| High energy density(HED) matter exists widely in our universe, and it is the intermediate state in inertial confinement fusion(ICF), hence laboratory research about the HED matter is not only important for astrophysics, but also is the critical issue of ICF study. Due to the special energy deposition mechanism of ion in matter, heavy ion beams open a new path for the HED physics research. Intense heavy ion driven beam driven HEDP research is one of the main scientific topics for the international project FAIR as well as HIAF. FAIR is already in the middle of the construction and HIAF project has been approved. To guide the accelerator construction and the experiment proposal, related precedent numerical simulation must be done one step earlier.In this thesis, we studied two critical issues which should be established in the first phase of HEDP research. One of them is numerical simulation of intense heavy ion beam-matter experiments, and the other one is concerned about the dynamic vacuum issue of the accelerator facility. The details are as follows:1. We systematically and quantitatively investigate the dependence of the state of generated HED matter on the incident beam energy, spot size, pulse length and target geometry. The result shows under direct heating, the achieved temperature in the target nearly linearly increase with the deposition power density; The hydrodynamic motion of the material begins at about tens of ns, so if the pulse length is larger than 100 ns, the energy deposition efficiency will be reduced; Different ion-target scheme serves for the generation of different state of matter. For example, hollow beam heats the two-layeredtarget is the first choice go get extreme high pressure. The shock wave produced in the outer shell will compress the inner shell until more than one hundreds of the initial density. With the normal circular beam, the inner shell material will reach extreme high temperature under direct heating and shock wave compression.2. Based on the beam parameter proposed by HIAF, the target hydrodynamic behavior with three typical ion-target scheme is predicted. The results shows that in the first phase of HIAF project, where only B-Ring is in the plan and the pulse length is 400 ns,the HED matter could be generated any way, however, the optimum compression happens at around 100 ns in the beam pulse length. This means more than half of the beam is not used efficiently. Once the beam pulsed is compressed to 50 ns, the pressure and the temperature of the generated matter will increase by one magnitude. There will be a great probability that the strong shock wave can be available. When C-Ring is built, it is quite promising that the radiation transport study of HED matter could be available.3. Taking plasma physics terminal of FAIR project as an example, we simulated the dynamic vacuum along the beam line following the target evaporation process resulting from high power energy deposition. The Monte-Carlo dynamic vacuum simulation is benchmarked by the pressure wave propagation measurement at current beam line. The result shows that with the current terminal design, the target evaporation will lead to the pressure deterioration by at least two magnitude. This is two dangerous for the accelerator ring. Fortunately, the simulation result about the timescale for evaporation wave propagation indicates that a ms fast valve is feasible to settle the vacuum issue.4. In the ultrahigh vacuum condition, the residual gas in the accelerator ring will interact with the heavy ion beam, and will lead to the particle deviation. The deviated particle will hit on the pipe wall and release more particle to the vacuum. As a result, the number of ions per pulse can not exceed 109. To make a breakthrough, collimators, which help to reduce the release coefficient, were installed in GSI-SIS18 to improve the beam intensity by one magnitude. In this thesis, we introduce the study about the cryocollimator for SIS-100. The experiment results indicate that the cryo-target behavior under heavy ion beams is totally different from that at room temperature. Further investigation is necessary.5. The cyclic dependence of projectile X-ray emission yield as function of target atomic number and the obvious charge state effect in Xe and Fe collision system imply the significance of vacancy transfer mechanism. On the basis of observed charge state effect and the vacancy transfer theory, equilibration time of highly charged ions in solid is estimated as 7 fs。... |
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