Speaker
Description
The PanEDM experiment aims to measure the neutron electric dipole moment using ultracold neutrons (UCN) produced by the superthermal UCN source SuperSUN at the Institut Laue-Langevin (ILL) and stored in double precession chambers, with a sensitivity of $4\cdot10^{-27}\,e\cdot$cm anticipated after 100 days of measurement time.
The interface between SuperSUN and PanEDM is responsible for efficiently transporting polarised UCN. Due to limited space and dilution losses, the interface components must be as compact as possible while simultaneously providing long enough storage times. To improve mechanical stability, precision, and robust mounting, we have replaced major sections of the interface with metallic guides.
We give an overview of the current interface components and present a first characterisation of two components carried out at the ILL.
UCN will be polarised using a superconducting 5T magnet manufactured by HTS-110.
The guide manifold serves as a splitter for polarised UCN and consists of eight guides coated with nickel-phosphorus arranged in an asymmetrical Y-shape.
The Y-shaped detection system of PanEDM relies on simultaneous spin detection, using magnetised iron-foil analysers and adiabatic radiofrequency spin flippers. We developed such a system for thin-walled aluminium guides coated with nickel-phsophorus.
The source switch is the first interface component and allows UCN to be guided towards the polariser or to a monitor detector. Two identical three-way switches serve as junctions between the guide manifold, the storage chambers, and the detection system.
Transmission and storage measurement with the guide manifold at SUN-2 resulted in a spectrally-integrated transmission of approximately $0.97$ and storage times of approximately 100s. A corresponding wall-loss factor of $\eta \approx 2.7\cdot10^{-4}$ is consistent with literature.
Proof-of-concept tests with the spin flippers and thin-walled guides at PF2 resulted in spectrally-integrated efficiencies of $0.998$ within the relevant longitudinal velocity range, proving efficient operation.