GFA Accelerator Seminars

Thin targets in extreme conditions: probing high-brightness hadron beams


Thin targets used in beam instrumentation for high-brightness hadron beams are subject to extreme conditions. Those of wire scanners reach very high temperatures due to the passage of the beam. In addition to the secondary electron current used to measure the transverse profile of the beam, this temperature increase will cause the emission of thermionic electrons that will distort the measured signal. At PSI's HIPA facility, to suppress these thermionic emissions, a bias voltage is applied to the wire of the probe called RRL. In the first part, this presentation shows the influence of this bias voltage on the measurements of the transverse beam profile with RRL. Then, a benchmarking of a code that simulates the thermal evolution of the wire will be presented. Thanks to this code, a series of simulations is done to compare the thermal evolution of wires made of various materials: carbon fiber wire, which is used now in RRL, and carbon nanotube wires which are characterized by significantly lower density. Simulations show that the low-density material could make bias voltage, routinely applied on RRL, redundant.

for details, contact Mariusz Sapinski