Measurement of the Circular Polarization of Gamma-Quanta Emitted from the Nuclei After the Capture of Polarized Thermal Neutrons

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Czechoslov. J. Phys.

DOI:https://doi.org/10.1007/BF01688831· OSTI ID:4800909

Michalec, R; Ruskov, T

Published data predict that non-polarized nuclei, after capturing polarized thermal neutrons, form polarized compound nuclei with isotropic emission of circularly polarized gamma quanta. The degree and sign of gamma polarization are functions of the transition multiplicity and the initial moments of composite and final nuclear states. The circular polarization of gamma quanta emitted by Fe⁵⁷ at E gamma = 7.64 Mev and Ni⁵⁹ at E_γ = 9.0 Mev was measured for calibrating the installation. For iron P = 2.52 x 10^-2, Q = 0.47 plus or minus 0.22 x 10^-2 and for nickel P = 1.16 x 10^-2, Q = (--0.54 + 0.27) x 10^-2; the results obtained for the two transitions were in good agreement with published data. Measurements were also made of the circular polarization of gamma -quanta emitted by Cu⁶⁴ where the Cu⁶³ has two closely distributed levels at resonance energies 0.59 and 2.0 kev that are responsible for the thermal neutron capture. The observed three very in tense and closely distributed transitions of Cu⁶⁴ (E _γ = 7.91, 7.63, and 7.31), measured as a total gamma circular polarization, were equal to P_σ = 2.52, R_σ = 10^-2 and Q = (-0.08 plus or minus 0.10) x 10^-2. On the basis of published data and correlations of R_σ, obtained by theoretical and experimental data on Q, it was concluded that all three transitions have L == 1(E1), while resonance spins at 0.59 kev and 2.0 kev have different magnitudes differing by a unit (2^- or 1^-). (R.V.J.)

• Research Organization: Moscow State Univ.
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-029806
• OSTI ID: 4800909
• Journal Information: Czechoslov. J. Phys., Journal Name: Czechoslov. J. Phys. Vol. Vol: 12
• Country of Publication: Country unknown/Code not available
• Language: Czech

Related Subjects

CAPTURE
COPPER 64
EMISSION
ENERGY LEVELS
GAMMA RADIATION
IRON 57
MEASURED VALUES
NICKEL 59
NUCLEI
PHYSICS
POLARIZATION
RESONANCE
SPIN
STANDARDS
THERMAL NEUTRONS
TRANSITIONS