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91.
Winter WT Freedman SJ Rehm KE Ahmad I Greene JP Heinz A Henderson D Janssens RV Jiang CL Moore EF Mukherjee G Pardo RC Pennington T Savard G Schiffer JP Seweryniak D Zinkann G Paul M 《Physical review letters》2003,91(25):252501
We have measured the total energy of the alpha particles following the beta decay of 8B by implanting 8B into a planar silicon surface barrier detector. Calibration was performed using alpha particles following the beta decay of 20Na, similarly implanted. The alpha spectrum is used to infer the 8B neutrino spectrum which is an important input in the interpretation of experiments that detect energetic neutrinos from the Sun. The alpha spectrum reported here is in disagreement with the previous best measurement which used two detectors in coincidence. 相似文献
92.
Zhu S Garg U Nayak BK Ghugre SS Pattabiraman NS Fossan DB Koike T Starosta K Vaman C Janssens RV Chakrawarthy RS Whitehead M Macchiavelli AO Frauendorf S 《Physical review letters》2003,91(13):132501
High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd reaction at a 30Si bombarding energy of 133 MeV. Two DeltaI=1 bands with close excitation energies and the same parity were observed. These bands are directly linked by DeltaI=1 and DeltaI=2 transitions. The chiral nature of these two bands is confirmed by comparison with three-dimensional tilted axis cranking calculations. This is the first observation of a three-quasiparticle chiral structure and establishes the primarily geometric nature of this phenomenon. 相似文献
93.
We investigated the stability of gold clusters doped with open 3d-shell atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni). Steps, peaks, and odd-even staggering in mass abundance spectra upon photofragmentation provide evidence for enhanced stability for specific cluster sizes. The observed magic numbers are explained in terms of size- and dopant-dependent modifications of the effective mean-field potential within a phenomenological shell-model approach. Element-dependent 3d electron delocalization and odd-even staggering amplitudes are related to the dopant-atom structure. 相似文献
94.
Sonzogni AA Rehm KE Ahmad I Borasi F Bowers DL Brumwell F Caggiano J Davids CN Greene JP Harss B Heinz A Henderson D Janssens RV Jiang CL McMichael G Nolen J Pardo RC Paul M Schiffer JP Segel RE Seweryniak D Siemssen RH Truran JW Uusitalo J Wiedenhover I Zabransky B 《Physical review letters》2000,84(8):1651-1654
Cross sections for the 44Ti(alpha,p)47V reaction which significantly affects the yield of 44Ti in supernovae were measured in the energy range 5.7 MeV=E(c.m.)=9 MeV, using a beam of radioactive 44Ti. The cross sections and the deduced astrophysical reaction rates are larger than the results from theoretical calculations by about a factor of 2. The implications of this increase in the reaction rate for the search of supernovae using space-based gamma detectors are discussed. 相似文献
95.
Svensson CE Macchiavelli AO Juodagalvis A Poves A Ragnarsson I Aberg S Appelbe DE Austin RA Baktash C Ball GC Carpenter MP Caurier E Clark RM Cromaz M Deleplanque MA Diamond RM Fallon P Furlotti M Galindo-Uribarri A Janssens RV Lane GJ Lee IY Lipoglavsek M Nowacki F Paul SD Radford DC 《Physical review letters》2000,85(13):2693-2696
A superdeformed rotational band has been identified in 36Ar, linked to known low-spin states, and observed to its high-spin termination at Ipi = 16(+). Cranked Nilsson-Strutinsky and spherical shell model calculations assign the band to a configuration in which four pf-shell orbitals are occupied, leading to a low-spin deformation beta(2) approximately 0.45. Two major shells are active for both protons and neutrons, yet the valence space remains small enough to be confronted with the shell model. This band thus provides an ideal case to study the microscopic structure of collective rotational motion. 相似文献
96.
97.
Guido Janssens 《Analytica chimica acta》1979,112(4):449-453
A Laboratory Automation System (Hewlett-Packard 3354 B) minimizes systematic errors in quantification problems when detector responses are not linear. The calibration curves for the various products are stored and results are calculated by linear segmental interpolation. The complete operating cycle is controlled by the System. 相似文献
98.
Jiang CL Esbensen H Rehm KE Back BB Janssens RV Caggiano JA Collon P Greene J Heinz AM Henderson DJ Nishinaka I Pennington TO Seweryniak D 《Physical review letters》2002,89(5):052701
The excitation function for fusion evaporation in the (60)Ni+ (89)Y system was measured over a range in cross section covering 6 orders of magnitude. The cross section exhibits an abrupt decrease at extreme sub-barrier energies. This behavior, which is also present in a few other systems found in the literature, cannot be reproduced with present models, including those based on a coupled-channels approach. Possible causes are discussed, including a dependence on the intrinsic structure of the participants. 相似文献
99.
Wiedenhöver I Wuosmaa AH Janssens RV Lister CJ Carpenter MP Amro H Bhattacharyya P Brown BA Caggiano J Devlin M Heinz A Kondev FG Lauritsen T Sarantites DG Siem S Sobotka LG Sonzogni A 《Physical review letters》2001,87(14):142502
Spins and parities of high spin states above the particle-binding threshold in 24Mg were determined with a basis expansion technique using triple and quadruple angular correlations between alpha particles and gamma rays. The first unambiguous identification of a 10(+) state is reported. Located at 19.2(1) MeV, this state decays predominantly by alpha emission, although a candidate gamma-decay branch with a 5.927 MeV transition connecting this 10(+) level to the rotational 8(+) state at 13.2 MeV was identified as well. The corresponding gamma-alpha branching ratio is 7(3)x10(-4). 相似文献
100.
J. H. Hamilton A. V. Ramayya J. K. Hwang G. M. Ter-Akopian A. V. Daniel T. N. Ginter C. J. Beyer J. Kormicki X. Q. Zhang A. M. Rodin A. S. Fomichev J. Kliman L. Krupa J. Jandel Yu. Ts. Oganessian W. Greiner D. N. Poenaru G. Chubaryan D. Seweryniak R. V. F. Janssens J. O. Rasmussen S. C. Wu R. Donangelo W. C. Ma R. B. Piercey J. D. Cole 《Acta Physica Hungarica A》2001,14(1-4):161-168
The spontaneous fission of 252Cf has been studied via γ-γ-γ coincidence and γ-γ light charged particle coincidence with Gammasphere. The binary fission yields of correlated Mo?Ba pairs with 0–10 neutron emission have been remeasured. The existence of “hot” fission mode with 8–10 neutron emission seen previously in the Mo?Ba split is confirmed but with lower intensities. By gating on the light charged particles detected in ΔE-E detectors and a γ ray in one partner, the relative yields of correlated pairs in alpha ternary SF with zero to 6n emission are observed for the first time with the distribution peaked at 2.5n. New correlated pairs are identified in 10Be ternary SF. We observed essentially only cold, On 10Be and little, if any, hot, xn 10Be. New γ-γ-γ data with 2.3 times the total events show weak non-Doppler broadened high energy peaks in coincidence with transitions in correlated pairs in 10Be SF shifted by the same 6,1 to 26 keV from the 2-0 energy in 10Be as seen earlier. 相似文献