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: Construction Schedule : Beam and Dump Lines, : Dump lines

Radiation budget

The radiation budget due to the primary beam and photons was estimated by the Jlab RADCON group and it is acceptable. The scattered electrons bent by the Splitter magnet but not accepted by the Enge Split-pole will hit the target chamber wall. This part of electrons produced immeasurable radiation budget above hall background due to E89-009 experiment, even during the period of using 2 $\mu $A beam. It is unable and inaccurate to make a direct scale up from the background measurement for this experiment as beam current increased to 30 $\mu $A. A calculation and simulation will be performed after the target chamber design is fixed. The calculation will show us whether additional local shielding is needed to maintain the acceptable overall radiation budget. This simulation aims also to estimate the effect of neutral background particles to the electron arm detectors.

Satoshi N. Nakamura 平成16年12月2日