Neutron polarization with a polarized 3He spin filter

Relaxation of spin polarizedH3ein mixtures ofH3eYe1, Dutta2, H3 et al. 2008Phys. Rev. A7170View full textAdd to dashboardCite

“…Hyper-polarized 3 He based on the technique of optical pumping [1,2] has found applications in diverse fields such as in the study of quantum phenomena in low temperature fluids [3] and in the search for violations of fundamental symmetries [4,5,6]. They are also routinely used as polarized neutron spin-filters [7], as effective polarized neutron targets for nuclear and particle physics experiments [8] and for low magnetic field magnetic resonance imaging [9]. All such applications have motivated, as well as benefited from, studies of the relaxation mechanisms of polarized 3 He in gas, liquid and superfluid phases and under different surface conditions.…”

Long-Lifetime Low-Scatter Neutron Polarization Target

“…It has been demonstrated that thermal neutrons can be polarized by passing them through a dense (~1 atmosphere), spin-polarized, gaseous 3 He target [14]. Because the neutron absorption cross section of polarized 3 He is strongly spin-dependent, a sufficiently thick polarized target transmits neutrons that are in one spin state and strongly attenuates the other.…”

“…The use of 3 He spin filters as spin analyzers is discussed in the next section. One important feature of the 3 He spin filter is that the polarization of the transmitted beam can be determined without precise knowledge of the 3 He polarization [14,20]. This is accomplished by measuring the filter transmission when the 3 He is unpolarized ( 0 t ) and when it is polarized ( t ).…”

Fundamental Neutron Physics

“…A JINR-ITEP collaboration is preparing to perform a search for the P -even T -odd fivefold correlation with low energy neutrons on p-wave resonances using microwave-induced dynamical nuclear alignment to order the nuclei [208][209][210]. A shift in the zero crossing of the forward-backward asymmetry in unpolarized neutron capture on p-wave resonances has also been considered as a signal for P -even, T -odd interactions [211] but it is not a null test and although the statistical precision of the bound from 113 Cd is at the 10 −4 level, one must accumulate a number of results either in different nuclei or in different resonances in the same nucleus in order to construct a statistically meaningful bound from such measurements [212].…”

“…The apparatus is being designed for use at a pulsed spallation source to exploit background reduction and perform neutron polarimetry. The neutrons can be polarized by transmission through polarized 3 He, whose spin-dependent absorption cross section possesses an accurately-known neutron energy dependence that can be exploited for accurate neutron polarization measurement [105,[112][113][114][115][116][117].…”