Measuring the target polarization for the Jefferson Lab Hall B Polarimeter

POSTER

Abstract

A significant portion of the CLAS12 physics program requires knowledge of the electron beam polarization, which is measured with a M{\o}ller polarimeter. The longitudinal component of the beam polarization is given by $P_{B}^{z}=\frac{A}{{\thinspace A}_{zz}P_{T}^{z}}$, where $A_{zz}$ is the M{\o}ller analyzing power, $P_{T}^{z}$ is the target polarization, and $A$ is the beam-spin asymmetry measured by detecting scattered electrons in coincidence after the beam strikes a polarized permendur target. To find the beam polarization, the polarization of the target must be known. We have used a bench-top apparatus consisting of solenoid coil to generate a polarizing field and a pickup coil surrounding the target material to measure the magnetization of the target when the solenoid field is reversed. In this poster we will present the details of our apparatus and analysis procedure along with results of measurements and the accompanying uncertainties. The total relative uncertainty in the target polarization is $\delta P_{T}^{z}/P_{T}^{z}\approx 0.02$.

Authors

  • Katherine Wild

    Florida International University

  • Emmanuel Sarpong

    Georgia State University, University of Alabama at Birmingham, American Association of Physics Teachers, Bradley University, Michigan State University, University of St. Thomas, Kansas State University, Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, University of Delhi, University of Mississippi, Vanderbilt University, Universidad de los Andes (Colombia), President of UNCW SPS Chapter, Duke University, NC Central University, Davidson College, Beijing Normal University, University of California, Los Angeles, University of Tennessee, Chattanooga, University of Kentucky, Syracuse University, Clemson University, Department of Physics & Astronomy, Florida International University, Oak Ridge National Lab, Indiana University, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Bowie State University, MD, Oak Ridge National Laboratory, University of Tennessee, Knoxville, Arizona State University, University of California, Davis, North Carolina State University, Virginia Commonwealth University, North Carolina A&T State University, UNC Charlotte