Theoretical analysis of beta- emission from 63-Ni nano-particles in   glassy 15-P
  The energy loss of $\beta^-$ emission emitting from a 63-Ni source in a phosphorus 15-P scintillation medium is theoretically studied. It has shown the $\beta$ energy spectrum absorption in ${15}P$ had nearly 100% efficiency for $\leq$ 28 keV in 800 {\mu}m scintillator thickness. This can eventually lead to the production of light sources using these beta-emitting radiation sources as a low energy source in the near future. 
S. R. Mirfayzi
cond-mat.other physics.atom-ph physics.ins-det