CEC-ICMC 2015 - Timetable, Abstracts and Presentations

Liquid hydrogen Moderator optimization for Neutron Sources with high brilliance

30 Jun 2015, 14:00

2h

Exhibit Hall (Arizona Ballroom)

Poster Presentation CEC-17 - Novel Concepts and New Devices C2PoM - Novel Concepts and New Devices II

Speaker

Yannick Bessler (Forschungszentrum Jülich)

Description

Neutron scattering experiments benefit from an increasing brilliance of the neutrons supplied. In addition to more powerful neutron sources, the efficiency providing those neutrons is becoming more important. Focus of the report presented here is therefore the optimization of one of the key components, the cold moderator. A cold moderator is usually a pressure vessel, which is filled with liquid hydrogen. So far, only the pressure and the temperature as well as the vessel geometry have been optimized. However, the nuclear spin of the hydrogen molecules was not considered yet. Novel theoretical studies suggest that the nuclear spin of the hydrogen molecule strongly affects the efficiency of moderation process. Therefore, a concept is presented which allows the characterization of such liquid hydrogen moderators for the full range of ortho-to-para ratios.