主持人：刘四明教授

时间：2022年3月25日14：00-17：25

地点：犀浦校区1号教学楼1403

　　 ZOOM会议号: 89024476958 会议密码123456

（会议链接: https://ihep-ac-cn.zoom.us/j/89024476958?）

题目：Plasma fluctuations in the intergalactic medium

主讲人：Reinhard Schlickeiser, Ruhr University Bochum, Germany

摘要：The diffusive propagation of nonrelativistic cosmic ray (CR) protons undergoing energy losses by ionization in a dense homogeneous infinitely extended interstellar molecular cloud (MC) is investigated. The steady-state transport equation for the differential number density of nonrelativistic CR protons is solved with the boundary condition that at the edge of cloud it agrees with the interstellar CR number density. It is shown that giant interstellar MCs with column depths much greater than about 7 ·1022 cm−2 are an efficient sink of nonrelativistic CRs. At small penetration depths the CRs lose energy by ionizing and heating the molecular gas, whereas at large penetration depths they are collectively dissipated by the streaming instability, which transfers one-half of the energy density of the incoming interstellar nonrelativistic CRs to Alfvenic magnetic field turbulence.