Eur. Phys. J. A (2007) 31: 509-511
https://doi.org/10.1140/epja/i2006-10248-8

QNP 2006

The HERMES Recoil Detector

II.Physikalisches Institut, University of Giessen, 35392, Giessen, Germany

Received: 23 November 2006
Accepted: 30 November 2006
Published online: 21 March 2007

Abstract

The HERMES Collaboration installed a new Recoil Detector to upgrade the existing spectrometer to study hard exclusive processes which provide access to generalised parton distributions (GPDs) and hence to the orbital angular momentum of quarks. The HERMES Recoil Detector mainly consists of three components: a silicon detector surrounding the target cell inside the beam vacuum, a scintillating fibre tracker and a photon detector with three layers of tungsten and scintillator bars in three different orientations. All three detectors are located inside a solenoidal magnet which provides a 1T longitudinal magnetic field. The Recoil Detector was installed in January 2006 and data taking will last until July of 2007.