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971.
R.E. Pollock V. Derenchuk X. Pei T. Sloan F. Sperisen H.-O. Meyer B. v. Przewoski T. Rinckel P. Pancella M.A. Ross W.K. Pitts 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1993,330(3):380-388
Measurements have been made in the Cooler ring at the Indiana University Cyclotron Facility (IUCF) of the mean lifetime of stored and electron-cooled proton beams in the presence of various target gas species at two ring locations differing in dispersion. A broad range of beam energy Tb, target atomic number Zt and thickness xt was employed. The loss (removal) cross sectionσL per target atom, extracted from the lifetime measurement, exhibits a minimum for small xt which is found to scale with
. This behavior is expected because forward Coulomb scattering from target nuclei should be the dominant loss mechanism under the conditions of measurement. A marked increase in σL for larger xt is attributed to emittance growth arising from multiple scattering in competition with the transverse cooling rate. Lattice dispersion at the target increases the contribution to beam heating by electrons in the target atoms and introduces an additional loss mechanism. From the measured σL and beam lifetime, a time cycle may be selected which gives the optimum time-averaged luminosity for a given experiment. Scaling of σL allows prediction of the optimum luminosity over the full operating regime of the cooling ring. 相似文献
972.
v. Braunschweig Müller-Using Nüsslein Rieck und Stahl 《Zeitschrift für Jagdwissenschaft》1971,17(1):43-48
Ohne Zusammenfassung 相似文献
973.
974.
975.
976.
977.
F. Schmidl L. Dörrer S. Wunderlich F. Machalett U. Hübner H. Schmidt S. Linzen H. Schneidewind N. v. Freyhold P. Seidel 《Journal of Low Temperature Physics》1997,106(3-4):405-416
We prepared ion beam modified microbridges based on thin sputtered or laser ablated YBCO films on SrTiO3 substrates. The microbridges with a width of 10 μm were irradiated through slits in a 700 nm thick double layer resist mask.
In our experiments we used O+ ions with an ion energy of 30 keV or 100 keV varying the dose between 1013 ions·cm−2 and 1014 ions·cm−2. We investigated the influence of film thickness and slit width on the superconducting properties of these junctions. We
show the temperature dependence of the junctions properties on microwave radiation or external magnetic fields. 相似文献
978.
The frequency of injuries of the urinary system which are very severe is as high as 4% of all the wounds of other localizations. The high frequency of associated injuries, critical states of the wounded give very short time for urological examinations which prevents making the exact diagnosis. Nephrectomy still remains the most common operative intervention for wounds of the kidneys (62.8%). The insufficient elimination of urine and inadequate drainage in wounds of the urinary bladder and urethra are followed by very severe complications. An analysis of the experience with treatment of wounds of the urinary system has shown that the medical evacuatory measures must be improved. 相似文献
979.
980.
Schleifer H. Ropp T.v.d. Hoffmann K. Reczek W. 《Solid-State Circuits, IEEE Journal of》1995,30(7):826-829
A radiation hard low power, low voltage dynamic memory is obtained by the use of a dummy cell concept. Compared to conventional dummy cell concepts, this concept applies a fully sized dummy cell. By optimizing the dummy cell precharge voltage for 5 V and 3 V operation and the timing of the dummy word-line, the overall soft error rate (SER) of the chip is improved by 2 orders of magnitude. An additional improvement of 1 order of magnitude is possible for 3 V operation by adjusting substrate bias and cell plate voltage. The results are verified by an accelerated SER measurement with a radium 226 source and an additional field soft error study 相似文献