S T R A W S

Common Muon and Proton Apparatus for Structure and Spectroscopy

Make COMPASS fly ..

Part of the Large Angle Tracking detectors for the COMPASS experiment will consist of Straw drift chambers. Presently only one station of this type, Tracking Station 2 (TS2) between the first Spectrometer Magnet (SM1) and the first Ring Imaging Cherenkov Detector (RICH1), is going to be build.

TS2 consists of 18 double layers of straws in 3 orientations (horizontal, vertical, inclined). Every layer contains straws of 6mm diameter at smaller angles and straws of 10mm diameter at larger angles. The area covered by these chambers is 326 cm x 238 cm.

In the year 1998 two prototypes were constructed (one at Moscow State University, one at JINR Dubna) and tested in order to measure their efficiency, resolution and aging properties when exposed to high-intensity radiation.
The tests were performed at the X5 beamline at CERN and at the Tandem accelerator in Garching near Munich. The results are summarized in the COMPASS internal note 1999-2 (ps, pdf).

Various groups are involved in the construction of TS2:

JINR Dubna
Albert Ludwigs University Freiburg
Moscow State University
Ludwig Maximilians University Munich
Warsaw University of Technology

More Information:

Testbeam Gallery
Detailed geometrical information (ps, pdf)