Speaker
Description
SuperSUN is a superthermal source for ultracold neutrons (UCNs) located at the Institut Laue-Langevin (ILL). Designed to have a saturation of 4E6 UCNs in the convertor volume, or a UCN density of 282/cc. It has reached operation within 3% of this goal with plans to increase this design value to 2E7 (1408/cc) with polarized neutrons using a magnetic octupole reflector. In this poster, we present preliminary results of work done to characterize the source and necessary efforts for its maintenance.
Namely that characterization of the source has included temperature variation of the superfluid helium via a current-induced heat load at the base of the transfer line from the He-3/He-4 heat exchanger to the conversion volume. This to both test the T^7 behavior of the upscattering phenomena as described by R. Golub, et al in a superfluid temperature regime not seen before and to demonstrate the UCN losses to this phenomena are negligible at the nominal cryogenic temperature range that SuperSUN's superfluid helium operates at (~0.5 - 0.6 K) given heat load variance induced by the cold neutron beam.
Additionally, measurements to observe the effects of treatment on the cytop coating used on SuperSUN's convertor volume with isopropyl alcohol were carried out using a CYTOP-coated bottle apparatus on the PF2 EDM beamline at the ILL. The results of these measurements are discussed here.