3 research outputs found
The GLUEX beamline and detector
The GLUEX experiment at Jefferson Lab has been designed to study
photoproduction reactions with a 9-GeV linearly polarized photon beam.
The energy and arrival time of beam photons are tagged using a
scintillator hodoscope and a scintillating fiber array. The photon flux
is determined using a pair spectrometer, while the linear polarization
of the photon beam is determined using a polarimeter based on triplet
photoproduction. Charged-particle tracks from interactions in the
central target are analyzed in a solenoidal field using a central
straw-tube drift chamber and six packages of planar chambers with
cathode strips and drift wires. Electromagnetic showers are
reconstructed in a cylindrical scintillating fiber calorimeter inside
the magnet and a lead-glass array downstream. Charged particle
identification is achieved by measuring energy loss in the wire chambers
and using the flight time of particles between the target and detectors
outside the magnet. The signals from all detectors are recorded with
flash ADCs and/or pipeline TDCs into memories allowing trigger decisions
with a latency of 3.3 mu s. The detector operates routinely at trigger
rates of 40 kHz and data rates of 600 megabytes per second. We describe
the photon beam, the GLUEX detector components, electronics,
data-acquisition and monitoring systems, and the performance of the
experiment during the first three years of operation
First Results from The GlueX Experiment
The GlueX experiment at Jefferson Lab ran with its first commissioning
beam in late 2014 and the spring of 2015. Data were collected on both
plastic and liquid hydrogen targets, and much of the detector has been
commissioned. All of the detector systems are now performing at or near
design specifications and events are being fully reconstructed,
including exclusive production of pi(0), eta and omega mesons.
Linearly-polarized photons were successfully produced through coherent
bremsstrahlung and polarization transfer to the rho has been observed