Time: 9:00AM, June 12 2014
Speaker: Dr. Alireza Nassiri (ANL)
主持人：高杰研究员
地点：5#厅二楼会议室
Topic : Toward Cryogen-Free SRF Accelerators
Abstract: Studies on the application of magnesium diboride (MgB2) high-Tc superconducting films have shown promise for use with rf cavities. Studies are directed towards applying the films to niobium cavities with the goal to increase accelerating gradients to greater than 50 MeV/m. However, studies also have shown that MgB2 films, with a critical temperature over four times higher than Nb, have surface resistances equal, or nearly equal, at 8-12 K, to what is achieved with niobium at 4 K. Our current research is focused on depositing MgB2 films onto copper or other high-thermal-conductivity metal substrates, which would allow future cavities to be fabricated as film-coated copper structures. We have started high-pressure chemical vapor deposition and testing of thin film MgB2 on sapphire along with a feasibility study of atomic layer deposition of MgB2 on copper coupons.
Lecturer’s short bio: Alireza Nassiri is a Senior Physicist and the head of the Radio Frequency Department of the Advanced Photon Source (APS) at the Argonne National Laboratory. He did his PhD work in Physics at Texas University. He joined the Advanced Photon Source Project in 1989 as the lead physicist assigned to the design of the APS electron and positron linac systems and later on became a member of machine physics commissioning team for the APS booster synchrotron and storage ring. He was one of the principal investigators who proposed a novel idea of applying micro-fabrication techniques using X-ray lithography to develop novel high frequency structure and microwave undulator for accelerator and medical applications. He has made significant contributions in the development of novel electron sources for accelerator applications and free electron lasers. He is a regulator lecturer for the US Particle Accelerator School (USPAS). He has authored over 100 journal articles, conference papers and technical reports in accelerator physics, rf and microwave science and technology.
