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Design of High-power Graphene Beam Window
| Content Provider | Semantic Scholar |
|---|---|
| Author | Wang, Haijing Jing, Hantao Qu, Huamin Tang, Jingyu |
| Copyright Year | 2018 |
| Abstract | Beam window is a key device in high-intensity hadron beam applications, and it is usually used to separate air or other gas environments in the end of beam vacuum duct. Compared with the usually-used window materials such as Inconel alloy, Aluminum alloy and so on, the graphene has extremely high thermal conductivity, high strength and high transparency to high-energy ions. With the maturation of large-size graphene manufacturing technology, we have studied this new-type window for MW-class proton beam. The thermal analyses by the theoretical formula and simulations based on FEA are presented in this paper. Simultaneously, the scattering effect and the lifetime are also discussed. The preliminary results are promising. The same material can also be possibly applied to other devices such as charge-exchange stripping foils, beam monitors and so on. INTRODUCTION For high-power hadron beam applications such as spallation neutron sources, accelerator-driven systems, beam window is a key device. It separates the high vacuum region in the accelerator from air or other gas environments. The beam passes through the window to impinge the target or beam dump. The commonly-used materials of hadron beam window are aluminum alloy, Inconel alloy and so on. For a beam dump window usually with reduced beam power, the cooling method can be air cooling [1]. However for the window in front of the target, the main cooling method is water cooling, though different cooling structures can be used according to beam power, such as surface cooling at SNS and J-PARC [2-3], side cooling at CSNS [4], and multi-pipe cooling at ESS and C-ADS [5-6]. Table 1 lists some window designs. Table 1: Beam Windows for Some Accelerators Location Material Cooling structure Beam power (MW) CSNS A5083 Side cooling 0.1 SNS Inconel718 Surface cooling 1.0 J-PARC A5083 Surface cooling 1.0 ISIS Inconel718 Surface cooling 0.16 ESS A6061-T6 Multi-pipe cooling 5 C-ADS A6061-T6 Multi-pipe cooling 15 As high power accelerators are developing rapidly, there are much stricter requirements on the hadron beam window. Important concerned issues include cooling, scattering effect, radiation damage, mechanical strength and so on, especially cooling. Therefore, it is important to find new types of materials to solve these problems. In this paper, graphene is introduced and studied as a candidate material for multiple-MW beam power, as it has extremely high thermal conductivity [7], high strength [8], high transparency to high-energy ions [9] and impermeability for gases including helium [10]. The study will show that the temperature in a graphene window is so low that there is no need for cooling water even for MW-class beams, and the scattering effect can also be neglected due to its very thin structure. Besides, the radiation damage effect in term of DPA (displacement per atom) is calculated and the lifetime is discussed. THERMAL AND STRESS ANALYSES OF GRAPHENE WINDOW The thermal conductivity of monolayer graphene can reach 4840-5300 W/(m. C) at room temperature [7] which outperforms the conventional window materials. Thermal analyses are performed to demonstrate the splendid thermal properties of a graphene window. Suppose a proton beam of 1.6 GeV in energy and 10 MW in beam power and 60 mm 60 mm in beam size with a uniform distribution is used. The window is air cooled on one side. For a graphene window of a square foil, the temperature distribution can be calculated using the method of separation of variables. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://accelconf.web.cern.ch/AccelConf/IPAC2014/papers/mooca03.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Air cooling Aluminum Hydroxide 40 MG/ML / Magnesium Hydroxide 40 MG/ML / Simethicone 4 MG/ML Oral Suspension Aluminum measurement Biologic Development Computer cooling Cool - action Differential Thermal Analysis Displacement mapping Durable power of attorney F9 EMBRYONIC ANTIGEN GENE Federal enterprise architecture Foil Device Component Gases Graphene Helium ISIS Ions Metal Ceramic Alloys Microsoft Windows Microwave Neutrons Numerous Phase II/III Trial Proton-Translocating ATPases Protons Psychologic Displacement Radiation Damage Requirement Simulation Thermal Conductivity Water cooling |
| Content Type | Text |
| Resource Type | Article |
