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11.
Micromegas prototypes with thermo-bond film separators 总被引:1,自引:0,他引:1
In this paper we report the results of Micromegas prototypes constructed by attaching micromesh to an anode using thermo-bond films. The excellent metal attaching ability and good dielectical property of this kind of film make it a promising material to be used as avalanche gap spacers. Several prototypes are successfully made. The electron transmission properties are first studied and then the gas gain is measured in argon-isobutane mixtures. The maximum gain of more than 104 is easily obtained. The energy resolutions for 55Fe 5.9 keV Kα ray can be better than 20% over one magnitude in gain for different operational gas mixtures and the best energy resolution of 13.7% (FWHM) can be achieved with the gas mixture of 94% argon concentration. The preliminary test results of the prototypes with sensitive area of 45 mm×45 mm without internal support show good uniformity across the sensitive area. 相似文献
12.
R. Albrecht T. C. Awes C. Baktash P. Beckmann F. Berger R. Bock G. Claesson G. Clewing L. Dragon R. L. Ferguson A. Franz S. Garpman R. Glasow H. ?. Gustafsson H. H. Gutbrod K. H. Kampert B. W. Kolb P. Kristiansson I. Y. Lee H. L?hner I. Lund F. E. Obershain A. Oskarsson I. Otterlund T. Peitzmann S. Persson F. Plasil A. M. Poskanzer M. Purschke H. G. Ritter R. Santo H. R. Schmidt T. Siemiarczuk S. P. S?rensen E. Stenlund G. R. Young WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,47(3):367-375
The production of neutral pions by the interaction of 200A·GeV p and16O projectiles with a Au target has been studied in the pseudorapidity range 1.5≦η≦2.1. Transverse momentum spectra have been measured between 0.4 GeV/c and 3.6 GeV/c and their dependence on the centrality of the collision has been investigated. The peripheral-collision spectra display a marked change of slope with a hard component starting at about 1.8 GeV/c, in contrast to central-collision data. The data are discussed in comparison to p+p and α+α data from the ISR. 相似文献
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R. Albrecht T. C. Awes C. Baktash P. Beckmann G. Claesson F. Berger R. Bock L. Dragon R. L. Ferguson A. Franz S. Garpman R. Glasow H. ?. Gustafsson H. H. Gutbrod K. H. Kampert B. W. Kolb P. Kristiansson I. Y. Lee H. L?hner I. Lund F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann S. Persson F. Plasil A. M. Poskanzer M. Purschke H. G. Ritter R. Santo H. R. Schmidt T. Siemiarczuk S. P. Sorensen E. Stenlund G. R. Young WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,38(1):109-115
Target remnants withZ<3 from proton-nucleus and16O-nucleus reactions at 60 and 200 GeV/nucleon were measured in the angular range from 30° to 160° (?1.7<η<1.3) employing the Plastic Ball detector. The excitation energy of the target spectator matter in central oxygen-induced collisions is found to be high enough to allow for complete disintegration of the target nucleus into fragments withZ<3. The average longitudinal momentum transfer per proton to the target in central collisions is considerably higher in the case of16O-induced reactions (≈300 MeV/c) than in proton-induced reactions (≈130 MeV/c). The baryon rapidity distributions are roughly in agreement with one-fluid hydrodynamical calculations at 60 GeV/nucleon16O+Au but are in disagreement at 200 GeV/nucleon, indicating the higher degree of transparency at the higher bombarding energy. Both, the transverse momenta of target spectators and the entropy produced in the target fragmentation region are compared to those attained in head-on collisions of two heavy nuclei at Bevalac energies. They are found to be comparable or do even exceed the values for the participant matter at beam energies of about 1–2 GeV/nucleon. 相似文献
15.
R. Albrecht T. C. Awes C. Baktash P. Beckmann F. Berger R. Bock G. Claesson L. Dragon R. L. Ferguson A. Franz S. I. A. Garpman R. Glasow H. ?. Gustafsson H. H. Gutbrod J. W. Johnson K. -H. Kampert B. W. Kolb P. Kristiansson I. Y. Lee H. L?hner I. Lund F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann S. Persson F. Plasil A. M. Poskanzer M. Purschke H. G. Ritter R. Santo H. R. Schmidt T. Siemiarczuk S. P. Sorensen E. Stenlund G. R. Young WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,38(1):51-57
Charged particle multiplicity distributions and pseudo-rapidity density distributions from16O induced nuclear collisions at 200 and 60A GeV are presented. The data were taken, using a minimumbias trigger, with the WA80 set-up at the CERN SPS. In this presentation we focus on how the yield of charged particles depends on the projectile energy, the mass number of the target nucleus and the energy measured in a uranium-plastic sampling calorimeter covering angles close to zero degrees. The data are compared to simulations from the event generator FRITIOF. 相似文献
16.
We report a dye-encapsulated silica nanoparticle as a label, with the advantages of high fluorescence intensity, photostability, and biocompatibility, in conjunction with microarray technology for sensitive immunoassay of a biomarker, interleukin-6 (IL-6), on a microarray format. The tris(2,2'-bipyridyl)ruthenium(ii) chloride hexahydrate (Rubpy) dye was incorporated into silica nanoparticles using a simple one-step microemulsion synthesis. In this synthesis process, Igepal CA520 was used as the surfactant, therefore, no requirement of cosolvent during the synthesis and the particle size was reduced comparing to the commonly used Triton surfactant system. The nanoparticles are uniform in size with a diameter of 50 nm. The microarray fluorescent immunoassay approach based on dye-doped silica nanoparticle labels has high sensitivity for practical applications with a limit of detection for IL-6 down to 0.1 ng mL(-1). The calibration curve is linear over the range from 0.1 ng mL(-1) to 10 ng mL(-1). Furthermore, results illustrated that the assay is highly specific for IL-6 in the presence of range of cytokines or proteins. The RuDS dye-labeled nanoparticles in connection with protein microarrays show the promise for clinical diagnosis of biomarkers. 相似文献
17.
A newly developed interface coupling a CHN combustion device (elemental analyser 'EA') to an isotope ratio mass spectrometer is described and evaluated. The purpose of the device is to extend the dynamic range of delta(13)C and delta(15)N analysis from less than 2 orders of magnitude to more than 3 orders of magnitude. Carbon isotope ratio measurements of atropine as a model compound have been performed analysing between 1 μg to 5 mg C with acceptable to excellent precision (0.6 to 0.06 per thousand, delta-notation). The correction due to the blank signal is critical for sample amounts smaller than 4 μg C. The maximum sample weight is determined by the combustion capacity of the EA. Larger sample amounts are measured using dilution of a small part of the EA effluent with helium. The dilution mechanism works virtually free of isotope fractionation. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
18.
David G. Parker 《中国颗粒学报》2009,7(2)
This paper describes the operation and outcome of one of the United Kingdom's largest multi-partner research activities in nanoparticles.The research covers the discovery and development of organic and inorganic crystals/nanoparticles,nanoparticle properties towards specific product applications,The research also encompassed bespoke measurement technology for nanoparticles and structure interactions.Significant research outcomes are summarised.The paper illustrates the advantages from industrially motivated research and value of collective action between a broad group of researchers in a nation. 相似文献
19.
D. Allasia C. Angelini A. Baldini L. Bertanza F. Bianchi A. Bigi F. Bobisut A. Borg P. Capiluppi R. Cirio J. Derkaoui M. L. Faccini-Turluer A. G. Frodesen D. Gamba G. Giacomelli B. Jongejans G. Mandrioli A. Margiotta-Neri A. Marzari-Chiesa R. Pazzi L. Patrizii C. Petri F. Predieri A. Romero A. M. Rossi A. Sconza P. Serra-Lugaresi M. Spurio A. G. Tenner G. W. van Apeldoorn P. H. A. van Dam N. A. M. van Eijndoven D. Vignaud WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,37(4):527-533
Bose-Einstein correlations between pions of equal charge have been observed in Charged Current and Neutral Current (anti)neutrino-deuterium interactions in the BEBC bubble chamber exposed to the SPS wide band beam. The pion emission region is found to be essentially spherical with a mean radius of (0.48±0.07) fm; the chaoticity parameter is 0.36±0.04. 相似文献
20.
M. Bonesini E. Bonvin P. S. L. Booth R. Bopp L. J. Carroll A. J. Cass D. Cavalli S. U. Chung G. Costa M. Donnat P. A. Dorsaz E. Durieux M. E. J. Feliks J. R. Fischer L. Fluri F. Gianotti S. Jack J. N. Jackson M. Kelly M. N. Kienzle-Focacci R. Lucock J. G. Lynch L. Mandelli M. Martin L. Mathys A. Maxwell M. Mazzanti P. J. Negus L. Perini D. Perrin G. Polesello R. Poultney W. H. Range L. Rosselet S. W. Snow A. S. Thompson R. M. Turnbull M. Werlen WA -Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,42(4):527-532
The inclusive cross sections for η production by the interactions of 280 GeV/c momentum π?, π+, and proton beams in hydrogen have been measured. The kinematical range covered is ?0.45<x F <0.45, and 4.0<P T <7.0 GeV/c for Feynmanx F and transverse momentum respectively. The η to π0 cross section ratios are given for the three reactions. The ratio of π? p to π+ p cross sections for η production in the above kinematic ranges is 1.22±0.08±0.11. 相似文献