Precise energies of gamma rays from thermal neutron capture in nitrogen

Ishaq, A.F.M.; Khan, A.; Anwar-ul-Islam, M.; Najam, M.R.

doi:10.1016/0029-554x(74)90157-8

Cited by 5 publications

(2 citation statements)

References 7 publications

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“…About half of the 93 tran- The spin-parity assignments are based on the NDS compilation [14] and the observed decay properties as discussed in the text sitions assigned to 63Ni were placed in this level scheme and represent more than 98% of the total ),-ray flux through this nucleus. This small discrepancy is possibly accounted for by the fact that the previous value of B, was based on a 15N standard [18] the transition energies of which seem to be systematically higher than those of the recent 14N(n,y)study of Kennett et al [19]. Adding an absolute calibration error of 25 ppm in quadrature yields a total error of 175eV.…”

Section: Resultsmentioning

confidence: 87%

Double neutron capture in62Ni

Harder

Michaelsen

Jungclaus

et al. 1992

Z. Physik A - Hadrons and Nuclei

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The 7-radiation following single and double neutron capture in isotopieally enriched 62Ni was studied at the high flux reactor of the Institut Laue-Langevin, using a pair and Compton suppressed germanium detector. Measurements before and after 170 d of breeding were performed. The 7-ray fluxes through 63Ni and 64Ni are discussed; several new levels and spin-parity assignments were found. On the basis of the known discrete levels and the low-energy neutron resonances, level density parameters were determined within the Constant Temperature Fermi Gas model. The neutron binding energies were measured as B, (63Ni)= 6837.92(18) keV and B, (64Ni)= 9657.64(24) keV. The 63Ni (n, 7) cross section for reactor neutrons was / L'Y measured to be a = 20" _J b. 2

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Section: Resultsmentioning

confidence: 87%

Double neutron capture in62Ni

Harder

Michaelsen

Jungclaus

et al. 1992

Z. Physik A - Hadrons and Nuclei

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“…Since some of the required counting times, listed in Table 1, were fairly lengthy, digital spectrum-stabilization was used to guard against gain and zero shifts. Energy calibration of the spectrometer was achieved via the 7 rays from thermal neutron capture in nitrogen, a reaction for which precise data exist [20]. A mixed source technique was employed in each instance to minimize the error in energy determinations.…”

Section: Experimental Methodsmentioning

confidence: 99%

Thermal neutron capture in isotopes of nickel

et al. 1977

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The gamma-ray spectra associated with thermal neutron capture in targets of 5SNi, 6~ 62Ni, and 64Ni have been observed with a high-sensitivity pair-spectrometer. Level schemes for the four product nuclei are discussed, correlation of widths with neutron single-particle states examined, and estimates for M1 and E2 7-ray strength functions obtained.The stable isotopes of nickel, which range in mass number from 58 to 64, fall within a mass region commanding considerable interest. In particular, since four of the five naturally occurring isotopes provide even-even target nuclei, one might expect strong correlation between (d, p) single-particle strengths and reduced radiative widths for transitions to l, = 1 final states following thermal neutron capture. Since in the latter reaction much of the radiated strength is concentrated in a few high-energy ~ rays, the characteristics of such 7 rays, and associated energy levels, are well known. The low-energy 7 rays from thermal neutron capture in nickel isotopes have also been well established [1 6]. In addition, several studies of the nickel isotopes have been conducted by means of (d, p) reactions employing either polarized [7][8][9] or unpolarized [l(L13] deuterons. Summaries of energylevel information for nickel are available in recent compilations of the Nuclear Data Sheets [14][15][16][17]. In the present thermal-neutron-capture study, 7 rays of intermediate to high energy, 2 to 9 MeV, were examined by means of Ge(Li)-NaI(T1) pairspectrometer system of greatly improved sensitivity, as reported by Robertson et al. [18]. The remarkable reduction in continuum achieved by this system, in particular at intermediate photon energies, permitted detection of several low intensity y rays helpful in the understanding of decay characteristics, and, in gen-* Permanent Address: Nuclear Physics Division, Pinstech, P.O. Nilore, Rawalpindi, Pakistan eral, led to a more complete collection of information than available to date. Moreover, since the nickel isotopes were studied en bloc, both as constituents of a natural target and as enriched targets, it was possible to obtain accurate estimates of intensities and widths, which checked as consistent with known isotopic abundances and thermal neutron-capture cross sections. Improved Q-value estimates were correspondingly obtained for all isotopes studied.

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