fake a contribution to first harmonic errors in the machine.

Speaker: Dr Jarno Van de Walle (Ion Beam Applications)

Slides P6-Poster-S2C2-mapping-system.pdf

11:30 IBA S2C2 Quench Study: Induced Forces on Dees and Liner

The S2C2 is the new compact protontherapy accelerator for the IBA ProteusOne range of products. It is the first synchrocyclotron as well as the first superconducting cyclotron ever produced at IBA. In this communication, a study is presented of the forces that are acting on the accelerating structure (dees and liner) due to the eddy currents that would be induced in these copper structures by the decaying magnetic field after a quench of the main coils. For this purpose a simplified semi-analytical approach is developed. It is found that these forces are not small (about 400 N) but can be handled by the mechanical design of the accelerating structure.

Speaker: Dr Willem Kleeven (IBA)

Poster P7-s2c2_quench_forces_poster.pdf

11:30 IBA S2C2: Coil forces and median plane errors due to coil displacements

The S2C2 is the new compact proton-therapy accelerator for the IBA ProteusOne range of products. It is the first synchrocyclotron as well as the first superconducting cyclotron ever produced at IBA. During the commissioning of the S2C2 it is intended to move the main coil assembly in the cryostat into an optimum position such that the overall effect of the median plane error during acceleration and extraction has the smallest impact on the extracted beam. The main coils are held in position by horizontal and vertical tie-rods. This allows placing these coils with five degrees of freedom (3 displacements and 2 rotations). During this operation care has to taken, because the forces and torques acting on the coils can be large. Furthermore the system is unstable, in the sense that the forces acting on a displaced coil are directed such that they intend to increase the displacement. A study is made of forces and torques that act on the main coils and the median plane errors that are produced due to coil displacement and rotations in the S2C2. Four different OPERA finite elements models in 2D as well as 3D are used to calculate and compare these quantities.

Speaker: Dr Willem Kleeven (IBA)

Poster P8-s2c2_coil_forces_poster.pdf

11:30 IBA S2C2: Median plane error produced by external magnetic shields and other equipment and its compensation by main coil shifts

The S2C2 is the new compact proton-therapy accelerator for the IBA ProteusOne range of products. It is the first synchrocyclotron as well as the first superconducting cyclotron ever produced at IBA. A study is made of the median plane error in the S2C2 due to the vertical asymmetry in the magnetic structure. A full OPERA3D model is used to calculate the magnetic field error. The main coils are shifted vertically in order to compensate this error in the extraction region. An analytical formula is derived for the median plane displacement. The iron of the magnet is almost completely saturated because of the high magnetic field (5.7 Tesla in the cyclotron center) that is applied. One of the consequences of this is that subsystems with moving parts such as the cryo-coolers and also the rotating condenser (rotco) require magnetic shielding. Another consequence is that the cyclotron is more sensitive to magnetized iron that is placed at the exterior of the machine because for such an additional source of flux, the pole and yoke almost behave like air and therefore do not provide any magnetic shielding.

Speakers: Dr Eric Forton (IBA), Dr Willem Kleeven (IBA)

Slides P9-s2c2_med_plane_error-poster.pdf

11:50 Fields extrapolation in the axial injection and central region of cyclotrons

IBA developed an evolution of its well-known Cyclone 30 cyclotron. The Cyclone 30XP is a multi-particle, multiport cyclotron capable of accelerating alpha particles up to 30 MeV (electrostatic extraction), deuteron (D-) beams between 7.5 and 15 MeV and proton (H-) beams between 15 and 30 MeV (stripping extraction). The cyclotron injection line, based on the Cyclone 70 design, has different external ion sources connected to a recombination magnet. The beam is axially injected in the cyclotron median plane through a spiral inflector. The Cyclone 30XP electrostatic inflector and central region design is very similar to the proven design of the high current Cyclone 30HC central region. However, a careful study was carried out in order to validate the geometry and injection efficiency for the various ion species. This leads to the opportunity to improve the IBA particle tracking code. This poster describes a new method of magnetic field extrapolation in the inflector volume based on magnetic field measurements along the injection axis and in the median plane of the cyclotron.

Speaker: Dr Vincent Nuttens (IBA)

Poster P11-Field_extrapolation_ECPM-poster.pdf

11:50 IBA S2C2: The influence of first harmonic field errors on the beam quality

The S2C2 is the new compact proton-therapy accelerator for the IBA ProteusOne range of products. It is the first synchrocyclotron as well as the first superconducting cyclotron ever produced at IBA. In this communication a study is made of the deteriorating effect of a first harmonic field error due to the r=1 resonance in the S2C2, thereby taking into account the acceleration process. It is shown that in the main part of the accelerating region this deteriorating effect is almost non-existing. This is due to the very slow acceleration used in the S2C2. The beam centroid adiabatically follows the magnetic center of the machine and no coherent oscillations are generated. Only the central region and the extraction region require special care in terms of the shimming of the first harmonic error. For the intermediate region the shimming requirement is less strict and can be determined by setting an upper limit for the allowable shift of the magnetic center with respect to the geometrical center. For the purpose of the study, a new tracking program was developed that numerically integrates the equations of orbit center motion in a cyclotron.

Speaker: Dr Willem Kleeven (IBA)

Slides P12-s2c2_orbit_center_poster.pdf

11:50 Last development on IBA Cyclone30 family

During these 2 last years, IBA developed and proposed two new versions of its famous Cyclone 30: the Cyclone 30HC, which is a high current version able to accelerate up to 1.2 mA at 30 MeV, and the Cyclone 30XP, which is a multi-particle version (proton-deuterons and alphas), inspired by the Cyclone 70 XP. During the last months, the high current version successfully completed the site acceptance tests in Turkey (1.2 mA accelerated on one extraction port, dual beam production in 2*500 µA).The machine shows an exemplary behavior during commissioning and acceptance and the handover by the customer have been done in begin of March. The multi-particle version ended up its factory acceptance tests (e.g. mechanical integration, tests of functionalities) at Louvain La Neuve and the rigging and installation is planned for mid of April. The beam acceleration and full power tests will be validated on site but most of the risks have been mitigated during the factory tests. The poster will summarize the achievements and current development status for both of the new machines.

Speaker: Mr Benoît Nactergal (IBA)

Poster P13-C30_HC-C30XP_ECPM-poster-final.pdf

11:50 Optimization of tube based RF power amplifiers by 3D EM codes

Modern electromagnetic computation codes, together with the help of last generation of computers, open new doors for RF design. A calculation code like CST Microwave Studio®, thanks to its Frequency Domain Solver, is able to calculate S matrix between ports over a given frequency band. In addition, the tetrahedral curved meshing is then able to define accurately very small volumes inside very large structures without reaching a prohibitive number of meshes. As a consequence, a standard computer with 16GB of installed RAM is now able to solve problems with up to 200,000 meshes in a few minutes. The present communication shows examples of such complex calculations of amplifiers coupled to their load (like an accelerating cavity) by means of small coupling loops. Some reverse engineering of existing designs have been simulated in order to validate the accuracy of the results. The code also helps to predict the behavior of the amplifier outside its working band in order to avoid problems with the harmonics. Finally, using the eigenmode solver, typical TE modes inside tube structures have been found and the efficiency of special Eccosorb® microwave absorbers has been investigated.

Speaker: Mr Michem Abs (IBA)

Poster P14-Power_amp_ECPM-poster.pdf

12:10 Phase_motion: a program for the study of the longitudinal beam optics in a synchrocyclotron

During the development of a synchrocyclotron the RF-frequency and voltage behavior during the pulse must be specified. The efficiency of capturing injected ions into the RF-bucket and also the stability of the RF bucket size during the acceleration depend on this. It is possible to study these processes with a full 3-D tracking code but such calculations are complex and time-consuming. The goal of the current study is to develop a simplified tracking code where only the longitudinal motion is calculated. The central region is decoupled from the longitudinal effects and is considered as a ‘filter’ which excludes certain ranges of RF phase which will in practice be lost horizontally or vertically during the first few turns. This is an approximation, but it serves as a helpful and fast additional design guideline for study of the RF-frequency and voltage curves and it also allows calculating the particle during the full acceleration cycle. The program integrates the equations of longitudinal motion (the phase-equations) in a synchrocyclotron assuming that the properties synchronous particle are known. The problem of capture in the S2C2 is studied as an example.

Speakers: Dr Emma Pearson (IBA), Dr Willem Kleeven (IBA)

Slides P15-s2c2_phase_motion_poster.pdf

12:10 Proton beam time structure of HZB cyclotron

The isochronous cyclotron at HZB is mainly used for providing a proton beam of 68MeV for the eye tumor therapy, which is conducted in cooperation with the Charité Berlin. The existing possibilities to produce a time structured beam, as well as the in-house developed testing instrumentation, will be shown in this poster. Our accelerating facility can generate pulse structures of a high variability; from single pulses of 1ns at a maximum repetition rate of 75kHz to pulse packets with a length up to 100µs or a quasi-DC-beam exists a wide range of possible proton beam structures. A proton beam with a temporal structure can be used for several applications and experiments. One example is the producing of pulsed neutron radiation for dosimetry.

Speaker: Mr Christoph Kunert (Helmholtz-Zentrum Berlin)

Poster Poster_ECPM2012final.pdf

12:10 Status of the Proteus One S2C2 RF System

IBA is currently developing a compact superconducting synchro-cyclotron intended for a low cost, single room proton therapy treatment system called Proteus One. The RF system of such a machine is challenging to optimize when compared with a fixed frequency isochronous cyclotron RF system. During acceleration, the RF cavity resonating frequency must be varying from 90MHz to 60MHz. This is realized thanks to an innovative rotating condenser (Rotco) design. The RF power is provided by a triode based oscillator directly coupled to the cavity in the vicinity of the Rotco. In order to get a constant coupling a special anode circuit is used. Different oscillator configurations have been studied and finally a system with re injection onto the cathode has been selected. The signal is provided by a pick-up loop emerging in the main Dee resonator and transmitted to the cathode by an optimized equalizing circuit. This paper describes the optimization method of the cavity in order to face the numerous space and RF constraints. It also describes how the oscillator is coupled and fed-back. Some details on how the Rotco is designed in order to solve the technical challengesare also shown.

Speakers: Mr Michel Abs (IBA), Mr Patrick Verbruggen (IBA)

Slides P17-S2C2_RF_ECPM-poster.pdf

12:10 Status report of proton therapy and the irradiation facility at TSL, Uppsala

TSL has a long history of producing beams of accelerated particles. The laboratory was restructured in 2005/2006 with nuclear physics phased out, the CELSIUS ring dismantled and the WASA detector moved to Jülich. The focus of activities became thereby shifted towards, mainly, proton therapy and, in addition, radiation effects testing using protons and neutrons in a beam sharing mode. The increase in demand on (a) beam time and (b) faster changes between various set-ups necessitated the upgrading of various aspects. Two of these will be presented: a new camera system to verify beam position and an improved ion source positioning system. As a consequence of the restructuring, night shifts have been phased out. Studies indicated that a substantial energy saving can be accomplished by switching off certain power supplies. Results of this energy saving programme will be presented. To ensure that beam quality requirements are met, the stabilization of beam characteristics as a function of the elapsed time since start-up have been investigated. Finally some beam time statistics will be presented.

Speakers: Daniel van Rooyen (The Svedberg Laboratory), M Lindberg (The Svedberg Laboratory)

Poster TSL_poster_Van_Rooyen_300.pdf

12:10 The procedure and results of magnetic field formation at the cyclotron with the magnetic channel of the beam extraction system.

Using the magnetic channel in the beam extraction system causes perturbation in the cyclotron magnetic field. As a result the radial magnetic field distribution changes and the first harmonic of the magnetic field appears. The procedure of compensation of the magnetic channel influence is presented by the example of the formation of the DC-110 cyclotron magnetic field. The calculation results and the final magnetic field measurements are presented in this work. The magnetic field of DC-110 cyclotron is formed in a good agreement with the computer simulation results.

Speaker: Dr Ivan Ivanenko (JINR)

12:30 → 13:30 Lunch

13:30 → 14:45 Beam dynamics

Convener: Dr Willem Kleeven (IBA)

13:30 Transverse-Longitudinal Coupling in High-Intensity Cyclotrons

Isochronous cyclotrons have no longitudinal focusing at low beam intensities. However, at high intensities the space charge force induces coupling of longitudinal and horizontal motion. This effect is used in the INJECTOR II cyclotron and allows operation without flattop cavity. The linear coupling terms are modeled and analyzed with emphasis on the cyclotron phase curve.

Speaker: Dr Christian Baumgarten (Paul Scherrer Institut, 5232 Villigen PSI, Switzerland)

Slides baumgarten_ecpm2012.pdf

13:55 High intensity problems study on the H2+ cyclotrons for the DAEdALUS project

In the DAE$\delta$ALUS (Decay-At-rest Experiment for $\delta_{CP}$ studies At the Laboratory for Underground Science) project, ultra-high power proton cyclotrons are proposed, which should efficiently provide the necessary proton beams in the range of 1 to 8 MW with a kinetic energy up to 800 MeV. The evaluation of space charge effects are challenging, for both the injector cyclotron (DIC) and the main ring cyclotron (DSRC). We report on precise calculations w.r.t. high intensity problems for both machines. Large scale particle simulations show, that in the current design, the beam losses are associated to the single turn extraction in the DIC. This constitutes the bottleneck in achieving more than 5 mA of H2+ beam. On the other hand, in the DSRC, with multi turn and stripping extraction, space charge plays a minor role.

Speaker: Dr Jianjun Yang (Massachusetts Institute of Technology)

Slides yang_talk.pdf

14:20 OPAL Simulation for PSI Medical Cyclotron COMET

The PSI medical cyclotron COMET is modelled using the program OPAL, a tool developed at PSI for charged particle optics in accelerator structures and beam lines. For the proper simulation of the COMET cyclotron including the crucial central region, a new feature is introduced to OPAL, which enables a versatile combination of multiple 3D field maps for the acceleration. For the beam collimation in the centre of the COMET cyclotron, the existing collimator in OPAL is extended towards lower energies.

Speaker: Dr Hui Zhang (Paul Scherrer Institut)

Slides ECPM_PSI_ZhangHui.pdf

14:45 → 15:15 Coffee Break

15:15 → 16:55 Technology

Convener: Sytze Brandenburg (Kernfysisch Versneller Instituut)

15:15 A target system for ion-beam activation of particulate nanomaterials

The application range of manufactured nanomaterials is steadily increasing, as is their use in industry and consumer products. In parallel, there is growing concern about the safety of these materials. Radiolabelling techniques are extremely sensitive and useful tools for tracing studies to assess the fate of nanoparticles and possible risks for human health and environment arising from the large scale industrial application of nanotechnologies. At the Joint Research Centre’s Cyclotron laboratory in Ispra several types of industrially produced nanoparticles have been successfully radiolabelled by proton bombardment and recoil implantation. The particle properties were compared before and after irradiation to investigate the consequences of the radiolabelling process since enhanced aggregation or agglomeration of nanoparticles may easily result from overheating. Particular care has been devoted to the design of a target system able to mitigate the effect of the temperature increase and of the generally low thermal conductivity. To study the temperature profile within the irradiation capsule, a simple simulation model has been compared with experimental results on nanoparticulate.

Speaker: Dr Antonio Bulgheroni (EC - JRC)

Slides ecpm2012-abulgheroni.pdf

15:40 Facts and figures on S2C2 ion source: experimental characterization and extrapolated results for application in PT

IBA will equip its new superconducting synchrocyclotron (S2C2) with an internal PIG ion source. This choice is motivated by the source compactness, simplicity and cost but is not easy to implement in the present case. As an example, the high magnetic field and central region turn pattern imply the use an extremely thin chimney. Therefore, experimental design validation and testing is currently under progress on a dedicated test bench at AIMA-Developpement (Nice, France). The main characteristics of the source, such as its dynamic range, noise, lifetime, stability of the extracted beam have been obtained and are detailed in this communication. This characterization also includes a statistical approach of the source behavior. The discussion will finally present how these results can be used to simulate the source performance in the context of the treatment modalities of the ProteusOne system.

Speaker: Mr Sébastien Henrotin (IBA)

Slides ecpm.pdf

16:05 New dual frequency RF system for Cyclone 30XP

The IBA famous Cyclone 30 has been recently upgraded in order to not only accelerate protons but also deuterons and alpha particles. For efficient acceleration and easier central region design all the particles are accelerated along the same turn pattern, on the same harmonic mode. Consequently, the RF cavities must be resonating on two different frequencies. In order to provide a simple, reliable and cost effective design, a patented cavity design without sliding RF contacts has been implemented. It allows switching from 34MHz to 68 MHz with no cavity geometrical change and no moving parts. To provide RF power to the system a new 40kW tetrode based amplifier has been designed. It uses the same principles and has therefore no mobile elements to switch from one frequency to the other. The use of a high performance vacuum tube provide a fairly high gain in cathode driven operation that allows the amplifier to be easily driven by a small broadband solid-state amplifier. In this communication, the calculation method, design optimization and obtained results are presented.

Speaker: Mr Michel Abs (IBA)

Slides C30XP-ECPM2012.pdf

16:30 Program to improve the JYFL ion beam transport efficiency for K130 cyclotron

The transmission efficiency measurements of the JYFL accelerator facility were started in 2007. The motivation towards the studies was the fact that after a certain limit the beam intensity after the cyclotron did not increase with the beam intensity extracted from the JYFL 14 GHz ECRIS. Instead, the accelerated beam intensity reaches a saturation value and even starts to decrease if the total beam intensity from the ion source exceeds the value of about 1 mA. The result indicated that the beam quality starts to degrade severely with high total beam currents. Since 2007, comprehensive research program has been carried out in order to explain this unwanted behavior, to find the bottle-necks affecting the beam quality, and to find means to resolve these problems. Several parameters affecting the beam quality have been found and as a result a solid program with different intermediate steps for improving beam transport efficiency of our accelerator facility has been defined. In this presentation the afore-mentioned work and upgrade plan will be presented.

Speaker: Dr Hannu Koivisto (Department of Physics, University of Jyväskylä (JYFL))

Slides ECPM_Koivisto.pdf

16:55 → 22:00 END of DAY - Conference Dinner

Saturday, 12 May

09:00 → 10:15 Beam dynamics

Convener: Joachim Grillenberger (Paul Scherrer Institut)

09:00 An overview of the multiple simulation tools developed in the framework of the S2C2 project

So far the simulation tools and techniques available at IBA were all designed for isochronous cyclotrons. As a consequence, the fast development of the S2C2 was possible only through a close collaboration with AIMA development (Nice, France), who is a key driver in the design of the accelerator. Recently, IBA has developed and improved its existing beam simulation codes, wrote new ones and built its own synchrocyclotron models. Dedicated codes have been written to study the behaviour of the synchronous particle and the longitudinal motion. The 3D tracking code (AOC) has been extended in order to include pulsed RF. Other specific codes have also been developed, e.g. to study the orbit centring and magnetic shimming. Various magnetic models were made in opera2D and opera3D using both the pre-processor and modeller. Through the use of various solvers, these models are useful to study and understand a large number of features of the cyclotron and how design options interact with each other (Eddy currents, median plane errors, forces). The magnetic field mapping of the S2C2 will be done with the search coil method which also required new tool-development.

Speaker: Dr Willem Kleeven (IBA)

Slides simulation_overview_vs2.pdf

09:25 A Design of a Gantry With Super Conducting Magnets For 350 MeV Protons

Also for energies up to 350 MeV use of a gantry is essential in proton therapy. Compared to gantries for 250 MeV protons, the maximum field strength of all magnets must be increased with only 21% to keep the same gantry dimensions. A 230 MeV gantry design for 3D scanning recently developed by ProCure, employs super conducting magnets to limit the gantry weight to 18 tons. An arrangement of the SC-magnets as two achromatic bends yields a very large momentum acceptance of +/-3%. We present a gantry design for 350 MeV protons based on this principle. The ion optics uses a 1-1 imaging from coupling point to isocenter and the gantry radius has been kept the same. The gantry is suitable for fast energy scanning between 70 and 230 MeV. Since the SC-magnets limit the field-variation speed, the change of field is proposed to be performed during the delivery of an energy layer. The large momentum acceptance in the achromatic system would allow this feature, provided the magnets change field in a synchronous way. First prototype SC magnets have been built and are now being tested at ProCure under an SBIR development grant.

Speaker: Mattia Schaer (PSI)

09:50 Status of the HZB cyclotron

Since 2009 our cyclotron is again served by two injectors: a 5.5MV Van-de-Graaff and a 2MV tandetron. The tandetron has been optimized especially for the requirements of eye tumour therapy. The stability of the proton beam is of utmost importance for the therapy, both on the short-term and the long-term scale. Development of the ion source resulted in safe source operation times of more than 600h and extremely stable beam current after source tuning. After extensive beam tests, the permit for using the tandetron-cyclotron combination for therapy was granted in December 2010. The tandetron is now in full operation for therapy since the beginning of 2011. It proved to be a reliable machine with extremely high stability, causing no real down time to the accelerator operation during therapy. In 2009 the Van-de-Graaff was considered to be a temporary backup for the tandetron after its successful installation. However, new requests for pulsed beams with a very specific time structure occurred, which can be provided only with the Van-de-Graaff-cyclotron beamline. Accelerator operation, provisions to increase the uptime, and changes on the pulse suppressor will be discussed.

Speaker: Dr Andrea Denker (Helmholtz-Zentrum Berlin für Materialien und Energie)

Slides denker_a.pdf

10:15 → 10:40 Coffee Break

10:40 → 12:00 Status Reports

Convener: Prof. Luciano Calabretta (INFN-LNS)

10:40 Status of the Jyväskylä Accelerator Laboratory

The Jyväskylä Accelerator Laboratory has two cyclotrons, the K130 cyclotron which has been in use since 1992 and the MCC30/15 H-/D- cyclotron which is being commissioned. The K130 cyclotron has been used more than 6000 hours/year since 1996 for nuclear physics research and applications, such as isotope production, space electronics testing and filter membrane production. The new MCC30/15 cyclotron was delivered and installed by NIIEFA, St. Petersburg, Russia in 2009 – 2010. It will be used for nuclear physics experiments and isotope production. The first nuclear physics experiments will start in 2012. In addition to the two cyclotrons the laboratory houses also a 1.7 MV Pelletron accelerator which is used for materials physics experiments and applications. Present status and future plans of the laboratory will be given in the presentation.

Speaker: Dr Pauli Heikkinen (University of Jyväskylä, Department of Physics)

Slides P_Heikkinen.pdf

11:10 Status and Activities at COSY/Jülich and its Injector Cyclotron

The IKP at the Forschungszentrum Jülich is dedicated to fundamental research in the field of hadron, particle, and nuclear physics. Main activities of the accelerator division are the development of the high-energy storage ring HESR, with the PANDA experiment, and the operation of the 3.7 GeV/c Cooler Synchrotron COSY-Jülich with the injector cyclotron JULIC. HESR and PANDA are part of the GSI FAIR project. FAIR stands for "Facility for Antiproton and Ion Research". Jülich scientists will construct the HESR for the international accelerator centre FAIR in Darmstadt, one of the largest research endeavors in Europe. The contract between FAIR and FZJ has been signed in October 2011. The cooler synchrotron COSY offers excellent research opportunities for hadron physics experiments and for essential preparatory studies for the machine development of HESR. A 2 MeV electron cooler is under construction. Building on the experience with polarized light ions from the cyclotron, the Juelich Electric Dipole moment Investigation of light ions (JEDI) has been started. The report gives a brief overview of activities, performance, new and improved installations at COSY and JULIC.

Speaker: Dr Ralf Gebel (Forschungszentrum Juelich)

Slides RGebel_ECPM2012.pdf

11:35 Concluding Remarks

Speaker: Dr Andrea Denker (Helmholtz-Zentrum Berlin für Materialien und Energie)

Slides Concluding_Remarks.pdf

12:00 → 22:00 END of PROGRAMM - start of tour to Lucerne