Development of a compact helicon plasma source with two sets of ring array permanent magnets for the study of blue core plasma

A compact helicon plasma source for the study of helicon plasma, especially for the study of blue core plasma, is designed and developed with permanent magnets (PMs). The structure of the PMs consists of two sets of ring array magnets with opposite magnetization. This structure can provide a higher magnetic field with fewer PMs, which is helpful for controlling the device's mass. A quartz tube with 50 cm in length, 5 cm in outer diameter, and 0.3 cm in thickness is used. Argon helicon plasma is produced at ∼38 sccm (3.4 Pa inlet chamber and 0.122 Pa diffusion chamber) by a radio frequency (RF) power of ∼13.56 MHz using a helical antenna under a high magnetic field (∼1600 G). Preliminary results measured by the Langmuir probe, photomultiplier tube (PMT), CCD, and Hall coil are applied to characterize the helicon plasma in this source, such as the mode transition and the formation of the blue core with the RF power variation. The device generates the blue core (W mode) plasma at a lower power of about 200 W, and the energy coupling efficiency is as high as 65%.

Laparoscopic uterovaginal anastomosis in patients with congenital cervicovaginal atresia: An institutional experience with 23 patients

OBJECTIVE

To introduce our experience of laparoscopic uterovaginal anastomosis and operative outcomes following this technique and update the clinical management of congenital cervicovaginal atresia.

STUDY DESIGN

Between March 2015 and January 2019, twenty-three patients with congenital cervicovaginal atresia underwent laparoscopic uterovaginal anastomosis and Luohu procedure. Their clinical characteristics, surgical outcomes and follow-up data were retrospectively reviewed.

RESULTS

The mean ± SD age of the cases was 16.4 ± 4.0 (11-26) years. All patients had a history of primary amenorrhea and cyclical abdominal pain, and the average delay in diagnosis from first symptoms was 33.5 ± 38 (1-156) months. Most of the patients had 1-3 cm long vaginal pouch. The operative procedure lasted 125 ± 32 (80-190) min. The average vaginal length at 1 month was 7.9 ± 1.3 (range 6-9) cm. All patients showed resumption of menstruation. The patients were followed for a mean of 27 ± 13 (12-56) months. During the follow-up, cervical stenosis did not occur in any of the cases.

CONCLUSION

Laparoscopic uterovaginal anastomosis with Luohu procedure provided a minimally invasive, safe, and effective surgical option for the patients with congenital cervicovaginal atresia. The technique is uncomplicated, easy to learn and perform, and provides a functional and anatomic satisfactory result. No special surgical instruments are required with this technique.

Design of Langmuir probe diagnostic system for the upgraded lower tungsten divertor in EAST tokamak

In order to achieve long-pulse H-mode plasma scenario over 400 s with high heating power in the Experimental Advanced Superconducting Tokamak (EAST) device, the lower graphite divertor will be upgraded into a tungsten (W) divertor with active water cooling, which consists of the W/Cu monoblock units and the W flat-tile units as the divertor plasma facing components. As a fundamental diagnostic tool, the divertor Langmuir probe (Div-LP) diagnostic system will be upgraded accordingly. This paper presents the design of two kinds of new Div-LP systems, which are planned to be utilized on the W/Cu monoblock units and the W flat-tile units for the upgraded lower tungsten divertor, respectively, including their structures and preliminary poloidal and toroidal layouts. The Div-LP diagnostic system can measure the plasma parameters with the schemes of triple-probe, double-probe, and single-probe, to obtain the spatial and temporal distribution of plasma behavior on the divertor targets, which is useful for the discharge control and operation in EAST. In addition, the thermal analysis of the two kinds of probe assemblies is also carried out by using the three-dimensional finite element code ANSYS, which is aimed to get the optimal designs to withstand the long-pulse and high-power operation in EAST future experiments.

Remote in situ laser-induced breakdown spectroscopic approach for diagnosis of the plasma facing components on experimental advanced superconducting tokamak

The diagnosis of the fuel retention and impurity deposition on the plasma facing components (PFCs) is very important for monitoring plasma-wall interactions and improving the performance of long-pulse operation for tokamak devices. In this study, a remote in situ laser-induced breakdown spectroscopic (RIS-LIBS) system has been developed to be an effective and routine method for the diagnosis of the composition of the PFCs on Experimental Advanced Superconducting Tokamak (EAST). The RIS-LIBS system can be operated between EAST discharges via a remote network control system. This allows a flexible diagnosis for the PFCs at a specific EAST discharge operation or under planned plasma scenarios according to the experimental requirement. Measurements on the fuel retention and impurity deposition of the PFCs have been performed for the test of the RIS-LIBS system, and the depth resolution and the lateral resolution of the RIS-LIBS system have been achieved to be ∼100 nm and ∼3.0 mm, respectively. For the test of detectable elements, the fuel (deuterium) and impurities have been detected and identified clearly. In addition, the measurement of fuel abundance on the first wall as a function of the days of EAST deuterium plasma discharges has been carried out for the first time. These results well manifest a significant prospect of the RIS-LIBS for the diagnosis of the PFCs in the upcoming fusion devices like China Fusion Engineering Test Reactor (CFETR) and ITER.

Thermal strain measurement of EAST tungsten divertor component with bare fiber Bragg grating sensors

Fiber Bragg Gratings (FBGs) have been widely used in the sensor field to monitor temperature and strain. However, the weak mechanical property of optical fibers and insufficient heat-resistant property of general optic-fiber sensors have prevented it from being widely used, such as in some extreme engineering situations. In this work, a bare FBG sensor system had been introduced to measure thermal strain of an Experimental Advanced Superconducting Tokamak tungsten divertor component under baking condition. This strain measurement system had withstood as high temperature as 210 °C and finished the measurement experiment successfully. Meaningful measurement results had been obtained and analyzed, which showed the applicability of such a bare fiber grating sensor system and as well contributed to studying on tungsten divertor's thermal strain conditions.

A multichannel visible spectroscopy system for the ITER-like W divertor on EAST

To facilitate long-pulse high power operation, an ITER-like actively cooled tungsten (W) divertor was installed in Experimental Advanced Superconducting Tokamak (EAST) to replace the original upper graphite divertor in 2014. A dedicated multichannel visible spectroscopic diagnostic system has been accordingly developed for the characterization of the plasma and impurities in the W divertor. An array of 22 lines-of-sight (LOSs) provides a profile measurement of the light emitted from the plasma along upper outer divertor, and the other 17 vertical LOSs view the upper inner divertor, achieving a 13 mm poloidal resolution in both regions. The light emitted from the plasma is collected by a specially designed optical lens assembly and then transferred to a Czerny-Turner spectrometer via 40 m quartz fibers. At the end, the spectra dispersed by the spectrometer are recorded with an Electron-Multiplying Charge Coupled Device (EMCCD). The optical throughput and quantum efficiency of the system are optimized in the wavelength range 350-700 nm. The spectral resolution/coverage can be adjusted from 0.01 nm/3 nm to 0.41 nm/140 nm by switching the grating with suitable groove density. The frame rate depends on the setting of LOS number in EMCCD and can reach nearly 2 kHz for single LOS detection. The light collected by the front optical lens can also be divided and partly transferred to a photomultiplier tube array with specified bandpass filter, which can provide faster sampling rates by up to 200 kHz. The spectroscopic diagnostic is routinely operated in EAST discharges with absolute optical calibrations applied before and after each campaign, monitoring photon fluxes from impurities and H recycling in the upper divertor. This paper presents the technical details of the diagnostic and typical measurements during EAST discharges.

Upgrade of Langmuir probe diagnostic in ITER-like tungsten mono-block divertor on experimental advanced superconducting tokamak

In order to withstand rapid increase in particle and power impact onto the divertor and demonstrate the feasibility of the ITER design under long pulse operation, the upper divertor of the EAST tokamak has been upgraded to actively water-cooled, ITER-like tungsten mono-block structure since the 2014 campaign, which is the first attempt for ITER on the tokamak devices. Therefore, a new divertor Langmuir probe diagnostic system (DivLP) was designed and successfully upgraded on the tungsten divertor to obtain the plasma parameters in the divertor region such as electron temperature, electron density, particle and heat fluxes. More specifically, two identical triple probe arrays have been installed at two ports of different toroidal positions (112.5-deg separated toroidally), which can provide fundamental data to study the toroidal asymmetry of divertor power deposition and related 3-dimension (3D) physics, as induced by resonant magnetic perturbations, lower hybrid wave, and so on. The shape of graphite tip and fixed structure of the probe are designed according to the structure of the upper tungsten divertor. The ceramic support, small graphite tip, and proper connector installed make it possible to be successfully installed in the very narrow interval between the cassette body and tungsten mono-block, i.e., 13.5 mm. It was demonstrated during the 2014 and 2015 commissioning campaigns that the newly upgraded divertor Langmuir probe diagnostic system is successful. Representative experimental data are given and discussed for the DivLP measurements, then proving its availability and reliability.

Phenotypic and clinical aspects of Mayer-Rokitansky-Küster-Hauser syndrome in a Chinese population: an analysis of 594 patients

OBJECTIVE

To analyze the phenotypic and clinical aspects of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

Five hundred and ninety-four patients with MRKH syndrome.

INTERVENTION(S)

Clinical examination, abdominal or perineal/rectal ultrasound, magnetic resonance imaging, hormonal profile, karyotype, and laparoscopy.

MAIN OUTCOME MEASURE(S)

Clinicopathologic data, VCUAM (vagina cervix uterus adnex-associated malformation) classification, types with cycle phase, and karyotype.

RESULT(S)

We identified associated malformations in 43 out of 594 (7.2%) cases of MRKH. The 594 patients could be grouped into hormone phases: 53.7% follicular, 35.2% luteal, and 11.1% ovulatory. The major karyotype of MRKH patients was 46,XX; abnormal karyotypes were found in two cases.

CONCLUSION(S)

A lower proportion of associated malformations were found when compared with those provided in the current literature. Renal anomalies were the most frequent associated malformations, and most of the patients presented with a normal karyotype. Given the large cohort of this study, the lower malformation rates might be related to geographic or referral patterns, so further investigation is warranted.

Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m² thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength.

[Laparoscopy-insisted vaginoplasty with peritoneum in patients with androgen insensitivity syndrome]

OBJECTIVE

To investigate the technique and therapeutic effect of laparoscopy-insisted vaginoplasty with peritoneum in patients with androgen insensitivity syndrome.

METHODS

From May. in the Fifth People' s Hospital of Shenzhen. The therapeutic effect was retrospectively analyzed.

RESULTS

Laparoscopy-insisted vaginoplasty was successfully completely with peritoneum in patients with androgen in 4 cases. Ileumtivity segyndroment was used instead of peritoneum in one case. Open operation was not adopted in any cases. The ectopic testicles were removed during operation in 4 cases. The average operation time and bleeding volume was 60 min and 20 ml, respectively. Rectum, bladder and urethra were not injured in any case. The average vaginal length was 9 cm (range 8-10 cm) 21-28 days after operation. 6 months after operation, the surface of reconstructed vagina was smooth, ruddy and flexible, with satisfactory anatomical and functional results. Normal sexual activity was achieved in 2 cases.

CONCLUSIONS

Laparoscopy-insisted vaginoplasty with peritoneum could be used for female patients with androgen insensitivity syndrome. The ectopic testicles should be removed. Estrogen supplement and psychological guide after operation are also important.