60 research outputs found
Studies and application of bent crystals for beam steering at 70-GeV IHEP accelerator
This report overviews studies accomplished in the U70 proton synchrotron of
IHEP-Protvino during the recent two decades. Major attention is paid to a
routine application of bent crystals for beam extraction from the machine. It
has been confirmed experimentally that efficiency of beam extraction with a
crystal deflector of around 85% is well feasible for a proton beam with
intensity up to 1012 protons per cycle. Another trend is to use bent crystals
for halo collimation in a high energy collider. New promising options emerge
for, say, LHC and ILC based on the "volume reflection" effect, which has been
discovered recently in machine study runs at U70 of IHEP (50 GeV) and SPS of
CERN (400 GeV).Comment: 12 pages, 14 figure
Crystal collimation experiment on 70-GeV proton accelerator
The first proof-of-principle experiment on "crystal collimation" was performed with 70-GeV protons on IHEP accelerator. A bent crystal installed in the ring as a primary element upstream of a collimator has reduced the radiation levels downstream in the accelerator by a factor of two. The measurements agree with Monte Carlo predictions
Proton Extraction from IHEP Accelerator Using Bent Crystals
IHEP Protvino has pioneered the wide practical use of bent crystals as
optical elements in high-energy beams for beam extraction and deflection on
permanent basis since 1989. In the course of IHEP experiments, crystal
channeling has been developed into efficient instrument for particle steering
at accelerators, working in predictable, reliable manner with beams of very
high intensity over years. Crystal systems extract 70 GeV protons from IHEP
main ring with efficiency of 85% at intensity of 1.E12, basing on multi-pass
mechanism of channeling proposed theoretically and realised experimentally at
IHEP. Today, six locations on the IHEP 70-GeV main ring of the accelerator
facility are equipped by crystal extraction systems, serving mostly for routine
applications rather than for research and allowing a simultaneous run of
several particle physics experiments, thus significantly enriching the IHEP
physics program. The long successful history of large-scale crystal
exploitation at IHEP should help to incorporate channeling crystals into
accelerator systems worldwide in order to create unique systems for beam
delivery. We report recent results from the research and exploitation of
crystal extraction systems at IHEP.Comment: Invited talk at the International workshop "Relativistic Channeling
and Related Coherent Phenomena", Frascati (Rome) 23-26 March 200
Observation of focusing of 400 GeV/c proton beam with the help of bent crystals
The results of observation and studies of focusing of 400 GeV/ c proton beam with the help of bent single crystals are presented. Two silicon crystals have been used in the measurements. The focal length of the first and second crystals is found to be 1.48 m and 0.68 m, respectively. The mean square size of the horizontal profile in the focus was 3.1 and 4.3 times as small as at the exit of the crystals
Analysis on the Issue of East Financial Integration
在1997年金融危机发生后,东亚各国和地区意识到过分依赖外国的资金存在着巨大的风险。因此,为了避免对外国资金的过分依赖防止危机再次发生,东亚各国和地区通过完善金融体系,加强金融合作以推进金融一体化。 在此背景下,本文对东亚金融的一体化程度做出分析。本文对东亚各国和地区金融一体化的必要前提:东亚货币金融合作,东亚各国和地区资本市场放松管制情况、各国和地区的资本流动以及各国和地区股票及债券市场的发展进行了定性分析和描述,同时对各国投资与储蓄的相关性、各国消费者通过金融市场分散风险的程度、各国股票市场以及各国债券市场与两大国际市场间的联系,对东亚各国和地区金融市场一体化程度进行了实证分析。本文的研...East Asia has realized that it has great risk to depend on the foreign capital, after 1997 financial crisis. East Asia tried to improve the financial system and strengthen financial cooperation, so as to avoid the recurrence of financial crisis. This thesis tries to address the issue of the financial integration of East Asia. First of all, the basis of financial integration of East Asia was anal...学位:经济学博士院系专业:经济学院国际贸易系_世界经济学号:2005140292
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