1. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. © OPTOGALVANIC SPECTRA OF CALCIUM IN THE 6090- 6760 ANGSTROM REGION KHAN, MA; GONDAL, MA; RAIS, MH SPRINGER VERLAG, APPLIED PHYSICS B-PHOTOPHYSICS AND LASER CHEMISTRY; pp: 123-130; Vol: 57 King Fahd University of Petroleum & Minerals http://www.kfupm.edu.sa Summary Optogalvanic spectra of some 30 transitions of calcium originating from the ground state as well as from several excited states (4s4p P-1, P-3, 4s3d 1,3D, 4s5p 3P, 3d4p 3D, 3F) have been investigated using laser-irradiation of a low-current glow discharge in a thermionic diode. The influence of various experimental parameters such as bias field, oven temperature and buffer gas pressure on the spectra are reported. Seven previously unreported transitions are recorded including four ''forbidden'' transitions which violate the J selection rules. An interesting anomaly observed in the non- statistical population of the 4s3d 3D3,2,1 multiplet is discussed where the populations of 3D3 : 3D2 : 3D1 are in the ratio of 94 : 5 : 1. A possible explanation is based on avoided crossing between potential energy curves of the Ca-Ar molecule. References: BASHKIN S, 1978, ATOMIC ENERGY LEVELS, V2 BERNABEU E, 1984, J OPT SOC AM B, V1, P586 BRECKENRIDGE WH, 1988, J CHEM PHYS, V88, P2320 BRECKENRIDGE WH, 1988, J CHEM PHYS, V88, P2329 BUSSERT W, 1987, J CHEM PHYS, V87, P3833 CAMUS P, 1974, J PHYS B ATOM MOL PH, V7, P1154 CAMUS P, 1982, PHYS REV A, V26, P379 CHAN YC, 1991, CHEM PHYS LETT, V178, P523 COOKE WE, 1978, PHYS REV LETT, V40, P178 COUTTS J, 1987, J APPL PHYS, V62, P3514 COUTTS J, 1988, J APPL PHYS, V64, P8977 DEMARIA G, 1974, J CHEM THERMODYN, V6, P1 EICHMANN U, 1992, PHYS REV LETT, V68, P21 Copyright: King Fahd University of Petroleum & Minerals; http://www.kfupm.edu.sa

2. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. © GOLDSMITH JEM, 1981, CONTEMP PHYS, V22, P235 GUENTHER AH, 1978, J PHYS D, V11, P1577 HALE MO, 1983, J CHEM PHYS, V79, P3352 HARRIS M, 1987, J PHYS B ATOM MOL PH, V20, P5575 HIRSH MN, 1978, GASEOUS ELECTRONICS, V1 HUSAIN D, 1986, J CHEM SOC FARAD T 2, V82, P1921 KALLENBACH A, 1986, J PHYS B ATOM MOL PH, V19, P2645 KELLER RA, 1979, J OPT SOC AM, V69, P738 KHAN MA, IN PRESS J PHYS D KHAN MA, 1990, J PHYS B ATOM MOL PH, V23, L533 KHAN MA, 1991, OPT COMMUN, V86, P386 KHAN MA, 1993, J PHYS B ATOM MOL PH, V26, P393 KRAVIS SP, 1981, J PHYS D, V14, P151 LAWLER JE, 1980, PHYS REV A, V22, P1025 MALINS RJ, 1980, CHEM PHYS LETT, V74, P321 MORITA N, 1988, PHYS REV A, V38, P551 NESMEYANOV AN, 1963, VAPOR PRESSURE CHEM OKASAKA R, 1982, J PHYS B ATOM MOL PH, V15, P357 PASTERNACK L, 1980, J PHYS B ATOM MOL PH, V13, P2231 PAULICK TC, 1990, J APPL PHYS, V67, P2774 PENCE WH, 1981, J CHEM PHYS, V74, P5707 PFAFF J, 1984, MOL PHYS, V52, P541 RISBERG G, 1968, ARK FYS, V37, P231 SINGH R, 1992, J OPT SOC AM B, V9, P493 SMITH G, 1981, J PHYS B ATOM MOL PH, V14, P4015 STEARNS RG, 1990, J APPL PHYS, V67, P2789 STRIGANOV AR, 1968, TABLES SPECTRAL LINE SUGAR J, 1985, J PHYS CHEM REF D S2, V14, P51 TURK GC, 1978, ANAL CHEM, V50, P817 WIESE WE, 1969, NSRDS NBS, V22, P246 WRIGHT JJ, 1980, J CHEM PHYS, V73, P1617 YACKERSON N, 1988, APPL PHYS B, V46, P79 YACKERSON N, 1990, IEEE J QUANTUM ELECT, V26, P597 For pre-prints please write to: abstracts@kfupm.edu.sa Copyright: King Fahd University of Petroleum & Minerals; http://www.kfupm.edu.sa