Photon and neutron responses of optical absorption dosimeters used at SLAC

This paper reports the photon and neutron responses of four types of optical absorption dosimeters used at SLAC. The neutron responses are about 50% of their photon responses when expressed as tissue dose responses. The Stanford Linear Accelerator Center (SLAC) is a high energy physics research facility. It has a capability to delivery high energy (up to 50 GeV) and high power (up to 600 kW) electron beam to experimental areas. During an operation, photon and neutron radiation can reach inside shielding barriers as high as 1,000 Gy (Si)/hr and 1 x 108 n/cm2/s (1 MeV, Si) due to beam losses. This may result in large accumulated doses to the beamline components and nearby electronic devices. To study the pattern of beam losses and protect electronic devices, a high-level dosimetry system has been used at SLAC. Four types of optical absorption dosimeters are used to cover different radiation ranges (Optichromic FWT70-40M, Optichromic FWT70-83M, Radiochromic FWT60-1P, Red Perspex 2423). This paper reports the photon and neutron responses of these dosimeters