Design, fabrication, and characterization of a portable lead cave for field applications of gamma spectrometry
The most utilized detector shielding for gamma-ray spectrometry is lead (Pb) and it is sometimes layered with copper (Cu) and/or tin (Sn) as fluorescent x-rays absorber. However, traditional lead caves are heavy structures that are hard to handle and transport for field applications. In this study, a portable lead cave was designed, fabricated, and characterized. Background radiation measurement and MCNP5 simulations were performed for the characterization. Significant decrease in the background radiation was observed after using the designed lead cave. After the measurement, the source-to-lead cave distance needed to minimize the effect of nearby sources on the spectrometry was simulated. Results show that at least 10 cm source-to-lead cave distance is needed to have low interference and to avoid unwanted peaks when performing spectrometry with the portable lead cave. However, this still depends on the activity of the external source. Nonetheless, the designed lead cave exhibited sufficient shielding capabilities to reduce interferences from small sources as well as background radiation from naturally occurring radioactive nuclides.