Institut für Hochenergiephysik
Universität Heidelberg
Schröderstraße 90, D-69120 Heidelberg
M. KELLER, K. MEIER, O. NIX, G. SCHMIDT, A. STELLBERGER, J. STIEWE, A. STREICH
The VLQ spectrometer [1](VLQ=Very Low Momentum(Q) Transfer) is a new device dedicated to measure electrons scattered off protons under very low angles in the H1 experiment at the HERA e-p collider at DESY in Hamburg. It consists of a GaAs tracking detector a calorimeter and a time of flight system. In this article the calorimeter part will be discussed. The challenge of this project was to achieve the required energy and spatial resolution in a longitudinal space of only 16 cm. For this reason the calorimeter was built as a tungsten scintillator sandwich with a projective readout structure to obtain spatial resolution. In addition a very compact low noise readout electronics employing photodiodes and custom made integrated preamplifiers was developed.