Importance of limiting hohlraum leaks at cryogenic temperatures on NIF targets  

作　　者：Suhas Bhandarkar Nick Teslich Ben Haid Evan Mapoles Suhas Bhandarkar Nick Teslich Ben Haid Evan Mapoles(Lawrence Livermore National Laboratory)

机构地区：[1]Lawrence Livermore National Laboratory

出　　处：《High Power Laser Science and Engineering》2017年第3期41-48,共8页高功率激光科学与工程（英文版）

摘　　要：Inertial confinement fusion targets are complex systems designed to allow fine control of temperature and pressure for making precise spherical ice layers of hydrogen isotopes at cryogenic temperatures. We discuss the various technical considerations for a maximum leak rate based on heat load considerations. This maximum flow rate turns out to be 5 x 10-6 standard cc per second, which can be caused by an orifice less than half a micron in diameter. This makes the identification of the location and resolution of the leak a significant challenge. To illustrate this, we showcase one example of a peculiar failure mode that appeared suddenly but persisted whereby target production yield was severely lowered. Identification of the leak source and the root cause requires very careful analysis of multiple thermomechanical aspects to ensure that the end solution is indeed the right remedy and is robust.Inertial confinement fusion targets are complex systems designed to allow fine control of temperature and pressure for making precise spherical ice layers of hydrogen isotopes at cryogenic temperatures. We discuss the various technical considerations for a maximum leak rate based on heat load considerations. This maximum flow rate turns out to be 5×10^(-6) standard cc per second, which can be caused by an orifice less than half a micron in diameter. This makes the identification of the location and resolution of the leak a significant challenge. To illustrate this, we showcase one example of a peculiar failure mode that appeared suddenly but persisted whereby target production yield was severely lowered. Identification of the leak source and the root cause requires very careful analysis of multiple thermomechanical aspects to ensure that the end solution is indeed the right remedy and is robust.

关 键 词：CRYOGENIC leak rate target 

分 类 号：TL632[核科学技术—核技术及应用] TN249[电子电信—物理电子学]