Thermo-hydraulic test of the moderator cell of LH2 cold neutron source at BNC

Thermo-hydraulic experiment was carried out in order to test the performanc e of the direct cooled liquid hydrogen moderator cell to be installed at th e research reactor of the Budapest Neutron Center (BNC). Two electric heate rs up to 300 W each imitated the nuclear heat release in the liquid hydroge n as well as in the construction material. The test moderator cell was also equipped with temperature gauges to measure the hydrogen temperature at di fferent positions as well as the inlet and outlet temperatures of cooling H e gas. The hydrogen pressure in the connected buffer volume was also contro lled. At 140 W expected total heat load the moderator cell was filled with liquid hydrogen within 4 h. The heat load and hydrogen pressure characteris tics of the moderator cell are also presented. (C) 2000 Elsevier Science B. V. All rights reserved.