The European Synchrotron Radiation Facility, ESRF, operates a powerful source of light in the X-ray range. Serving fundamental research and industry, the ESRF provides experimental facilities to a wide community of scientific users in the fields of physics, chemistry, materials and life sciences. Supported by 17 participating countries, this 3rd generation synchrotron X-ray source is constantly pushing experimental possibilities to new limits.
Beam loss monitors inside the storage ring tunnel
Currently, 32 PTW 50 l ionization chambers plus UNIDOS electrometers are installed inside the ESRF storage ring. This installation allows an absolute beam loss monitoring by measuring the radiation produced by the interaction of the electrons with matter (vacuum vessels, magnet yokes, etc.) when they are lost.
Mobile radiation leakage monitors
For quick detection of radiation leakages in the surrounding of the storage ring, mobile monitors, each consisting of a 50 l ionization chamber and a UNIDOS electrometer, are used. A PC connected to the UNIDOS records the dose level continuously over time.
Stationary radiation monitors for the X-ray beamlines
At present during refilling of the storage ring all the X-ray beamline front ends must be closed. This is a safety measure because increased injection losses could lead to too high radiation doses outside the X-ray lead hutches if the front ends remained open. The obvious disadvantage of this mode of operation is the important change of the heat load on the beamline optical elements caused by the closing of the shutters.
A new mode of operation is therefore intended to be introduced at the ESRF from 2003 onwards, allowing the storage ring top-up with front ends open. Outside every optics hutch a PTW 50 l ionization chamber and a custom-built UNIDOS electrometer with interlock relay contacts will be installed to monitor the radiation dose levels outside the beamlines (32 in total). If the integrated dose would exceed the allowed dose limits the corresponding front end will automatically be closed, using the interlock relay contacts on these UNIDOS electrometers.
In total, 85 radiation monitor systems are available at the ESRF from November 2002 onwards.
Detailed information on the use of PTW 50 l ionization chambers and UNIDOS electrometers at the ESRF
European Synchrotron Radiation Facility
Avenue des Martyrs
BP 220 (Post Box)
38043 Grenoble Cédex 09
Attn. Mr Paul Berkvens
ESRF Safety Engineer
Phone +33-4-76 88-2071 or -2403
Fax +33-4-76 88-2418