Power positron beams for High Energy Density physics
In this talk I will discuss the modern theoretical developments and review today situation in power positron beams research, including physical and technical aspects of generation and absorption of the positron beams with GeV particle energy and about (0.01–0.1) A beam current, positive “charge pumping” process, with emphasis on suggestions for some HED (High Energy Density) physics applications: (1) macroparticle accelerator, (2) proton and heavy ion intermediate energy accelerator and (3) soft(about few MeV energy range) gaser. I will also describe the physics and conceptual design of the machines (1)–(3).
Power positron beams as a new branch of beaming
Despite being one of the most accessible forms of antimatter today, positron beams are barely used in High Energy Density Physics (HEDP). For classical problems of HEDP, they offer no immediate advantages in comparison to electron and ion beams, and their production requires more expensive and complicated procedure. However, they might be the solution for a number of advanced problems in HEDP, that have not yet been solved (even theoretically) in more than 50 years of extensive research, including: ; Accelerating macro (1 to 10 grams) particles to the speed of 100 - 1000 kilometers per second : Creating new generation of proton and ion accelerators : Creating the sources of coherent γ - radiation.
Optical isomer shift for the spontaneous-fission isomer /sup 240/Am/sup m/
The optical isomer shift in the /sup 8/S/sub 7/2/ ..-->.. /sup 10/P/sub 7/2/ atomic transition in neutral americium has been measured for the approx. 1-ms spontaneously fissioning isomer, /sup 240/Am/sup m/(SF). With use of a laser-excited optical pumping technique, this transition is shifted by +2.6 +- 0.2 A to 6407.2 +- 0.2 A implying a difference in nuclear mean square radii, delta, of 5.1 +- 0.2 fm/sup 2/ between the fission isomer and the normal ground state. These experiments provide the first direct experimental proof for the large deformations expected for fission isomers.