| Paper | Title | Page |
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| MOPAN028 | Current Status of Virtual Accelerator at J-PARC 3 GeV Rapid Cycling Synchrotron | 215 |
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| We have developed the logical accelerator called "Virtual Accelerator" based on EPICS for 3 GeV Rapid Cycling Synchrotron (RCS) in J-PARC. The Virtual Accelerator has a mathematical model of the beam dynamics in order to simulate the behavior of the beam and enables the revolutionary commissioning and operation of an accelerator. Additionally, we have constructed the commissioning tool based on the Virtual Accelerator. We will present a current status of the Virtual Accelerator system and some commissioning tool. | ||
| MOPAN039 | Development of Hybrid Type Carbon Stripper Foils with High Durability at >1800K for RCS of J-PARC | 242 |
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| The Japan Proton Accelerator Research Complex (J-PARC) requires thick carbon stripper foils (250-500 ug/cm2) to strip electrons from the H- beam supplied by the linac before injection into the RCS of J-PARC. For this high-intensity H- beam and circulating bunch beam, which gives much damage to conventional carbon stripper foils. Thus carbon stripper foils with high durability at 1800K produced by energy deposition in the foil are indispensable for this accelerator. Recently, we have successfully developed hybrid type thick boron mixed carbon stripper foils (HBC-foil). Namely, the lifetime measurement of the foils was tested by using a 3.2 MeV, Ne+ DC beams of 2.5 uA, in which a significant amount of energy was deposited in the foils. The maximum lifetime was found to be extremely long, 30-and 250-times longer than those of Diamond and commercially available best carbon foils, respectively. The foils were also found to be free from any shrinkage, and to show an extremely low thickness reduction rate even at a high temperature of 1800K during long beam irradiation. In this conference the foil preparation procedures and lifetime measurements with a 3.2 MeV, Ne+ is presented. | ||
| MOPAN040 | Comparative Study on Lifetime of Stripper Foil using 650keV H- Ion Beam | 245 |
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Funding: This work is supported by the Japan Society for the Promotion of Science, under contract No. 18540303. Thick carbon stripper foils of >300 μg/cm2 will be used as a stripping of H-ion beam for 3GeV Rapid Cycling Synchrotron (3GeV-RCS) of the J-PARC. The carbon foils with long lifetime even at >1800 K are required. For this purpose, we have developed a new irradiation system for the lifetime measurement using high current pulsed and dc H- beams of the KEK Cockcroft-Walton accelerator. These high power 650keV H- Ion beams can simulate the high energy deposition in carbon stripper foils at the J-PARC RCS. An automatic data acquisition system is also developed for recording the data of foil temperature and irradiated beam current. The Hybrid Boron mixed Carbon (HBC) stripper foils, which are developed at KEK are irradiated by high current H- ion beam up to 2000 K. A few SNS-diamond and commercially available carbon (CM) foils are also tested for comparing with HBC-foils. The results of the lifetime measurement of HBC and SNS-diamond including CM stripper foils are reported. |
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| MOPAS081 | Spallation Neutron Source (SNS) Diamond Stripper Foil Development | 620 |
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Funding: SNS is managed by UT-Battelle, LLC, for the U. S. DOE under contract DE-AC05-00OR22725. DOE contract W-7405-ENG-36 (LANL) and Japan SPS contract 18540303 (KEK) supported work at those institutions. Diamond stripping foils are under development for the SNS. Free-standing, flat 350 microgram/cm2 foils as large as 17 x 25 mm have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; typical fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 12 microCoulombs of protons, approximately 40% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 Coulombs of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (650 keV H-) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils. |
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| TUPAN061 | Updated Simulation for the Nuclear Scattering Loss Estimation at the RCS Injection Area | 1526 |
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| We have updated the simulation for the realistic beam loss estimation at the RCS (Rapid Cycling Synchrotron) injection area of J-PARC(Japan Proton Accelerator Research Complex). At the injection area, beam loss caused by the nuclear scattering together with the multiple coulomb scattering at the charge-exchange foil is the dominant one and is an important issue for designing mainly the foil thickness and other beam elements like, the falling time of bump magnets after the injection is finished and so on. The simulation tool GEANT for the scattering effect and the real injection process have been employed together in order to estimate the beam loss turn by turn including identification of loss points too. | ||
| FRPMN047 | Development of a Beam Induced Heat-Flow Monitor for the Beam Dump of the J-PARC RCS | 4084 |
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| A beam induced heat-flow monitor (BIHM) will be installed in front of the beam dump of the RCS (Rapid Cycling Synchrotron) at J-PARC (Japan Particle Accelerator Research Complex), where a power limitation of the beam dump is 4 kW. The purposes of this monitor are to observe a beam current injected into the beam dump and to generate an alarm signal for the main control system of the RCS. At the BIHM the beams penetrate a carbon plate of 1.5 mm in thickness, where the plate is supported by four rods on the monitor chamber. The heat generated by the interactions between the beam and the carbon plate propagates to the outer edge of the plate, and then to the monitor chamber through the four rods. By measuring the temperature differences between upstream and downstream ends of each rod, the total heat flow can be measured. The beam current can be determined by the measured heat flow with the help of the calculated stopping power of a proton in a carbon material. The design of the BIHM and test results of a prototype will be described. |