Karl Hauschild

Université de Sorbonne Nouvelle - Paris 3, Nuclear Structure, Faculty Member

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Address: Bures-sur-Yvette, Île-de-France, France

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Mustafa YILMAZ

University of Gaziantep

Luis M Fraile

Universidad Complutense de Madrid

César Fernández Ramírez

Universidad Complutense de Madrid

Yehuwdah Chad-Umoren

University of Port Harcourt

Mrutunjaya Bhuyan

Institute of Theoretical Physics, Chinese Academy of Sciences

S. Frauendorf

University of Notre Dame

V. Guimarães

Universidade de São Paulo

Costel Petrache

Paris Sud XI University

Jana Javornik

University of East London

Gwen Robbins Schug

University of North Carolina at Greensboro

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Papers by Karl Hauschild

Fine structure in the alpha decay of 224 U

The European Physical Journal A, 2014

Abstract.224U nuclei were populated in fusion-evaporation reactions using a 206Pb target and an i... more Abstract.224U nuclei were populated in fusion-evaporation reactions using a 206Pb target and an intense 22Ne beam. Fusion-evaporation residues were separated by the new separator SHELS at the FLNR, Dubna and implanted into a large-area double-sided silicon strip detector. Position- and time-correlated alpha decays were used to identify evaporation residues. A new $ \alpha$-decay line at 8095(11) keV was observed in this work and assigned as the decay from 224U to the first excited 2+ in the daughter nucleus 220Th. Coincident photons were also observed allowing to unambiguously determine the excitation energy of the first excited 2+ state in 220Th to be 386.5(1) keV and not 373.3(1)keV as previously reported. The half-life of 224U was measured to be 396(17)μs.

Probing reaction dynamics with the Pt-196(n,xn gamma) reactions for x <= 15

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High-fold gamma-ray spectroscopy of Xe-117

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States in Pt-196 observed with the (n,n 'gamma) reaction

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Preliminary simulations for the focal plane detection system of S3

In this report preliminary Geant4 simulations for the focal plane detection system of S 3 using s... more

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Tidal Waves and Onset of Collectivity Above N=126

Acta Physica Polonica Series B

Recent experiments in the actinide region, using Gammasphere and the evaporation residue detector... more Recent experiments in the actinide region, using Gammasphere and the evaporation residue detector HERCULES, have covered the territory between N = 126 and the center of static octupole deformation at N = 134. The (220)Th nucleus and the neighboring (218)Ra and (219)Th nuclei mark the emergence of quadrupole-octupole collectivity in this mass region. Their octupole bands have B(E1)/B(E2) ratios which are typical for the region, but the level spacings do not concur with a rotational-like behavior. In addition, a spin-dependent staggering of the B(E1)/B(E2) ratios is evident. These features can be described, based on a phonon picture, by a constant-frequency tidal-wave mode for a reflection-asymmetric nuclear surface.

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Coulomb excitation of Kr-78

The Kr isotopes are considered to be among the best cases for shape coexistence studies in the ma... more The Kr isotopes are considered to be among the best cases for shape coexistence studies in the mass A similar to 70 region. Our campaign to investigate in detail the development of the shape coexistence in the neutron deficient Kr isotopes was started with the stable nucleus Kr-78. To obtain the information about the intrinsic shape, Coulomb excitation experiments were performed. A total of 26 matrix elements were determined for Kr-78. Simple geometrical and algebraic models do not reproduce all details of the electromagnetic structure. A good interpretation of the complex structure of the nucleus with competing oblate and prolate shapes comes from a study within the complex EXCITED VAMPIR approximation using Hartree-Fock-Bogoliubov transformations with symmetry projection before variation. The measured matrix elements are compared with the predictions of this model. (c) 2006 Elsevier B.V. All fights reserved.

High-fold γ-ray spectroscopy of 117Xe

Nuclear Physics A, 1998

High-spin states have been populated in 54117Xe via the 90Zr(31P, p3n) reaction at 150 MeV, using... more High-spin states have been populated in 54117Xe via the 90Zr(31P, p3n) reaction at 150 MeV, using the EUROGAM II γ-ray spectrometer to record high-fold γ-ray coincidences. Although 117Xe accounts for only 20% of the total fusion cross-section, a high-fold (γ4) analysis of this weak channel has significantly extended the level scheme. In particular, the νh112 yrast band has been extended

A New Shape Isomer in the N=Z Nucleus 72KR

Nuclear Physics at Border Lines - Proceedings of the International Conference, 2002

60 A NEW SHAPE ISOMER IN THE N= Z NUCLEUS 72KR E. BOUCHEZ, K. HAUSCHILD, A. HURSTEL, W. KORTEN, Y... more

First measurement of magnetic properties in a superdeformed nucleus: Hg193

Physical Review Letters, 1993

Probing reaction dynamics with the 196Pt(n,xnγ) reactions for x~15

Physical Review C, 1998

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High-fold γ-ray spectroscopy of 117I: Coexistence of collective and noncollective structures

Physical Review C, 1999

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Decay and properties of the yrast superdeformed band in 192Pb

Physical Review C, 1997

The 173Yb(24Mg,5n) reaction at E(24Mg) = 134.5 MeV with a gold-backed target was used to populate... more The 173Yb(24Mg,5n) reaction at E(24Mg) = 134.5 MeV with a gold-backed target was used to populate high-angular momentum states in 192Pb. Resulting gamma rays were detected with Gammasphere located at the 88-Inch Cyclotron. A discrete transition of energy Egamma = 2057.7(6) keV has been identified in the depopulation the yrast superdeformed (SD) band in 192Pb. This transition has been tentatively

Yrast bands inI117andXe116−118: Anomalous quasiparticle alignment frequencies and band termination

Physical Review C, 1995

The yrast bands of neutron-deficient ' I and» Xe have been extended to I-34', and " "Xe to I-46fi... more The yrast bands of neutron-deficient ' I and» Xe have been extended to I-34', and " "Xe to I-46fi, , using highfold y-ray coincidence data collected with the Eurogam II spectrometer. Systematic quasi- particle alignment frequencies are discussed and compared to theoretical cranked Woods-Saxon calculations. The first pair alignment is attributed to h»&2 protons despite theoretical expectations for h»&2 neutron align- ment; the neutron alignment appears significantly delayed. At higher spins, the ' I and ' Xe isobars exhibit contrasting forms of band termination.

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Evidence for octupole correlations inBa124,125

Physical Review C, 2005

The γ decay of the nuclei 124,125 Ba has been investigated by means of the EUROBALL spectrometer,... more The γ decay of the nuclei 124,125 Ba has been investigated by means of the EUROBALL spectrometer, coupled to the DIAMANT array of charged-particle detectors, using the reaction 64 Ni + 64 Ni at E beam = 255 and 261 MeV. In the nucleus 125 Ba six new E1 transitions have been found to link opposite-parity bands currently interpreted as νd 5/2 (+g 7/2 ), νh 11/2 structures. The previously unknown J π = 3 -level in the nucleus 124 Ba has also been identified; its excitation energy is accurately reproduced by a microscopic calculation including octupole correlations. Both issues are bolstered by sizable B(E1)/B(E2) ratios.

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Γγ-Ray Tracking Algorithms: A Comparison

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004

In the context of the development of a new multi-detector for g-ray spectroscopy such as AGATA, w... more In the context of the development of a new multi-detector for g-ray spectroscopy such as AGATA, we discuss the performances of 2 different g-ray tracking algorithms: back-tracking and forward-tracking. The same Monte Carlo simulated data is used to compare the capacity of each algorithm to reconstruct the trajectories of a given number of photons emitted into a 4p germanium shell.

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Shape coexistence in138Sm and evidence for the rotational alignment of a pair of N=6 neutrons

Journal of Physics G: Nuclear and Particle Physics, 1994

ABSTRACT The level scheme of 138Sm has been extended up to Ipi =(32+) using gamma -ray coincidenc... more ABSTRACT The level scheme of 138Sm has been extended up to Ipi =(32+) using gamma -ray coincidence data collected with the Eurogam array. The 106Cd(35Cl,3p)138Sm fusion-evaporation reaction was used at a bombarding energy of 150 MeV. Several new bands have been observed and the known bands extended to higher spin. Band crossings and shape coexistence are discussed with the aid of Woods-Saxon cranking calculations (CMS and TRS). Evidence is presented for a neutron (i132/)2 pair alignment which is predicted to drive the nucleus to a prolate shape with enhanced quadrupole deformation beta 2=0.32. A strongly coupled band was also established and is interpreted as a collectively rotating oblate structure.

The SAGE spectrometer: A tool for combined in-beamγ-ray and conversion electron spectroscopy

Journal of Physics: Conference Series, 2011

The SAGE spectrometer allows simultaneous in-beam gamma-ray and internal conversion electron meas... more The SAGE spectrometer allows simultaneous in-beam gamma-ray and internal conversion electron measurements, by combining a germanium detector array with a highly segmented silicon detector and an electron transport system. SAGE is coupled with the ritu gas-filled recoil separator and the great focal-plane spectrometer for recoil-decay tagging studies. Digital electronics are used both for the gamma ray and the electron parts

Search for isomers in 254Rf

We have searched for predicted two-and four-quasiparticle isomers in 254 Rf using the 50 Ti + 206... more We have searched for predicted two-and four-quasiparticle isomers in 254 Rf using the 50 Ti + 206 Pb heavy-ion fusion-evaporation reaction and the Argonne Fragment Mass Analyzer (FMA). The beam was produced by the ATLAS accelerator with an energy of 242.5 MeV and an intensity of ∼200 pnA. The recoiling reaction products were separated by the FMA, identified by their m/q ratio using a Parallel Grid Avalanche Counter detector and implanted into a 160-by-160-strip Double-sided Silicon Strip Detector at the FMA focal plane where correlations between implants and their subsequent decays were established. The results of the experiment will be presented including the observation of spontaneous fission events correlated with mass 254 implants.

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Light Charged Particles as Gateway to Hyperdeformation

Following the prediction already in 1988 of hyperdeformed nuclei (HD) close to the highest spin n... more Following the prediction already in 1988 of hyperdeformed nuclei (HD) close to the highest spin nuclei can accommodate', many serious attempts have been made to verify these predictions. During the last 5 years we have been involved in searches looking for (xn) residues mostly from the compound nuclei 168,170 Hf, 140 Nd, 128 Ba, 130 Xe, and 116 Sn, produced at the highest possible spin by symmetric or semi-symmetric fusion reactions. As of today, no discrete rotational bands with large enough quadrupole moment or moment of inertia has been found. However, sensitive studies of quasi-continuum states, by the so-called Rotational Plane Mapping (RPM) of 3 dimensional (3D) γ-coincidence data have revealed rotational patterns indicating that the nuclei, 126 Ba and 126 Xe have many rotational bands with large and constant moment of inertia, J ~ 77 and 83 ħ 2 /MeV, respectively over several high spin transitions . Follow-up experiments on the first observations confirmed the moment of inertia. Inspired by these results, an extraordinary effort was made running the reaction 64 Ni + 64 Ni => 128 Ba again over 4 weeks at the Vivitron in Strasbourg, using the Euroball IV γ-detector array, equipped both with the inner ball of BGO detectors for γ-multiplicity selectivity, and the DIAMANT array of 84 CsI detectors for selecting the emitted light charged particles. The DIAMANT turned out to be very important. When selecting charged particles as part of the decay channel, we were able to identify 10 different nuclei, 124,125 Cs, 122,123,122,124 Xe, 121,122 I and 118,120 Te, all showing different rotational patterns in RPM spectra in the form of the so-called 2. ridge structures along the 2D diagonal, with J ranging from 71 to 111 ħ 2 /MeV. Theoretical calculations indicate that only the cases with J (2) ≥ 100 ħ 2 /MeV may be considered hyperdeformed. A detailed analysis of those cases, (2α2n) => 118 Te, (p2n) => 125 Cs and (2p,2n) => 124 Xe will be discussed and compared to the best populated case, (α2n) => 122 Xe with a J (2) ~ 77, indicating that in this case, the structure is most likely superdeformed. A statistical analysis of the homogeneity of the ridge structures, and also simple angular distributions of the emitted charged particles in coincidence with the observed ridge structures are discussed.

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Fine structure in the alpha decay of 224 U

The European Physical Journal A, 2014