A self-consistent set of neutron separation energies

Abstract

The (n,γ) reaction has been used to establish a self-consistent set of neutron separation energies. Through examination of composite targets with a common component 13 elements have been studied, yielding some 20 Q values. The average precision was estimated to be 0.08 keV with the separation energy differences having a precision of 0.14 keV. In most cases agreement between the present and the accepted values was within the quoted error of the latter. The isotopes reported and (the separation energy in kiloelectronvolts) are 10Be (6812.1), 25Mg (7330.5), 26Mg (11 092.9), 28Al (7725.2), 29Si (8473.7), 30Si (10 609.7), 33S (8641.6), 36Cl (8579.8), 41Ca (8362.8), 45Ca (7414.9), 48Ti (11 626.5), 49Ti (8142.3), 50Ti (10 939.7), 51Cr (9261.8), 53Cr (7939.6), 54Cr (9719.0), 56Mn (7270.6), 55Fe (9298.0), 57Fe (7646.2), and 58Fe (10 044.7).

The capture γ-ray spectrum of Mg

“…These energies and the level energies were calculated by least-squares refinement using the decay schemes outlined in Tables 2, 3, and 4 as models. The result for 14Mg obtained here is in slight disagreement with that of Hungerford et al (6), while agreeing with the earlier value of Islam et al (5). In the case of 151uIg, the value obtained here is slightly higher than that of Islam et al ( 9 , but essentially in agreement.…”

“…In later work two independent high-precision measurements of neutron separation energies were reported (5,6). The first of these gave values for the mass 24 and 25 targets while the second reported values for all three isotopes.…”

Investigation of the 47,49Ti(n, γ)48,50 reactions

“…The present value of the neutron binding energy of 10 939.20(4) keV deviates from the value of 10 939.7( 1) keV reported in ref. 24). A possible explanation for this difference of five standard deviations can be found in the fact that in ref.…”

“…The most recent value of the neutron binding energy has been reported in ref. 24) as 11 626.5 * 0.04 keV (where they fail to present the last digit). After an adjustment to 11 626.5(l) keV it is in agreement with the present value of 11 626.66(4) keV.…”

“…A possible explanation for this difference of five standard deviations can be found in the fact that in ref. 24) only two cascades were used. The chance of systematic errors occurring is thus larger than for 48Ti and 49Ti, where three and four cascades were used, respectively, and where the agreement with the present values is excellent.…”