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Updated: Jul 26, 2026

Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
Published on: October 9, 2012
Spallation ultracold-neutron production in superfluid helium
Y Masuda1, T Kitagaki, K Hatanaka
1High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan.
Abstract:
The first ultracold-neutron (UCN) production in superfluid helium placed in a spallation neutron source is carried out. A UCN density of 0.7 UCN/cm(3), which can be used in experiments, is achieved for a proton-beam power of 78 W and a He-II temperature of 1.2 K. The present new UCN source is not limited by Liouville's theorem and extraction losses, which were serious problems in the previous sources. The present source has the possibility of extremely high-density UCN production compared with previous UCN sources.
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