SCINTILLATION COUNTERS

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Acad. Rep. Populare Romine, Filiala Iasi, Studii Cercetari Stiint., Fiz. Stiinte Tehn.

OSTI ID:4674411

Tibu, M

Scintillation counters make use of the ability of alpha particles to ionize and to excite ZnS molecules, generating light which is transformed into electric current by a photomultiplier. Uncharged particles are unable to ionize the gases directly; they can be detected only if they transfer a portion of their energy to an electron by the Compton effect, photoelectric effect, or pair formation. In the case of neutrons, an alpha particle must be formed by a (n, alpha ) reaction. Transformation of the light into electric pulses by the photomultiplier results in a considerable increase of the counting rate. This is achieved by directing the light to the photocathode, causing the liberation of photoelectrons. The spectral sensitivity of the most used photocathodes, such as Cs/sub 3/Sb-Sb-Na, Sb-K, Sb--K-Na, and Sb-K--Na-Cs, are presented. The great amplification of the device, ranging from 10/sup 6/ to 10/sup 9/, causes a certain amount of instability in the system. The background noise level may be decreased by cooling but this presents some technical difficulties. The short duration of the pulses is very important for the resolution of individual counts; pulses of 6 x 10/sup -10/ sec were achieved with Ag-Mg alloy dinodes. The energy transfer mechanism by the excitation of vibrational states in organic and inorganic scintillators is reviewed. Gas scintillators, such as Ar, are useful for strongly ionizing particles, such as protons, alpha particles, and fission fragments. (33 references) (TTT)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-030860
• OSTI ID: 4674411
• Journal Information: Acad. Rep. Populare Romine, Filiala Iasi, Studii Cercetari Stiint., Fiz. Stiinte Tehn., Journal Name: Acad. Rep. Populare Romine, Filiala Iasi, Studii Cercetari Stiint., Fiz. Stiinte Tehn. Vol. Vol: 12
• Country of Publication: Country unknown/Code not available
• Language: Rumanian

Related Subjects

ALPHA PARTICLES
ANTIMONY
ANTIMONY ALLOYS
ANTIMONY COMPOUNDS
ARGON
BACKGROUND
BIBLIOGRAPHY
CATHODES
CESIUM
CESIUM COMPOUNDS
COATING
COMPTON EFFECT
CURRENTS
ELECTRODES
FISSION PRODUCTS
INSTRUMENTS AND INSTRUMENTATION
IONIZATION
MAGNESIUM ALLOYS
MOLECULES
NEUTRON BEAMS
PHOTOMULTIPLIERS
POTASSIUM
PROTONS
PULSES
RADIATION EFFECTS
RESOLUTION
SCINTILLATION COUNTERS
SCINTILLATIONS
SILVER ALLOYS
SODIUM
STABILITY
ZINC SULFIDES