https://doi.org/10.1140/epjti/s40485-024-00112-0
Research Article
Shot-noise-induced lower temperature limit of the nonneutral plasma parallel temperature diagnostic
1
Department of Physics, University of California, Berkeley, 366 Physics North, 94702, Berkeley, CA, US
2
Redwood Center for Theoretical Neuroscience, University of California, Berkeley, 366 Physics North, 94702, Berkeley, CA, US
Received:
18
September
2024
Accepted:
25
November
2024
Published online:
18
December
2024
We develop a new algorithm to estimate the temperature of a nonneutral plasma in a Penning-Malmberg trap. The algorithm analyzes data obtained by slowly lowering a voltage that confines one end of the plasma and collecting escaping charges, and is a maximum likelihood estimator based on a physically-motivated model of the escape protocol presented in (Beck in Measurement of the magnetic and temperature dependence of the electron-electron anisotropic temperature relaxation rate. PhD thesis, 1990). Significantly, our algorithm may be used on single-count data, allowing for improved fits with low numbers of escaping electrons. This is important for low-temperature plasmas such as those used in antihydrogen trapping. We perform a Monte Carlo simulation of our algorithm, and assess its robustness to intrinsic shot noise and external noise. The assumptions in this paper allow for a lower bound for measurable plasma temperatures of approximately 
for plasmas of length 
, with approximately 100 particle counts needed for an accuracy of 
.
Key words: Nonneutral plasma / Penning-Malmberg trap / Temperature diagnostic / Single-count data / Measurable temperature lower bound
© The Author(s) 2024
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
