Calibration of the Tagger Detectors with GlueX Commissioning Data

ORAL

Abstract

The GlueX experiment at Jefferson Lab uses a linearly polarized photon beam to search for mesons with gluonic excitations and measure their spectrum and couplings. This polarized photon beam will be created using a 12 GeV electron beam incident on a 20 $\mu$m thick diamond radiator, where it undergoes coherent bremsstrahlung to produce an intensity enhancement in the region of 9 GeV with a linear polarization around 40$\%$. The energy of the photon is inferred by analyzing the post-bremsstrahlung electron energy in the tagging spectrometer. A highly segmented tagging detector called the tagger microscope will intercept the electrons in the region of the coherent peak 8.4-9.0 GeV photon energy. These electrons are incident on a two-dimensional array of scintillating fibers which are read out using multi-photon pixel counters (MPPC). Post-bremsstrahlung electrons outside of the coherent peak region corresponding to photon energies of 3.0-11.8 GeV are incident on a hodoscope of plastic scintillators which are read out by photomultiplier tubes (PMT). The calibration results for the tagger microscope and hodoscope using commissioning data will be presented.

Authors

  • Alexander Barnes

    Univ of Connecticut - Storrs

  • Nathan Sparks

    Catholic Univ of America