Study on fabrication and manipulation of HEDgeHOB cryogenic targets

HEDgeHOB collaboration plans to carry out a set of experimental researches in the field of High Energy Density (HED) matter generated by the interaction of intense heavy ion beams. One line of the researchers was named LAPLAS (Laboratory PLAnetary Science). This scheme proposes low-entropy compression of a material like frozen hydrogen or deuterium ice that is enclosed in a cylindrical shell of a high-Z material like gold or lead. Such type of experiment is suitable for studying the problem of hydrogen metallization or for creating physical conditions that are expected to exist in the interiors of the giant planets. This paper presents a thorough analysis of different possible approaches to the cylindrical cryogenic targets preparation to the LAPLAS experiments, including targets fabrication, their delivery and positioning in the radiation area. The researches are performed in the following directions: (i) Target fabrication. For the first time there was considered a possibility of cryogenic cylindrical target fabrication with a parameter l/diameter = 5.00 / 6.25 (where l and diameter are the length and the diameter of the cryogenic target core, respectively). There were also investigated different technical approaches for designing the target elements. The target quality criteria were stated as well. (ii) Target handling. There were investigated different variants for the target elements assembly, target delivery and positioning. There was made a thorough analysis of diagnostics possibilities for cryogenic cylindrical target placed inside the target chamber. (iii) Target survival. There was made a modelling of the target heating process up to the triple point of solid hydrogen or deuterium under the different heat-exchange conditions. There was given an estimation and made an optimization of the cryogenic target lifetime inside the chamber with hot wall. On the basis of the performed researchers there were defined the technical requirements to the corresponding specialized cryogenic system (SCS). The SCS conception aimed at the potential risks minimization during the system designing and functioning is in the research stage now. (author)