Speaker
Description
A Gabor lens, a type of plasma lens, utilizes the internal electric field of a trapped electron plasma to focus high energy positively charged particles, such as protons or ions [1]. This lens is formed within a non-neutral plasma confined by magnetic and electric fields in a Penning-Malmberg trap [2]. Compared to traditional magnetic lenses, Gabor lenses offer the potential for highly efficient and compact particle focusing. The focal length ($f$) of the Gabor lens depends on the strength of the radial field generated by the non-neutral plasma, which is determined by the plasma density ($n_e$), the kinetic energy of the positively charged particle ($U$), and the length of the plasma ($l$) via $\frac{1}{f}=\frac{e^2 n_e l}{4\epsilon_0 U}$ where $e$ is the magnitude of the electric charge of the electron, and $\epsilon_0$ is the permittivity of free space [3]. In this study, our aim is to attain a plasma density on the order of $10^{15}$ $m^{-3}$ to achieve a desired focal length of $1$ $m$ for the Gabor lens.
The practical implementation of an electron plasma faces challenges related to confinement, density, lifetime, and stability. We analyze these characteristics within our trapped electron plasma. Additionally, we present the results of applying a well-established manipulation technique—rotating electric fields—to control the plasma radius [4], aiming for longer plasma lifetimes and higher plasma densities. The attainment of prolonged plasma storage times and elevated plasma densities holds significant promise for advancing Gabor lens technology, crucial for a multitude of applications including particle accelerators and beam focusing systems.
[1] Gabor, D. (1947). A space-charge lens for the focusing of ion beams. Nature, 160(4055), 89-90.
[2] Fajans, J., & Surko, C. M. (2020). Plasma and trap-based techniques for science with antimatter. Physics of Plasmas, 27(3), 030601.
[3] Pozimski, J., & Aslaninejad, M. (2013). Gabor lenses for capture and energy selection of laser driven ion beams in cancer treatment. Laser and Particle Beams, 31(4), 723-733.
[4] Ahmadi, M., et al. (Alpha Collaboration). (2018). Enhanced control and reproducibility of non-neutral plasmas. Physical Review Letters, 120(2), 025001.
