Vacuum control system for the Space Plasma Environment Research Facility

Abstract

The Space Plasma Environment Research Facility (SPERF) is a ground simulation user facility for studying the space plasma physical processes. This study presents the design and construction of a vacuum control system for the SPERF to set up an appropriate vacuum environment for plasma experiments, including the terrestrial space and near space vacuum control systems. Based on the requirements of remote automation, distributed control, centralized management, high reliability, expansibility, and safety, the architecture of the vacuum control system has been divided into three levels. Among these, the local level is the most essential part of the control system, which adopts the programmable logical controller (PLC) with Siemens S7-1500 CPU as the core. The PLC supports multiple communication protocols and can accurately control and monitor the actuators in the process of establishing a vacuum environment. Furthermore, it has the ability to communicate and interact with remote upper computers and the central control system through the supervisory control and data acquisition (scada) software developed based on iFix. Based on the architecture of the vacuum control system, the control process for establishing the vacuum environment, including the ultimate vacuum and experimental vacuum, was designed. It is noteworthy that in experimental vacuum acquisition, the injection of working fluid gas is controlled directly by the central control system, considering the different requirements of the terrestrial space and near space systems for the experimental working pressure and flexibility of the experimental vacuum control. The vacuum control system designed in this study provides technical support for the SPERF to perform the plasma experiments successfully. In addition, it offers reference and insights for the design of vacuum control systems in similar large-scale plasma simulation facilities.

Design and construction of the near-earth space plasma simulation system of the Space Plasma Environment Research Facility

“…Meanwhile, the leakage rates of the main components in the vacuum vessel are reduced and considered in the design. The operation test shows that an ultimate vacuum of pressure at 10 −4 Pa can be attained within 24 h based on the design, and the total leakage is smaller than 7.1 × 10 −7 Pa • L s −1 (Jin et al 2023). The reader is FIGURE 2.…”

“…To achieve the goal, an ultimate background vacuum is built first and then working gases are injected into the vacuum chamber to obtain the experimental pressure. The main challenges posed on the vacuum system lie in the fact that the vacuum vessel is large in volume, has a lot of outgassing objects in it (Jin et al 2023), and possesses hundreds of interfaces on it for supporting the magnets, feeding the electrical currents into the magnets, installing the plasma sources, diagnosing the plasma, etc. As shown in figure 2, a multi-stage pumping unit is designed to achieve the ultimate background vacuum, and a pulsed gas-injection unit controlled by piezoelectric ceramic valves is adopted to establish the experimental vacuum.…”

“…The reader is FIGURE 2. Schematic view of the vacuum system (Jin et al 2023). referred to the previous papers (Jin et al 2022a(Jin et al ,b, 2023 to grasp the technology details of the vacuum system.…”

“…Now, a new user facility named as SPERF (Space Plasma Environment Research Facility) is being constructed in Harbin for space plasma environment simulation. A near-earth space plasma simulation system is built on the SPERF to simulate the earth's magnetosphere (Jin et al 2022a), thus resolving the basic space plasma physics problems, such as 3-D asymmetric magnetic reconnection, dynamics of radiation-belt charged particles (Fox & Burch 2014), geomagnetic storm, etc. Remarkably, the facility is the first device to investigate asymmetric magnetic reconnection with 3-D geometry, which is not accessible in the available facilities with 2-D magnetic geometry (Ren et al 2008;Zhong et al 2010;Bohlin et al 2014;Olson et al 2016;Hare et al 2017a;E et al 2021a).…”

The overload reliability assessment and enhancement of insensitive initiator

“…[1] As the most sensitive and first component of explosive train, the safety and reliability of the insensitive initiation unit directly affected the safety and combat effectiveness of ammunition. [2] A large number of novel intrinsically safe explosive devices represented by EFI, which shown an important way to improve the safety of ammunition. [3] However, there were few researches on the reliability and safety of EFI explosive devices under highly overloaded acceleration condition, which couldn't meet the requirements of new ammunitions' design and development.…”