Speaker
Description
The PRad experiment was recently performed
at Jefferson Lab in Hall B. It was designed
to measure the proton charge radius up to
a sub-percent precision through elastic electron
proton scattering process.
It reached very small 4-momentum
transfer squared region
($Q^2$ from $2 \times 10^{-4}$ to 0.1 $(GeV/c)^2$) for the first time.
To achieve the
experimental goal, a pair of large area
GEM detectors were designed and constructed at the University of Virginia.
These two GEM detectors are the largest active area GEM detectors ever built.
Both GEM detectors worked very well through out the experiment,
yielding excellent performance, meeting design parameters.
GEM detectors improved the experimental
resolution by a factor of at least 20.
In this talk,
we will present the performance, such as efficiency,
spatial resolution, etc, of these GEM detectors during experiment,
and also
a short introduction to PRad experiment.
