THE DECAY OF Os191 AND Os193

1958 ◽  
Vol 36 (10) ◽  
pp. 1409-1429 ◽  
Author(s):  
S. V. Nablo ◽  
M. W. Johns ◽  
R. H. Goodman ◽  
A. Artna
Keyword(s):  
Excited States ◽  
Gamma Rays ◽  
Cross Sections ◽  
Decay Scheme ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Internal Conversion Coefficients ◽  
Gamma Coincidence ◽  
Conversion Coefficients ◽  
Activation Cross Sections

The beta- and gamma-ray spectra of Os191 and Os193 have been studied with a magnetic beta-ray spectrometer, scintillation spectrometers, and coincidence circuits. The 14-hour isomer of Os191 decays via a 0.0742-Mev (M3) transition. Gamma rays of energy 0.0418 (100%, E3), 0.0809 (1%, M1 + E2), 0.1287 (100%, M1 + E2), and 0.1858 (0.1%) Mev have been found to be associated with the 14.6 ± 0.3 day decay of Os191 and an extension of the accepted decay scheme proposed. The following 19 transitions have been associated with the 31.5 ± 0.5 hour decay of Os193: 0.0730 (14%), 0.1068 (~1%), 0.1393 (10%), 0.180 (0.3%), 0.196 (0.1%), 0.243 (~0.2%), 0.2485 (0.3%), 0.2514 (0.4%), 0.278 (0.6%), 0.2810 (1.6%), 0.2885 (0.3%), 0.2994 (0.4%), 0.314 (0.3%), 0.3218 (1.7%), 0.3620 (0.6%), 0.3878 (1.6%), 0.4604 (4.1%), 0.4857 (0.3%), and 0.5585 (2.2%). The internal conversion coefficients for all the stronger transitions suggest that they are M1 + E2 in character. The decay energy of Os193 is 1.132 ± 0.005 Mev. Fermi analyses and beta–gamma coincidence experiments have established excited states of Ir193 at 0.073, 0.139, 0.281, 0.362, 0.460, and 0.559 Mev above the ground state. Six otherwise unclassified weak gamma rays can be accommodated if levels at 0.247, 0.315, and 0.613 Mev are included in the decay scheme.The activation cross sections of Os184 and Os190 are (2.2 ± 0.5) × 103and 5.3 ± 2 barns respectively, relative to Seren's value of 1.6 ± 0.4 barns for Os192.

Level Structure of 171Tm

1972 ◽  
Vol 50 (6) ◽  
pp. 513-528 ◽  
Author(s):  
R. L. Graham ◽  
J. S. Geiger ◽  
M. W. Johns
Keyword(s):  
Excited States ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Level Structure ◽  
Line Intensities ◽  
Gamma Coincidence ◽  
Coincidence Data ◽  
Conversion Coefficients ◽  
Beta Spectrometer

The properties of the γ-ray transitions in 171Tm, following beta decay of 7.5 h 171Er, have been studied using an iron-free π√2 beta spectrometer and Ge(Li) detectors, singly and in coincidence. The multipolarities of 8 lower-energy γ transitions have been established from a study of L- or M-subshell-internal-conversion lines. The measured K-line intensities of 20 higher-energy transitions yield K conversion coefficients and hence additional multipolarity assignments. Gamma-ray energy measurements, together with an extensive series of gamma–gamma coincidence experiments, have been used to establish the role of 59 (out of 65) γ transitions in the 171Tm level scheme. Sixteen excited states are identified at energies of 5.025 (3/2+), 116.6 (5/2+), 129.0 (7/2+), 326.7* (9/2+), 424.8 (7/2−), 635.4 (7/2+), 675.7 (3/2+), 737.2 (5/2+), 822.3* (7/2+), 912.8 (5/2+), 998.6 (7/2+), 1225.5* (3/2, 5/2, or 7/2+), 1284.7* (5/2+), 1296.3*, 1391.2*, and 1400.5* (5/2+) keV. The asterisks indicate levels which are new or at variance with those proposed by some other workers. The coincidence data does not support a level at 861 keV proposed by two other groups of workers on the basis of energy sums. Nilsson orbital assignments are proposed and discussed for 12 levels.

High-resolution gamma-ray study of 185Wm

1970 ◽  
Vol 48 (5) ◽  
pp. 502-510 ◽  
Author(s):  
S. C. Gujrathi ◽  
J. M. D'auria
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Ground State ◽  
Internal Conversion ◽  
Gamma Ray ◽  
X Ray ◽  
Isomeric Level ◽  
Coincidence System ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients

The decay of 185Wm has been investigated using a high-resolution Ge(Li) X-ray spectrometer and a Ge(Li)–NaI(Tl) coincidence system. The energies and relative intensities (given in parentheses) of the observed gamma rays associated with the decay of the 185Wm (T1,2 = 1.68 min) are: 23.54 (3.3), 42.29 (1.1), 65.857 (100), 93.30 (0.5), 94.59 (2.2), 107.850 (6.8), 122.05 (1.5), 131.554 (84.0), 164.334 (11), 173.675(61.5),and 187.879(15.4) keV. The energy of the isomeric level has been deduced to be 197.41 keV and decays to the ground state through levels at 187.88, 173.68, 93.29, 65.86, and 23.54 keV. In addition, it was deduced experimentally from measured internal-conversion coefficients that the multipolarity of the 131.55 keV transition is E3 while the 65.86 keV transition is an M1 + E2 mixture with a 30 ± 7.5% M1 component.

LX-ray Spectra and E2 Internal Conversion Coefficients in Radon and Radium

1973 ◽  
Vol 28 (10) ◽  
pp. 1635-1641 ◽  
Author(s):  
A. G. de Pinho ◽  
M. Weksler
Keyword(s):  
Excited States ◽  
Internal Conversion ◽  
Electric Quadrupole ◽  
Alpha Decay ◽  
X Ray ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Good Agreement

The X-ray spectra resulting from the internal conversion of electric quadrupole transitions following the alpha decay of Th230 and Ra226 were analysed with a Si (Li) spectrometer. From the knowledge of the Coster-Kronig and fluorescence yields, the internal conversion coefficients of the E2 transitions from the first excited states in Ra226 and Rn222 could be deduced. Results are in good agreement with theoretical values.

STUDIES IN THE ACTIVE DEPOSIT OF ACTINIUM: PART II: THE DECAY OF 211Pb (AcB)

1965 ◽  
Vol 43 (3) ◽  
pp. 383-403 ◽  
Author(s):  
C. R. Cothern ◽  
R. D. Connor
Keyword(s):  
Gamma Rays ◽  
Level Scheme ◽  
Gamma Ray ◽  
Ground Level ◽  
Conversion Line ◽  
Point Energy ◽  
Correlation Studies ◽  
Absolute Intensities ◽  
Gamma Coincidence ◽  
Conversion Coefficients

Studies of the active deposit of actinium using a Siegbahn–Slatis beta-ray spectrometer and scintillation counters together with gamma–gamma coincidence work and gamma–gamma angular correlation measurements have led to the establishment of a new decay scheme for 211Pb and a level scheme for 211Bi involving five excited states.The gamma rays have the following energies and absolute intensities:[Formula: see text]Conversion-line studies yielded energy values for the transitions marked with an asterisk as 403.3 ± 0.5 and 426.5 ± 0.5 keV respectively. The K conversion coefficients of the 400- and 430-keV transitions have been determined as 0.091 ± 0.018 and 0.117 ± 0.024 respectively.Fermi analysis yields 1.378 MeV as the highest end-point energy of the beta partial spectra. The remaining end points and the component intensities as deduced from the level scheme are as follows:[Formula: see text]The much less accurate results from Fermi analysis of the complete active deposit are in reasonable agreement with these data.Angular correlation studies of the 430–400- and 706–400-keV gamma-ray cascades have yielded spins for the levels concerned: ground level (9/2), 400-keV level (7/2), 830-keV level (9/2), and 1 100-keV level (7/2). These spins are the only ones consistent with the experimental evidence and the theoretical arguments presented.

Study of thermal neutron capture in potassium

1970 ◽  
Vol 48 (10) ◽  
pp. 1109-1129 ◽  
Author(s):  
L. V. Johnson ◽  
T. J. Kennett
Keyword(s):  
Thermal Neutron ◽  
Excited States ◽  
Neutron Capture ◽  
Decay Scheme ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Experimental Results ◽  
Thermal Neutron Capture ◽  
Gamma Coincidence

The 39K(n,γ)40K reaction has been studied using a Ge(Li) and a Ge(Li)–Ge(Li) spectrometer. A total of 252 gamma-ray transitions has been observed and a gamma–gamma coincidence matrix involving 62 transitions has been established. A decay scheme based on the experimental results is deduced for 202 of the observed gamma-ray transitions. Spins and parities of some excited states have been estimated from the deduced branching ratios. The neutron separation energies of the 40K and 42K nuclei have been determined as 7800.5 ± 0.2 and 7535.2 ± 1.5 keV respectively.

Levels in 148Tb excited by the (6,7Li,xn) and (10B,xn) reactions

1979 ◽  
Vol 57 (3) ◽  
pp. 358-367 ◽  
Author(s):  
N. C. Singhal ◽  
M. W. Johns
Keyword(s):  
High Spin ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Γ Ray ◽  
Coincidence Measurements

High spin slates in 148Tb have been excited by means of 144Sm(6Li,2n), 144Sm(7Li,3n), and 142Nd(10B,4n) reactions and studied by γ-ray and electron measurements. Gamma-ray singles, excitation functions, angular distributions, internal conversion coefficients, and γ–γ coincidence measurements have been made. A seven-fold gamma–gamma cascade feeding the 9+ isomeric state in 148Tb and originating in a level 4137 keV above that state is strongly excited. The spin and parity assignments are made on the basis of angular distribution and internal conversion coefficients. On the basis of these measurements, the 1006 keV transition is E3 in character; the half-life of the 1006 keV (12−) level is established to be 25 ± 2 ns.These experiments also confirm the existence of a number of high spin states in 148Gd seen by earlier workers.

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