Provided are a scintillator with improved energy sensitivity dependence within the energy range of diagnostic X-rays, more specifically in the range of 40-150 kV, and a radiation dosimeter using same. Due to the scintillator comprising a photopolymer resin that contains a polymerizable monomer, a filler, and a photopolymerization initiator, energy sensitivity dependence within the range of 40-150 kV is improved. Furthermore, changes in relative sensitivity within this energy range can be reduced to 3% or less by containing an inorganic fluorescent substance such as Zn.sub.2SiO.sub.4.

A method for increasing emission output from an energy modulation agent, involving: drying the energy modulation agent in particulate form to reduce moisture level of the energy modulation agent by at least 25% to provide a dried energy modulation agent; and coating the dried energy modulation agent with a coating having high transmissibility at a wavelength of primary emission from the energy modulation agent upon excitation, and energy modulation agents prepared thereby.