At the CERN Proton Synchrotron (PS) accelerator complex, two experimental zones allow the irradiation of samples in a 23 GeV pure proton beam and in a secondary particle environment dominated by 1-MeV neutrons and gamma rays. In this paper a review of the operative irradiation systems named IRRADI and IRRAD2 is presented, as well as the improvements in the techniques used for the beam characterizations and dosimetry.

A novel real-time optical fibered dosimetry system based on optically stirn ulated luminescence (OSL) of SrS:Ce,Sm phosphor was developed and is presented. The advantages of this system are the combination of OSL and optical fibers, immediate readout, simplicity of use, low cost, reliability, flexibility, and robustness. Experimental results show an excellent linearity with the dose (0.01 to 6 Gy), repeatability better than 2%, radiation sensitivity up to 80 mV.cGy-l and accuracy since error on dose is less than 5%. The applications targeted are the measurement of the dose delivered during a treatment in radiation therapy and the monitoring of the dose or dose-rate around or in nuclear reactor and accelerator facilities in high energy physics. Further experiments are still to be conducted in order to fully characterize the system and evaluate the feasibility of each application mentioned.

Abstract-The BPW34 p-i-n diode was characterized at CERN in view of its utilization as radiation monitor at the LHC to cover the broad 1-MeV neutron equivalent fluence (8 eq ) range expected for the LHC machine and experiments during operation. Electrical measurements for both forward and reverse bias were used to characterize the device and to understand its behavior under irradiation. When the device is powered forward, a sensitivity to fast hadrons for 8 eq 2 10 12 cm 2 has been observed. With increasing particle fluences the forward I-V characteristics of the diode shifts towards higher voltages. At 8 eq 3 10 13 cm 2 , the forward characteristic starts to bend back assuming a thyristorlike behavior. An explanation for this phenomenon is given in this article. Finally, detailed radiation-response curves for the forward bias-operation and annealing studies of the diode's forward voltage are presented for proton, neutron and gamma irradiation.