The HERMES experiment is investigating the spin structure of the proton and neutron via deep-inelastic scattering of polarized positrons from polarized nuclear targets. The polarized positrons are provided by the HERA positron storage ring at DESY, Hamburg, Germany. The targets are pure internal gas targets. Data acquisition began in 1995, utilizing a polarized 3He internal gas target to study the spin structure of the neutron. The target gas was polarized using the metastability-exchange optical-pumping technique and then injected into a cryogenically cooled target cell. The target was designed to operate with either longitudinal or transverse directions of polarization. Operating conditions included polarizations of up to 54% and target thicknesses of 1 × 1015 nucleons/cm2. In this paper the HERMES polarized 3He internal gas target is described in detail.
|Number of pages||29|
|Journal||Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|State||Published - Dec 11 1998|
Bibliographical noteFunding Information:
The research is supported in part by the U.S. Department of Energy, Nuclear Physics Division under cooperative agreement No. DE-FC01-94ER40818 (MIT) and grants No. DE-FG03-94ER-40847 (NMSU), No. DE-FG02-88ER-40438 (Madison), No. DE-FG03-95ER-40913 (Colorado), and No. W-31-109-ENG-38 (Argonne), by the National Science Foundation under Grants PHY 94-20470 (Caltech), PHY 93-14783 (IUCF), PHY 94-20787 (UIUC), the U.K. Particle Physics and Astronomy Research Council, and also by the Sloan Fund of the Massachusetts Institute of Technology (MIT). Further, RGM thanks the National Science Foundation for a Presidential Young Investigator Award.
ASJC Scopus subject areas
- Nuclear and High Energy Physics