Radiation skyshine from a 6 MeV medical accelerator.
This study assesses the dose level from skyshine produced by a 6 MeV medical accelerator. The analysis of data collected on skyshine yields professional guidance for future investigators as they attempt to quantify and qualify radiation protection concerns in shielding therapy vaults. Survey measurements using various field sizes and at varying distances from a primary barrier have enabled us to identify unique skyshine behavior in comparison to other energies already seen in literature. In order to correctly quantify such measurements outside a shielded barrier, one must take into consideration the fact that a skyshine maximum may not be observed at the same distance for all field sizes. A physical attribute of the skyshine scatter component was shown to increase to a maximum value at 4.6 m from the barrier for the largest field size used. We recommend that the largest field sizes be used in the field for the determination of skyshine effect and that the peak value be further analyzed specifically when considering shielding designs.
Gossman
Michael S
MS
Tri-State Regional Cancer Center, Medical Physics Section, Ashland, KY 41101, USA. mgossman@tsrcc.com
McGinley
Patton H
PH
Rising
Mary B
MB
Pahikkala
A Jussi
AJ
D003196:Computer Graphics; D006801:Humans; D010315:Particle Accelerators / Q000295:instrumentation*; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection / Q000379:methods*; D011878:Radiotherapy / Q000295:instrumentation*; D012542:Scattering, Radiation