共查询到20条相似文献,搜索用时 31 毫秒
1.
A. Visvanathan E. G. Funk J. W. Mihelich 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(4):339-343
TheK-internal conversion coefficients have been measured by the XPG technique for a number of low energyγ-ray transitions whose energies do not exceed theK-binding energies by more than 4 keV. Using Si(Li) detectors in singles and coincidence arrangements, the following results were obtained: 63.1 keV El in169Tm(αK=1.02±0.15), 72.0 keV E1 in187Re (0.75±0.05), 57.8 keV M1 in162Ho (11.42±0.67), 56.6 keV M1 in164Ho (12.04±0.70), and 67.1 keV M1 in174Lu(10.25±0.58). The experimental results are compared with the theoretical calculations which include transition energies down to 1 keV above threshold. 相似文献
2.
A. F. Kluk D. Krmpotic J. H. Hamilton J. J. Pinajian 《Zeitschrift für Physik A Hadrons and Nuclei》1970,235(5):391-394
TheK conversion coefficients of the 388 and 483 keV transitions in87Sr populated in the decay of87Y have been measured with Ge(Li) and Si(Li) detectors by the NPG method. We find α K values of 0.162 ± 0.010 and 0.00260 ± 0.00013 for the 388 and 483 keV transitions, respectively. 相似文献
3.
D. J. McMillan J. H. Hamilton M. Mladjenović J. C. Manthuruthil J. J. Pinajian 《Zeitschrift für Physik A Hadrons and Nuclei》1971,241(2):103-116
The conversion electron spectrum from the decay of156Tb to156Gd was measured with an iron, double-focusing spectrometer. TheK conversion coefficient of the 1222.4 keV transition was measured relative to theK conversion coefficient of the 661.6 keV transition in137Cs and found to be 0.00174±0.00013. This result was used to normalize electron and gamma-ray data to obtain theK conversion coefficients of 33 transitions in156Gd. The 1009.6 and 1040.6 keV transitions have largeE0 components. 相似文献
4.
With calibrated Ge(Li) x-ray detectorsK x rays in the conversion of the 30 keV isomeric transition in the decay of108mAg were observed in coincidence with 79 keV γ-rays. Thus, the fraction of 30 keV transitions which take place byK conversion was measured to be (2.44±0.23) × 10?2. Making use of a theoretical total conversion coefficient (K conversion contributes only a minor part of the total conversion coefficient), an experimental value of theK-conversion coefficient was obtained, αK=(1.07 ± 0.10) × 104 (where the error represents twice the standard deviation to which the error in the detector efficiency has been added linearly). This value agrees with the theory of Hager and Seltzer forM4 conversion. The energy of the cascading γ-ray was remeasured to be 79.20 ± 0.05 keV. 相似文献
5.
Gamma-gamma directional correlations have been investigated for the cascades of 135-30 keV and 135-32 keV in201Hg from the decay of201Tl. A combination of NaI (Tl) and Si (Li) detectors was used for the experiments. Spin values ofI=1/2, 3/2 and 1/2 have been assigned to 1.58, 32.19 and 167.49 keV energy levels. In addition, the relative intensities of theγ rays have been measured with a Ge (Li) detector system. The results are 2.2±0.2, 2.2±0.2, 26.5±1.3, 1.6±0.1 and 100 for theγ rays of 30.60, 32.19, 135.34, 165.88 and 167.43 keV energies, respectively. 相似文献
6.
The spectrum ofK X-rays andγ-rays following the decay of170Tm has been reinvestigated using a high resolution Si(Li) detector. The intensities of theEC-branches from the ground state of170Tm to the ground state as well as to the first excited level in170Er have been measured. The total intensity of theEC-decay is (0.25 ± 0.05)% of all170Tm disintegrations with (0.18 ± 0.05)% leading to the ground state and (0.07±0.02)% leading to the first excited level of170Er. The energy of the de-excitingγ-ray has been determined to (78.7±0.5) keV. Its intensity is (0.28 ± 0.06)% of that of the 84.3 keVγ-ray in170Yb. 相似文献
7.
S. Antman H. Pettersson Z. Zehlev I. Adam 《Zeitschrift für Physik A Hadrons and Nuclei》1970,237(4):292-312
Transitions in146Eu and146Sm were studied using a double-focussing beta-ray spectrometer and a Ge(Li) detector. Internal conversion and gamma-ray intensities were determined. The internal conversion spectrum of the three 155, 115 and 116 keV cascading transitions in146Eu was studied for all subshells.K-,L- andM-subshell ratios were determined andE2/M1 mixing ratios were deduced for these three transitions. Intensities from theN- andO+P-shells were determined and compared to theoretical calculations. All internal conversion intensities were found to be in agreement with theoretical data for pureM1 character with smallE2 admixtures for all the three transitions. Selected parts of the internal conversion spectrum of the transitions in146Sm were restudied at 0.06% momentum resolution. This study was mainly concentrated on four transition doublets feeding and deexciting the close lying levels at 1,380 and 1,381 keV. A new transition with 702.20 keV energy was detected in the 702–703 keV transition group. Internal conversion coefficients were deduced using reported gamma-ray intensities. Multipole characters of the transitions were deduced and used as a basis for a discussion of the spins and parities of the lower lying excited states of146Sm. 相似文献
8.
Jean Kern J. B. Carlson R. G. Lanier L. G. Mann G. L. Struble 《Zeitschrift für Physik A Hadrons and Nuclei》1980,296(3):195-200
Levels in174Lu have been investigated using the176Yb(p,3n) reaction. Prompt and delayedγ-ray spectra have been observed with a 0.56-cm3 Ge(Li) detector by a multispectrum analysis method. The half-life and decay mode of two isomeric levels, one at 240.8keV (395±15ns) and the other at 365.1keV (145±3ns) have been firmly established. Hindrance factors are discussed. New delayed transitions in175Lu are also noted. 相似文献
9.
H. H. Hansen E. de Roost W. van der Eijk R. Vaninbroukx 《Zeitschrift für Physik A Hadrons and Nuclei》1974,269(2):155-161
The decay of115m In has been investigated using accurate counting methods. The emission rate of conversion electrons plusβ ?-particles was determined with a 4π proportional flow counter. The total andK-shell internal conversion coefficients of the 336 keVγ-ray in115In were measured by the electron X-ray coincidence method using combinations of a Si surface barrier with a NaI(Tl) detector and of a magneticβ-spectrometer with a high energy resolution Si(Li) detector, respectively. The conversion ratioR=K/(L+M+...) was deduced from electron spectra recorded with the magneticβ-spectrometer. The 336 keVγ-ray emission rate of all used sources was determined with a calibrated NaI(Tl)γ-ray spectrometer. A Ge(Li) detector has been used to determine the relative intensity of the 497 keVγ-ray in115Sn. As results have been deduced the 336 keVγ-ray emission per decay (N γ1/N 0=(45.9 ± 0.1)%), the total internal conversion coefficient (α=1.073 ± 0.014), theK-shell internal conversion coefficient (α K=0.843±0.012), the conversion ratioR=3.63±0.07, theβ ?-transition per decay going to the ground state (N β1/N 0=(5.0 ± 0.7)%) and to the first excited level in115Sn115Sn(N β2/N 0=(0.047 ± 0.002)%), and the 497 keVγ-ray emission (N γ2/N γ1=(0.103 ± 0.004)%). From the obtained internal conversion data it follows that the 336 keVγ-ray transition is ofM4 character with anE5 admixture of less than (3.5±1.5)%. The half-life of the isomeric state115 mIn has been determined with four different methods. The result isT 1/2=(4.486±0.004) h. 相似文献
10.
Dr. H. H. Hansen G. Lowenthal A. Spernol W. van der Eijk R. Vaninbroukx 《Zeitschrift für Physik A Hadrons and Nuclei》1969,218(1):25-36
The decay of137Cs has been reinvestigated using several precision counting methods. The emission rate ofβ-particles plus internal conversion electrons was measured by the 4π-proportional counter method using vacuum evaporated sources free of self-absorption and checked by the liquid scintillation method. TheK-conversion coefficient was determined by the electron X-ray coincidence method using a magnetic spectrometer and a high resolution Si(Li) detector. TheK/(L+M+...) conversion ratio and a second less accurate value for the β-branching ratio were obtained from the recorded electron spectra. Theγ-ray emission rate of all sources was determined to within ±0.14%, on the average, with a calibrated NaI(Tl) crystal detector. As results the intensity of theβ-decay to the ground state of137Ba could be determined to (5.4±0.3)% of the137Cs decays, theK-conversion coefficient to 0.0916±0.0004, and theK/(L+M+...) conversion ratio to 4.41±0.04. From these values the γ-ray emission intensity is (85.1±0.4)% of the137Cs decays and theK X-ray emission intensity is (8.13±0.10)% of the emittedγ-rays. All errors are discussed in detail. 相似文献
11.
J. Glatz K. E. G. Löbner F. Oppermann 《Zeitschrift für Physik A Hadrons and Nuclei》1969,227(1):83-98
The half-lives of the intrinsic states at 1,285.8 and 1,502.2 keV in184W have been measured in the decay of184Re m to be 8.33±0.18Μs and 2.35±0.10 ns, respectively. These half-lives determine absolute gamma-ray transition probabilities of eight transitions and yield upper limits for three transitions. The decay scheme of184Re m →184W is improved through measurements of delayed gamma-ray spectra with a Ge(Li) detector. Spin and Nilsson model interpretations are discussed. 相似文献
12.
M. C. Cambiaggio G. Garcia Bermúdez M. Behar 《Zeitschrift für Physik A Hadrons and Nuclei》1975,275(2):183-188
Directional-correlation measurements of several cascades in the74As decay have been made with a NaI — Ge(Li) detectors system. In the74Ge the following cascades were measured: 608–596 keV, 994–1,204 keV, 994-(608)-596 keV and 887-596 keV. The corresponding results give a unique spin assignment of 2 for the 2,198 keV level and determine theE2/M 1 mixing ratios ofδ(608)=3.4±0.4 andδ(994)=?(2.8 ± 0.2). In the74Se it was measured the 635-635 keV cascade. The result obtained assigned the spin of the 1,270 keV level as 2 and fixed the E2/M1 mixing ratio of δ(635)=?(2.6 ± 0.2). Also aγ-intensity study has been made to determine the branching ratios of the transitions that deexcite the 1,270 keV level in74Se. From these data aI(635)/I(1,270)=12.5 ± 5.0 is obtained. 相似文献
13.
A. H. El-farrash M. G. Abdel Hamid B. Sc. 《Zeitschrift für Physik A Hadrons and Nuclei》1970,236(5):417-423
TheK-conversion coefficients of seven low energy transitions (~100–400 keV) in182W following the decay of182Ta have been determined by the NPG method using the newly reported γ-ray intensities measured by Ge(Li) detectors. The results are compared with theoretical values deduced from the tabulations of Rose, Sliv and Band, and Pauli. The weak peak corresponding to theK-conversion line of the 351.3 keV transition could be observed in accordance with the previous investigations, however the existance of the previously reported 146.3 keV transition could not be confirmed. Also theK-conversion line of the recently reported 110.4 transition could not be observed. 相似文献
14.
F. Freund 《Zeitschrift für Physik A Hadrons and Nuclei》1973,264(3):259-272
Using a Ge(Li)-Si (Li)-spectrometer the 161 keV and 223 keV transitions of133Cs were investigated. TheK-conversion coefficients were deduced to beα K =0.205±0.007 andK-conversion coefficients were deduced to beα K =0.0743±0.0043, respectively. TheK/L ratio for the 161 keV transition is 4.72±0.37. From theK-conversion coefficients were deduced to beα K -values,M1 penetration factors ofλ=8.6±3.4 andλ=7.8 ?2.8 3.0 were deduced which are inconsistent with known data from angular correlation experiments (λ=40±10 andλ=90±13). The penetration factor fromK/L-measurement for the 161 keV-transition isλ=52±19. A theoretical reinvestigation of the formulas used in the literature appears recommendable. Furthermore, theK/L ratio of the 1770 keV transition of207Pb was determined experimentally to be 5.52±0.54. 相似文献
15.
The internal conversion process of theM1+E 2 mixed 279 keVγ-ray transition in the decay of203Hg has been reinvestigated. The emission rate of theK-shell internal conversion electrons was determined with an electron X-ray coincidence measurement using a magneticΒ-spectrometer and a Si(Li) detector of high energy resolution. Conversion electron ratios were obtained from electron spectra recorded as a function of momentum. The disintegration rate has been taken from measurements with a calibrated NaI(Tl)γ-ray spectrometer. Following results have been deduced: α=0.2279±0.0024, α K =0.1653±0.0017, α L =0.0475±0.0013,K/(L+M+?)=2.64±0.03,K/L=3.48±0.12,L/(M+N+ ?)=3.14±0.12. On the basis of the experimental results on theK-shell internal conversion coefficient,α k , and the conversion ratioK/(L+M+?) the penetration effect on the internal conversion of theM1 part and the mixing ratio,δ 2, of the 279 keVγ-ray transition in203Tl have been studied. Calculations were made using Hager and Seltzer's formalism and their theoretical internal conversion coefficients. The results are consistent with a mixing ratio ofδ 2=1.32±0.11 and a penetration parameter ofλ=6.8 ±0.8. 相似文献
16.
O. Dragoun V. Brabec M. Ryšavý A. Špalek 《Zeitschrift für Physik A Hadrons and Nuclei》1977,281(4):347-353
The internal conversion coefficients were calculated for the transitions in199Hg using both Hartree-Fock and Hartree-Fock-Slater atomic models. The relative conversion line intensities were measured with the magnetic spectrometers in Prague and Heidelberg. The multipolarities were determined to be:M1+(0.20±0.03)%E2, pure E2 and M 1+ (13.4 ±0.4)%E2 for the 50, 158 and 208 keV transitions, respectively. Allowing for the nuclear structure effect in M1 component we obtained: M1+(0.15±0.03) %E2,λ = 2.4±1.0 for the 50 keV and M1+ (10.9±0.7)% E2, λ=3.8±0.5 for the 208 keV transitions. Very good agreement was found between theory and experiment for the atomic subshells,K, L1?3,M 1?5,N, andO + P. 相似文献
17.
The level scheme of75Se has been studied through the75As (p, n) reaction at proton energies from 1.5 to 5.0 MeV.γ-ray and internal conversion electron measurements were made using NaI (T1) and Ge(Li) detectors and a six-gap electron spectrometer. A proportional counter and a thin window NaI(T1) detector were used to detectγ-rays with energies less than 30 keV. The level scheme has been established by observing the thresholds of variousγ-rays and byγ-γ and e?-γ coincidence measurements. New levels at 133.0, 293.2, 790.0, 953.0, 1020.8, 1184.3, 1198.5 and 1258.2 keV not observed in earlier (p, n) studies have been established. Conversion coefficients of most of the low-lying transitions have been determined. Angular distributions of some of theγ-rays were also measured and compared with the statistical model calculations. DefiniteJ π assignments have been made to most of the low-lying levels. Life-times of the 112.1, 133.0, 286.7 and 293.2 keV levels have been measured to be 0.69±0.12, 5.3±0.6, 1.35±0.15 and 31±2 nsec respectively. The reduced transition probabilities for various low-lying transitions have been determined and compared with recent calculations. The 1/2? and 9/2+ levels hitherto unknown in this nucleus has been identified. The structure of the low-lying levels is discussed in terms of the existing models. 相似文献
18.
High resolution Si(Li)-Si(Li) and Si(Li)-Ge(Li) detector arrangements have been used to studyL x-ray spectra in coincidence withL-shell internal conversion electrons, gamma rays, andK x-rays emitted in249Cf decay. TheL 1 subshell fluorescence and Coster-Kronig yields determined forZ=96 from these spectra are ω1=0.25±0.06,f 12≦0.10, andf 13=0.69 ±0.08. The presence of theL 1-L 3 radiative transition is also further confirmed in this work. 相似文献
19.
S. K. Sen S. I. H. Rizvi D. A. Dohan 《Zeitschrift für Physik A Hadrons and Nuclei》1968,209(3):254-259
The absoluteK-conversion coefficients of the 496 keV-124 keV cascadeγ-rays in131Cs have been determined from angular correlation experiments using a new approach. The value ofα K =0.0100±0.0007 obtained for the 496 keV transition is in excellent agreement with the theory whereas a strong case is presented for the existence of an anomalous nuclear-structure-dependent conversion coefficient for the 124 keV transition. TheK-conversion coefficient for this transition has been measured to be 0.742±0.077 giving a value of 1.25±0.13 for the ratioα K (expet) /α K (theory) . The result is interpreted as being due to the presence of electric monopole,E0, electron transition. A value of 0.26±0.14 has been obtained for theE0/E2 electron conversion ratio and the absolute value of the electric monopole matrix element has been determined to be 0.07±0.02. 相似文献
20.
The electron capture probabilities to 690.70 and 580.37 keV levels and theK-conversion coefficients of 205.9 and 316.5 keV transitions in the decay of Ir-192 have been determined from the measurement
of gamma-ray intensities in conjunction with an analysis of theKX-ray-γ-ray sum peaks observed with a co-axial HPGe detector. TheK-capture probability to 690.70 keV level was determined by an approach which is independent ofK-shell fluorescence yield and absolute detection efficiency forKX-rays. TheK-shell fluorescence yields of the daughter products, namely, Os and Pt of Ir-192 have also been determined by the same technique
and were found to be 0.964±0.077 and 0.969±0.068 respectively. 相似文献