TEST OF PARITY CONSERVATION IN pp SCATTERING AT 46 MEV
An experiment has been designed to measure the effect of parity non conservation in {vector p}-p scattering near 50 MeV. A target-detector system has been constructed which permits an extremely accurate comparison of the cross sections for incident protons of positive versus negative helicity. Our first measurements give a value of A{sub z}=(-1.3±2.3)x10{sup -7} for the longitudinal analyzing power. The present is done with a 50-MeV polarized proton beam from the Lawrence Berkeley Laboratory 88-Inch cyclotron. The atomic-beam type polarized ion source permits selection of ground state atomic hydrogen hyperfine states to provide the reversal of the proton polarization, This is done by rapid and automatic switching of the weak and intermediate field RF transitions, This selection in the neutral atomic beam minimizes beam intensity and position modulations which are coherent (i.e, in phase) with the reversal of the spin, as compared with any scheme whereby the spin reversal is achieved by magnetic and/or electric fields acting on an ion beam. Since the polarization direction is provided by the magnetic field, the beam from the cyclotron has only transverse (vertical) polarition. A solenoidal magnetic field used to precess the spin axis 90° into the horizontal plane, after which a dipole beam through an angle of 47.7° and precesses the spin axis into the beam direction, Thus, spin-reversal at the source results in proton helicity reversal at the target.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Nuclear Science Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 1072226
- Report Number(s):
- LBL-11122
- Resource Relation:
- Conference: 5th International Symposium on Polarization in Nuclear Physics, Santa Fe, NM, August 11-15, 1980
- Country of Publication:
- United States
- Language:
- English
Similar Records
200 nA variable energy polarized proton beam at TRIUMF
The TRIUMF parity violation experiment