INFLUENCE OF CERTAIN FACTORS ON THE ENERGY RESOLUTION OF NaI(Tl) CRYSTAL SCINTILLATION COUNTERS

Journal Article · Fri Sep 01 04:00:00 EDT 1961 · Ukrain. Fiz. Zhur.

OSTI ID:4796348

Dobrovinskaya, E R; Mokhir, E P; Eidel'man, L G

The dependence of the scintillation counter energy resolution on the activator distribution in NaI(Tl) crystals is studied. It is shown experimentally that for improvement of the resolution a special irregular activator distribution is required in the crystal. As a result an increase in scintillation efficiency compensates for the decrease of the light collecting coefficient, so that the light output along the crystal length remains constant. NaI(TI) single crystals, 40 mm in diameter and 40 mm in height, were grown from a melt by Stockbarg's method; during the growth the melt was mixed up by convection. The light output distribution along the height was determined by means of the collimated gamma-ray beam for crystals of various concentrations, which correspond to various scintillation efficiency gradients along the crystal axis. The mibimum scatter of the light output was observed in crystals with 0.15 to 1.18% Tl in the charge. Both the increase and the decrease of Tl concentration lead to irregular light output distribution along the height and reduce the energy resolution. The optimum activator concentration is also affected by the treatment of the crystal reflecting surfaces. Hightemperature annealing of NaI(Tl) crystals gives rise to an increase in self-absorption and consequently to an increase in the light output scatter along the crystal height. (auth)

• Research Organization: All-Union Scientific-Research Inst. of Chemical Reagents, Kharkov
• NSA Number: NSA-16-015340
• OSTI ID: 4796348
• Journal Information: Ukrain. Fiz. Zhur., Journal Name: Ukrain. Fiz. Zhur. Vol. Vol: 6
• Country of Publication: Country unknown/Code not available
• Language: Ukrainian

Related Subjects

ABSORPTION
ANNEALING
BEAMS
CONVECTION
CRYSTALLIZATION
CRYSTALS
DISTRIBUTION
EFFICIENCY
ENERGY
FUSED SALTS
GAMMA RADIATION
HIGH TEMPERATURE
LATTICES
LIGHT
MIXING
MONOCRYSTALS
PHYSICS
QUANTITY RATIO
REFLECTION
RESOLUTION
SCINTILLATION COUNTERS
SCINTILLATIONS
SELF- ABSORPTION
SODIUM IODIDES
SURFACES
THALLIUM
VARIATIONS