TY  - JOUR
AU  - Tatsumoto, H.
AU  - Lyngh, D.
AU  - Lee, Y.
AU  - Hartl, M.
AU  - Sina, H.
AU  - Beßler, Y.
AU  - Kobayashi, H.
AU  - Sakamoto, Y.
AU  - Hasegawa, T.
TI  - Design of an in-situ measurement system for ortho and para liquid hydrogen fractions at ESS
JO  - IOP conference series / Materials science and engineering
VL  - 1240
IS  - 1
SN  - 1757-8981
CY  - London [u.a.]
PB  - Institute of Physics
M1  - FZJ-2023-01673
SP  - 012117 -
PY  - 2022
AB  - The Cryogenic Moderator System (CMS) is equipped with a catalyst to convert hydrogen from the ortho state to the para state, to keep desirably high parahydrogen fractions in the cold moderators, which is required to deliver a high brightness cold neutron beams to the scientific instruments using neutron scattering. An in-situ measurement system for the ortho and para fractions of liquid hydrogen (OPMS) where a Raman spectroscopy will be used is being developed. The required measurement precision is 0.1% to detect an undesirable shift towards a high orthohydrogen fraction caused by neutron scattering driven para-to-ortho back conversion. The dedicated OPMS sampling line has been designed and is placed in a bypass line from and to the CMS to minimize the hydrogen inventory and to make it physically isolated from the CMS if a sapphire window failure happens. Accident analysis for a hydrogen leak due to the sapphire window failure was carried out using an inhouse-developed simulation code, and the required safety relief size has been determined.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1088/1757-899X/1240/1/012117
UR  - https://juser.fz-juelich.de/record/1006439
ER  -