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Musser, J.A.
California Univ., Berkeley (USA)1984
California Univ., Berkeley (USA)1984
AbstractAbstract
[en] The design and operation of a detector used to study the particle stability of light isotopes are described. This detector is capable of achieving greater sensitivity than any previously employed in the observation of new rare isotopes. The study of nuclei off the valley of beta stability is primarily motivated by the desire to understand the isospin dependence of nuclear system behavior. In particular, obtaining information about nuclidic masses as a function of isospin determines the variation of the nuclear Hamiltonian with this generalized coordinate. The purpose of this experiment is to define the limits of stability of the nuclear system for extreme values of the isospin. This thesis contains the results of an experiment performed at the LBL Bevalac, which is capable of accelerating heavy ions to maximum energies of 2 GeV/N. A 600 MeV/N 56Fe beam interacting in a 7 g/cm2 Be target produced neutron rich projectile fragments whose masses and charges were analyzed in an electronic detector telescope. A total beam fluence of approx.1 x 1011 particles was obtained during the course of a 72 hour run. This allowed the first observation of 19B, and of the apparent particle instability of 18B, in agreement with the predictions of current mass models
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1984; 149 p; University Microfilms Order No. 85-12,927; Thesis (Ph. D.).
Record Type
Report
Literature Type
Thesis/Dissertation; Numerical Data
Country of publication
ACCELERATORS, ALKALINE EARTH METALS, BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, BORON ISOTOPES, DATA, DECAY, DETECTION, ELEMENTS, ENERGY RANGE, HEAVY ION REACTIONS, INFORMATION, ISOTOPES, LIGHT NUCLEI, MATHEMATICAL OPERATORS, METALS, MEV RANGE, NUCLEAR DECAY, NUCLEAR REACTIONS, NUCLEI, NUMERICAL DATA, ODD-EVEN NUCLEI, ODD-ODD NUCLEI, PARTICLE PROPERTIES, QUANTUM OPERATORS, RADIATION DETECTION, RADIOISOTOPES
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Barwick, S.W.; Musser, J.A.; Stevenson, J.D.
Nuclear Science Division annual report, October 1, 1983-September 30, 19841985
Nuclear Science Division annual report, October 1, 1983-September 30, 19841985
AbstractAbstract
[en] Projectile fragments of 1.8 GeV/nucleon 40Ar were used to search for fractionally charged nuclei. The authors present results of the first large statistics electronic counter telescope experiment. Charge histograms are presented and limits for fractional charge are deduced
Primary Subject
Source
Mahoney, J. (ed.); Lawrence Berkeley Lab., CA (USA); p. 125-127; May 1985; p. 125-127; Available from NTIS, PC A12/MF A01; 1 as DE85013312
Record Type
Report
Literature Type
Numerical Data
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Reference NumberReference Number
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Musser, J.A.; Stevenson, J.D.
Nuclear Science Division annual report, October 1, 1983-September 30, 19841985
Nuclear Science Division annual report, October 1, 1983-September 30, 19841985
AbstractAbstract
[en] In the experiment the authors produced projectile fragments by interactions of an intense 670 MeV/nucleon 56Fe beam in a 7.9 g/cm2 Be target. The charges and masses of the projectile fragments were obtained using the 00 spectrometer facility at the Bevalac in conjunction with a detector telescope (in the focal plane of the spectrometer) consisting of a wire chamber hodoscope, a front scintillator paddle, a set of threshold Cerenkov counters, and a back scintillator paddle. The data indicate for the first time that 19B is particle-stable, whereas 18B is unstable to prompt neutron emission
Primary Subject
Source
Mahoney, J. (ed.); Lawrence Berkeley Lab., CA (USA); p. 58-59; May 1985; p. 58-59; Available from NTIS, PC A12/MF A01; 1 as DE85013312
Record Type
Report
Literature Type
Numerical Data
Report Number
Country of publication
Reference NumberReference Number
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INIS IssueINIS Issue
Stevenson, J.D.; Musser, J.A.; Barwick, S.W.
Nuclear Science Division annual report, October 1, 1982-September 30, 19831984
Nuclear Science Division annual report, October 1, 1982-September 30, 19831984
AbstractAbstract
[en] Recent experiments have claimed that a small fraction of projectile fragments in relativistic nucleus-nucleus collisions have properties very different from normal nuclei. Measurements of the mean free path of secondary projectile fragments measured in nuclear emulsion within a few centimeters of their point of formation were observed to be shorter than those of primary nuclei of the same charge. Measurements of the mean free path of secondary projectile fragments as a function of distance from their formation point indicated the existence of a small component of projectile fragments with anomalously short mean free paths. The authors present here the result of an electronic experiment to measure projectile fragment mean free paths
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Mahoney, J. (ed.); Lawrence Berkeley Lab., CA (USA); p. 149-151; Aug 1984; p. 149-151; Available from NTIS, PC A16/MF A01; 1 as DE85001035
Record Type
Report
Literature Type
Numerical Data
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Country of publication
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Stevenson, J.D.; Musser, J.A.; Barwick, S.W.
Proceedings of the 6th high energy heavy ion study and 2nd workshop on anomalons1983
Proceedings of the 6th high energy heavy ion study and 2nd workshop on anomalons1983
AbstractAbstract
[en] We plan to look for the anomalon effect using a stack of thin plastic Cerenkov paddles, each of which provides an independent measurement of the projectile fragment charge. Determination of the projectile fragment charge by measurement of the intensity of Cerenkov radiation is superior to ionization measurements because it is insensitive to fragments below the Cerenkov threshold of approx. 310 MeV/nucleon. Low-energy fragments represent a real danger in analysis of ionization-type experiments since fragments coming to the end of range can mimic nuclear interactions. The chief disadvantage of the use of Cerenkov detectors is their feeble light output. The charge resolution of thin Cerenkov detectors is thus invariably limited by photon counting statistics and efficient light collection schemes are required to achieve satisfactory charge resolution
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Lawrence Berkeley Lab., CA (USA); p. 83-85; Dec 1983; p. 83-85; 6. high energy heavy ion study and 2. workshop on anomalons; Berkeley, CA (USA); 28 Jun - 1 Jul 1983; Available from NTIS, PC A99/MF A01 as TI84005862
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Report
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Conference
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AbstractAbstract
[en] This report is a follow-up to experiments performed in October, 1983 at the Lawrence Berkeley Laboratory Bevalac. These experiments used a 14 element Lucite Cherenkov detector telescope to observe charge-changing fragmentation reactions of 1.8 AGeV40Ar and 2.1 AGeV20Ne. No evidence for any short mean-free-path component was found among the combined proportional 155000 secondary interactions. A search for fractionally charged nuclei among proportional22000 projectile fragments found none differing in charge from integer values by more than +-1/3e. Here these results are recapitulated, and a few new details are presented. (orig./HSI)
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Bock, R.; Gutbrod, H.H.; Stock, R. (eds.); Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany, F.R.); 850 p; Mar 1985; p. 545-549; 7. high energy heavy ion study; Darmstadt (Germany, F.R.); 8-12 Oct 1984
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Report
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Conference
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AbstractAbstract
[en] Results are presented from an electronic experiment to check directly the anomalous mean-free-path phenomena observed in high-energy heavy-ion collisions. The mean-free-path measurements presented are based on interactions of 1.25 x 105 secondary fragments produced by interactions of 1.8A-GeV 40Ar in Lucite. The result is consistent with no anomalon phenomena and rules out (95% confidence limit) anomalons being more than 2% abundant if they have interaction lengths between 0.4 and 3 cm
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Journal Article
Journal
Physical Review Letters; ISSN 0031-9007; ; v. 52(7); p. 515-517
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AbstractAbstract
[en] An experiment was performed to search for fractionally charged nuclei with charge Z, 14< or =Z< or =18, produced as projectile fragments of 1.8-GeV/nucleon 40Ar. Analysis of 1.75 x 105 projectile fragments yielded no fragments with charges differing from integer values by more than +- (1/3)e. This experiment places limits (90% C.L.) on the relative abundance of fractionally charged projectile fragments with residual charge +(1/3)e (-(1/3)e) of less than 1.8 x 10-4 (2.3 x 10-4)
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Journal Article
Journal
Physical Review. D, Particles Fields; ISSN 0556-2821; ; v. 30(3); p. 691-693
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AbstractAbstract
[en] The particle stability of sup19B and the particle instability of sup18B are demonstrated. Light neutron-rich nuclei were searched for among the projectile fragments resulting from interactions of a 670A-MeV sup56Fe beam in a 7.9-g/cmsup2 Be target. A detector consisting of a magnetic spectrometer, threshold Cherenkov paddles, and scintillator paddles was used to determine the charge and mass of the projectile fragments
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Journal Article
Journal
Physical Review Letters; ISSN 0031-9007; ; v. 53(27); p. 2544-2546
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AbstractAbstract
[en] The sensitivity of scintillators to grand unification monopoles and other supermassive charged particles is inferred from measurements of scintillation by recoil protons with velocities as low as 2.5 x 10/sup -4/c. No evidence for a response cutoff is observed at velocities extending well below the electronic-excitation threshold of 6 x 10/sup -4/c expected from two-body kinematics. The relevance of these measurements to searches for supermassive relic charged particles is discussed
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Journal Article
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