SCINTILLATION RESPONSE OF ACTIVATED INORGANIC CRYSTALS TO VARIOUS CHARGED PARTICLES

Journal Article · Mon May 01 04:00:00 EDT 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.122.815· OSTI ID:4022198

Murray, R B; Meyer, A

Experimental studies of the response of activated ionic crystals such as NaI(Tl) and Csl(Tl) to heavy charged parti cles indicate decreasing scintillation efficiency with increasing panticle mass, and a nonlinearity in pulse height versus energy for heavier panticles. Recent experiments indicate that the scintillation efficiency to electrons, however, is less that that to protons. In an attempt to account for these effects, this paper presents a calculation based on a model of ths process of energy transfer from the incoming particle to the activator sites. In this model, the energy carriers are taken to be excitons resulting from recombination of electron-hole pairs in the wake of the particle. The migration of carriers to activator sites is described by a one-velocity diffusion equation in which the density of unoccupied activator sites, N/sub a/, is a function of space and time. The diffusion equation is coupled with a second differential equation describing the time dependence of N/sub a/. The solution to these equations indicates that the depletion of available activator sites by a particle with high dE/dx can account for observed saturation effects. This model further contains the activator concentration as a parameter, and permits a prediction of scintillation efficiency as a function of both dE/dx and concentration. The low scintillation efficiency to electrons is predicted as a consequencs of the smaller recombination probability for particles of vsry low dE/ dx. Finally, for a low-dE/dx particle in a crystal of 0.1-mole-percent activator concentration the diffusion length of energy carriers is found to be.of order 20 A. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• NSA Number: NSA-15-017422
• OSTI ID: 4022198
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 122; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CARRIERS
CESIUM IODIDES
CHARGED PARTICLES
CRYSTALS
DIFFERENTIAL EQUATIONS
DIFFUSION
DIFFUSION LENGTH
EFFICIENCY
ELECTRONS
IMPURITIES
PHOSPHORS
PHYSICS
PROTONS
SCINTILLATIONS
SODIUM IODIDES
TELLURIUM