[Triumf-seminars] TRIUMF Colloquium today at 14:00

[TRIUMF Seminars]

Date/Time: Mon 2015-11-23 at 14:00

Location:  Auditorium          

Speaker:   Shinsuke Kawasaki (KEK)

Title:     Super-Thermal UCN Source using Super-Fluid 4Helium

Abstract: Ultra-cold neutrons (UCN) are free neutrons which have extremely low kinetic energy of few 100 neV. UCN can be confined in a material bottle. Because of its unique property, UCN is used for various experiments. Super-thermal method is a way to produce UCN proposed by R. Golub and J. M. Pendlebury [Phys. lett.A, Vol. 62, 337 (1977)]. Cold neutrons excite phonon in superfluid helium4 and then lose their kinetic energy down to UCN region. Using large phonon phase space in superfluid helium4, UCN production by super-thermal method is free from Liouville's theorem. In order to avoid up-scattering by phonon, superfluid helium4 temperature must be kept below 1K.

A UCN source has been developed at RCNP, Osaka, Japan. The UCN source has unique combination of a spallation neutron source and a super thermal method using superfluid helium4. Based on success of a prototype UCN source at RCNP, we built a new UCN source with higher cooling power in order to use TRIUMF proton beam line. In my talk, performance of the new UCN source and future possibility at TRIUMF will be discussed.



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