Internal energy effects in photodissociation: relaxation of excited thiophenol ions formed by electron-impact ionization

✍ Scribed by Bruce Asamoto; Robert C. Dunbar

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 534 KB
• Volume: 139
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(87)80183-5

✦ Synopsis

The internal energy of thiophenol ions formed by moderate energy electron-impact ionization was measured as a function of the ttme after ionization using a visible laser probe. Immediately after ionization, it was found that about 60% of the ions had internal energies greater than 0.8 eV. At collisionless pressures, the ions were found to relax below 0.8 eV at a rate of 3 s-'. At higher pressure, where the collision rate is approximately 1 s-l, the relaxation rate was measured at 4.5 s-i. The results are compared with the energy deposition function inferred from the PES spectrum, and it is suggested that electron impact at 17 eV gives a somewhat smaller fraction of ions above 0.8 eV than does photoiomzation at 2 1 eV.