Primary Research Of ILC Positron Source Target Cooling Technology Using Sliding Contact Cooling

The positron source for ILC(International Linear Collider), based on the undulator function, is the key component of the facility. High-energy gamma photon beam impinges on the rotating target to generate large number of positrons. There is more than 23 kw thermo-power deposited in rotating target during the process. To solve this problem, Argonne National Laboratory in the United States put forward a new idea that by using sliding contact pads to cool ILC positron target. But this idea demands the feasibility of validation.According to Argonne Laboratory proposed the idea and design a primary design to cool rotating positron source target. So the purpose of this paper is to explore whether the scheme have enough to take away deposited energy of rotating positron source target. Initially, this paper introduces the basic principle about sliding contact cooling. By using this principle to design a prototype and verify this plan. In order to tackle this issue, the following steps are needed, firstly building a model based on the prototype and making use of one-dimensioned and multiple-layered heat transfer theory to calculate the cooling process. The calculation of results showed that this cooling method can meet the design requirements. Secondly, Finite element model of cooling system was built and use it to analyze heat transfer process of rotating target system. From two different simulation results about temperature distribution of cool and non-cool rotating target, which indicated that this simplified device non-cooltarget, which indicated that this simplified device have enough ability to cool rotating target. At the same time, it also confirmed that using sliding contact cooling can take away deposited energy from rotating target.In order to futher verify the cooling scheme. According to the simulation parameters and results, we came up with four different heat sources(direct heating source, convection heating source, frictional heating source, eddy heating source)to apply in the rotating target surface, and then observed the temperature distribution of rotating target in the experiments. Cooling and non-cooling comparison figures based on frictional heating source showed that the scheme can take away the heat source and additional frictional heat source. So, it can realize to cool rotating target. Meanwhile, Cooling and non-cooling comparison figures based on eddy heating source showed that the scheme can take away the heat source. So the results of experiments further proved that primary design can achieve the effect of cooling, which also confirmed that the cooling technology using sliding contact cooling is feasibility and effectiveness.