One of the most important devices for the High Energy Photon Source Test Facility project,the 2.6 T 32-pole 3W1 superconducting wiggler,was designed by the Institute of High Energy Physics(IHEP);its magnetic gap is 68...One of the most important devices for the High Energy Photon Source Test Facility project,the 2.6 T 32-pole 3W1 superconducting wiggler,was designed by the Institute of High Energy Physics(IHEP);its magnetic gap is 68 mm,and its storage energy is 286 kJ.It will be installed at the storage ring of the Beijing Electron Positron Collider Upgrade Project at the IHEP to replace the old permanent wiggler.The primary purpose of the cryostat is to create a safe and reliable system and realize long-term operation with zero liquid helium consumption.To maintain liquid helium temperature,four identical two-stage cryocoolers are placed symmetrically at the wiggler ends.The cryostat has only one 60 K thermal shield,which is used to reduce the heat load to the liquid helium vessel.The cryostat has several novel features,including a suspension system with little heat leakage that is self-centered during cooling of the cryostat,a special copper liner and high-efficiency condensers,three pairs of binary current leads,and three-level safety design.The cryogenic system has been cooled three times,and the residual cooling capacity is approximately 0.41 W at 4.2 K without current.展开更多
Wire position monitor(WPM)is designed to monitor contraction of the cold masses during the cooling-down operation in an accelerator driven system.Because of material difference,machining error,assembly error,etc.,each...Wire position monitor(WPM)is designed to monitor contraction of the cold masses during the cooling-down operation in an accelerator driven system.Because of material difference,machining error,assembly error,etc.,each WPM has to be calibrated.The sensing voltage and wire position are of a nonlinear relationship,which is expressed by high order polynomial.Root mean square(RMS)of the polynomial fitting error were 3.8μm and 7.4μm at x and y directions,respectively.The alignment test was carried out on the beta cryostat.Optical instruments were used to verify the WPM measuring results.The differences between WPM measuring results and optical measurements were 0.044 and 0.05 mm in x and y direction,respectively.A significant asymmetric contraction was detected,and asymmetry of material was taken as the main reason through analysis.展开更多
JT-60SA is a fully superconducting coil tokamak upgraded from the JT-60U. This paper focused on the integrity of the top lid of cryostat in JT-60SA. The design requirement for the cryostat in normal operations is to a...JT-60SA is a fully superconducting coil tokamak upgraded from the JT-60U. This paper focused on the integrity of the top lid of cryostat in JT-60SA. The design requirement for the cryostat in normal operations is to achieve vacuum insulation of 10-1 Pa, and the top flange of the top lid is lightly welded onto its body flange. The weld is tensile-loaded by bending deformation of the top lid due to vacuum pressure of external 0.1 MPa. This weld integrity is evaluated with tensile-load reduction, which results in clamp reinforcement. The structural integrity of the top lid is validated.展开更多
A suitable simple optical cryostat for optical, magneto-optical, electrical and thermo-electrical measurements was designed. It is suitable for use in a magnetic pool gap as narrow as less than 1 cm. Throughout a long...A suitable simple optical cryostat for optical, magneto-optical, electrical and thermo-electrical measurements was designed. It is suitable for use in a magnetic pool gap as narrow as less than 1 cm. Throughout a long period of time, the heat diffusion process of the cryostat can be easily operated at slow increase in sample temperature in a range 1.25 K/min at 200 K that will be reduced gradually to 0.66 K at room temperature. Liquid nitrogen was used to cool down the temperature. During the operation, the change in the measured energy gap of a semiconductor sample and other physical parameters resulting from the change of temperature can be corrected through the temperature coefficient of that parameter at the corresponding temperature. The cryostat was successfully used for all experiments mentioned above to measure the properties of a single crystal of GaP (Gallium Phosphate) semiconductor.展开更多
A 3W1 superconducting wiggler(SCW)with the pole gap of 68 mm was successfully tested and installed in a BEPC II storage ring in November,2019.The goal of zero liquid helium consumption was achieved,and the cryogenic s...A 3W1 superconducting wiggler(SCW)with the pole gap of 68 mm was successfully tested and installed in a BEPC II storage ring in November,2019.The goal of zero liquid helium consumption was achieved,and the cryogenic system exhibited a 12%residual cooling capacity(approximately 0.69 W@4.2 K).The 3W1-SCW was set to operate at 2.49 T and has been operating for more than seven months.Three instances of magnet quenching occurred during the normal operation.The evaporated helium gas can be recycled to the helium gas recycling system when the pressure in the helium tank is higher than the parameter value(the setpoint of the pressure value is 1.2 bara).The cryogenic system can be recovered within 4 h if sufficient liquid helium is available to inject into the cryostat.展开更多
基金supported by the High Energy Photon Source Test Facility(HEPS-TF)project。
文摘One of the most important devices for the High Energy Photon Source Test Facility project,the 2.6 T 32-pole 3W1 superconducting wiggler,was designed by the Institute of High Energy Physics(IHEP);its magnetic gap is 68 mm,and its storage energy is 286 kJ.It will be installed at the storage ring of the Beijing Electron Positron Collider Upgrade Project at the IHEP to replace the old permanent wiggler.The primary purpose of the cryostat is to create a safe and reliable system and realize long-term operation with zero liquid helium consumption.To maintain liquid helium temperature,four identical two-stage cryocoolers are placed symmetrically at the wiggler ends.The cryostat has only one 60 K thermal shield,which is used to reduce the heat load to the liquid helium vessel.The cryostat has several novel features,including a suspension system with little heat leakage that is self-centered during cooling of the cryostat,a special copper liner and high-efficiency condensers,three pairs of binary current leads,and three-level safety design.The cryogenic system has been cooled three times,and the residual cooling capacity is approximately 0.41 W at 4.2 K without current.
基金Supported by the Project of Injector I Mechanical&Technical Support System
文摘Wire position monitor(WPM)is designed to monitor contraction of the cold masses during the cooling-down operation in an accelerator driven system.Because of material difference,machining error,assembly error,etc.,each WPM has to be calibrated.The sensing voltage and wire position are of a nonlinear relationship,which is expressed by high order polynomial.Root mean square(RMS)of the polynomial fitting error were 3.8μm and 7.4μm at x and y directions,respectively.The alignment test was carried out on the beta cryostat.Optical instruments were used to verify the WPM measuring results.The differences between WPM measuring results and optical measurements were 0.044 and 0.05 mm in x and y direction,respectively.A significant asymmetric contraction was detected,and asymmetry of material was taken as the main reason through analysis.
文摘JT-60SA is a fully superconducting coil tokamak upgraded from the JT-60U. This paper focused on the integrity of the top lid of cryostat in JT-60SA. The design requirement for the cryostat in normal operations is to achieve vacuum insulation of 10-1 Pa, and the top flange of the top lid is lightly welded onto its body flange. The weld is tensile-loaded by bending deformation of the top lid due to vacuum pressure of external 0.1 MPa. This weld integrity is evaluated with tensile-load reduction, which results in clamp reinforcement. The structural integrity of the top lid is validated.
基金Project (No. 3/2/5638) support by the University of Salahaddin in Arbil, Iraqi Kurdistan, Iraq
文摘A suitable simple optical cryostat for optical, magneto-optical, electrical and thermo-electrical measurements was designed. It is suitable for use in a magnetic pool gap as narrow as less than 1 cm. Throughout a long period of time, the heat diffusion process of the cryostat can be easily operated at slow increase in sample temperature in a range 1.25 K/min at 200 K that will be reduced gradually to 0.66 K at room temperature. Liquid nitrogen was used to cool down the temperature. During the operation, the change in the measured energy gap of a semiconductor sample and other physical parameters resulting from the change of temperature can be corrected through the temperature coefficient of that parameter at the corresponding temperature. The cryostat was successfully used for all experiments mentioned above to measure the properties of a single crystal of GaP (Gallium Phosphate) semiconductor.
基金supported in part by the High Energy Photon Source Test Facility and the Key Laboratory of Particle Acceleration Physics and Technology, Institute of High Energy Physics, Chinese Academy of Sciences
文摘A 3W1 superconducting wiggler(SCW)with the pole gap of 68 mm was successfully tested and installed in a BEPC II storage ring in November,2019.The goal of zero liquid helium consumption was achieved,and the cryogenic system exhibited a 12%residual cooling capacity(approximately 0.69 W@4.2 K).The 3W1-SCW was set to operate at 2.49 T and has been operating for more than seven months.Three instances of magnet quenching occurred during the normal operation.The evaporated helium gas can be recycled to the helium gas recycling system when the pressure in the helium tank is higher than the parameter value(the setpoint of the pressure value is 1.2 bara).The cryogenic system can be recovered within 4 h if sufficient liquid helium is available to inject into the cryostat.
