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High-power PW laser systems (HPLS) provide intense beams of accelerated reaction-driving protons simultaneously with spatially localized keV-plasmas. We herein depict our groundwork and strategy to use these unique features of the HPLS at the Extreme Light Infrastructure (ELI-NP) by exposing the long-lived nuclear isomer 93 m Mo at 2.425 MeV ( t 1 / 2 = 6.85 h) to plasma facilitating the local petawatt beamlines. An intermediate short-lived ( t 1 / 2 = 3.52 ns) state situated only 4.85 keV above 93 m Mo constitutes a gateway to allow for its prompt release. The controllable release of the nuclear isomer energy will henceforth enable harvesting energy densities in the nuclear regime of GJkg - 1 (‘Nuclear Battery’). The campaign was inspired by the observation of the triggered release of 93 m Mo via the intermediate state by Chiara et al. [1] published in Nature. They assigned the hitherto elusive Nuclear Excitation by Electron Capture (NEEC) as the driving process and claimed a very high probability of P NEEC exp = 0.010 (3) . However, these claims are challenged by experimentalists [2-3] and theory [4]. We herein outline our strategy following bespoke theoretical guidance in the quest to unambiguously and independently demonstrate the onset of NEEC in 93 m Mo . With the yield estimations derived for our forthcoming HPLS experiment at ELI-NP, we draw optimism to resolve the current conundrum between the conflicting experimental observations and theoretical interpretations as discussed in world-leading journals and to pave the way for the future utilization of isomer depopulation in applied physics. [ABSTRACT FROM AUTHOR]

By using a liquid metal as a target one may significantly enhance the yield of hard x-rays with a sequence of two intense femtosecond laser pulses. The influence of the time delay between the two pulses is studied experimentally and interpreted with numerical simulations. It was suggested that the first arbitrary weak pulse produces microjets from the target surface, while the second intense pulse provides an efficient electron heating and acceleration along the jet surface. These energetic electrons are the source of x-ray emission while striking the target surface. The microjet formation is explained based on the results given by both optical diagnostics and hydrodynamic modeling by a collision of shocks originated from two distinct zones of laser energy deposition. [ABSTRACT FROM AUTHOR]

High-spin states of the 44Sc nucleus, populated in the 68 MeV 18O + 30Si reaction, have been studied in a γ-γ-recoil coincidence experiment. The detailed decay pattern, with various paths and cross-transitions, has been extended up to 9.1 MeV. High-quality DCO and polarization information assign spins and parities for the majority of the observed levels. The negative-parity states are discussed and compared with rotational bands in neighbouring f7/2-shell nuclei. [ABSTRACT FROM AUTHOR]

High-spin states of the nucleus 163Lu have been populated through the fusion-evaporation reaction 139La(29Si, 5n) with a beam energy of 157 MeV. In addition to the two lowest excited triaxial strongly deformed (TSD) bands, recently interpreted as one- and two-phonon wobbling excitations, a third excited TSD band has been firmly established decaying to the yrast TSD band. The assignment of this band as a three-quasiparticle band shows together with the normal deformed (ND) level scheme the presence not only of shape coexistence between ND and TSD structures, but also an interplay of wobbling and quasiparticle excitations in the triaxial strongly deformed potential well of 163Lu. [ABSTRACT FROM AUTHOR]

High-spin states in 167Hf, populated in the 141Pr(30Si, p3n)167Hf reaction, have been studied using the nordball Ge detector array. Three rotational cascades have been observed for the first time and the previously-known level scheme has been extended to significantly higher spin. Band-crossing effects are discussed within the framework of Woods-Saxon cranking calculations and are found to be in good agreement. [ABSTRACT FROM AUTHOR]

Excited states in the Z= 85 nucleus 197At have been identified for the first time using the recoil-decay-tagging (RDT) technique. The excitation energy of these states is found to be consistent with the systematics of neutron-deficient astatine nuclei and with theoretical calculations indicating that the nucleus may be deformed in its ground state. [ABSTRACT FROM AUTHOR]

Measurements of ion-induced nuclear reactions have been used to diagnose ion acceleration from the interaction of high-intensity (>10[sup 19] W cm[sup -2]) laser light with solid targets. Nuclear activation of catcher materials surrounding the interaction region has been studied using a high-resolution germanium detector. It was found that, when a 100 μm thick Al target foil was preheated, the proton flux produced from the laser–foil interaction was considerably reduced. Observed heavy-ion-induced reactions are used with calculated reaction cross sections to quantify ion acceleration. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

High-spin states of the42Ca nucleus, populated in the 68 MeV18O +30Si reaction, have been studied in a γ-γ-recoil coincidence experiment. The level scheme of42Ca has been extended up to 13.7 MeV. An elaborate decay pattern with various paths, together with high-quality DCO and polarization information assigns spins and parities for almost all observed levels. The sequence of non-yrast positive-parity states is discussed and compared with highly deformed bands in36Ar and40Ca. [ABSTRACT FROM AUTHOR]

Excited states of the rubidium isotopes 3787, 89, 91Rb have been studied at the INFN Legnaro National Laboratory. Measurements of the γ -ray decay of fragments produced in binary grazing reactions resulting from the interaction of a beam of 530 MeV 96Zr ions with a 124Sn target have been complemented by studies of the γ -ray decay of fission fragments produced in the interaction of a beam of 230 MeV 36S ions with a thick 176Yb target. The structure of the yrast states of 3787, 89, 91Rb has been discussed within the context of spherical shell-model and cranked Nilsson-Strutinsky calculations. [ABSTRACT FROM AUTHOR]

Intruder rotational bands in 45Sc and 45Ti have been investigated up to the maximum aligned angular momentum by means of EUROBALL IV and the Recoil Filter Detector (RED). The use of the RED allowed for a reduction of the γ-line Doppler broadening and, moreover, for a determination of very short level lifetimes. In the studied nuclei, the estimated deformation shows a gradual disappearance of the collectivity at the highest available spins. [ABSTRACT FROM AUTHOR]

The highly sensitive GASP array at the INFN Legnaro Laboratory was used to study the γ-ray de-excitation of neutron-rich nuclei produced in the deep-inelastic processes which occur when 230 MeV 36S ions interact with a target of 176Yb. Yrast decay schemes were identified in over forty target-like fragments and in over twenty projectile-like fragments. Analysis of the data has resulted in extensions to the yrast decay sequences of the target-like species, 176Hf, 166Er, 172Yb, and 152Sm. New transitions have also been observed in a number of projectile-like species including 34P and 41Cl. Experimental results are compared with the results of shell model calculations. [ABSTRACT FROM AUTHOR]

The γ-decay and half life of the t=60(3) ns I=8 isomer inCd have been studied with a recoil catcher setup inside the multidetector π-array OSIRIS. Evaporation neutrons and charged particles from the reactionNi+Ti were measured in coincidence with delayed γ-rays. Six new γ-ray transitions with intensities of 1-10% of the main γ-ray cascade were found, two new states established and firm spin-parity assignments were made to all states below the isomer. The new states were identified as the 4 and 6 members of the proton πg multiplet. [ABSTRACT FROM AUTHOR]

Abstract: Yrast and near-yrast states in 30Al and 30Si have been populated to high spin with the fusion–evaporation reaction in inverse kinematics. The level schemes for these two isobars have been extended up to at 9.4 and 15.5 MeV, respectively. Their decay schemes indicate that cross-shell excitations dominate at high spin, where negative-parity structures exist. Positive-parity states are compared to the results of shell-model calculations using the USD, USDA, and USDB effective interactions. The negative-parity levels are compared to predictions of the WBP interaction and the recently-developed WBP-a Hamiltonian, by allowing 1p–1h excitations to fp-shell orbitals. The results suggest that single-neutron excitations to the orbital play a significant role at high spin. [ABSTRACT FROM AUTHOR]

Wobbling is a rotational mode unique to a triaxial body. The Lu–Hf isotopes with N∼94 at high spin provide a possible region of nuclei with pronounced triaxiality. We have investigated 163Lu through the fusion-evaporation reaction 139La(29Si,5n)163Lu with a beam energy of 152 MeV. Three excited bands decaying into the known, presumably triaxial, superdeformed (TSD) band built on the i13/2 proton orbital are observed. The electromagnetic properties of the connecting transitions from the two strongest populated excited TSD bands have been investigated. New particle-rotor calculations in which one i13/2 quasiproton is coupled to the core of triaxial shape produce a variety of bands, whose properties can clearly be interpreted either as “wobbling” or “cranking” motion of the core. Evidence for the assignment of the excited TSD bands as one, and possibly even two wobbling phonon modes built on the yrast TSD band in 163Lu is given. These triaxial bands coexist with bands built on quasiparticle excitations in the normal deformed (ND) minimum for which new data are also presented. [Copyright &y& Elsevier]

The transfer of neutrons onto 24Ne has been measured using a reaccelerated radioactive beam of 24Ne to study the (d,p) reaction in inverse kinematics. The unusual raising of the first 3/2+ level in 25Ne and its significance in terms of the migration of the neutron magic number from N=20 to N=16 is put on a firm footing by confirmation of this state's identity. The raised 3/2+ level is observed simultaneously with the intruder negative parity 7/2- and 3/2- levels, providing evidence for the reduction in the N=20 gap. The coincident gamma-ray decays allowed the assignment of spins as well as the transferred orbital angular momentum. The excitation energy of the 3/2+ state shows that the established USD shell model breaks down well within the sd model space and requires a revised treatment of the proton-neutron monopole interaction.

Results from the gamma-ray spectroscopy of {47,48}Ar exemplifying new limits of sensitivity for characterizing neutron-rich nuclei at energies around the Coulomb barrier are presented. The present results, along with interacting shell model calculations, highlight the role of cross-shell excitations and indicate the presence of a nonaxial deformation in 48Ar.

Proton and heavy ion acceleration in ultrahigh intensity ( approximately 2 x 10(20) W cm(-2) ) laser plasma interactions has been investigated using the new petawatt arm of the VULCAN laser. Nuclear activation techniques have been applied to make the first spatially integrated measurements of both proton and heavy ion acceleration from the same laser shots with heated and unheated Fe foil targets. Fe ions with energies greater than 10 MeV per nucleon have been observed. Effects of target heating on the accelerated ion energy spectra and the laser-to-ion energy conversion efficiencies are discussed. The laser-driven production of the long-lived isotope (57 )Co (271 days) via a heavy ion induced reaction is demonstrated.

Heavy-ion induced nuclear reactions in materials exposed to energetic ions produced from high-intensity (approximately 5 x 10(19) W/cm(2)) laser-solid interactions have been experimentally investigated for the first time. Many of the radionuclides produced result from the creation of "compound nuclei" with the subsequent evaporation of proton, neutron, and alpha particles. Results are compared with previous measurements with monochromatic ion beams from a conventional accelerator. Measured nuclide yields are used to diagnose the acceleration of ions from laser-ablated plasma to energies greater than 100 MeV.

The nucleus 163Lu has been populated through the reaction 139La(29Si,5n) with a beam energy of 157 MeV. Three triaxial, strongly deformed (TSD) bands have been observed with very similar rotational properties. The first excited TSD band has earlier been assigned as a one-phonon wobbling excitation built on the lowest-lying (yrast) TSD band. The large B(E2)(out)/B(E2)(in) value obtainable for one of four observed transitions between the second and first excited TSD bands is in good agreement with particle-rotor calculations for a two-phonon wobbling excitation.

The nucleus (163)Lu has been populated through the fusion-evaporation reaction (139)La((29)Si,5n)(163)Lu with a beam energy of 152 MeV. The electromagnetic properties of several connecting transitions between two presumably triaxial, strongly deformed (TSD) bands have been studied. Evidence is presented for the assignment of the excited TSD band as a wobbling mode built on the yrast TSD band, based on comparisons to new calculations in which an aligned particle is coupled to a strongly deformed triaxial rotor. The wobbling mode is uniquely related to triaxiality in nuclei.