Vacuum Ultraviolet Radiation and Jesse Effects in the Noble Gases

When charged particles interact with the noble gases, energy is radiated in the vacuum ultraviolet (VUV) region of the electromagnetic spectrum. Some recent measurements of the absolute yield of VUV energy per cm of proton track length show that this quantity $\frac{d\epsilon }{\mathrm{dx}}$ is an appreciable part of the total stopping power $\frac{\mathrm{dE}}{\mathrm{dx}}$. Here, we show by direct comparisons and by arguments based on the principle of conservation of energy that the Jesse effect (Penning ionization) in helium, neon, and argon is associated with radiation energy in the VUV region.