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Energies and intensities of 53 nuclear γ-lines in muonic atoms of Sm, Gd, Eu, Tm, Yb, Ta, W, Re, Os, Ir, Pt, Hg, Tl, and Bi have been measured with Ge(Li) detectors. By comparison with γ-lines from radioactive sources the isomer shifts for transitions from nuclear rotational levels, quadrupole and octupole vibrational levels, and single-particle levels have been deduced. The effect limiting the accuracy of the extracted isomer shifts is the correction for the magnetic hyperfine splitting of the nuclear levels.

NaI(Tl) and Ge(Li) detectors have been used singly and in a two-parameter configuration to study the gamma rays associated with the decay of 2.9-day 97Ru. Thirteen transitions have been observed and accounted for in a decay scheme involving levels at 96.4, 215.8, 324.4, 656.7, 785.1, 855.4, 969.7, and 994.4 keV. Spin and parity assignments are discussed.

Experiments using Ge(Li) and Nal(Tl) detectors singly and in a 2-parameter coincidence arrangement have been carried out to establish the role of a number of weak transitions in the decay of 143Ce. Twenty-six of the twenty-seven observed γ rays have been placed in a decay scheme with levels at 57.4, 350.6, 490.2, 721.8, 739.9, 847.9, 937.3, 1059.8, (1156.5), 1160.1, 1381.6, and 1397.4 keV. The K-conversion coefficients of the 293 and 350 keV transitions, measured with a Si(Li) detector, are 0.10 ± 02 and 0.024 ± 0.03 respectively.

Energies and intensities of muonic X-rays, nuclear γ-rays and μ-capture γ-rays were measured in natural muonic thallium with Ge(Li) detectors. The absolute intensities of higher μ X-rays were reproduced by a cascade calculation starting with a statistical population at n = 20 including K-, L- and M- conversion. The electron screening effect was deduced from energies of higher μ X-rays. Eight prompt nuclear μ-rays were found, due to an excitation of (4.1 ±1.0) % and (14.6 ± 3.0) % of the first 3 2 + level in μ 203 T1 and μ, 205 T1, respectively, and of (8.8 ± 0.9) % of the 5 2 − level at 2.63 MeV in 205 T1. This excitation explains the anomalous intensity ratios of the 2p-ls and 3d-2p fine structure components. From the nuclear y-rays of the first excited states were deduced: the magnetic h.f. splittings e 203 ( 1 2 ) = 2.57 ± 0.15 keV , e 205 ( 1 2 ) = 2.30 ± 0.02 keV, muonic isomer shifts ΔE is (203) = 0.26 ± 0.15 keV, ΔE is (205) = −(0.31 ± 0.11) keV; E2/M1 mixing ratios δ μ 2 (203) = 0.89 ± 0.27, δ μ 2 (205) = 1.00 ± 0.05, and the half-life in the presence of the muon T μ ( 3 2 ) = 1.4 ± 0.1 nsec in 205 T1. The values of e( 1 2 ) and ΔE ls were compared with shell-model calculations. From δ μ 2 and T gm ( 3 2 ) evidence for a magnetic nuclear polarization was found. From the 2p-ls, 3d-2p, 3p-2s and 2s-2p transitions the size and shape of the nuclear charge distribution and a nuclear polarization due to the 1s 1 2 muon of ΔE np = 8.3 ± 1.2 keV and 9.5 ± 1.2 keV for 203 Tl and 205 T1 respectively were determined in agreement with theoretical estimates. An isotope shift of ΔE = 10.35 ± 0.25 keV was measured for the 1s 1 2 state which is compared with data from optical spectroscopy. From an analysis of the time distribution of delayed γ-rays from μ-capture, an isotopic effect of (5.4 ± 2.5) % was found for the capture rates, in fair agreement with predictions from Primakoff's μ-capture formula.

NaI(T1) and Ge(L1) detectors have been used singly and in coincidence to study the gamma rays associated with the decay of 67 h 99 Mo Twenty-four of the twenty-eight observed transitions have been located by energy fit and by coincidence data, the remainder by energy fit alone The resulting decay scheme consists of levels at 140 5 ( 7 2 + ) , 142 6 ( 1 2 − ) , 181 1 ( 5 2 + ) 509 1 ( 3 2 − ) , 534 3, 671 5 ( 5 2 − ) , 761 6 ( 5 2 + ) , 920 5 ( 3 2 + , 1 2 + ) , 1004 0 ( 3 2 − ) , 1072 9 ( 5 2 − ) , 1129 3 ( 1 2 − , 3 2 − ) , 1142 0 3 2 − ) , 1199 ( 1 2 − , 3 2 − )

The following conversion ratios of the 191 keV transition in 197Au have been measured with a double focussing β-spectrometer: K/L = 5.9±0.2, LI/LII = 10.7±0.5, LI/LIII = 74±15. The LI/LII value is consistent witg a practically pure M1 transition (E0(LI)/M1 ≦0.9% orE2/M1 ≦ 0.6%). which leads to a calculated αK = 1.01±0.03. The LI/lIII value corresponds to a mixture E2M1 = (0.9−0.5+0.7)% giving αK = 0.983±0.005. The two derived αK agree with each other. Their values exclude reported αK which give strong E0 admixtures and spin 1 2 + of the 269 keV level. Some other αK measurements and the theoretical value (core-particle model) are in good agreement with our result and give a strong preference for spin 3 2 + of the 197Au 269 keV level.

Es wird eine Anordnung zur Erzeugung monochromatischer (d,d)-Neutronen beschrieben. Sie beruht auf einer Koinzidenzmethode, bei der als Koinzidenzpartner die in der (d,d)-Reaktion gleichzeitig entstehenden He3-Kerne und Neutronen benützt werden. In der angeführten Anordnung werden die He3-Kerne unter 90° zum einfallenden Deuteronenstrahl beobachtet. Als Target wird ein D2-Gastarget benutzt. Die berechnete Energiebreite der Neutronen für die gewählte Anordnung beträgt ca. 10 keV. Für eine Deuteronenenergie von 900 keV und 5 μA Stromstärke ergeben sich ca. l Koinzidenzimpuls pro Sekunde. Es sollte möglich sein, diese Zahl durch Vergrößerung des benutzten Neutronenzählers um einen Faktor 10 zu erhöhen, ohne das Energieauflösungsvermögen zu verschlechtern. Die Zahl der zufälligen Koinzidenzen variiert zwischen 5 — 10% der wahren Koinzidenzen.

A special construction of a double focusing iron β-spectrometer, with a normal radius of 30 cm, was designed, which can be taken as a combination of the two classical models, namely the core-in-the-center and the inside-out type, with subdivided induction coils. The advantage of this construction is that the field shape produced can be varied by changing the ratios of the currents in the separate sub-coils, so that it may be made to fit the theoretical proposal better than the one produced by a simple iron joke. Furthermore, it may be reasonably expected that the fringing effect would be smaller in such a construction than in the usual design. Construction details, such as the form of pole surfaces, coil dimensions, baffle shape, detector and source arrangements, current supply and field stabilisation are described. With the aid of Hall plate measurements, the field shape was made to fit as well as possible to the theoretical curve, given by H Z ( ϱ ) = H 0 (1−0.5 ϱ + 0.375 ϱ 2 −0.299 ϱ ). Finer adjustments were carried out, using different performance criteria, which respond more sensibly to the changes of field shape. With the optimum field chosen, combinations of initial conditions were studied experimentally and compared with the theoretical prediction, with a view to obtain maximum luminosity for a given resolution. At an impulse resolution setting of 0.1%, a source of 1 × 20 mm 2 and a solid angle of 0.5% can be used. The highest resolution as yet achieved is 3.6 × 10 −4 with a source of 0.2 mm width.

Electric quadrupole X-ray transitions (5g → 3d, 4f → 2p, and 3d → 1s) have been observed in muonic Tl, Pb and Bi. From the 3 → 1 transitions, energy splittings of the n = 3 levels were deduced. From a comparison of the relative intensities of E1 and E2 transitions, the population ratios 5g 5f , 4f 4d , and 3d 3p were deduced. These ratios are well reproduced by a cascade calculation assuming a statistical initial population at n = 20, including K, L and M shell conversion. In the case of 205 T1 discrepancies between the experimental and the calculated 3d-1s/3p-1s intensity ratio can be explained by nuclear excitation. From the 3 p 3 2 → 1 s 1 2 intensity in 209 Bi we can deduce the ratio of the radiationless to the X-ray transition width and give limits for prompt neutron emission from the 3d level.

In muonic 190,192Os the magnetic hf-spliting of the 2+ → 0+ nuclear transition was measured. The hf-splittings ΔE( 190 Os ) = 665 ± 80 eV and ΔE( 192 Os ) = 800 ± 80 eV of the 2+ state are reduced at 59% compared to a point-like magnetic moment in agreement with the assumption of a magnetization density of a magnetization density distribution proportional to R2 ϱcharge(R) as calculated from a rigid rotator. The influence of these results on the analysis of muonic isomer shifts is pointed out.

Energies of the 5g-4f muonic X-rays have been measured in nat Hg and 203 Tl with an accuracy of about 25 eV. They are found to be smaller than theoretical energies including recently revised calculations of higher-order vacuum polarization, by about two standard deviations.