共查询到20条相似文献,搜索用时 31 毫秒
1.
Liddick SN Grzywacz R Mazzocchi C Page RD Rykaczewski KP Batchelder JC Bingham CR Darby IG Drafta G Goodin C Gross CJ Hamilton JH Hecht AA Hwang JK Ilyushkin S Joss DT Korgul A Królas W Lagergren K Li K Tantawy MN Thomson J Winger JA 《Physical review letters》2006,97(8):082501
Two new alpha emitters 109Xe and 105Te were identified through the observation of the 109Xe --> 105Te --> 101Sn alpha-decay chain. The 109Xe nuclei were produced in the fusion-evaporation reaction 54Fe(58Ni,3n)109Xe and studied using the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility. Two transitions at Ealpha = 4062 +/- 7 keV and Ealpha = 3918 +/- 9 keV were interpreted as the l = 2 and l = 0 transitions from the 7/2+ ground state in 109Xe (T1/2 = 13 +/- 2 ms) to the 5/2+ ground state and a 7/2+ excited state, located at 150 +/- 13 keV in 105Te. The observation of the subsequent decay of 105Te marks the discovery of the lightest known alpha-decaying nucleus. The measured transition energy Ealpha = 4703 +/- 5 keV and half-life T1/2 = 620 +/- 70 ns were used to determine the reduced alpha-decay width delta2. The ratio delta105Te(2)/delta213Po(2) of approximately 3 indicates a superallowed character of the alpha emission from 105Te. 相似文献
2.
The levels in124Te have been investigated by studying the gamma rays emitted following the decay of 60d124Sb. Gamma-gamma coincidence spectra have been taken with gates set at 603, 646, 709, 714 and 723 keV gamma rays by using 105 cm3 Ge(Li)-110 cm3 HPGe coincidence system. 69 gamma rays have been observed and nine of them are reported for the first time. Four new levels in124Te at 2512, 2550.2, 2808 and 2814.5 keV are proposed. Levels reported in literatures at 2412 and 2733 keV are excluded from the level scheme of124Te based on the present study. The experimentally determined energy spectrum of low-lying positive parity states, B(E2) ratios and electric quadrupole moment of the first excited state are compared with the IBM-1 predictions. 相似文献
3.
N.
zkan A. St. J. Murphy R. N. Boyd A. L. Cole M. Famiano R. T. Güray M. Howard L.
ahin J. J. ZachR. deHaan J. Grres M. C. WiescherM. S. IslamT. Rauscher 《Nuclear Physics A》2002,710(3-4)
Total cross section measurements for the 102Pd(p, γ)103Ag and 116Sn(p, γ)117Sb reactions have been performed in the proton energy range 2.6 to 4.25 MeV, and for the 112Sn(α, γ)116Te reaction over the alpha beam energy range 7.0 to 10.5 MeV. An activation technique was used in which gamma rays from decays of the reaction products were detected off-line by two hyper-pure germanium detectors in a low background environment. Where possible, reaction rates are derived and the results compared to those of calculations generated by the NON-SMOKER and the MOST statistical model codes so as to judge their applicability for describing the cross sections needed for network calculations of nucleosynthesis in explosive astrophysical environments via the γ- and rp-processes. 相似文献
4.
S. Rahaman V.-V. ElomaaT. Eronen J. HakalaA. Jokinen A. KankainenJ. Rissanen J. SuhonenC. Weber J. Äystö 《Physics letters. [Part B]》2011,703(4):412-416
The Q values of the 116Cd and 130Te double-beta decaying nuclei were determined by using a Penning trap mass spectrometer. The new atomic mass difference between 116Cd and 116Sn of 2813.50(13) keV differs by 4.5 keV and is 30 times more precise than the previous value of 2809(4) keV. The new value for 130Te, 2526.97(23) keV is close to the Canadian Penning trap value of 2527.01 ± 0.32 keV (Scielzo et al., 2009) [1], but differs from the Florida State University trap value of 2527.518 ± 0.013 keV (Redshaw et al., 2009) [2] by 0.55 keV (2σ). These values are sufficiently precise for ongoing neutrinoless double-beta decay searches in 116Cd and 130Te. Hence, our Q values were used to compute accurate phase-space integrals for these double-beta decay nuclei. In addition, experimental two-neutrino double-beta decay nuclear matrix elements were determined and compared with the theoretical values. The neutrinoless double-beta decay half-lives for these nuclei were estimated using our precise phase-space integrals and considering the range of the best available matrix elements values. 相似文献
5.
Alavi-Harati A Alexopoulos T Arenton M Arisaka K Averitte S Barker AR Bellantoni L Bellavance A Belz J Ben-David R Bergman DR Blucher E Bock GJ Bown C Bright S Cheu E Childress S Coleman R Corcoran MD Corti G Cox B Crisler MB Erwin AR Ford R Glazov A Golossanov A Graham G Graham J Hagan K Halkiadakis E Hamm J Hanagaki K Hidaka S Hsiung YB Jejer V Jensen DA Kessler R Kobrak HG LaDue J Lath A Ledovskoy A McBride PL Mikelsons P Monnier E Nakaya T Nelson KS Nguyen H O'Dell V Pang M Pordes R 《Physical review letters》2001,86(15):3239-3243
We have studied the rare weak radiative hyperon decay Xi degrees -->Sigma degrees gamma in the KTeV experiment at Fermilab. We have identified 4045 signal events over a background of 804 events. The dominant Xi degrees -->Lambdapi degrees decay, which was used for normalization, is the only important background source. An analysis of the acceptance of both modes yields a branching ratio of B(Xi degrees -->Sigma degrees gamma)/B(Xi degrees -->Lambdapi degrees ) = (3.34+/-0.05+/-0.09)x10(-3). By analyzing the final state decay distributions, we have also determined that the Sigma degrees emission asymmetry parameter for this decay is alpha(XiSigma) = -0.63+/-0.09. 相似文献
6.
R. D. Page P. J. Woods S. J. Bennett M. Freer B. R. Fulton R. A. Cunningham J. Groves M. A. C. Hotchkis A. N. James 《Zeitschrift für Physik A Hadrons and Nuclei》1991,338(3):295-301
A Residue Implantation Detection System has been used in conjunction with the Daresbury Recoil Mass Separator in a search for radioactivity from the unknown nuclides108I and105Te. In the reaction of 260 MeV58Ni ions with a54Fe target two new decay lines at energies of 3.730±0.025 MeV and 3.885±0.025 MeV corresponding to cross sections of approximately 0.3 b and 0.4 b respectively were identified in theA=108 region of the separator's focal plane. These decay lines are tentatively assigned to the alpha decays of108I. No evidence for a proton decay branch of this nuclide could be found. In a second reaction in which a50Cr target was bombarded with 230 MeV58Ni ions, no alpha decay peak from105Te could be identified. Cross section dependent half life limits were determined from which correspondingQ-value limits were deduced.RDP, SJB and MF would like to thank the SERC for financial support during the course of this work and all of us would like to thank the crews at Daresbury for providing the58Ni beams. 相似文献
7.
Hornidge DL Warkentin BJ Igarashi R Bergstrom JC Hallin EL Kolb NR Pywell RE Skopik DM Vogt JM Feldman G 《Physical review letters》2000,84(11):2334-2337
Cross sections for elastic Compton scattering from the deuteron were measured over the laboratory angles straight theta(gamma) = 35 degrees -150 degrees. Tagged photons in the laboratory energy range E(gamma) = 84-105 MeV were scattered from liquid deuterium and detected in the large-volume Boston University NaI spectrometer. Using the calculations of Levchuk and L'vov, along with the measured differential cross sections, the isospin-averaged nucleon polarizabilities in the deuteron were estimated. A best-fit value of (alpha;-beta;) = 2.6+/-1.8 was determined, constrained by dispersion sum rules. This is markedly different from the accepted value for the proton of (alpha;-beta;)(p) = 10.0+/-1.5+/-0.9. 相似文献
8.
R. U. Khafizov N. Severijns O. Zimmer H. -F. Wirth D. Rich S. V. Tolokonnikov V. A. Solovei M. R. Kolhidashvili 《JETP Letters》2006,83(1):5-9
The aim of this work is the experimental observation of and research into a rare neutron mode, the radiative beta decay, where
a new particle, the radiative gamma quantum, is formed along with the expected decay products: a beta electron, a recoil proton,
and an antineutrino. The discovery of this rare neutron decay mode was conducted through identification of triple-coincidence
events: simultaneous registration of a beta electron, a proton, and a radiative gamma quantum. The ordinary neutron decay
was registered by double coincidences of a beta electron and a recoil proton. The statistics collected allow one to deduce
the branching ratio (BR) BR = (3.2 ± 1.6) × 10−3 (90% C.L.) in the gamma energy region greater than 35 keV. This value of BR is consistent with standard electroweak theory.
The text was submitted by the authors in English.
An erratum to this article is available at . 相似文献
9.
J. B. Gupta N. C. Singhal J. H. Hamilton 《Zeitschrift für Physik A Hadrons and Nuclei》1973,261(2):137-142
The weak transitions in the decay of125Sb have been investigated through gamma ray measurements with high resolution X-ray and with large volume Ge(Li) detectors. The 172.6, 178.8 and 198.5 keV gamma rays are confirmed, while others previously reported were not. Accurate intensities were obtained for the stronger transitions. The weighted averages of these intensities which cover the range of 116 to 670 keV are useful for calibration of Ge(Li) systems. 相似文献
10.
The γ-ray spectra associated with the decay of 59.3 min 128Sn have been measured with Ge(Li) detectors. In order to recognize γ-rays of 128Sn and 128mSb, the decay and/or growth of γ-rays emitted from a tin sample separated chemically from fission products were measured. The decay of 128Sn is followed by the intense Sb X-rays and 32.1, 45.8, 75.1, 80.9, 115.9, 152.6, 404.4, 482.3, 557.3 and 680.2 keV γ-rays. On the basis of the measured singles and γ-γ coincidence spectra and the analysis of intensities of true sum peaks, a new decay scheme has been constructed. The 10.0 min isomer in 128Sb decays by β-emission (96.4%) to excited levels in 128Te and by an isomeric transition (3.6 %) to the 9.1 h ground state. 相似文献
11.
The decay of 2.76y 125Sb to levels of 125Te has been studied using an HPGe detector for gamma-ray and a mini orange electron spectrometer for conversion electron measurements.
We identify 38 transitions in this decay, including 13 gamma rays and 4 conversion electron lines being reported for the first
time. New results also include E1 multipolarity assignments to 3 newly observed transitions and M-shell conversion coefficient for the 109 keV M4 transition. A revised 125Te level scheme is constructed using Ritz combination principle. While confirming the existence of 10 well established levels
below 700 keV excitation, we introduce 3 other levels at 402.0, 538.6 and 652.9 keV. Interpretation of the observed levels
in terms of various theoretical approaches is briefly discussed. The newly introduced 538.6 keV (1/2+) and 652.9 keV (3/2+) levels are seen as the two missing members of the (s
1/2 ⊗ 2+) and (d
3/2 ⊗ 2+) sextuplet in the quasiparticle-phonon coupling scheme. 相似文献
12.
Ruiz C Parikh A José J Buchmann L Caggiano JA Chen AA Clark JA Crawford H Davids B D'Auria JM Davis C Deibel C Erikson L Fogarty L Frekers D Greife U Hussein A Hutcheon DA Huyse M Jewett C Laird AM Lewis R Mumby-Croft P Olin A Ottewell DF Ouellet CV Parker P Pearson J Ruprecht G Trinczek M Vockenhuber C Wrede C 《Physical review letters》2006,96(25):252501
The strength of the Ec.m. = 184 keV resonance in the 26gAl(p, gamma)27 reaction has been measured in inverse kinematics using the DRAGON recoil separator at TRIUMF's ISAC facility. We measure a value of omega gamma = 35 +/- 7 microeV and a resonance energy of Ec.m. = 184 +/- 1 keV, consistent with p-wave proton capture into the 7652(3) keV state in 27Si, and discuss the implications of these values for 26GAl nucleosynthesis in typical oxygen-neon white-dwarf novae. 相似文献
13.
Robinson AP Woods PJ Seweryniak D Davids CN Carpenter MP Hecht AA Peterson D Sinha S Walters WB Zhu S 《Physical review letters》2005,95(3):032502
Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon. 相似文献
14.
O. Kavatsyuk M. Kavatsyuk L. Batist A. Banu F. Becker A. Blazhev W. Brüchle J. Döring T. Faestermann M. Górska H. Grawe Z. Janas A. Jungclaus M. Karny R. Kirchner M. La Commara S. Mandal C. Mazzocchi I. Mukha S. Muralithar C. Plettner A. Płochocki E. Roeckl M. Romoli M. Schädel R. Schwengner J. Żylicz 《The European Physical Journal A - Hadrons and Nuclei》2005,25(2):211-222
The β decay of 103Sn, a three-neutron-particle nucleus with respect to the 100Sn core, was investigated at the GSI on-line mass separator using an array of 17 germanium crystals and a total absorption spectrometer. A total of 31 β-delayed γ-rays (29 new) of the 103Sn →103 In decay were observed and, on the basis of β-γ-γ coincidences, the 103Sn decay scheme was established for the first time. By means of total absorption spectroscopy, β intensities, the Gamow-Teller strength distribution and the summed Gamow-Teller strength value of 3.5±0.5 were determined for this decay. Its half-life and QEC value were found to be 7.0±0.2 s and 7.64±0.7 MeV, respectively. The β-delayed proton branching ratio was measured to be 1.2±0.1%. The results are discussed in comparison with shell-model predictions based on realistic and empirical interactions. 相似文献
15.
K. S. N. Murty B. P. Pathak S. C. Gujrathi 《Zeitschrift für Physik A Hadrons and Nuclei》1970,237(4):313-319
The decay characteristics of 19 min126m Sb have been studied using Ge(Li) and scintillation spectrometers. The sources of126m Sb were obtained by the (n, p) reaction on enriched126Te. The gamma rays of energies 414.4±0.3, 666.7±0.5 and 696.1±0.5 keV were found decaying with a half-life of 19 min. The study of beta spectra employing an anthracene crystal yielded two beta groups with end-point energies of 1.9±0.15 and 2.5±0.15 MeV. The results of singles and coincidence measurements have been incorporated into a decay scheme with excited states of126Te at 666.7, 1,362.8 and 1,777.2 keV. 相似文献
16.
Hammache F Bogaert G Aguer P Angulo C Barhoumi S Brillard L Chemin JF Claverie G Coc A Hussonnois M Jacotin M Kiener J Lefebvre A Le Naour C Ouichaoui S Scheurer JN Tatischeff V Thibaud JP Virassamynaïken E 《Physical review letters》2001,86(18):3985-3988
We have measured the cross section of the 7Be(p,gamma)8B reaction for E(c.m.) = 185.8, 134.7, and 111.7 keV using a radioactive 7Be target (132 mCi). Single and coincidence spectra of beta+ and alpha particles from 8B and 8Be* decay, respectively, were measured using a large acceptance spectrometer. The zero energy S factor inferred from these data is 18.5+/-2.4 eV b and a weighted mean value of 18.8+/-1.7 eV b (theoretical uncertainty included) is deduced when combining this value with our previous results at higher energies. 相似文献
17.
Runkle RC Champagne AE Angulo C Fox C Iliadis C Longland R Pollanen J 《Physical review letters》2005,94(8):082503
The 14N(p,gamma)15O reaction regulates the rate of energy generation in the stellar CN cycle. Because discrepancies have been found in the analysis and interpretation of previous capture data, we have measured the 14N(p,gamma)15O excitation function for energies in the range E(lab)(p)=155-524 keV. Fits of these data using R-matrix theory yield a value for the S factor at zero energy of 1.68+/-0.09(stat)+/-0.16(syst) keV b, which is significantly smaller than the previous result. The corresponding reduction in the stellar reaction rate for 14N(p,gamma)15O has a number of interesting consequences, including an impact on estimates for the age of the Galaxy derived from globular clusters. 相似文献
18.
O. Kavatsyuk C. Mazzocchi Z. Janas A. Banu L. Batist F. Becker A. Blazhev W. Brüchle J. Döring T. Faestermann M. Górska H. Grawe A. Jungclaus M. Karny M. Kavatsyuk O. Klepper R. Kirchner M. La Commara K. Miernik I. Mukha C. Plettner A. Płochocki E. Roeckl M. Romoli K. Rykaczewski M. Schädel K. Schmidt R. Schwengner J. Żylicz 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):319-325
The β decay of the very neutron-deficient isotope 101Sn was studied at the GSI on-line mass separator using silicon detectors for recording charged particles and germanium detectors
for γ-ray spectroscopy. Based on the β-delayed proton data the production cross-section of 101Sn in the 50Cr + 58Ni fusion-evaporation reaction was determined to be about 60nb. The half-life of 101Sn was measured to be 1.9(3)s. For the first time β-delayed γ-rays of 101Sn were tentatively identified, yielding weak evidence for a cascade of 352 and 1065keV transitions in 101In. The results for the 101Sn decay as well as those from previous work on the 103Sn decay are discussed by comparing them to predictions obtained from shell model calculations employing a new interaction
in the 88Sr to 132Sn model space. 相似文献
19.
S. N. Liddick R. Grzywacz C. Mazzocchi R. D. Page K. P. Rykaczewski J. C. Batchelder C. R. Bingham I. G. Darby G. Drafta C. Goodin C. J. Gross J. H. Hamilton A. A. Hecht J. K. Hwang S. Ilyushkin D. T. Joss A. Korgul W. Królas K. Lagergren K. Li M. N. Tantawy J. Thomson J. A. Winger 《The European physical journal. Special topics》2007,150(1):131-134
The α-decay chain 109Xe → 105Te → 101Sn was identified at the Holifield Radioactive Ion Beam Facility. Advances in digital electronics have made possible the identification
of both alpha emitters in the same experiment despite the disparate half-lives of 13 ±2 ms and 620 ±70 ns for 109Xe and 105Te, respectively. Two α-decay transitions were observed from 109Xe with Qα values of 4067 ±10 and 4217 ±8 keV. One transition between the ground states of 105Te and 101Sn was observed with a Qα value of 4889 ±6 keV. Using the measured half-lives, branching ratios, and Qα values the reduced α-decay widths, δ2, were determined. Comparison of the δ2 value for 105Te with 213Po indicates a “superallowed" character in the α emission of 105Te. 相似文献
20.
Gómez Del Campo J Galindo-Uribarri A Beene JR Gross CJ Liang JF Halbert ML Stracener DW Shapira D Varner RL Chavez-Lomeli E Ortiz ME 《Physical review letters》2001,86(1):43-46
Radioactive ion beams of 17F were used to study several resonance states in 18Ne. Clear evidence for simultaneous two-proton emission from the 6.15 MeV state (Jpi = 1(-)) in 18Ne has been observed with the reaction 17F+1H. Because of limited angular coverage, the data did not differentiate between the two possible mechanisms of simultaneous decay, diproton (2He) emission or direct three-body decay. The two-proton partial width was found to be 21+/-3 eV assuming 2He emission and 57+/-6 eV assuming three-body decay. The total width of the 1(-) state was measured to be 50+/-5 keV. Several additional resonances that decay by single proton emission were also studied. 相似文献