G 1 BIS resonance -echo MUSES Neutron resonance spin-echo Spectrometer MUSES G 1 BIS

high magnetic precession coil (NSE option)

µ−meta l shieldin g

analyser

General set-up of the spin-echo spectrometer G 1 BIS.

frequency field B1(t) rotating in the horizontal sity at the wavelength maximum and at the plane. Such a configuration allows measure- sample position of the spectrometer MUSES is 7 -2 -1 ments at high Fourier times without the need of 10 n.cm s for λ ~ 5 Å, this total integrated flux high magnetic fields. It is particulary interesting 2 of the 40 x 40 mm beam at the sample position for measurements at high angles, because of the 8 -1 difficulty of keeping the field line path in the is ~ 1.6 10 n.s . Due to the presence of µ-metal sample position with conventional NSE option shielding, very small Fourier times can be mea- (needs of tunning devices). It allows a very high sured (at low current) with NSE option because flexibility with respect to wavevector changes : the depolarization of the beam due to the earth the resolution function is negligibly angle magnetic field or any environmental fields is absent. dependent for a given wavelength. MUSES is a mixed resonance-conventional measurements at longer times. In resonance Typical studies performed on the instrument are neutron spectrometer installed on the spin-echo spectrometry, the two high magnetic The neutron beam is polarized by a bender of 4 dynamics in liquids and supercooled liquids (in guide G 1 bis. The aim of this spectrometer is to precession coils are replaced by four radio- m length and 76 m radius made out with NiTi bulk or confined geometries), dynamical studies study high resolution quasielastic scattering in frequency coils ; two in the first arm and two in super mirrors. A velocity selector roughly mono- of soft condensed matter (polymers, colloids...), -1 the medium wavevector range (0.05 Å < Q < the second. Only within these coils the spins are chromizes the incident flux with a wavelength Biologically relevant systems, critical -1 2.75 Å ) bridging the gap between Time-of-flight submitted to magnetic field and consequently the band of δλ/λ ~ 0.1 - 0.15. The polarized flux phenomena, molecular motions in crystals... and SANS Neutron Spin-Echo at remaining neutron path has to be shielded from inten the LLB. any magnetic contamination (earth magnetic The spectrometer is divided into two distinct field...). The field geometry in the coils is very parts, a conventional NSE spectrometer for similar to the one used in nuclear magnetic measurements at small Fourier times (typically τ resonance : a static high field in the vertical < 200 ps for λ~10 Å) and an NRSE option for direction B0, and a horizontal radio

Responsible : J-M. Zanotti e-mail : [email protected]

LLB edition - 2015 LLB edition - 2015