Helium Clusters Capture of Heliophobes, Strong Depletion and Spin dependent Pick-up Statistics

TL;DR

This thesis explores helium droplet interactions with various particles, focusing on experimental techniques, ionization processes, and the challenges faced, aiming to advance understanding of helium cluster physics.

Contribution

It provides a detailed analysis of helium droplet experiments, highlighting methodological issues and presenting new insights into cluster behavior and ionization phenomena.

Findings

First observation of alkali clusters A_k on He_N with k > 3

Proof of alkali cluster surface location

Prediction of constant signal ratios via spin statistics

Abstract

This much revised and shortened PhD thesis contains many ideas that I could not follow up on, like self destructing beams in scattering cells, the depletion enhancing Wittig tube, ionic seeding via beta-decay foil or Langmuir-Taylor filaments, analysis of the popular <N> ~ Delta(N) relation in droplet size distributions, etc. Avoiding pasting again the usual that is found in many a thesis in the He-droplet field, we focus instead on what is presented insufficiently rigorous elsewhere, like chopper selection, ionization yield curves, or certain widely employed yet wrong derivations. It is not telling much about successes (e.g. first observation of alkali clusters A_k on He_N with k > 3, proof of their surface location, prediction of constant signal ratios via spin statistics) but goes mainly into the failures, as these are more interesting to those who like to explore truly new territory. Some ideas here may just need a single good insight of yours to turn them into success.