Accession Number:

AD0272034

Title:

THE EFFECT OF COLLIMATION ON THE RESOLUTION AND PEAK-TO-TOTAL RATIO OF A NAI(T1) CRYSTAL,

Descriptive Note:

Corporate Author:

NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s):

• Tomnovec ,F. M.
• Read,P. A.

Report Date:

1962-01-31

Pagination or Media Count:

17.0

Abstract:

Restricting the incident radiation to a small area of a NaT1 scintillation crystal improves the resolution and peak-to-total ratio of the spectrometer. This effect was studied with a series of tapered lead collimators, all with the same apex but with differing apertures, in front of a 4 in. by 4 in. diameter NaIT1 scintillation crystal. Sources of gamma rays with energies from 0.28 to 2.76 Mev were located at the apex of the taper. Optimum resolution of about 25 percent greater than broad-beam resolution was obtained with a 0.25-in. diameter aperture. Anomalous effects were observed with a smaller opening. Author

Descriptors:

• *GAMMA RAY SPECTROSCOPY
• *NUCLEAR RADIATION SPECTROMETERS
• *PHOSPHORESCENT MATERIALS
• COLLIMATORS
• GAMMA RAY SPECTRA
• IODIDES
• RADIOACTIVE ISOTOPES
• SODIUM COMPOUNDS
• THALLIUM COMPOUNDS

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE