Study of the levels in 167Tm by the 165Ho(α, 2nγ)167Tm reaction

Gamma-ray spectra following the ¹⁶⁵Ho(α, 2n)¹⁶⁷Tm reaction have been studied using different semiconductor detector systems including a Compton suppression spectrometer. Approxi- mately 400 transitions have been observed in the energy range 60 to 1250 keV and 4 × 10⁷ γγ coincidence events have been recorded. The angular distributions of the more intense γ-rays have been determined. The level scheme of ¹⁶⁷Tm has been extended in several respects: The four previously known rotational bands based on the Nilsson orbitais $\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}$, $\text{7}\text{2}{}^{\mathrm{+}}\text{[404]}$, $\text{7}\text{2}{}^{\mathrm{?}}\text{[523]}$ an $\text{1}\text{2}{}^{\mathrm{?}}\text{[541]}$ have been extended up to spin values $\text{31}\text{2}$, $\text{31}\text{2}$, $\text{31}\text{2}$, $\text{33}\text{2}$ respective based on the $\text{3}\text{2}{}^{\mathrm{+}}\text{[411]}$ and $\text{5}\text{2}{}^{\mathrm{+}}\text{[402]}$ orbitals have been established for which only few levels were known previously. Finally two hitherto unknown rotational bands have been found for which we propose the assignments $\text{{}\text{7}\text{2}{}^{\mathrm{+}}\text{[404]; K + 2}}$ and $\text{3}\text{2}{}^{\mathrm{?}}\text{[532] + {}\text{1}\text{2}{}^{\mathrm{?}}\text{[541]; K?2}}$. Coriolis coup calculations are presented. The value of $\text{(1?δ}{}_{\mathrm{<mtext>K,\; </mtext><mtext>1</mtext><mtext>2</mtext>}}\text{b}{}_0\text{) (g}{}_{\mathrm{K}}\text{?g}{}_{\mathrm{R}}\text{)/Q}{}_0$ was determined for three bands from branching ratios and from angular distributions.     

Two-quasiproton states in 168Er studied by the 169Tm(t, α)168Er reaction

The ${}^{169}\text{Tm}\text{(}\text{t}\text{, α)}{}^{168}\text{Er}$ reaction has been studied using 17 MeV polarized tritons from the Los Alamos National Laboratory tandem Van de Graaff accelerator. The α-spectra were analyzed with a Q3D magnetic spectrometer. The overall energy resolution was typically ~ 15 keV (FHWM) and angular distributions of cross sections and analyzing powers were obtained for levels up to ~ 2.7 MeV. The fact that spins and parities for all levels up to ? 2 MeV were previously known from an extensive series of (n, γ) studies made it possible to determine specific two-quasiproton structures for many bands from the present results. The K^π = 2⁺ γ-vibrational band was found to have a large $\text{3}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}\text{+}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ admixture, consistent with the predicted microscopic composition of this phonon, but no $\text{5}\text{2}\text{[413]}{}_{\mathrm{<mtext>p</mtext>}}\text{?}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ component was observed. The K^π = 0₄⁺ band at 1833 keV has ～ 25% of the $\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}\text{?}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ two-quasiproton strength. This is in excellent agreement with the Soloviev model but is inconsistent with the interacting boson model, in which the K^π = 0₄⁺ band is composed almost completely of multiphonon configurations that should not be populated in a single-nucleon transfer reaction. The $\text{K}{}^{\mathrm{\pi }}\text{= 4}{}^{\mathrm{?}}\text{,}\text{7}\text{2}{}^{\mathrm{?}}\text{[523]}{}_{\mathrm{<mtext>p</mtext>}}\text{+}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ two-quasiproton and the $\text{K}{}^{\mathrm{\pi }}\text{= 4}{}^{\mathrm{?}}\text{,}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}{}_{\mathrm{<mtext>n</mtext>}}\text{+}\text{1}\text{2}{}^{\mathrm{?}}\text{[521]}{}_{\mathrm{<mtext>n</mtext>}}$ two-quasineutron states are mixed strongly with each other, but the two K^π = 3^? bands composed of antiparallel couplings of the same particles are not. A good qualitative explanation of this mixing pattern is provided in terms of the effective neutron-proton interaction.     

The rotational bands 12+[411]and 12−[541]in 175Lu

In a study of the γ-radiation emitted in the reaction ¹⁷⁶Yb(p, 2n) excited states of the nucleus ¹⁷⁵Lu up to spin I = $\text{13}\text{2}$ have been investigated. The main results concern the rotational bands $\text{1}\text{2}$⁺ [411]and $\text{1}\text{2}$^? [541]with the corresponding band heads found at 626.60 and 370.88 keV, respectively. The half-life of the $\text{1}\text{2}$⁺[411] level has been determined to be $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 10.7±0.5}\text{ns}$. Furthermore, the band heads $\text{3}\text{2}$^?[532]and $\text{3}\text{2}{}^{\mathrm{+}}$[411]are proposed at energies of 999.0 and 1150.8 keV, respectively. Experimental E1 transition probabilities between both $\text{K =}\text{1}\text{2}$ bands are compared with calculations including the Coriolis and pairing effects, as well as theoretically deduced quadrupole deformation parameters.     

Single-proton states in 175Tm studied with the (t, α) reaction

The ${}^{176}\text{Yb(}\text{t}\text{, α)}{}^{176}\text{Tm}$ reaction has been studied using 17 MeV tritons with a polarization of ≈ 0.78 from the Los Alamos tandem Van de Graaff accelerator facility. The reaction products were momentum analyzed with a Q3D magnetic spectrometer and detected with a helical-cathode position-sensitive proportional counter. No nuclear structure information is available in the literature for the neutron-rich ¹⁷⁵Tm isotope. A comparison of the measured angular distribution for the $\text{(}\text{t}\text{, α)}$ reaction with DWBA predictions permitted spin and parity assignments for many levels. Rotational bands have been assigned for the $\text{1}\text{2}{}^{\mathrm{+}}\text{[411],}\text{7}\text{2}{}^{\mathrm{?}}\text{[523],}\text{3}\text{2}{}^{\mathrm{+}}\text{[411],}\text{5}\text{2}{}^{\mathrm{+}}\text{[413]}\text{and}\text{5}\text{2}{}^{\mathrm{?}}\text{[532]}$ orbitals, and tentative suggestions are given for the location of the $\text{5}\text{2}{}^{\mathrm{+}}\text{[402]}\text{and}\text{7}\text{2}{}^{\mathrm{+}}\text{[404]}$ Nilsson states. For the weakly populated band members the assignments rest strongly on the Nilsson model and are based mostly on energy relations and comparison with experimental population patterns observed in neighbouring nuclei for the same orbitals.     

Investigation of the low-lying levels of 179Hf with the (n, γ) and (n,e) reactions

The excited levels of ¹⁷⁹Hf are investigated using the thermal neutron capture γ-ray and conversion electron spectra measured with the bent crystal diffraction spectrometer in Risø and the β-spectrograph in Riga. The level scheme contains the odd parity rotational bands $\text{7}\text{2}{}^{\mathrm{?}}\text{[514],}\text{1}\text{2}{}^{\mathrm{?}}\text{[510],}\text{5}\text{2}{}^{\mathrm{?}}\text{[512],}\text{1}\text{2}{}^{\mathrm{?}}\text{[521],}\text{3}\text{2}{}^{\mathrm{?}}\text{[512]}$ and $\text{7}\text{2}{}^{\mathrm{?}}\text{[503]}$. The energies of these levels and the intensity ratios of the transitions between them are calculated taking into account the rotation-particle coupling (RPC). The following even parity levels are proposed: 859.0 and 942.2 keV $\text{(}\text{7}\text{2}{}^{\mathrm{+}}\text{and}\text{9}\text{2}{}^{\mathrm{+}}\text{of the}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}\text{band}\text{)}$; 1004.1 and 1079.2 keV $\text{(}\text{5}\text{2}{}^{\mathrm{+}}\text{and}\text{7}\text{2}{}^{\mathrm{+}}\text{of the}\text{9}\text{2}{}^{\mathrm{+}}\text{[624] + Q(22)}\text{band}\text{)}$; 1186.0, 1199.2 and 1296.4 keV $\text{(}\text{1}\text{2}{}^{\mathrm{+}}\text{,}\text{5}\text{2}{}^{\mathrm{+}}\text{and}\text{3}\text{2}{}^{\mathrm{+}}\text{of the}\text{1}\text{2}{}^{\mathrm{+}}\text{[651]}\text{band}\text{)}$. The levels at 1249.8, 1269.7, 1432.9, 1482.2 and 1755.5 keV, supported by the analysis of the γγ coincidence spectrum and Ge(Li) singles data, are discussed.     

One- and three-quasiparticle states in 171Hf and high spin rotational bands

The $\text{1}\text{2}{}^{\mathrm{?}}\text{[521]}\text{and}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}$ one-quasiparticle bands in the N = 99 nucleus ¹⁷¹Hf have been identified to spins of about $\text{45}\text{2}$ using (heavy ion, xn) reactions. The moments of inertia of these bands are consistent with the absence of backbending in the N = 98 core nucleus. The half-life of the $\text{5}\text{2}{}^{\mathrm{?}}\text{[512]}$ intrinsic state was measured as 63.6 ns. The strength of the $\text{5}\text{2}{}^{\mathrm{?}}\text{[512] →}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}\text{E}\text{1}$ transition is discussed. Two three-quasiparticle isomers with spins and parities $\text{19}\text{2}{}^{\mathrm{+}}\text{and}\text{23}\text{2}{}^{\mathrm{?}}$ have been identified and their suggested configurations are a $\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}$ neutron added to the 6⁺ and 8^? two-quasiproton states of the core. The moment of inertia of a rotational band based on the $\text{23}\text{2}{}^{\mathrm{?}}$ isomer supports this suggestion, and shows the effect of partial rotation alignment of the $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron.     

Nuclear reaction studies of 168Tm

The intrinsic structure of ¹⁶⁸Tm has been studied using the (³He, d) and (α, t) proton stripping reactions as well as the (d, t) and (³He, α) neutron pick-up reactions. The beams of 24 MeV ³He particles, 25 MeV α-particles and 12 MeV deuterons were obtained from the McMaster tandem Van de Graaff accelerator. The reaction products were analyzed with an Enge-type magnetic spectrograph and detected with photographic emulsions. The spectra have been interpreted in terms of the coupling of an odd proton and an odd neutron, each moving independently in a spheroidal potential, which gives rise to intrinsic two-quasiparticle states with $\text{K = ¦Ω}{}_1\text{±Ω}{}_2\text{¦}$. The identification of the intrinsic states was made by comparing the experimental cross-section patterns with those predicted with the aid of Coriolis coupling and distorted-wave Born approximation (DWBA) calculations. Rotational bands superimposed on the K^π = 3⁺ and $\text{K}{}^{\mathrm{\pi }}\text{= 4}{}^{\mathrm{+}}\text{, {}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}{}_{\mathrm{n}}\text{±}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{p}}\text{}}$ configurations, the first of which is the ground state, ha been observed in the spectra of all four reactions. New assignments have been made for configurations resulting from coupling the $\text{1}\text{2}$^? [541], $\text{7}\text{2}$⁺ [404], $\text{5}\text{4}$⁺ [402] and $\text{1}\text{2}$^? [530] p to the $\text{7}\text{2}$⁺ [633] neutron state. The neutron pick-up measurements confirmed the earlier assignments based on (d, t) reaction studies and suggested tentative assignments for the {$\text{1}\text{2}$⁺ [400]_n±$\text{1}\text{2}$⁺ [411]_p} and {$\text{3}\text{2}$⁺ [402]_n±$\text{1}\text{2}$⁺ [411]_p}     

Excited states of the transitional 189Ir and 187Ir nuclei populated by the (α, 2n) reaction

Enriched targets of ¹⁸⁷Re and ¹⁸⁵Re were bombarded with α-particles of energy between 23.0 and 42.8 MeV. The levels characteristic of ¹⁸⁹Ir and ¹⁸⁷Ir produced by the (α, 2n) reaction were studied. The positive parity bands built on the $\text{3}\text{2}{}^{\mathrm{+}}$ ground state and on the $\text{1}\text{2}{}^{\mathrm{+}}$ first excited state in both nuclei were observed and interpreted as bands built on the $\text{1}\text{2}$⁺[402] and $\text{1}\text{2}{}^{\mathrm{+}}$ [400] Nilsson states. The negative parity levels form two independent systems: the first one possesses characteristics typical of a rotation-aligned band and is interpreted as belonging to the h_{$\text{9}\text{2}$} orbital; the second one is connected with the $\text{11}\text{2}{}^{\mathrm{?}}$ isomeric state which originates from the h_{$\text{11}\text{2}$} orbital. The possibility of a triaxial shape for this h_{$\text{11}\text{2}$}. level system is discussed. In ¹⁸⁹Ir a 3.2 ms isomeric state of 2333 keV excitation energy has been found and, as a by-product, some information has been gathered on the 4.1 ms isomer in ¹⁸⁸Ir.     

Single-proton states in 151Pm

The ${}^{152}\text{Sm}\text{(}\text{t}\text{, α)}{}^{151}\text{Pm}$ reaction was studied using 17 MeV polarized tritons from the tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. The α-particles were analyzed using a Q3D magnetic spectrometer and detected with a helical-cathode position-sensitive counter. The overall resolution was ～ 18 keV FWHM. Measurements of the ¹⁵⁰Nd(³He, d)¹⁵¹Pm reaction were made using 24 MeV ³He beams from the McMaster University tandem accelerator. The deuteron spectra were analyzed with a magnetic spectrograph using photographic emulsions for detectors, yielding a resolution of ～ 13 keV FWHM. By comparing the measured angular distributions of ($\text{t}\text{, α}$) and (³He, d) cross sections and ($\text{t}\text{, α}$) analyzing powers with DWBA predictions it was possible to assign spins and parities to many levels. The present results confirm earlier assignments of rotational bands based on the low-lying $\text{5}\text{2}{}^{\mathrm{+}}\text{[413],}\text{5}\text{2}{}^{\mathrm{?}}\text{[532],}\text{3}\text{2}{}^{\mathrm{+}}\text{[411]}\text{and}\text{1}\text{2}{}^{\mathrm{+}}\text{[420]}$ orbitals. In addition, states at higher excitation have now been assigned to the $\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}\text{and}\text{7}\text{2}{}^{\mathrm{+}}\text{[404]}$ orbitals, and members of the $\text{3}\text{2}{}^{\mathrm{+}}\text{[422],}\text{5}\text{2}{}^{\mathrm{+}}\text{[402],}\text{3}\text{2}{}^{\mathrm{?}}\text{[541]}\text{and}\text{7}\text{2}{}^{\mathrm{?}}\text{[523]}$ bands are tentatively proposed. The spectroscopic strengths can be explained reasonably well by the Nilsson model when pairing and Coriolis mixing effects are included.     

Rotational bands in 195, 197Tl

High-spin states in ^{195, 197}Tl have been populated with (α, xn) reactions and studied by means of in-beam γ-ray and e^? spectroscopic methods. Complementary studies of the decay of ^{195, 197}Pb to ^{195, 197}Tl have been carried out. Several new features have been observed in these nuclei. The $\text{9}\text{2}{}^{\mathrm{?}}$ bands of ^{195, 197}T1. extended to $\text{27}\text{2}{}^{\mathrm{(?)}}$ and $\text{29}\text{2}{}^{\mathrm{(?)}}$, respectively, show a quenching of energy spacings between the $\text{23}\text{2}{}^{\mathrm{?}}$, $\text{25}\text{2}{}^{\mathrm{?}}$, $\text{27}\text{2}{}^{\mathrm{(?}}$ and $\text{29}\text{2}{}^{\mathrm{(?}}$ states. This has been interpreted as resulting from the coupling of a $\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ proton to the ($\text{π}\text{h}{}^{\mathrm{?2}}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}\text{)}{}_{\mathrm{8+,\; 10+}}$ configurations in the core nuclei ^{194, 196}Hg. Furthermore, positive-parity bands based on $\text{15}\text{2}{}^{\mathrm{+}}$ states were established up to the $\text{35}\text{2}{}^{\mathrm{(+)}}$ and $\text{29}\text{2}{}^{\mathrm{(+)}}$ states in ^{195, 197}Tl respectively. Probably these bands originate from the coupling of a h${}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ proton to a broken neutron pair. This pair consists of a rotation-aligned $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron and a low-j neutron in the $\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, $\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ or $\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ shell. It is known to constitute the 5^? bands in ^{194, 196}Hg.     

Backbending behaviour of rotational bands in 163,165,167Yb

Several rotational bands in ^163,165,167Yb are observed in (HI,xnγe^?) experiments. The $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ and $\text{3}\text{2}{}^{\mathrm{?}}\text{[521]}$ bands do not backbend, whereas the $\text{5}\text{2}{}^{\mathrm{?}}\text{[523]}$ bands do, indicating additional processes besides the rotational alignment of one $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron pair that are responsible for the backbending.     

Structure of positive parity states in 29P and two-step processes in (p,t) reactions

From a study of (p,t) reactions on ³¹P and ³⁰Si it is suggested that in ²⁹P the states with $\text{J}{}^{\mathrm{\pi }}\text{=}\text{1}\text{2}{}_1{}^{\mathrm{+}}$ and $\text{1}\text{2}{}_2{}^{\mathrm{+}}$, the pair $\text{3}\text{2}{}_2{}^{\mathrm{+}}$, $\text{5}\text{2}{}_1{}^{\mathrm{+}}$, and the pair $\text{7}\text{2}{}_3{}^{\mathrm{+}}$, $\text{9}\text{2}{}_1{}^{\mathrm{+}}$ are related by weak coupling of a s${}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ proton with the states 0₁⁺, 0₂⁺, 2₁⁺ and 4₁⁺ respectively of ²⁸Si. Completely atypical L = 2 angular distributions have been obtained for the $\text{3}\text{2}{}_1{}^{\mathrm{+}}$ and $\text{5}\text{2}{}_2{}^{\mathrm{+}}$ states in ²⁹P and it is suggested that this is due to contribution by two-step processes.     

The level structure of 156Gd studied by means of the (α, 2nγ) reaction

A complete set of conventional γ-ray spectroscopic techniques has been applied to investigate the level structure of ¹⁵⁶Gd. A total of twenty-five new levels has been established; unambiguous spin assignments could be given for twelve of them on the basis of angular distributions and conversion electron measurements. The proposed level scheme contains 49 levels, which can be ordered in seven rotational bands. The ground-state band was excited up to J^π = 14⁺, the β-band up to 10⁺, the γ-band up to (11⁺), the second K^π = 0⁺ band tentatively up to (10⁺), the K^π = 4⁺ band up to (8⁺). Two negative-parity bands, one with even spins and one with odd spins, were excited to J^π = (12^?) and (13^?). An isomeric state was established with $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 1.3 μs, J}{}^{\mathrm{\pi }}\text{= 7}{}^{\mathrm{?}}\text{, E}{}_{\mathrm{<mtext>x</mtext>}}\text{= 2137.7}\text{keV}$. The properties of the K^π = 4⁺ band and the isomeric state can be well explained by two-quasiparticle configurations. The negative-parity bands are interpreted as aligned octupole bands. Positive and negative-parity bands have been calculated in terms of the IBA model. Good agreement with the experimental results is obtained.     

The infrared part of the C2 Phillips system (2.3–0.9 μm)

Line positions and molecular constants for the 0-0, 1-0, 2-0, 0-1, 2-1, 3-1, 0-2, 1-2, and 4-2 bands of the C₂ Phillips system ($\text{A}{}^1\text{Π}{}_{\mathrm{u}}\text{-X}{}^1\text{Σ}{}_{\mathrm{g}}{}^{\mathrm{+}}$) are reported. Among them, five bands have not been reported previously. Rotational perturbations have been observed in the previously unobserved v = 1 level of the $\text{A}{}^1\text{Π}{}_{\mathrm{u}}$ state. This state is perturbed by the $\text{c}{}^3\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$ state which was discovered by Ballik and Ramsay. These observations provide new information regarding the perturbing state. In particular, the minimum of the potential energy for the $\text{c}{}^3\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$ state has been found to be at 9227.4 cm^?1 instead of 13 310 cm^?1, which was the previous T_e value for this electronic state.     

The level structure of 184W FROM THE β− decay of 184Ta

Levels of ¹⁸⁴W populated in the decay of 8.7 h ¹⁸⁴Ta have been studied by a variety of experimental techniques. As a result of β and γ-ray energy and intensity determinations and extensive β-γ and γ-γ coincidence measurements, a detailed ¹⁸⁴Ta decay scheme accommodating more than 99.5% of the decay intensity has been established. Intense β-ray groups of end-point energies 1165±26 and 1123±26 keV populate levels in ¹⁸⁴W at 1699 and 1746 keV, which de-excite predominantly to the 8.3 μs isomeric level at 1285 keV, recently identified as the $\text{1}\text{2}{}^{\mathrm{?}}\text{[510]ν?}\text{11}\text{2}{}^{\mathrm{+}}\text{[615]ν K}{}^{\mathrm{\pi }}\text{= 5}{}^{\mathrm{?}}$ band origin. The 1699 keV level also de-excites to members of a $\text{1}\text{2}{}^{\mathrm{?}}\text{[510]ν?}\text{7}\text{2}\text{[503]ν K}{}^{\mathrm{\pi }}\text{= 3}{}^{\mathrm{+}}$ band based at 1425 keV. New information about the properties of the γ-vibrational and K = 2 octupole bands in ¹⁸⁴W is presented and the possible configurations of the levels directly populated in the β^? decay are discussed. The configuration $\text{7}\text{2}{}^{\mathrm{+}}\text{[404]π ?}\text{3}\text{2}{}^{\mathrm{?}}\text{[512]ν K}{}^{\mathrm{\pi }}\text{= 5}{}^{\mathrm{?}}$ is indicated for the ¹⁸⁴Ta ground state.     

Level structure of 48Sc from the 48Ca(p,nγ) reaction

Levels of ⁴⁸Sc up to 3.33 MeV excitation were studied by the reaction ⁴⁸Ca(p,nγ)⁴⁸Sc employing a variety of experimental techniques. A level scheme of ⁴⁸Sc comprising 29 excited states and 54 transitions were determined from the measurements of γ-γ coincidences and γ-ray excitation functions. Within the framework of the statistical compound nucleus model spins and parities of the ⁴⁸Sc levels were assigned from the angular distributions and linear polarizations of the de-excitation γ-rays as well as the excitation functions of the residual levels. From the present experimental results and other available data we tentatively identified some of the levels of the ($\text{1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^9$, $\text{1}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}\text{)}$, ($\text{1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^9\text{, 2}\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$), ($\text{1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^7\text{, 2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$) and ($\text{1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^7\text{, 1}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$) configurations in addition to the well-known ($\text{π}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{, v}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$) multiplet.     

The 154Eu(t,p) reaction: Some new systematics in the N = 90 spherical-deformed transition region

A radioactive target of ¹⁵⁴Eu(8.3y) has been used to study the ¹⁵⁴Eu(t, p)¹⁵⁶Eu reaction at an incident energy of 17 MeV. The bandhead and one rotational state of the configuration have been identified in ¹⁵⁶Eu. The excitation energy of the 3^? bandhead is determined to be 448 ± 15 keV. The angular distribution of the first excited rotational state is anamolous and may indicate evidence for a strong two-step component in the reaction mechanism. The energy systematics of the Eu-Sm transition region are also investigated. We find that the systematics of $\text{h}\text{?}{}^2\text{2}\text{I}$ suggest that at N = 87 the ¹⁵⁰Eu excited configurations has a significantly more stable deformed structure than the corresponding $\text{11}\text{2}\text{[505]}$ one-quasiparticle structure in ¹⁴⁹Sm.     

Intensity measurements and self-broadening coefficients in the γ band of O2 at 628 nm using intracavity laser-absorption spectroscopy (ICLAS)

Quantitative measurements of intensities and widths were made for individual rotational lines of the atmospheric oxygen $\text{b}{}^1\text{Σ}{}_{\mathrm{g}}{}^{\mathrm{+}}\text{(ν′ = 2) ← X}{}^3\text{Σ}{}_{\mathrm{g}}{}^{\mathrm{?}}\text{(ν″ = 0)}$ γ band by using a recently developed, highly sensitive, intracavity laser-absorption spectroscopic technique (ICLAS) at 300 torr m. The total band intensity derived from the line intensities is $\text{1.26 ± 0.05}\text{cm}{}^{\mathrm{?1}}\text{km}{}^{\mathrm{?1}}\text{atm}{}^{\mathrm{?1}}$ (STP). Self-broadening collision coefficients for the ^PP and ^PQ branch lines have been determined from the absorption line width and were found to vary from 0.055 cm^?1 atm^?1 at N″ = 1 to 0.037 cm^?1 atm^?1 at N″ = 27.