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41.
T. Case D.V. Balin W.H. Breunlich K.M. Crowe H. Daniel B. Gartner F.J. Hartmann P. Kammel B. Lauss E.M. Maev V.E. Markushin M. Mühlbauer C. Petitjean G.E. Petrov W. Prymas G.N. Schapkin W. Schott G.G. Semenchuk Yu.V. Smirenin A.A. Vasiliev A.A. Vorobyov N.I. Voropaev J. Zmeskal 《Hyperfine Interactions》1999,118(1-4):197-202
Data from the recent PSI high statistics experiment on d μ d fusion are used to measure the stripping process in d μ d→
n+μ,3He and test current calculations of the stripping process. The PSI results in μ3He capture are also used to remove a troubling background from this measurement. Combination of these results with the old
dμ t sticking analysis slightly raise and improve that result to ωs= (0.58± 0.04)% and indicate that theory and experiment can meet if theoretical stripping is increased only at the beginning
of the track. This conclusion is in accord with the new stripping calculations where excited state stripping is increased
significantly.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
42.
van Eis MJ Wijsman GW de Wolf WH Bickelhaupt F Rogers DW Kooijman H Spek AL 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(9):1537-1546
The course of the hydrogenation of [5]- and [6]metacyclophane (1b and 1c) and their thermochemistry is described. Both compounds are hydrogenated rapidly (within 10 s) to furnish the bridgehead olefins 13b and 12c. The accompanying hydrogenation enthalpies are -220 and -141 kJmol(-1), respectively. Strain energies (SE) and olefinic strains (OS) of a number of bridgehead olefins have been evaluated by DFT calculations; it was concluded that 13b belongs to the class of hyperstable olefins which correlates nicely with its reluctance to undergo hydrogenation. By combining experimental hydrogenation enthalpies and DFT calculations, SE of 187 and 121 kJmol(-1) were derived for 1b and 1c. 相似文献
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Maev E. M. Ackerbauer P. Balin D. V. Baturin V. N. Beer G. A. Breunlich W. H. Case T. Crowe K. M. Daniel H. Deutsch J. von Egidy T. Govaerts J. Grigoriev Yu. S. Hartmann F. J. Kammel P. Lauss B. Marton J. Mühlbauer M. Petitjean C. Petitjean Th. Petrov G. E. Prieels R. Prymas W. Schott W. Semenchuk G. G. Smirenin Yu. V. Vorobyov A. A. Voropaev N. I. Wojciechowski P. 《Hyperfine Interactions》1996,101(1):423-427
The rates of the breakup reactions B(3He) and B(4He) in nuclear muon capture by3He and4He have been measured. The measurements were performed on the muon beam of PSI with a multi-anode high-pressure ionization chamber filled with isotopically pure3He or4He at 120 bar. The chamber was used as a target and detector for both the incoming muons and for the charged reaction products (tritons, deuterons and protons) of the breakup reactions B(3He) and B(4He). Our statistics, about 5 × 105 of breakup events, provides a possibility to improve the precision of evaluated rates. The preliminary results: B(3He)=720 ± 70 s–1, B(4He)=415 ± 40 s–1 are compared to theoretical predictions and to previous experiments. 相似文献
46.
N.I. Voropaev D.V. Balin W.N. Breunlich T. Case K.M. Crowe H. Daniel V.A. Ganzha B. Gartner F.J. Hartmann P. Kammel S.M. Kozlov B. Lauss E.M. Maev V.E. Markushin Yu.A. Misko M. Mühlbauer C. Petitjean G.E. Petrov W. Prymas G.N. Schapkin W. Schott G.G. Semenchuk Yu.V. Smirenin V.A. Trofimov A.A. Vasiliev A.A. Vorobyov J. Zmeskal 《Hyperfine Interactions》1999,118(1-4):135-140
We present the results of precision measurements of dμ spin-flip rates in pure D2, in pure HD gas, and in the non-equilibrium and equilibrium H2+D2 gas mixtures. The experiments were performed at PSI in 1994-1996 using the high pressure ionization chamber from Gatchina
as a 100% efficient detector of the charged fusion products. The measurements have been carried out in the temperature range
28-300 K, at gas density of 5% of LHD. In pure deuterium, the measured temperature dependence of the spin-flip rate allowed
us to separate the two components (resonant and non-resonant) of the spin-flip processes. From the experiments in H/D mixtures
we have measured the non-resonant spin-flip rate in collisions of dμ-atoms with HD molecules. Comparison with the theory revealed considerable disagreement in the case of non-resonant spin-flip
in collisions of the dμ-atoms with D2 molecules.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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C. Petrascu S. Bianco A.M. Bragadireanu F.L. Fabbri C. Guaraldo M. Iliescu T.M. Ito V. Lucherini M. Bregant E. Milotti A. Vacchi E. Zavattini M. Augsburger D. Chatellard P. Knowles F. Mulhauser L.A. Schaller L. Schellenberg H. Schneuwly J.-P. Egger D. Varidel W.H. Breunlich M. Cargnelli B. Gartner R. King B. Lauss J. Marton J. Zmeskal T. Ponta S.N. Nakamura T. Koike R.S. Hayano M. Hori T. Ishikawa T. Ishiwatari M. Iwasaki Y. Akaishi G. Beer A.C. Sanderson R. Seki 《Hyperfine Interactions》1999,118(1-4):53-57
The DEAR (DAΦNE Exotic Atom Research) experiment at the new φ-factory DAΦNE of Laboratori Nazionali di Frascati aims for a
1% measurement of the line shift of the K-complex due to strong interaction in kaonic hydrogen. This presentation is meant to prove that the high statistics and good
resolution obtainable with DEAR will be able to disentangle the kaonic hydrogen K-complex lines (a cascade unconstrained fit), obtaining in this way constraints for what concerns the cascade parameters and,
consequently, information regarding the physical processes involved in the kaonic hydrogen atomic cascade.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
49.
Tresch S. Ackerbauer P. Breunlich W. H. Cargnelli M. Chatellard D. Egger J. -P. von Egidy T. Fischer A. Gartner B. Hartmann F. J. Jacot-Guillarmod R. Jeannet E. Kammel P. King R. Kminek G. Lauss B. Marton J. Mühlbauer M. Mulhauser F. Petitjean C. Piller C. Prymas W. Schaller L. A. Schellenberg L. Schneuwly H. Steininger E. Thalmann Y. A. Werthmüller A. Zmeskal J. 《Hyperfine Interactions》1996,101(1):221-227
Muon transfer from hydrogen isotopes to helium is of importance in muon-catalyzed fusion and serves as a unique tool for the direct observation of the mesomolecular ion (pµHe)*. During two data-taking runs in 1994 and 1995 at PSI, measurements of the transfer from protium to helium were carried out using CCD's and Ge-diodes as independent X-ray detectors to obtain information on the time distribution and intensity of the 7 keV decay X-ray of the mesomolecular ion. Dual1H2 +4 He and triple1H2 + Ne +3,4He gas mixtures at low temperatures were investigated to extract transfer rates. Protium of high purity was available. For the first time a transfer rate from muonic protium to3He was measured. A general survey of our measurements and preliminary analysis is presented. 相似文献
50.
C. Petitjean D.V. Balin W.H. Breunlich T. Case K.M. Crowe H. Daniel M.P. Faifman V.A. Ganzha B. Gartner F.J. Hartmann P. Kammel S. Kozlov B. Lauss E.M. Maev V.E. Markushin Yu.A. Misko M. Mühlbauer G.E. Petrov W. Prymas G.N. Schapkin W. Schott G.G. Semenchuk Yu.V. Smirenin V.A. Trofimov A.A. Vasiliev A.A. Vorobyov N.I. Voropaev J. Zmeskal 《Hyperfine Interactions》1999,118(1-4):127-133
We present the results of an experiment performed at PSI to investigate muon catalyzed fusion in pure deuterium gas of 5%
density (LHD) at temperatures ranging from 28 K to 350 K. Using a new high pressure ionization chamber the reactions dd → n + 3He and dd → p+t were observed with 100% detection efficiency. The rates of dμd formation were measured with the absolute precision of 1% and the μd spin-flip rates with 0.5%. The temperature dependence of molecular formation and spin-flip rates display pronounced resonance
structures. A preliminary fit based on the Vesman mechanism of resonant muonic molecule formation was carried out yielding
a dd fusion rate of 3.5·108 s-1 and a hfs splitting energy
of 24.3 meV, both in good agreement with the theory.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献