Chopper mode of Drabkin energy filters for pulsed neutron sources

Yamazaki, Dai; Soyama, Kazuhiko; Ebisawa, Toru*; Takeda, Masayasu; Maruyama, Ryuji*; Tasaki, Seiji*

Physica B; Condensed Matter, 356(1-4), p.174 - 177, 2005/02

https://doi.org/10.1016/j.physb.2004.10.071

Drabkin energy filter could be used as a fast chopper for pulsed neutrons by varying the resonant wavelength fast in such a way that resonant wavelength matches neutron wavelength at a small time region. The faster are varied, the smaller time window we could obtain. Neutron pulses could be sharpened much more effectively for a small wavelength band than in the wide-band pulse-shaping mode in which is varied in synchronization with the time-of-flight from the moderator. In our preliminary test of a chopper-mode with a prototype Drabkin energy filter, time-window of 0.21 ms was obtained while it was 1.08 ms with the filter driven stationary. Narrower time-window could have been obtained if we had more beam-time and it could be also narrowed with higher-resolution Drabkin filters.