An optimization study for the RHIC polarized jet target

Development of a Hydrogen and Deuterium Polarized Gas Target for Application in Storage Rings

“…This intensity, the highest intensity achieved anywhere, was the results of an extensive design study undertaken at Wisconsin. The optimization calculations [12] considered a large number of parameters: dissociator temperature, distribution of sixpole diameters, tapers, lengths and spacing, as well as intensity loss by gas scattering. The actually measured intensity somewhat exceeds the design value of 0.9x10 17 by 30% for reasons which are not entirely understood.…”

Nanosecond control and high-density production of spin-polarized hydrogen atoms

“…9 For collision experiments, conventional methods for SPH production use large and involved experimental setups, such as Stern-Gerlach separation, 10,11 or spin-exchange optical pumping, 1 that achieve densities of only up to about 10 12 cm -3 . 11,12 SPH is usually detected non-remotely with atom polarimeters, which have limited time and spatial resolution, or optically with fluorescence at 121.6 nm, which has been achieved with spin-state selectivity only with hyperfine resolution, requiring the SPH translational temperature to be colder than about 80 K. 13 Recently, a new method for SPH production was demonstrated: the pulsed-laser photodissociation of HCl or HBr at 193 nm, in a supersonically cooled skimmed molecular beam of about 15 K. 14,15 However, the SPH was not detected directly: the degree of polarization of the SPH was inferred from the measurement of the halogen cofragment polarization, which does not allow direct monitoring and use of the SPH.…”

“…However, despite the fact that hydrogen is the simplest atom and is a natural choice for fundamental studies of spin-dependent collision processes, many such experiments are particularly challenging because of difficulties in both the production and the detection of SPH, especially optically [8], due to the sub-Doppler spin-orbit splitting of the 2p state at room temperature, and the difficulty in producing intense continuous-wave 121.6 nm light for optical pumping of the 2p ← 1s transition [9]. For collision experiments, conventional methods for SPH production use large and involved experimental setups, such as Stern-Gerlach separation [10,11], or spin-exchange optical pumping [1] that achieve densities of only up to about 10 12 cm −3 [11,12]. SPH is usually detected non-remotely with atom polarimeters, which have limited time and spatial resolution, or optically with fluorescence at 121.6 nm, which has been achieved with spin-state selectivity only with hyperfine resolution, (a) E-mail: ptr@iesl.forth.gr requiring the SPH translational temperature to be colder than about 80 K [13].…”

“…For the HERMES target at DESY (Deutsches Elecktronen-Synchrotron) [25], and the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory [12], the SPH production rates are about 10 17 atoms s −1 . Recently, about 10 18 atoms s −1 has been 68002-p3 achieved using spin-exchange optical pumping [26].…”