Investigation of65Cu by means of the average resonance proton capture method

Abstract

The 64Ni(p,~)65Cu reaction has been studied in the proton energy range Ep=2.05-2.55 MeV. The gamma-ray spectra were recorded with a three-crystal pair spectrometer at proton energy differences of 19keV covering the proton energy range. An average gamma-ray spectrum was formed by adding all the individual spectra after proper adjustment as a result of the alterations in proton energy. The intensities of the gamma rays to final states with known J~-values were tested against theoretical calculations based on the Hauser-Eeshbach theory. The gamma-ray strength function for energies lower than 9 MeV has been extracted from the experiment. IntroduetiofiBollinger and Thomas [1][2][3] have pointed out the usefulness of the average resonance neutron capture in nuclear spectroscopy for spin and parity assignment. Recently this method has been examined in proton capture for As, Tc, Y and Zr isotopes as product nuclei [4][5][6][7][8][9]. It has been shown that, when the intensities of the primary gamma rays are summed over many resonances of the compound nucleus, which is formed in low energy proton capture, the variations of the intensities due to nuclear structure effects are damped out. The average intensities of the primary gamma rays depend only on the multipolarity and the parity change of the transition, and can be predicted on the basis of the Hauser-Feshbach theory, thus allowing J~ assignment to low-lying final states. The proton capture results are however less unique because of complications due to the different partial waves contributing at MeV energies. It was also shown that the gamma-ray strength function can be extracted from the average resonance proton capture and that it varies with energy according to the prescription of the giant dipole resonance [9].

Core-coupled protons,f7/2intruder states, and competingg9/2proton and neutron structures inChiara1, Stefanescu2, Walters3 et al. 2012Phys. Rev. C

“…It should be noted that the 808-and 1762-keV gamma rays found to depopulate the 2533.04-keV level in Ref. [37] were not observed here either, but this is consistent with that level having a low spin and not being strongly populated in inelastic reactions. Therefore, only a single level at 2534 keV is present in the decay scheme of Fig.…”

“…on a comparison with Hauser-Feshbach theory in (p, γ) [37] and L = 3 transfer in (d, 3 He) [38] and (t, α) [29] reactions. The previous determination of negative parity for these states implies that the gamma rays must be parity-changing E1 transitions, and the spins of both final levels are confirmed to be 7/2.…”

“…Both of these levels are consistent with an I π = 9/2 + assignment. The third state, at 2533.04 (15) keV, was observed in (p, γ) [37] and (n, n ′ γ) [11] reactions to decay to 1/2 − and 3/2 − levels.…”

Validation of an optical potential for incident and emitted low-energy $$\alpha $$-particles in the $$A\sim 60$$ mass range

“…Thus, the corresponding calculated results are two times larger than the measured point at ∼ 2.5 MeV, and then larger by ∼ 50% from 4 MeV. 68 Zn de-excitation The (n, p) reaction has fortunately more recent data at incident energies between 1.6 and 6 MeV, as shown in Fig. 12a.…”

“…3. There is an obvious difference between the measured RSF data that are smaller for 62 Cu [66] than for 65 Cu [68]. We have described it within the EGLO model using different values of the constant nuclear temperature T f .…”