THE DECAY OF Pm149

1960 ◽  
Vol 38 (12) ◽  
pp. 1577-1585 ◽  
Author(s):  
Agda Artna ◽  
Margaret E. Law
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Conversion Coefficient ◽  
Beta Spectrum ◽  
Multichannel Analyzer ◽  
Coincidence Spectrometer ◽  
Beta Spectrometer ◽  
Beta Group

The 52.8-hour activity of Pm149 has been investigated using a high resolution beta spectrometer, a lens type coincidence spectrometer, and a scintillation spectrometer in conjunction with a multichannel analyzer. The beta spectrum was found to consist of two groups with maximum energies of 1.072 ± 0.002 Mev and 0.786 ± 0.004 Mev, and intensities of 97.1 ± 0.4% and 2.9 ± 0.4% respectively. A gamma ray of energy 285.7 ± 0.3 kev was found to be in coincidence with the 0.786-Mev beta group. No other gamma rays with intensities greater than 0.1% were found. The K conversion coefficient for the 286-kev transition was measured to be 0.075 ± 0.008. This together with the values of 6.5 ± 0.7 and 4 ± 1 obtained for the K/L and L/M conversion ratios respectively indicate that this transition is M1 in character with less than 10% E2 admixture.

Decay of 101Mo and 101Tc

1972 ◽  
Vol 50 (17) ◽  
pp. 1957-1977 ◽  
Author(s):  
W. B. Cook ◽  
M. W. Johns
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Energy Levels ◽  
Spin Parity ◽  
Coincidence Data ◽  
Parameter Configuration ◽  
Coincidence Spectrometer ◽  
Gamma Transitions ◽  
Two Parameter

The energy levels of 101Tc and 101Ru have been investigated through a study of the decays of 14.6 min 101Mo and 14.0 min 101Tc. Singles gamma-ray spectra were obtained with high-resolution Ge(Li) detectors having volumes of 0.8 cm3 and 12 cm3. A 36 cm3 Ge(Li)–40 cm3 Ge(Li) coincidence spectrometer operated in a two-parameter configuration (4096 × 4096) was employed in collecting coincidence data. More than 180 gamma transitions have been observed in the two decays: 152 are definitely assigned to the decay of 101Mo, 25 to the decay of 101Tc. These gamma rays have been incorporated into level schemes involving 45 levels in 101Tc and 10 levels in 101Ru. On the basis of beta and gamma selection rules, spin–parity assignments have been suggested for many of the levels.

Gamma-ray production in the 170Er(p,n)170Tm nuclear reaction

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Alexandru Mihailescu ◽  
Gheorghe Cata-Danil
Keyword(s):  
High Resolution ◽  
Energy Range ◽  
Nuclear Reaction ◽  
Gamma Rays ◽  
Compound Nucleus ◽  
Beam Energy ◽  
Gamma Ray ◽  
Excitation Functions ◽  
Γ Ray ◽  
First Time

AbstractFor the first time discrete gamma-rays following the nuclear reaction 170Er(p,n)170Tm with enriched target were measured with a high resolution GeHP spectrometer. Protons delivered by the Bucharest FN Tandem Van de Graaff accelerator bombarded a thin self-supporting film of enriched erbium. Measured γ-ray energies (Eγ), their relative intensities (Iγ) and corresponding excitation functions for the beam energy range 2.0–3.6 MeV are reported in the present work. The measured excitation functions were fairly well reproduced by compound nucleus calculations based on the Hauser-Feshbach formalism.

The Decay of 169Yb

1972 ◽  
Vol 50 (19) ◽  
pp. 2348-2354 ◽  
Author(s):  
S. K. Sen ◽  
D. L. Salie ◽  
E. Tomchuk
Keyword(s):  
Direct Measurement ◽  
Gamma Rays ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Conversion Coefficient ◽  
Coulomb Excitation ◽  
Internal Conversion Coefficient ◽  
Electron Capture Decay ◽  
Upper Limits ◽  
First Time

The decay of 169Yb was investigated using several Ge(Li) detectors of different sizes. The following gamma rays (energies in keV and intensities within brackets) were definitely identified with the 169Yb decay: 20.7 (0.66 ± 0.04), 63.1 (124 ± 5), 93.6 (7.2 ± 0.3), 109.8 (50 ± 2), 117.3 (0.08 ± 0.04), 118.2 (5.4 ± 0.2), 130.5 (34 ± 2), 156.7 (0.023 ± 0.004), 177.2(59 ± 3), 198.0 (100), 240.4 (0.33 ± 0.02), 261.0 (4.7 ± 0.2), and 307.7 (28 ± 1). The recently reported weak gamma-ray peaks at 515 (0.008 ± 0.002) and 625 (0.010 ± 0.002) were also observed and could not be ruled out as not belonging to 169Yb. The recently reported gamma-ray peaks at 140, 160, 207, 288, 295, 316, 320, 328, 355, 371, 379, 396, and 417 were detected and shown not to be from the decay of 169Yb while those at 218, 229, 285, 304, 335, 388, 411, and 425 were not observed and upper limits were placed on their intensities. The presence of very weak peaks at 515 and 625 establishes the formation of the 633 keV state of 169Tm following electron capture decay of 169Yb as reported by George. (This level has been previously observed only in Coulomb excitation of 169Tm.) The total internal conversion coefficient for the 20.7 keV transition was determined for the first time from the direct measurement of the gamma-ray intensity as 51 ± 10 corresponding to an M1 transition.

scholarly journals Nuclear Structure Investigations of some Medium-Weight Isotopes

2021 ◽  
Author(s):  
◽  
Gavin Wallace
Keyword(s):  
Nuclear Structure ◽  
Beta Decay ◽  
Cross Section ◽  
Gamma Rays ◽  
Half Life ◽  
Decay Scheme ◽  
Gamma Ray ◽  
Calculated Cross Section ◽  
Beta Spectrum ◽  
Gamma Ray Detectors

<p>This thesis describes the methods and results of investigations made to determine the decay schemes of three short-lived isotopes 112Ag, 114Ag and 116Ag. A total of 76 gamma-rays was observed with a Ge(Li) detector in the gamma-radiation which follows the Beta-decay of 112Ag to levels of 112Cd. gamma- gamma coincidence and angular correlation measurements were made with Ge(Li)-NaI(T1) and NaI(T1)-NaI(T1) systems. A decay scheme consistent with the present data is proposed. Cross sections for the reactions 112Cd(n,p)112Ag and 115In(n, alpha)112Ag were measured, and the half-life of the 112Ag decay was found to be 3.14 plus-minus 0.01 hr. The decay scheme of 114Ag was studied with Ge(Li) gamma-ray detectors and plastic Beta-ray detectors. 9 of the 11 gamma-rays observed in the decay were incorporated into 114Cd level structure previously determined by conversion electron measurements on the 113Cd(n,gamma)114Cd reaction. The endpoint energy of the Beta-decay was determined as 4.90 plus-minus 0.26 MeV; no branching was evident in the Beta-spectrum. A decay scheme is proposed for which the Beta-branching was deduced from the measured gamma-ray yield and a calculated cross section value for the 114Cd(n,p)114Ag reaction. The 114Ag half-life was determined as 4.52 plus-minus 0.03 sec; a search for a previously reported isomeric state of 114Ag was unsuccessful. Ge(Li) and NaI(T1) gamma-ray detectors were used to study the direct and coincidence spectra that result from the decay of 116Ag, the half-life of which was found to be 2.50 plus-minus 0.02 min. 53 gamma-rays were observed from this decay. The Beta-branching to the 17 excited states of 116Cd in the proposed decay scheme was derived from the measured gamma-ray yield and a calculated cross section value for the 116Cd(n,p)Ag reaction. Spin and parity assignments for ihe energy levels of 116Cd are made. An investigation of the applicability of two collective models to nuclear structure typical of the Cd nuclei studied demonstrated that one of the models was misleading when applied to vibrational nuclei. A potential function was developed in the other model to extend the investigation to include a study of the transition between extremes of collective motion. This was used to examine the correspondence between nuclear level schemes representative of rotational and vibrational excitations.</p>

Determination of mixing ratios for some cascades corresponding to 109Ag

1977 ◽  
Vol 55 (2) ◽  
pp. 175-179 ◽  
Author(s):  
H. E. Bosch ◽  
V. M. Silbergleit ◽  
M. Davidson ◽  
J. Davidson
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Angular Correlations ◽  
Mixing Ratios ◽  
Multichannel Analyzer ◽  
Level 3 ◽  
Gamma Ray Detector

An investigation of the gamma–gamma ray angular correlations following the decay of 109Pd was made by using a Ge(Li) semiconductor counter and NaI(Tl) gamma-ray detector. Coincidences measurements at six different angles were made between the 311 keV gamma ray (gated in the movable counter) and 390, 413, 424, 551, and 558 keV gamma rays (displayed in a multichannel analyzer (MCA)). Chance coincidences as well as coincidence background were taken into account. The following spins and mixing ratios were determined: 701 keV level 3/2, δ(390) = 0.19 ± 0.06; 724 keV level 3/2, δ(413) = 0.18 ± 0.05; 735 keV level 5/2, δ(424) = −0.27 ± 0.03; 862 keV level 5/2, δ(551) = −0.28 ± 0.04; 869 keV level 5/2, δ(558) = −0.26 ± 0.05. The result indicates that the anisotropies are consistent with mixing ratios less than 28% in all cases.

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.

Low Energy Gamma Transitions in 171Tm

1970 ◽  
Vol 25 (7) ◽  
pp. 1043-1045 ◽  
Author(s):  
M. S. El-Nesr
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Low Energy ◽  
Conversion Coefficients ◽  
Energy Gamma ◽  
Gamma Transitions ◽  
Double Focusing

The low energy gamma-ray spectrum of 171Er has been studied with the use of both Ge (Li) gamma-ray and a high resolution iron free double focusing beta-ray spectrometer. The data provide K-conversion coefficients and multipolarities of eight gamma-rays. Spin and parity assignments 7/2+, 3/2+, 5/2+ and 5/2+ are given to the 636, 676, 738 and 913 keV levels respectively

Use of single planar Ge(Li) detectors as gamma-ray polarimeters

1970 ◽  
Vol 48 (19) ◽  
pp. 2320-2330 ◽  
Author(s):  
A. E. Litherland ◽  
G. T. Ewan ◽  
S. T. Lam
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Ion Beam ◽  
Quantitative Agreement ◽  
Polarization Sensitivity ◽  
Total Absorption ◽  
Asymmetry Ratio ◽  
Large Volume Detector ◽  
Lead Collimator

The polarization sensitivity of a single rectangular Ge(Li) detector 40 × 25 × 3.5 mm has been studied as a function of energy using gamma rays of known linear polarization produced in (p,p′γ) reactions. The counting rates in the total absorption peaks were measured with the 40 × 25 mm face perpendicular [Formula: see text] and parallel [Formula: see text] to the plane defined by the ion beam and gamma-ray direction. The asymmetry ratio [Formula: see text] was measured using E2 gamma rays with known polarization. From these results the following values of Q for complete polarization were deduced for a series of energies: 0.847 MeV (16.4 ± 1.0)%, 1.368 MeV (13.1 ± 1.0)%, 1.779 MeV (12.4 ± 1.5)%, and 4.43 MeV (6.4 ± 1.0)%. These results were in quantitative agreement with calculations made using the Klein–Nishina formula. A large volume detector 60 × 35 × 6.5 mm was studied in a similar manner. The corresponding results for complete polarization are: 0.847 MeV (16.4 ± 1.0)%, 1.368 MeV (14.3 ± 2.0)%, 1.779 MeV (11.6 ± 1.2)%, and 4.43 MeV (5.8 ± 1.5)%. These values are slightly higher than those obtained in calculations. Tests were also made with a lead collimator 6.25 cm long with an aperture of 1 cm in front of the larger polarimeter. The results for complete polarization are: 1.779 MeV (14.0 ± 1.5)% and 4.43 MeV (9.0 ± 1.0)%. Some recent applications of high-resolution Ge(Li) linear polarimeters are briefly discussed.

scholarly journals Nuclear Structure Investigations of some Medium-Weight Isotopes

2021 ◽  
Author(s):  
◽  
Gavin Wallace
Keyword(s):  
Nuclear Structure ◽  
Beta Decay ◽  
Cross Section ◽  
Gamma Rays ◽  
Half Life ◽  
Decay Scheme ◽  
Gamma Ray ◽  
Calculated Cross Section ◽  
Beta Spectrum ◽  
Gamma Ray Detectors

<p>This thesis describes the methods and results of investigations made to determine the decay schemes of three short-lived isotopes 112Ag, 114Ag and 116Ag. A total of 76 gamma-rays was observed with a Ge(Li) detector in the gamma-radiation which follows the Beta-decay of 112Ag to levels of 112Cd. gamma- gamma coincidence and angular correlation measurements were made with Ge(Li)-NaI(T1) and NaI(T1)-NaI(T1) systems. A decay scheme consistent with the present data is proposed. Cross sections for the reactions 112Cd(n,p)112Ag and 115In(n, alpha)112Ag were measured, and the half-life of the 112Ag decay was found to be 3.14 plus-minus 0.01 hr. The decay scheme of 114Ag was studied with Ge(Li) gamma-ray detectors and plastic Beta-ray detectors. 9 of the 11 gamma-rays observed in the decay were incorporated into 114Cd level structure previously determined by conversion electron measurements on the 113Cd(n,gamma)114Cd reaction. The endpoint energy of the Beta-decay was determined as 4.90 plus-minus 0.26 MeV; no branching was evident in the Beta-spectrum. A decay scheme is proposed for which the Beta-branching was deduced from the measured gamma-ray yield and a calculated cross section value for the 114Cd(n,p)114Ag reaction. The 114Ag half-life was determined as 4.52 plus-minus 0.03 sec; a search for a previously reported isomeric state of 114Ag was unsuccessful. Ge(Li) and NaI(T1) gamma-ray detectors were used to study the direct and coincidence spectra that result from the decay of 116Ag, the half-life of which was found to be 2.50 plus-minus 0.02 min. 53 gamma-rays were observed from this decay. The Beta-branching to the 17 excited states of 116Cd in the proposed decay scheme was derived from the measured gamma-ray yield and a calculated cross section value for the 116Cd(n,p)Ag reaction. Spin and parity assignments for ihe energy levels of 116Cd are made. An investigation of the applicability of two collective models to nuclear structure typical of the Cd nuclei studied demonstrated that one of the models was misleading when applied to vibrational nuclei. A potential function was developed in the other model to extend the investigation to include a study of the transition between extremes of collective motion. This was used to examine the correspondence between nuclear level schemes representative of rotational and vibrational excitations.</p>

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