Neutron energy spectrometry diagnosis plays an important role in magnetic con- finement fusion. A new neutron time-of-flight （TOF） spectrometer with double scintillators is designed and optimized for the EAST toknma...Neutron energy spectrometry diagnosis plays an important role in magnetic con- finement fusion. A new neutron time-of-flight （TOF） spectrometer with double scintillators is designed and optimized for the EAST toknmak. A set of optimM parameters is obtained by Monte Carlo simulation, based on the GEANT4 and ROOT codes. The electronic setup of the measurement system is designed. The count rate capability is increased by introducing a flash ADC. The designed spectrometer with high resolution and efficiency is capable of being applied to fusion neutron diagnostics. Applications in mixed-energy and continuous energy neutron fields can also be considered.展开更多
Neutron emission in EAST was investigated by a time-resolved monitor system which consists of four 3He proportional counters and a 235U fission chamber. The D-D neutron flux increased approximately an order of magnitu...Neutron emission in EAST was investigated by a time-resolved monitor system which consists of four 3He proportional counters and a 235U fission chamber. The D-D neutron flux increased approximately an order of magnitude during the 27 MHz ion-cyclotron radio frequency （ICRF） heating, demonstrating that the ICRF wave heated the plasma effectively. In addition in lower hybrid wave （LHW） experiment with higher plasma parameters D-D neutrons were also detected. However, masses of photoneutrons were generated in Ohmic discharges with low plasma density. Effect of plasma density on the production of photoneutrons was studied, and it is found that LHW can suppress the generation of the runaway electrons and reduce the share of the photoneutrons effectively.展开更多
基金supported by the State Key Development Program for Basic Research of China(Nos.2008CB717803,2009GB107001,and2007CB209903)the Research Fund for the Doctoral Program of Higher Education of China(No.200610011023)the National Natural Science Foundation of China(No.10875002)
文摘Neutron energy spectrometry diagnosis plays an important role in magnetic con- finement fusion. A new neutron time-of-flight （TOF） spectrometer with double scintillators is designed and optimized for the EAST toknmak. A set of optimM parameters is obtained by Monte Carlo simulation, based on the GEANT4 and ROOT codes. The electronic setup of the measurement system is designed. The count rate capability is increased by introducing a flash ADC. The designed spectrometer with high resolution and efficiency is capable of being applied to fusion neutron diagnostics. Applications in mixed-energy and continuous energy neutron fields can also be considered.
基金supported by the Key Program of the National Natural Science Foundation of China (No. 10775041)the National Magaetic Confinement Fusion Science Program of China (Nos. 2010GB106000, 2010GB106004)
文摘Neutron emission in EAST was investigated by a time-resolved monitor system which consists of four 3He proportional counters and a 235U fission chamber. The D-D neutron flux increased approximately an order of magnitude during the 27 MHz ion-cyclotron radio frequency （ICRF） heating, demonstrating that the ICRF wave heated the plasma effectively. In addition in lower hybrid wave （LHW） experiment with higher plasma parameters D-D neutrons were also detected. However, masses of photoneutrons were generated in Ohmic discharges with low plasma density. Effect of plasma density on the production of photoneutrons was studied, and it is found that LHW can suppress the generation of the runaway electrons and reduce the share of the photoneutrons effectively.
