Recently,the first gas generator-turbopump joint test for the 500-ton LOX/kerosene engine was completed with success.The engine developed independently by the Academy of Aerospace Liquid Propulsion Technology（AALPT）...Recently,the first gas generator-turbopump joint test for the 500-ton LOX/kerosene engine was completed with success.The engine developed independently by the Academy of Aerospace Liquid Propulsion Technology（AALPT）will be used for the heavy-lift rocket.The 500-ton LOX/kerosene engine has the thrust of the largest ever developed by China and in the foreseeable future.展开更多
A low background thermal neutron flux detection system has been designed to measure the ambient thermal neutron flux of the second phase of the China Jinping Underground Laboratory（CJPL-Ⅱ）,right after completion of...A low background thermal neutron flux detection system has been designed to measure the ambient thermal neutron flux of the second phase of the China Jinping Underground Laboratory（CJPL-Ⅱ）,right after completion of the rock bolting work.A ~3He proportional counter tube combined with an identical ~4He proportional counter tube was employed as the thermal neutron detector,which has been optimised in energy resolution,wall effect and radioactivity of construction materials for low background performance.The readout electronics were specially designed for long-term stable operation and easy maintenance in an underground laboratory under construction.The system was installed in Lab Hall No.3 of CJPL-Ⅱ and accumulated data for about 80 days.The ambient thermal neutron flux was determined under the assumption that the neutron field is fully thermalized,uniform and isotropic at the measurement position.展开更多
文摘Recently,the first gas generator-turbopump joint test for the 500-ton LOX/kerosene engine was completed with success.The engine developed independently by the Academy of Aerospace Liquid Propulsion Technology（AALPT）will be used for the heavy-lift rocket.The 500-ton LOX/kerosene engine has the thrust of the largest ever developed by China and in the foreseeable future.
基金Supported by National Natural Science Foundation of China(11475094)
文摘A low background thermal neutron flux detection system has been designed to measure the ambient thermal neutron flux of the second phase of the China Jinping Underground Laboratory（CJPL-Ⅱ）,right after completion of the rock bolting work.A ~3He proportional counter tube combined with an identical ~4He proportional counter tube was employed as the thermal neutron detector,which has been optimised in energy resolution,wall effect and radioactivity of construction materials for low background performance.The readout electronics were specially designed for long-term stable operation and easy maintenance in an underground laboratory under construction.The system was installed in Lab Hall No.3 of CJPL-Ⅱ and accumulated data for about 80 days.The ambient thermal neutron flux was determined under the assumption that the neutron field is fully thermalized,uniform and isotropic at the measurement position.
