Paper | Title | Page |
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THPMN030 | Enhancement of the Positron Intensity by a Tungsten Single Crystal Target at the KEKB Injector Linac | 2778 |
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Funding: This work was supported by the Grant-in-Aid of Ministry of Education, Culture, Sports, Science and Technology of Japan and by the grant of Ministry of Education and Science of the Russian Federation. A new tungsten single-crystalline positron target has been successfully employed for generation of the intense positron beam at the KEKB injector linac in September 2006. The target is composed of a tungsten single-crystal with a thickness of 10.5 mm. The positron production target is bombarded at an incident electron energy of 4 GeV, and the produced positrons are collected and accelerated up to the final injection energy of 3.5 GeV in the succeeding sections. A conventional tungsten plate with a thickness of 14 mm has been used previously, and the conversion efficiency (Ne+/Ne-), the ratio between the number of positrons (Ne+) captured in the positron capture section and the number of the incident electrons (Ne-), was 0.20 on average. By replacing the tungsten plate with the tungsten crystal, it increased to 0.25 on average. The increase of the conversion efficiency has boosted the positron intensity to its maximum since the beginning of KEKB operation in 1999. Now this new positron source is stably operating and is contributing to increasing the integrated luminosity of the KEKB B-factory. |
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THPAN044 | Global COD Correction of SAGA-LS Storage Ring | 3327 |
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SAGA Light Source is a medium size light source which has been operated from February, 2006. The stored beam orbit has been corrected by a closed orbit correction system consisted of 24 beam position monitors, 40 steering magnets and PC-LabView based control system. The singular value decomposition method has been applied for the global COD correction by using a measured response matrix. As a result, the standard deviation of the orbit error around the ring was reduced to 20 micro-meters both for horizontal plane and for vertical plane, respectively. |