Source term test in Hall C Title Page Vashek Vylet March 4, 2016

Motivation Measure photon and neutron source terms from a “standard” thick target at multiple angles from 0 to 180 degres, for multiple energies of electron beams Establish benchmark skyshine measurements using Jlab boundary monitors for losses on thick-targets Interior Page Design 1

Method Standard target: Cu cylinder 25 cm long and 5 cm in diameter – used in a parametric model (P. Degtiarenko, G. Stapleton, 1997) Passive OSL detectors for photons and CR-39 track etch for neutrons; optichromic detectors for high doses Dosimeters positioned at variable distances as function of angle so as to keep total dose within desirable range (~10s rems photons, upper 10s to >100 mrem neutrons) Interior Page Design 1

Method Polyethylene fitration envisioned to reduce electron dose Passive detectors will require ~10 min or less of irradiation Jlab active photon and neutron boundary monitors will record dose at the boundary – up to 1 hour of irradiation time would provide sufficient accuracy Interior Page Design 1

Other Aspects Activation calculations of the target under way, will provide dose rates after irradiation Activation of surrounding areas, based on experience, will be negligible; also estimated by simulations RadCon will adjust the RSAD, including contribution to boundary dose (estimated to ~4 mrem neutron, ~1 mrem photon) Interior Page Design 1