EFFECTIVE COLLISION STRENGTHS FOR ELECTRON-IMPACT EXCITATION OF Ne IV

✍ Scribed by C.A RAMSBOTTOM; K.L BELL

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 541 KB
• Volume: 68
• Category: Article
• ISSN: 0092-640X
• DOI: 10.1006/adnd.1997.0765

✦ Synopsis

The multichannel R-matrix method is employed to compute effective collision strengths for electron-impact excitation of triply ionized neon. Eleven target eigenstates, represented by sophisticated configuration-interaction-type wave functions, are included in the close-coupling expansion, corresponding to 22 j-resolved fine-structure levels connected by 231 transitions. The effective collision strengths, obtained by averaging the collision strengths over a Maxwellian distribution of electron velocities, are presented in tabular form for all 231 forbidden and allowed transitions over the wide range of electron temperatures from log T(K) Å 4.7 to log T(K) Å 5.8. This range encompasses the temperatures of particular importance for many astrophysical and plasma applications. Enhancement of the effective collision strengths due to autoionizing resonances converging to the target state thresholds is, as expected, a common feature for many of the forbidden transitions, whereas contributions from the higher partial waves are found to be more important for the allowed lines. The results presented in this paper make up the most comprehensive tabulation to date of accurate effective collision strengths for the Ne IV ion.