The world’s first 1.3 GHz cryomodule containing eight 9-cell superconducting radio-frequency (rf) cavities treated by medium-temperature furnace baking (mid-T bake) was developed at the Institute of High Energy Physi...
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The world’s first 1.3 GHz cryomodule containing eight 9-cell superconducting radio-frequency (rf) cavities treated by medium-temperature furnace baking (mid-T bake) was developed at the Institute of High Energy Physics, Chinese Academy of Sciences. The 9-cell cavities in the cryomodule achieved an unprecedented high average intrinsic quality factor (Q0) of 3.8×1010 at 16 MV/m and 3.6×1010 at 21 MV/m in the horizontal test. The cryomodule can operate stably up to a total continuous wave rf voltage greater than 193 MV, with an average cavity usable accelerating gradient of more than 23 MV/m. The results significantly exceed the specifications of Circular Electron Positron Collider and Dalian advanced light source and the other high repetition rate free electron laser facilities [linac Coherent Light Source II (LCLS-II), LCLS-II-high energy, Shanghai High Repetition Rate X-ray FEL and Extreme Light Facility, Shenzhen Superconducting Soft X-Ray Free Electron Laser, etc.]. There is evidence that the mid-T bake cavity may not require fast cooldown or long processing time in the cryomodule. This paper reviews the cryomodule performance and discusses some important issues in cryomodule assembly and testing.
The CW RF test of 1.3 GHz 9-cell cavity in liquid helium bath at 2 K is a very important key point in the cavity procurement. Some problems can be found through the test, according which to optimized and improve the p...
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World’s first 1.3 GHz cryomodule containing eight 9-cell superconducting radio-frequency (RF) cavities treated by medium-temperature furnace baking (mid-T bake) was developed, assembled and tested at IHEP for the Dal...
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Cardiotocography (CTG) is the basic method of monitoring foetal condition in the perinatal period. However, due to the limited insight into the CTG generation mechanism, some CTG recordings can be mistreated as a pred...
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Cardiotocography (CTG) is the basic method of monitoring foetal condition in the perinatal period. However, due to the limited insight into the CTG generation mechanism, some CTG recordings can be mistreated as a predictor of neonatal asphyxia, leading to a wrong assessment of the foetal status and improper obstetric intervention. Therefore, in case of suspicious CTG indications, a reliable verification of the true foetal status is vital for reducing the clinical diagnosis false-positive rate and avoiding the unnecessary obstetrician intervention. The paper presents the results obtained for 44 foetuses on the shares of three heart rate variation (HRV) ranges and quiet sleep cycles. This approach uses the parameters of the HRV range shares and quiet sleep cycles to analyse different types of foetuses. The results obtained show that most parameters reveal significant differences between normal and suspicious groups. This is quite lucrative for defining a set of coefficients, whose incorporation into a classifier will improve the accuracy of distinguishing the normal foetuses from suspicious ones.
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