The decay of 184gRe and 184mRe
Abstract
A total of 24 gamma rays have been observed accompanying the decay of the 38 d ground state of 184Re and the 169 d isomeric state. Three of these gamma rays have not been reported previously. A level scheme is proposed for 184W with levels at 111.1, 364.3, 748.3, 903.1, 1005.9, 1121.3, 1130, 1133.8, 1221.4, 1285.2. 1386.2 and 1501.6 keV. The ratios of the reduced E2 transition probabilities are calculated for several pairs of transitions.
References (11)
- B. Harmatz et al.
Nucl. Phys
(1964) - N.R. Johnson
Phys. Rev.
(1963) - N.R. Johnson
Nucl. Data
(1966) - K.T. Faler et al.
Phys. Rev.
(1968) - S.B. Bodenstedt et al.
Nucl. Phys.
(1960)
Cited by (16)
Nuclear Data Sheets for A = 184
2010, Nuclear Data SheetsNuclear structure and decay data for all nuclei with mass number A=184 (Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi) have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented. This evaluation supersedes the previous publication (R.B. Firestone, Nuclear Data Sheets 58, 243 (1989) (literature cutoff date 1 June 1989)) and subsequent revisions of high spin data for several nuclides by Huo Junde (31 July, 1995) and evaluations by C.M. Baglin for 184Au, 184Pb and the new nuclide 184Bi (literature cutoff dates 4 April 2003, 28 July 2003 and 21 January 2004, respectively). The present evaluation includes literature available by 1 October 2009. Subsequent to those evaluations, (HI, xnγ) studies have contributed significantly to our knowledge of the structure of 184Re (2005Wh04), 184Os (2002Sh21, 2002Wh01, 1998Sh36), 184Hg (1995De30, 1995Sf01) and 184Au (2004Zh38). Additional information on the level structure of 184W has become available from new thermal neutron capture measurements (2003Bo52, 2004Lo22, 2007ChZX), from detailed reaction studies (2006Me25), new Coulomb excitation (1991Wu05) and (1993He15) studies, and from the 198Pt(136Xe,Xγ) reaction (2004Wh02); knowledge of 184Pt has benefited from a new 184Au ε decay study (2006KrZT, 1992Xu02, 1992Xu06, 1992XuZY), but this decay cannot yet be normalized due to the mixed parentage of the sources used.
Nuclear data sheets for A = 184
1989, Nuclear Data SheetsSpectroscopic data for all nuclei with mass number A=184 have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented.
Nuclear Data Sheets for A=184
1977, Nuclear Data SheetsDetailed level schemes, and the experimental reaction and decay data on which they are based, are presented for all nuclei with mass number A=184. The experimental data are evaluated; inconsistencies and discrepancies are noted; and adopted values for level and gamma-ray energies, gamma intensities, as well as other nuclear properties are given.
Additional radiation listings generated by the program MEDLIST§ are presented for 184Ta β−-decay, 184Re ε-decay (38−d, 165−d), 184Re IT-decay, and 184Ir ε-decay. These listings are given immediately following the usual Eγ, Iγ, etc., data sections and are based on these data. The MEDLIST output lists the recommended values for half-life, energies, absolute intensities (in % decay of the parent), and mean energy per decay for each of the atomic and nuclear radiations emitted by a radioactive atom. Only radiations with intensity >0.1% have been chosen for inclusion in the present listings. The content and tabular form of this output have been designed for the convenience of applied users.
Level structure of <sup>184</sup>W from the decay of <sup>184g</sup>Re and <sup>184m</sup>Re
1974, Nuclear Physics, Section AThe level scheme of 184W has been studied from the decay of 38d 184gRe and 165d 184mRe. Gamma-ray energy and intensity measurements were made using Ge(Li) and Si(Li) detectors; and conversion-electron measurements were made using an iron-free π√2 double-focusing spectrometer. From these data and extensive γ-γ coincidence measurements decay schemes for both 184Re activities have been proposed which incorporate all 42 of the observed γ-ray transitions. Unique spin and parity assignments have been made for all the energy levels observed. Detailed intensity-balance considerations for each energy level have led to improved electron-capture branching ratios and log ft values. In addition to the previously known features of the 184Re decay schemes, it has been established that levels at 1424 and 1431 keV in 184W are weakly populated and that their Iπ assignments are 3+ and 2+, respectively. Also, the 4+ → 2+ transition within the γ-vibrational band has been observed, which enables an estimate of the relative magnitudes of the intrinsic quadrupole moments of γ-vibrational and ground-state bands to be made. Within the experimental uncertainties involved (≈ 10%), these two moments are equal. A one-parameter analysis of the E2 transition probabilities between these two bands gives zγ = +0.0408 ±0.0041. Absolute transition probabilities are obtained and discussed for the γ-rays de-exciting the 3− state at 1221 keV and the 5− isomeric state at 1284 keV. Evidence for mixing of Kπ = 2− and 3− excitations in the 5− isomeric state is presented; and a formalism for treating such admixtures, of both collective and two-quasiparticle character, is developed and applied. A close similarity of the M4 γ-decay of 184mRe to that of the 10− isomeric state in 182Ta is noted.
Study of the <sup>182</sup>W(t, p)<sup>184</sup>W reaction at 20 MeV
1973, Nuclear Physics, Section AThe 182W(t, p)184W reaction has been studied at 20 MeV. The outgoing protons were detected in an Elbek broad range magnetic spectrograph. Absolute cross sections and angular distributions were measured. Evidence for inelastic effects in the reaction mechanism was observed for the first excited 2+ state, the 3− level at 1221 keV and the 5+ state at 1295 keV. The 0+ level at 1002 keV was populated with ≈ 2% the ground state cross section. A 4+ level at 1536 keV was observed with ≈ 50% the ground state cross section. Calculations of the absolute (t, p) cross sections to this and other states with known structure resulted in excellent agreement with the measured values.
Two-quasiparticle states and the microscopic composition of K<sup>π</sup> = 2<sup>+</sup> collective excitations in <sup>182</sup>W and <sup>184</sup>W
1973, Nuclear Physics, Section AEnergy levels of 182Wand 184W have been investigated by (d, p), (d, t) and (τ, α) reactions on enriched 183W targets. In the deuteron induced reactions, the reaction products at 60°, 90° and 125° were magnetically analysed and approximate l-transfer values were deduced from the cross-section ratios at these angles. The (τ, α) measurements provided important complementary data locating several 182W states populated with l = 6 transfer. The two-neutron configurations identified include [624], [510] Kπ = 4− and 5−, [512], [510] Kπ = 2+ and 1+, and tentatively [521], [510] Kπ = 1+ in 182W, and [615], [510] Kπ = 5− and (6−), [503], [510] Kπ = 3+ and (4+), and [512], [510] Kπ = 2+ and (1+) in 184W. The results also provide valuable insight into the microscopic structure of the γ-vibrations and higher-lying Kπ = 2+ excitations in these nuclei and made possible a detailed test of the predictions of microscopic calculations. Our analysis indicates that the distinct difference in the observed collective character of the higher-lying Kπ = 2+ excitations in the two nuclei is associated with the N = 108 energy gap in the Nilsson diagram.
- †
Permanent address: Inst. “B. Kidrich” Belgrade, P.O. Box 522, Yugoslavia.