For The Development Of The Shanghai Ebit High-energy Dr Resonance Process In The Energy Measurement Precision High-pressure Partial Pressure Instrument

Highly charged ions (HCI) plays a key role in studies of atomic structure, many body interactions, relativistic effects and quantum electrodynamics, and also in diagnostics of high temperature plasmas.Electron beam ion traps (EBIT) are devices which can be used both as a HCI source and as a HCI light source, making them excellent tools for studying highly charged ions. EBITs require much smaller space and lower running costs than particle accelerators for producing similar charge state ions. Dielectronic recombination (DR) of highly charged ions is very important in astrophysics and hot plasmas, because of its large resonant strength and hence effect on the charge state distribution in a plasma. Since the energy spread of the electron beam in an EBIT is as small as several tens of eV, EBITs are also excellents tools to study DR of highly charged ions, and to disentangle different atomic processes in hot plasmas. This paper introduced a new high precision voltage divider (HVD) for mearuring the very high voltages used at the shanghai EBIT. The new divider provides the capability to measure very high energy DR processes precisely. Compared with high voltage dividers previously built, the shanghai high voltage divider (HVD) has many improvements in structure and in the method of calibration, These improvements will be discussed in this thesis along the lines outlined below:1. Structeral improvements:(1) The material of the main devider structure is clear polycarbonate, the material of the resistor holders is PTFE which helps to reduce leakage current. (2) The current devider uses a totally non adhesive design, which makes it convenient to assemble and disassemble, test and maintain; (3) A corona ring is mounted to homogenize the electric field near the resistors of the HVD; (4) We chose large surface area resistors to reduce self-heating effects; (5) The links between the resistors are capsulated by metal capsules to avoid point discharges; (6) When run in the high voltage mode, we can inject SF6 gas into the area enclosing the high voltage components, this can help to extend the operational range.2. Improvements in the Method of calibration:according to our conditions, we have improved the methods used the parallel connection calibration. Also we have added to the analyse of the measurement systematic error and its elimination, and aoso discuss a correct error analysis. This greatly increases the reliablility of the calibration.After testing under conditions whith input voltages between 0～-85kV, the HVD can reach high reliability and long-term stability and the total uncertainty is less than 10ppm. Moreover, when the absolute value of the input voltage is higher than 35kV, the total uncertainty of the HVD is less than 3ppm, thus qualifying it for precision measurements of DR using the shanghai EBIT.