Speaker
Nils Pickert
(Uni Erlangen)
Description
The Hermes collaboration installed a new Recoil Detector surrounding the
internal gas target to upgrade the existing spectrometer. It will allow the
detection and identification of low energy protons at large angles originating
from hard exclusive processes. These measurements will provide access to
generalised parton distributions. This Recoil Detector consists of three
subdetectors: a silicon detector inside the beam vacuum using a charge
division read out to achieve energy deposition measurements over a large
dynamic range, a four layer scintillating fibre tracker for space-point
reconstruction, and a photon detector using tungsten as shower generating
material. All three sub-detectors are located inside a solenoidal
superconducting magnet, which provides a 1 T longitudinal magnetic field.
The Recoil Detector was installed in January 2006 and will take data until
July 2007. An overview of the first measurements of recoil protons by the
detectors will be given, with an emphasis on the silicon detector
performance. Changes to the original design shown at this conference in
2004 will be presented. Estimates on tracking efficiencies and energy
resolutions will be shown.
Author
Nils Pickert
(Uni Erlangen)
