ABSOLUTE PAIR CROSS SECTIONS AT 1.119 Mev

Journal Article · Wed May 01 04:00:00 EDT 1963 · Proc. Phys. Soc. (London)

DOI:https://doi.org/10.1088/0370-1328/81/5/320· OSTI ID:4693268

Rao, J R; Lakshminarayana, V; Jnanananda, S

Absolute pair cross sections in the elements Cu, Zr, Rh, Sn, Ta, Pt, Au and Pb for gamma rays of energy 1.119 Mev are determined, using a scandium-46 source of intensity 1 curie and a coincidence scintillation spectrometer. The results are found to support the general viewpoint that Bethe-Heitler theory fails at energies of this magnitude. Good agreement is observed between the present experimental value for lead and the value reported by previous investigators. The usual Z dependence formula valid at high energies is, however, found to be inadequate at this energy. A modified formula of the type olytic C and = olytic C and /sub BH/ STA1 + dZ/sup 2/ exp(--bZ)! for the Z dependence of the pair cross section is found to give a better fit of the experimental data. (auth)

• Research Organization: Andhra Univ., Waltair, India
• NSA Number: NSA-17-025972
• OSTI ID: 4693268
• Journal Information: Proc. Phys. Soc. (London), Journal Name: Proc. Phys. Soc. (London) Vol. Vol: 81
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ATOMS
BETHE-HEITLER THEORY
BREMSSTRAHLUNG
COINCIDENCE METHODS
COPPER
CROSS SECTIONS
ELECTRIC CHARGES
ENERGY
ENERGY RANGE
GAMMA RADIATION
GOLD
LEAD
MEV RANGE
PAIR PRODUCTION
PHYSICS
QUANTITATIVE ANALYSIS
RADIATION SOURCES
RUTHENIUM
SCANDIUM 46
SCINTILLATION COUNTERS
SPECTROMETERS
TANTALUM
TIN
ZIRCONIUM