Rapid cycling synchrotron(RCS) is an important component of China Spallation Neutron Source(CSNS). Its main function is to receive the 80MeV kinetic energy pulse H^- ion beam accelerated by the linear accelerator, and convert it into a proton beam by stripper foil. It is then accelerated to 1.6GeV, which are extracted and strike a solid metal target to produce spallation neutrons. The vacuum system of RCS is an important carrier to realize the function. This paper starts with the overall layout of RCS, and mainly introduces the structure design, the equipment layout and the distribution of the pumps of the vacuum system of RCS. This work also focuses on the application of large-scale ceramic chamber on accelerators and some necessary pretreatment process for ceramic chamberTiN coating and RF shielding. The operating status of the vacuum system is introduced at end of the paper.

To explore the vacuum pump equipment and pipeline structure performance of low vacuum pipeline system in specific conditions, the experiment platform of low vacuum pipeline system was set up in this paper. The experimental study was carried out on vacuum pump equipment performance and pipeline structure deformation law based on the platform, and the following conclusions were reached. The tube wall compressive strain increases with the increase of the absolute value of relative vacuum degree. The increase of the absolute value of relative vacuum degree can reduce the tensile strain caused by the increase of temperature in the tube, while the increase of temperature is beneficial to reduce the compressive strain caused by the increase of relative vacuum degree. When the cooling circulation system is used, the extraction rate of the vacuum pump is basically constant at different temperatures. In different vacuum circumstance the rising rate of temperature heated by the shortwave twin-tube is basically constant. The vacuum can reduce the internal temperature of pipeline structure to some extent under the condition of temperature difference between inside and outside. When cyclic loading is applied, the rebound of structural strain is greater than the initial value after unloading the vacuum.

This article introduced the test methods of ion pump performance for Shanghai Synchrotron Radiation Facility. The ultimate vacuum, effective pumping speed and cleanliness of ion pump were investigated. The study showed that the measured values of the ultimate vacuum of the ion pump meet the requirements of ≤5.0×10^-8Pa. The SIP200 and SIP400 both had a maximum nitrogen regeneration pumping rate in excess of their respective nominal pumping rates. The saturation pumping speed of the inert gas argon also exceeded 60% of their respective nominal pumping rates. The residual gas spectra measured by the quadrupole mass spectrometer indicated that the cleanliness of the ion pump meets the cleanliness requirements of the beamline of Shanghai Synchrotron Radiation Facility. The tested ion pump, installed on the beamline, works properly and the dynamic vacuum meets the vacuum design specifications.

Oil sealed rotary vane vacuum pump has a long history with complete production process, mature technology, the characteristics of high efficiency, reliability, low noise and easy maintenance. It is not only widely used in coating, packaging, absorption, refrigeration, refrigerator, air conditioning, lighting, color tube, vacuum heat treatment, vacuum defoaming, pouring, molding and other industries, but also used in the laboratory and scientific research sites. Its market use is very large. This paper summarizes and analyzes the causes of some common failures, in order to make the majority of users have a relatively systematic understanding of the failure of the rotary vane vacuum pump, so as to correctly use and reasonably maintain the rotary vane vacuum pump. It may bring considerable economic and social benefits to the enterprise.

The NiCrAlYSi bonding layer was prepared by vacuum arc plating. The YSZ ceramic layer was prepared by electron beam physical vapor deposition(EB-PVD). Microstructure,crack morphology and elemental composition of the as-deposited coatings and TBCs after thermal cyclic were analyzed by using SEM with energy dispersive spectrometer. The behavior of interlayer damage and elements diffusion of TBCs from early stage of thermal cycling to failure process were investigated.The results show that, with the increase of the thermal cycling time, NiCrAlYSi/YSZ TBCs experienced rapid oxidation and low oxidation rate stages. After 1100h, the ceramic layer fell off and the bond coat continued to oxidize, resulting in a sudden increase in coatings weight. At the beginning of the thermal cyclic, Al, Ni, and Cr in bond coat diffused outwards, while O and Zr diffused inwards from the ceramic layer. Al in the TGO layer is sufficient and the selective oxidation of Al mainly occurred.After 1100h, Al in the TGO layer was insufficient, Cr and Ni began to oxidize, forming Al_1.92Cr_0.08O₃ and nickel aluminum oxide. The uneven oxidation resulted in the local volume expansion in the coatings and the cracks initiated in the TGO layer. With the proliferation and growth of cracks, the cracks eventually penetrated the equiaxed crystal region and TGO layer, leading to the failure of TBCs.

In this paper, the pure β-Ga₂O₃ thin film and Mg-doped β-Ga₂O₃ thin films with different Mg content were deposited on the Si and quartz substrates by radio frequency magnetron sputtering. The structure, optical and electrical properties of thin films were studied. The X-ray diffraction measurement results show that, there was no diffraction peak corresponding to other crystal phases for Mg-doped β-Ga₂O₃ thin films within our Mg content. And the intensities of diffraction peaks(401)and(601)of thin films weaken with the increase of Mg content. The X-ray photoelectron spectroscopy was used to test the binding energy and chemical states of the elements of the film. The UV transmission measurement results show that the average transmittance of the thin films is more than 80% in the test range, and the band gap of the thin films increases with the increase of Mg content. The Hall measurement results show that the conductivity type of Mg-doped β-Ga₂O₃ thin film by radio frequency magnetron sputtering is p-type, and the carrier concentration increases from 3.76×10¹⁰cm^-3 to 1.89×10¹³cm^-3. The Hall measurement results indicate that Mg-doped β-Ga₂O₃ thin film is a potential p-type material.

This paper introduces in detail the working principle, structure composition, technical characteristics and main innovative design points for a large-scale metal strip surface modification continuous roll to roll coating production line. It analyzes and points out the main factors and solutions that affect the coating quality and production efficiency of the metal strip with large diameter and width. It focuses on the scientific basis of improving the coating speed and film adhesion,and solves the problems of low coating efficiency, poor uniformity, unstable optical properties of spectrum L, a, b value and so on in the current metal strip continuous winding coating production line. The comprehensive application of the independently developed AEG arc ion etching auxiliary system, cylindrical cathode arc ion evaporation technology and medium frequency magnetron sputtering technology help to increase the deposition rate by 1.3~2 times. The color difference fluctuation of L value, a value and b value of the whole roll coating is not more than ± 1.0,± 1.5 and ± 1.8, respectively.

This paper reports the study on the uniformity of DLC coating deposited in the inner wall of tubal samples(such as carbon steel, PET bottle, plastic syringe) by microwave surface wave plasma. The main factors affecting the uniformity of as-deposited nanoscale coatings along the antenna direction were explored. By measuring the deposition rates of the coatings at different positions,it can be concluded that the generation and strength of surface wave dominate the uniformity of the DLC coating in the inner wall of tubes. Penning discharge can only affect the discharge characteristics regionally by the enhancement of the discharge, not the discharge model. Therefore, it is impossible to improve the uniformity of the coatings in the tube in whole antenna range.

AZO thin films were respectively deposited on the preheated glass substrate and room temperature by DC magnetron sputtering, and AZO films prepared at room temperature were annealed in vacuum. X-ray diffractometer, ultraviolet-visible spectrometer, four-point probes and Hall tester were used to character the prepared samples. The effects of two heat treatment methods, i.e.substrate pre-heating and vacuum annealing, on the structure and photoelectric properties of AZO thin films were comparatively studied. The results show that AZO thin films prepared under substrate preheating condition effectively inhibit the formation of（101）polycrystalline phase. AZO thin films prepared at room temperature have more（101）polycrystalline phase formation, and after vacuum annealing heat treatment, the（101）polycrystalline phase cannot be well eliminated. AZO thin films with a thickness of 380 nm and a square resistance of 20Ω/□ were prepared under the substrate preheating condition, the average transmittance between 400 nm and 1200 nm wavelength is 81.5%. The vacuum-annealed AZO film with a thickness of 403nm and a square resistance of 33Ω/□ has an average transmittance of 81.9% in the 400-1200nm band.

Asymmetrical accelerated erosion of one of the two turnarounds on each target in a cathode pair is due to the asymmetrical anode arrangement.The side of the racetrack closest to the anode builds a stronger plasma that travels in the hall current direction and is dragged into the turnarounds leading to a higher erosion rate.The side of the racetrack,that is furthest from the anode,does not carry as much energy into the turnarounds and thus does not erode the target as much.This phenomenon is called Cross-Cathode effect.This article analyzes the Cross-Cathode effect and discusses how to minimize the Cross-Cathode effect.

In order to solve the problem for online calibration of vacuum gauge,an online calibration system of vacuum gauge is developed. The online calibration system of vacuum gauge solves the problem of wide range calibration by optimizing design, material and process treatment. Through the research of online calibration technology, the comparison method is adopted. Three high-precision baratrons and one high-precision ionization gauge are used as reference standard to solve the problem that the calibration conditions are basically the same as the application conditions, which can reduce the uncertainty in the process of value transfer and ensure the accuracy and reliability of measurement. The online calibration system can realize the online measurement of vacuum gauge in the range of 10⁵~10^-5Pa. The relative expanded uncertainty is not more than 13%.

This paper proposes a method to indirectly measure the vacuum degree using the leak rate to solve the problem of measuring the vacuum degree in the seal cavity. On this basis,relevant experiments are carried out to explore the feasibility of the method in practical applications and relevant applicable conditions. The experiment takes a simulation part connected with metal capillaries of different sizes as the research object,and uses the dynamic flow method to measure the leakage rate of the simulation part,thereby indirectly obtaining the vacuum degree in the cavity of the simulation part. The experimental results show that the difference between the vacuum of the simulated part measured indirectly using the leak rate and the vacuum of the simulated part measured in situ using the Pirani gauge is about 15%,and the deviation is small. At the same time,the experiment also indicated that the method has restrictive applicable conditions including measurement range,reaction time and so on,and made a reasonable explanation in theory,and then perfected the method and laid the foundation for practical application.

In order to improve the design efficiency of ejectors, the calculation method of ejector structure size was systematically investigated, and a software was designed by VB. NET based on the combination of the classic theory of ejectors and the excellent design models of both domestic and foreign countries. The software is mainly composed of four parts of modules, which are the input/output module, the eject coefficient calculation module, the structural design module and the performance curve drawing module. This software has a wide range of application because it can not only resolve the ejector of three different compression ratios, but also deal with the two-phase ejector of gas-liquid and gas-solid operating condition, which greatly enriched the function of the software. The interface of the software is simple and easy to operate, leading to the improvement of the calculation accuracy and the design efficiency of ejector structure.

The activity of titanium increases rapidly by the elevation of temperature, and it tends to react with various material intensively at high temperature. Currently, the predominate melting technique of high quality titanium alloys is the 3 times vacuum consumable melting protected by vacuum or inert gas. The temperature of titanium alloy liquid is above 1750 ℃, thus the use of cooling water is necessary to protect the important devices such as copper crucible, electrode rod and furnace body. Under improper handling or equipment fault conditions, the cooling water may flow into the crucible and react with the hot titanium alloy liquid. In practical mass production, severe explosion may occur, which will lead to casualty and property losses. The current work is based on mass production and equipment management experience. Potential risks of the design of vacuum consumable melting device is identified, and precautions are systematically analyzed in this paper.

The article introduces the application status of vacuum technology in the aerospace field from five aspects：vacuum brazing, vacuum heat treatment, vacuum thermal test, application of vacuum technology in flight simulation experiments, and vacuum measurement, and looks forward to the prospects of vacuum technology in the aerospace field. The application of vacuum technology has greatly promoted the development of our country′s aerospace industry. In the future, the vacuum technology will certainly play a greater role.

The prestressed steel wire winding cylinder is an important processing equipment in vacuum aerospace and other fields. The article uses load steps to establish a simulation calculation model for the winding process of prestressed steel wire wound thick-walled cylinders. Based on the large-scale general finite element software, through the structural analysis of the working cylinder of the isostatic press steel belt winding form, the stress distribution of its preload and working state can be determined. This work may provide an important basis for the design of the working cylinder of the isostatic press.