Studies of Limits on Uncontrolled Heavy Ion Beam Losses for Allowing Hands-On Maintenance

Reginald M. Ronningen ; Igor Remec

关键词: ACCELERATOR FACILITIES;    ACCELERATORS;    DOSE RATES;    HEAVY IONS;    IRRADIATION;    LINEAR ACCELERATORS;    MAINTENANCE;    NEUTRONS;    PROTON BEAMS;    PROTONS;    TRANSPORT hands-on maintenance dose rate limi;   

DOI  :  10.2172/988186
RP-ID  :  DOE/ER/41475
PID  :  OSTI ID: 988186
Others  :  TRN: US1202516

学科分类：核物理和高能物理

美国|英语

来源: SciTech Connect

【 摘 要 】

Dose rates from accelerator components activated by 1 W/m beam losses are obtained semiempirically for a 1 GeV proton beam and by use of Monte Carlo transport codes for the proton beam and for 777 MeV/u 3He, 500 MeV/u 48Ca, 86Kr, 136Xe, and 400 MeV/u 238U ions. The dose rate obtained by the semi-empirical method, 0.99 mSv/h (99 mrem/h) at 30 cm, 4 h after 100 d irradiation by a 1-GeV proton beam, is consistent with studies at several accelerator facilities and with adopted hands-on maintenance dose rate limits. Monte Carlo simulations verify this result for protons and extend studies to heavy ion beam losses in drift-tube linac and superconducting linac accelerating structures. The studies indicate that the 1 W/m limit imposed on uncontrolled beam losses for high-energy proton beams might be relaxed for heavy ion beams. These studies further suggest that using the ratio of neutrons produced by a heavy ion beam to neutrons produced by a proton beam along with the dose rate from the proton beam (for thin-target scenarios) should allow an estimate of the dose rates expected from heavy ion beam losses.