High spin states in128Ba

High spin states of ¹²⁸ Ba have been investigated via the ⁹⁶ Zr (³⁶ S, 4n)reaction at 150Me V beam energy using the Osiris anti- compton spectrometer. 14new levels and 23new transitions up to a maximum spin of 34? could be placed in the levelscheme.     

High spin states in 128Ba

High spin states in ¹²⁸Ba have been investigated with the fusion–evaporation reaction ⁹⁶Zr(³⁶S,4n)¹²⁸Ba at a beam energy of 150 MeV with the GASP-spectrometer at INFN in Legnaro, Italy. The level scheme could be extended to higher spins and six-quasiparticle states have been observed. The deduced alignments are compared to the predictions of previously reported cranked shell model calculations. Received: 4 January 1999     

High spin states of120Ba

The very neutron deficient nucleus¹²⁰Ba has been investigated in a high-spin γ-spectroscopic study. The yrast band of¹²⁰Ba is extended up to spin 22? and one tentatively assigned negative-parity side band is observed up to spin 15?. The experimental results are compared with Total Routhian Surface calculations.     

Excited states in128Ba

A group of proton emitters of Au, Ir, Re, Ta has been identified by means of mass values derived from the experimental data. The proton drip line has been determined. It is shown that on the boundary of the proton stability the values of proton pairing energies increase by about 50% as compared with the isotone nuclei near the betastability line.     

High spin properties of 124Ba

The ¹²⁴Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function of angular momentum is used to study the dependence of shell correction on angular momentum using the Strutinsky smoothing procedure. The most important observation is that the shell correction is almost the same for all spins for ¹²⁴Ba. The spin cutoff parameter and the single particle level density parameter are studied as a function of spin and temperature. Constant entropy lines drawn by plotting the excitation energy against angular momentum are found to be roughly at constant energy above the yrast line and are almost equally spaced. It is observed that no yrast traps are present for ¹²⁴Ba.     

High spin states in106in

High spin states have been investigated by the reaction⁹⁰Zr(¹⁹F, 3nγ), using an Anticompton spectrometer device, for the nucleus¹⁰⁶In, for which no in-beamγ-spectroscopic information was available up to now. A level scheme has been constructed up to anI =(13,14) state.     

High spin states in147Tb

The level scheme of¹⁴⁷Tb has been extended to 116 levels and 198 transitions in two experiments with the OSIRIS Compton suppressed detector array at the HMI Berlin with the reactions¹²²Sn(³¹P, 6n)¹⁴⁷Tb at 160 MeV and¹²⁰Sn(³¹P, 4n)¹⁴⁷Tb at 152 MeV. Evidence for a new high spin isomer atE=7664.1 keV with a life-time of the order of 2 ns has been found.     

High spin states in 210Pb

High spin states in nuclei in the ²⁰⁸Pb region were populated in deep inelastic collisions of ¹³⁶Xe and ²⁰⁸Pb projectiles with thick ²⁰⁸Pb targets at about 50 MeV above the Coulomb barrier. Prompt and prompt-delayed γ-ray coincidences were measured. Four new states above the 8⁺ isomer in ²¹⁰Pb were found and spins and parities assigned from theoretical expectations. The results are discussed in the frame of shell model theory.     

High spin states in116Te

The high spin states in¹¹⁶Te were populated in the Ru(¹⁹F,p4n) reaction at E_lab=90MeV and the subsequent deexcitation was studied using the γ-ray spectroscopic techniques. Ninteen new transitions have been added to extend the level scheme. A ΔI=2 rotational band is identified for the first time in an even-A Tellurium nucleus.     

High spin states in153Er

High spin states in¹⁵³Er have been populated in the¹⁴⁴Sm(¹²C, 3n)¹³³Er reaction. Excitation functions, lifetimes, angular distributions,γ-γ coincidences and internal conversion coefficients were measured. Three isomeric states at 2.75 MeV (T _1/2=400 ns), 2.95 MeV (T _1/2～10 ns) and 5.2 MeV (T _1/2=200 ns) have been observed. A fourth isomer seems to be weakly excited above 6.8 MeV. The level scheme proposed is discussed in term of the nuclear shell model.     

High spin states in 63Cu

Excited states of ⁶³Cu were populated via the ⁵²Cr+¹⁰O (65 MeV) reaction using the gamma detector array equipped with charged particle detector array for reaction channel separation. On the basis of γ-γ coincidence relations and angular distribution ratios, a level scheme was constructed up to E _n=7 MeV and J ^π=23/2⁽⁺⁾. The decay scheme deduced was interpreted in terms of shell model calculations, with a restricted basis of the f _5/2, p _3/2, p _1/2, g _9/2 orbitals outside a ⁵⁶ ₂₈Ni core.     

High spin states in145Gd

The data from two experiments with heavy ion induced reactions at the OSIRIS Compton suppressed Ge detector array has been analyzed to study high spin states in¹⁴⁵Gd. The level scheme of¹⁴⁵Gd has been extended up to an excitation energy of 12 MeV and an estimated spin of 25 ?. No evidence for high spin isomers was found.     

High spin states in103Rh

High spin states in¹⁰³Rh have been studied using the¹⁰⁰Mo(⁷Li, 4n) reaction. Standard in-beam measurements involving singlesγ-ray,γ-γ-t coincidences, angular distribution and linear polarization measurements have been performed. A perturbed band based on a 9/2⁺ state is interpreted as ag _9/2 coupled band. A sequence built on a 1/2^? state is related to thep _1/2 state. At higher excitation energy, in the range 2.2–3.7 MeV, the strongΔI=1 cascade observed, connecting negative parity levels, probably arises from states including three quasi-particle configurations.     

High spin states in131Ce

Gamma ray spectra from the¹¹⁷Sn(¹⁸O,4n)¹³¹ Ce reaction have been studied with the NORDBALL array of 15 Compton-suppressed Ge detectors. States up to I=51/2 , E8 MeV are populated. Observed bands are interpreted in terms of quasiparticle configurations.     

High spin states in66,68Ge

High spin states of^66,68Ge have been investigated at the FN Tandem accelerator of the University of Köln via the reactions⁴⁰Ca(³²S,2p,4p)^66,68Ge at a beam energy of 100 MeV and⁵⁸Ni(¹⁶O,2p)⁶⁸Ge at 65 MeV. The OSIRIS spectrometer with 12 escape suppressed Ge detectors was used to measure coincidences and -ray angular distributions. In⁶⁶Ge (⁶⁸Ge) 33 (22) new levels were found and 63 (62) new -transitions were placed in the level scheme. Both nuclei show a rather complicated but similar excitation pattern, ruled by the interplay of quasiparticle and collective degrees of freedom. The results are compared to the recently published EXVAM calculations for⁶⁸Ge.Supported by German BMFT under contract No. 06 OK 143.     

High spin states in121Te

High spin states of¹²¹Te, populated in the¹¹⁴Cd(¹¹B,p3n) reaction, have been studied throughγ-ray spectroscopy. The level scheme has been established up toJ ^π=51/2^?. Three-quasiparticle states, based on the πg _7/2 ²?νh _11/2 andπg _7/2 d _5/2?νh _11/2 configurations, have been identified. A favoured 39/2^? state is suggested to be the fully aligned [πg _7/2 ²]₆₊?[νh _11/2 ³ _27/2? yrast non-collective oblate configuration. This assignment is supported by Total Routhian Surface (TRS) calculations which also suggest a similar oblate assignment to the states atJ ^π=21/2^? and 23/2^?. A higher 47/2^? state is also found and is suggested to be the fully aligned [πg _7/2 ²]₆₊?[νh _11/2 ⁵]_35/2? configuration.     

High spin states in97Rh

High spin states in⁹⁷Rh were excited via the⁹⁶Ru (α,2np) reaction at 45 MeV. As a main finding we have observed a positive parity band, built on the 9/2⁺ ground state, which depopulated levels at 3,550.7 (25/2⁺), 3,259.1 (23/2⁺), 2,895.1 (23/2⁺), 1,961.3 (19/2⁺), 1,553.1 (17/2⁺) and 857.1 (13/2⁺). Also we have excited levels at 3,055.8 (21/2), 2,225.4 (17/2) and 1,463.5 (15/2), which most likely are negative parity states.     

High spin states in117Te

High spin states in ¹¹⁷Tewere populated following the ¹⁰⁸Pd(¹⁶O,2p5n)reaction at E_lab=84MeV and the subsequent de-excitation was studied using ray spectroscopic techniques. Two new bands consisting of E2 transitions were established upto spins 41/2 and 45/2, above the band built on v[505]11/2^– orbital. Such bands are seen for the first time in the systematics of odd- mass Te- nuclei.     

High spin states in116,118Te

High spin states in^116,118Te, populated in¹⁰²Ru(¹⁹F,p ⁴ n) and¹¹⁰Pd (¹³C, 5n) reactions, have been studied throughγ-ray spectroscopy. The level schemes have been established up toI?25?. A favouredI ^π = 16⁺ state in these nuclei is suggested to be based on the fully alignedπ[(g _7/2)²]₆ ⁺?ν[(h _11/2)²]₁₀ ⁺ non-collective oblate configuration. This assignment is supported by TRS cranking calculations, which also predict similar non-collective oblate assignment for states at 14^?, 19^? and 22^? in these nuclei.     

High spin states in115Te

Isotopic ratios were measured for Li, Be and B produced in p+Al, p+Nl and p+Ag reactions. The experimental data were analysed in the framework of the Quantum Statistical Model in order to relate the isotopic yield ratios to the baryonic entropy.