Speaker
Description
The cold triple-axis spectrometer (TAS) FLEXX at HZB was a highly successful instrument that underwent several upgrades during its operation [1–4]. Preserving its capabilities for the neutron scattering community has been a major motivation for the development of the new LaDiff instrument at MLZ. In particular, LaDiff addresses the current lack of Larmor diffraction (LD) [5–6] and, as a natural extension, neutron resonance spin echo (NRSE) capabilities while utilizing the proven TAS concept as its backbone.
Here we present the design of the primary neutron beam shutter developed for LaDiff. The shutter consists of two vertically moving lead elements that open and close symmetrically about the beam center. A geared coupling synchronizes the motion of both elements and provides a passive fail-safe mechanism. In the event of a power or compressed-air failure, gravity automatically closes the shutter. This counterbalanced design also significantly reduces the required actuator force, since the pneumatic cylinder only has to overcome the weight difference between the two shutter elements rather than their combined weight. In addition, a neutron beam attenuator is integrated on the rear side of the shutter, providing a compact and space-efficient solution.
[1] M. Skoulatos et al., NIMA 647, 100 (2011).
[2] M.D. Le et al., Nucl. Instr. Meth. Phys. Res. A 729, 220 (2013).
[3] F. Groitl et al., Rev. Sci. Instrum. 86 025110 (2015).
[4] K. Habicht et al., EPJ Web of Conferences 83, 03007 (2015).
[5] M.T. Rekveldt, Jour. Appl. Phys. 84, 31 (1998).
[6] M.T. Rekveldt et al., Europhys. Lett. 54, 342 (2001).
Zahreddin D1, Hertwig M1, Georgii R1, Keller T2, Tralmer F2, Skoulatos M1
1 Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany
2 Max Planck Society Outstation at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany
Key Words
LaDiff, FLEXX, Larmordiffraction, Tripleaxisspectrometer, Instrumentation, Beamshutter, Neutronbeam, Attenuator, Pneumatics, Failsafe