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Measurement of average L-shell fluorescence yields in elements 73⩽Z⩽92
Physica 132(2(1985) 119--121 North-Holland, Amsterdam
M E A S U R E M E N T O F A V E R A G E L-SHELL FLUORESCENCE YIELDS IN E L E M E N T S 73 ~< Z ~< 92
Inderjit SINGH, Raj M I T I ' A L , K.L. A L L A W A D H I and B.S. S O O D Nuclear Science Laboratories, Department of Physics, Punjabi University, Patiala-147002, India
Received 6 September 1984 Revised 30 November 1984 The average L-shell fluorescenceyields in the elements Ta, W, Au, Hg, TI, Pb, Bi, Th and U have been measured using photoionization for creating the vacancies. The measured values are found to agree well with those calculated using the fitted values of L-shell fluorescence and the Coster-Kronig yields given by Krause et al. We have extended our earlier measurements [1] of the average L-shell fluorescence yields in elements 40~
is straightforward. The average L-shell yields were determined by comparing the intensities of the L-shell fluorescent X-rays with the 59.57 keV gamma-rays incident on the targets [1]. As the targets used in the present measurements were not infinitely thick for the incident and emitted photon energies, their self-absorption correction factors /3L were calculated using the following equation as explained in the earlier paper [1]. n
/3r = ~ PJ" 1 - exp[-(/% +/Zrj)(t/cos 0)] j=~ 0 ~ + ~,~j)(t/cos 0) ' where t is the thickness of the target, 0 the angle at which the 59.57-keV gamma-rays are incident on the target and the characteristic L X-rays are emergent from the target, pj the fractional intensity of the ]th component in a mixture of n components of the emitted L X-rays, /z r the absorption coefficient of the target material at the 59.57-keV gamma-ray energy and /ZLj the absorption coefficient of the target material at the energy of the jth components of the emitted L X-rays. In table I, the values of o3L as measured in the present experiment are compared with the other available measurements [4-27] and those calculated by using the theoretical [28-30] as well as fitted values [31] of the subshell fluorescence yields and the Coster-Kronig transition probabilities. As explained earlier [1] the values of o3L were calculated from the relation [32]
0378-4363/85/$03.30 O Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division)
I. Singh et al. / Average L-shell fluorescence yields
120
Table I Comparison of the present measurements of the average L-shell fluorescence yield o3L with the previous measurements and calculated values Average L-shell fluorescence yield t~L
Element
Present measurements
Previous measurements
Ta
0.28 -+ 0.02
0.225 -+ 0.01
[4]
0.261 -)
W
0.29 + 0.02
0.298
[5]
0.275 a) 0.272 b) 0.280 ~)
Au
0.36 - 0.02
0.365 0.374+0.018 0.430-+ 0.012
[5] [6] [7]
0.339 ~) 0.356 c)
Hg
0.38 -- 0.02
0.24 -+ 0.04 0.371-+0.035 0.24-+0.04 0.41---0.04 0.40+0.05 0.39+0.06
[8] [9] [101 [11] [12] [13]
0.353 a) 0.345 b)
TI
0.39_+0.03
0.50+0.02 0.48-+0.03 0.32 0.41 -+0.04
[14] [15] [16] [17]
0.367 a)
Pb
0.38 -+ 0.03
0.398 0.39-+ 0.02 0.29-+ 0.03 0.36 + 0.02
[5] [18] [201 [19]
0.381 a)
Bi
0.42 -+ 0.03
0.402 0.51-+0.03 0.38-+ 0.02 0.38-+ 0.04 0.37 0.40
[5] [14] [21] [22] [23] [16]
0.393 a) 0.416 c)
Th
0.49 -+ 0.03
0.480 -+ 0.008 [24]
0.489") 0.513 e)
U
0.60_+0.04
0.478-+0.009 0.603-+ 0.004 0.570 - 0.019 0.42-+ 0.01 0.53-+ 0.06
0.514")
a) Using the data of Krause et al. [31]. b) Using the data of Chen et ak [28]. c) Using the data of McGurie. [30].
Calculated values
[24] [7] [25] [261 [27]
I. Singh et al. / Average L-shell fluorescence yields 3 O)L= E ~ilJi, i=1 w h e r e n~ and vi give the relative v a c a n c y distribution and the effective fluorescence yields for the three L subshells, respectively. Scofield's theoretical values [33] of L-subshell p h o t o ionization cross-sections were used to obtain the values of n~(i -- 1, 2, 3). T h e fitted values of L subshell fluorescence yields and the C o s t e r Kronig transition probabilities o b t a i n e d by Krause et al. [31] were used to d e t e r m i n e v~(i = 1, 2, 3). F o r a few e l e m e n t s theoretical values of L subshell fluorescence yields and C o s t e r - K r o n i g transition probabilities were also available [28-30]. T h e values of the vi for these e l e m e n t s were also d e t e r m i n e d using the theoretical values. T h e values of 0.~L calculated by using these Vl-Values are listed in c o l u m n 4 of table I. It is seen that the present values for W and Th agree, within the experimental uncertainties, with the only o t h e r available experimental values, while for Ta the present value is higher by about 20 percent than the only available experimental value. H o w e v e r , it is closer to the semi-empirically fitted value of Krause. F o r Au, Hg, Tl, Pb, Bi and U a n u m b e r of experimental values using different m o d e s of v a c a n c y p r o d u c tion, have been r e p o r t e d by various authors. T h e r e is a considerable scatter a m o n g the values of different w o r k e r s ; the difference b e t w e e n the m a x i m u m and m i n i m u m values varies f r o m 15 to 60%. H o w e v e r , the present values for all the e l e m e n t s agree with m o s t of the previous values. T h e present values are also f o u n d to agree fairly well with the semi-empirical values of Krause except for U. Acknowledgement Financial assistance f r o m the U G C , Delhi, India, is gratefully a c k n o w l e d g e d .
New
References [1] N. Singh, R. Mittal, K.L. Allawadhi and B.S. Sood, Physica 123C (1983) 115.
121
[2] S.K. Arora, K.L. Allawadhi and B.S. Sood, Physica 111C (1981) 71. [3] K.L. Allawadhi, S.L. Verma, B.S. Ghumman and B.S. Sood, Physica 95C (1978) 424. [4] P.V. Rao and B. Crasemann, Phys. Rev. 142 (1966) 768. [5] H. Lay, Z. Phys. 91 (1934) 533. [6] R.C. Jopson, H. Mark, C.D. Swift and M.A. Williamson, Phys. Rev. 131 (1963) 1165. [7] M.A. di Lazzaro, Instituto Superiore di Sanita Report, ISS 65/11 (1965), unpublished. [8] H. Jaffe, Univ. Calif. Lawrence Radiation Lab. Report, UCRI-2537 (1954), unpublished. [9] S.K. Haynes, M. Velinsky and L.J. Velinsky, Nucl. Phys. A90 (1967) 573. [10] H. Schmied and R.W. Fink, Phys. Rev. 107 (1957) 1062. [11] J.C. Nail, Q.L. Baird and S.K. Haynes, Phys. Rev. 118 (1960) 1278. [12] P.V. Rao and B. Crasemann, Phys. Rev. 137 (1965) B64. [13] P.V. Rao and B. Crasemann, Phys. Rev. 139 (1965) A1926. [14] J. Burde and S.G. Cohen, Phys. Rev. 104 (1956) 1985. [15] K. Risch, Z. Phys. 150 (1958) 87. [16] H. Winkenbach, Z. Phys. 152 (1958) 387. [17] M.K. Ramaswamy, Nucl. Phys. 33 (1962) 320. [18] E.T. Patronics, Jr., C.H. Braden and L.D. Wyly, Phys. Rev. 105 (1957) 681. [19] R.C. Jopson, H. Mark and C.D. Swift, Phys. Rev. 128 (1962) 2671. [20] P.V. Rao, Proc. of Conf. on Electron Capture and Higher Order Processes in Nuclear Decay (E,otvor Lorand Physical Society, Budapest, 1968) p. 222. [21] R.W. Fink, Phys. Rev. 106 (1957) 266. [22] N.K. Lee, Thesis, Vanderbilt University, U.S. Atomic Energy Commission Report, TID-14963 (1958), unpublished. [23] J. Tousset and A. Moussa, J. Phys. Radium 19 (1958) 39. [24] J.W. Halley and D. Engeikemeir, Phys. Rev. 134 (1964) A24. [25] J. Byrns, W. Gelletly, M.A.S. Ross and F. Shaikh, Phys. Rev. 170 (1968) 80. [26] L. Salguerio, J.G. Ferreira, M.T. Ramos, M.J. Bettancourt and F.B. Gil, C.R. Acad. Sci. 267A (1968) 1293. [27] M.J. Zender, W. Pou and R.G. Albridge, Z. Phys. 218 (1969) 245. [28] B. Crasemann, M.H. Chen and V.O. Kostroum, Phys. Rev. A4 (1971) 2161. [29] M.H. Chen, B. Crasemann and V.O. Kostroum, Phys. Rev. A4 (1971) 1. [30] E.J. McGurie, Phys. Rev. A3 (1971) 587. [31] M.O. Krause, C.W. Nestor, Jr., C.J. Sparks, Jr. and R. Ricci, ORNL Report No. 5399 (June 1978), unpublished. [32] W. Bambynek, B. Crasemann, R.W. Fink, H.U. Freund, H. Mark, C.D. Swift, R.E. Price and P.V. Rao, Rev. Mod. Phys. 44 (1972) 716. [33] J.H. Scofield, Lawrence Livermore Lab. Report No. UCRL-51326 (1973), unpublished.
M E A S U R E M E N T O F A V E R A G E L-SHELL FLUORESCENCE YIELDS IN E L E M E N T S 73 ~< Z ~< 92
Inderjit SINGH, Raj M I T I ' A L , K.L. A L L A W A D H I and B.S. S O O D Nuclear Science Laboratories, Department of Physics, Punjabi University, Patiala-147002, India
Received 6 September 1984 Revised 30 November 1984 The average L-shell fluorescenceyields in the elements Ta, W, Au, Hg, TI, Pb, Bi, Th and U have been measured using photoionization for creating the vacancies. The measured values are found to agree well with those calculated using the fitted values of L-shell fluorescence and the Coster-Kronig yields given by Krause et al. We have extended our earlier measurements [1] of the average L-shell fluorescence yields in elements 40~
is straightforward. The average L-shell yields were determined by comparing the intensities of the L-shell fluorescent X-rays with the 59.57 keV gamma-rays incident on the targets [1]. As the targets used in the present measurements were not infinitely thick for the incident and emitted photon energies, their self-absorption correction factors /3L were calculated using the following equation as explained in the earlier paper [1]. n
/3r = ~ PJ" 1 - exp[-(/% +/Zrj)(t/cos 0)] j=~ 0 ~ + ~,~j)(t/cos 0) ' where t is the thickness of the target, 0 the angle at which the 59.57-keV gamma-rays are incident on the target and the characteristic L X-rays are emergent from the target, pj the fractional intensity of the ]th component in a mixture of n components of the emitted L X-rays, /z r the absorption coefficient of the target material at the 59.57-keV gamma-ray energy and /ZLj the absorption coefficient of the target material at the energy of the jth components of the emitted L X-rays. In table I, the values of o3L as measured in the present experiment are compared with the other available measurements [4-27] and those calculated by using the theoretical [28-30] as well as fitted values [31] of the subshell fluorescence yields and the Coster-Kronig transition probabilities. As explained earlier [1] the values of o3L were calculated from the relation [32]
0378-4363/85/$03.30 O Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division)
I. Singh et al. / Average L-shell fluorescence yields
120
Table I Comparison of the present measurements of the average L-shell fluorescence yield o3L with the previous measurements and calculated values Average L-shell fluorescence yield t~L
Element
Present measurements
Previous measurements
Ta
0.28 -+ 0.02
0.225 -+ 0.01
[4]
0.261 -)
W
0.29 + 0.02
0.298
[5]
0.275 a) 0.272 b) 0.280 ~)
Au
0.36 - 0.02
0.365 0.374+0.018 0.430-+ 0.012
[5] [6] [7]
0.339 ~) 0.356 c)
Hg
0.38 -- 0.02
0.24 -+ 0.04 0.371-+0.035 0.24-+0.04 0.41---0.04 0.40+0.05 0.39+0.06
[8] [9] [101 [11] [12] [13]
0.353 a) 0.345 b)
TI
0.39_+0.03
0.50+0.02 0.48-+0.03 0.32 0.41 -+0.04
[14] [15] [16] [17]
0.367 a)
Pb
0.38 -+ 0.03
0.398 0.39-+ 0.02 0.29-+ 0.03 0.36 + 0.02
[5] [18] [201 [19]
0.381 a)
Bi
0.42 -+ 0.03
0.402 0.51-+0.03 0.38-+ 0.02 0.38-+ 0.04 0.37 0.40
[5] [14] [21] [22] [23] [16]
0.393 a) 0.416 c)
Th
0.49 -+ 0.03
0.480 -+ 0.008 [24]
0.489") 0.513 e)
U
0.60_+0.04
0.478-+0.009 0.603-+ 0.004 0.570 - 0.019 0.42-+ 0.01 0.53-+ 0.06
0.514")
a) Using the data of Krause et al. [31]. b) Using the data of Chen et ak [28]. c) Using the data of McGurie. [30].
Calculated values
[24] [7] [25] [261 [27]
I. Singh et al. / Average L-shell fluorescence yields 3 O)L= E ~ilJi, i=1 w h e r e n~ and vi give the relative v a c a n c y distribution and the effective fluorescence yields for the three L subshells, respectively. Scofield's theoretical values [33] of L-subshell p h o t o ionization cross-sections were used to obtain the values of n~(i -- 1, 2, 3). T h e fitted values of L subshell fluorescence yields and the C o s t e r Kronig transition probabilities o b t a i n e d by Krause et al. [31] were used to d e t e r m i n e v~(i = 1, 2, 3). F o r a few e l e m e n t s theoretical values of L subshell fluorescence yields and C o s t e r - K r o n i g transition probabilities were also available [28-30]. T h e values of the vi for these e l e m e n t s were also d e t e r m i n e d using the theoretical values. T h e values of 0.~L calculated by using these Vl-Values are listed in c o l u m n 4 of table I. It is seen that the present values for W and Th agree, within the experimental uncertainties, with the only o t h e r available experimental values, while for Ta the present value is higher by about 20 percent than the only available experimental value. H o w e v e r , it is closer to the semi-empirically fitted value of Krause. F o r Au, Hg, Tl, Pb, Bi and U a n u m b e r of experimental values using different m o d e s of v a c a n c y p r o d u c tion, have been r e p o r t e d by various authors. T h e r e is a considerable scatter a m o n g the values of different w o r k e r s ; the difference b e t w e e n the m a x i m u m and m i n i m u m values varies f r o m 15 to 60%. H o w e v e r , the present values for all the e l e m e n t s agree with m o s t of the previous values. T h e present values are also f o u n d to agree fairly well with the semi-empirical values of Krause except for U. Acknowledgement Financial assistance f r o m the U G C , Delhi, India, is gratefully a c k n o w l e d g e d .
New
References [1] N. Singh, R. Mittal, K.L. Allawadhi and B.S. Sood, Physica 123C (1983) 115.
121
[2] S.K. Arora, K.L. Allawadhi and B.S. Sood, Physica 111C (1981) 71. [3] K.L. Allawadhi, S.L. Verma, B.S. Ghumman and B.S. Sood, Physica 95C (1978) 424. [4] P.V. Rao and B. Crasemann, Phys. Rev. 142 (1966) 768. [5] H. Lay, Z. Phys. 91 (1934) 533. [6] R.C. Jopson, H. Mark, C.D. Swift and M.A. Williamson, Phys. Rev. 131 (1963) 1165. [7] M.A. di Lazzaro, Instituto Superiore di Sanita Report, ISS 65/11 (1965), unpublished. [8] H. Jaffe, Univ. Calif. Lawrence Radiation Lab. Report, UCRI-2537 (1954), unpublished. [9] S.K. Haynes, M. Velinsky and L.J. Velinsky, Nucl. Phys. A90 (1967) 573. [10] H. Schmied and R.W. Fink, Phys. Rev. 107 (1957) 1062. [11] J.C. Nail, Q.L. Baird and S.K. Haynes, Phys. Rev. 118 (1960) 1278. [12] P.V. Rao and B. Crasemann, Phys. Rev. 137 (1965) B64. [13] P.V. Rao and B. Crasemann, Phys. Rev. 139 (1965) A1926. [14] J. Burde and S.G. Cohen, Phys. Rev. 104 (1956) 1985. [15] K. Risch, Z. Phys. 150 (1958) 87. [16] H. Winkenbach, Z. Phys. 152 (1958) 387. [17] M.K. Ramaswamy, Nucl. Phys. 33 (1962) 320. [18] E.T. Patronics, Jr., C.H. Braden and L.D. Wyly, Phys. Rev. 105 (1957) 681. [19] R.C. Jopson, H. Mark and C.D. Swift, Phys. Rev. 128 (1962) 2671. [20] P.V. Rao, Proc. of Conf. on Electron Capture and Higher Order Processes in Nuclear Decay (E,otvor Lorand Physical Society, Budapest, 1968) p. 222. [21] R.W. Fink, Phys. Rev. 106 (1957) 266. [22] N.K. Lee, Thesis, Vanderbilt University, U.S. Atomic Energy Commission Report, TID-14963 (1958), unpublished. [23] J. Tousset and A. Moussa, J. Phys. Radium 19 (1958) 39. [24] J.W. Halley and D. Engeikemeir, Phys. Rev. 134 (1964) A24. [25] J. Byrns, W. Gelletly, M.A.S. Ross and F. Shaikh, Phys. Rev. 170 (1968) 80. [26] L. Salguerio, J.G. Ferreira, M.T. Ramos, M.J. Bettancourt and F.B. Gil, C.R. Acad. Sci. 267A (1968) 1293. [27] M.J. Zender, W. Pou and R.G. Albridge, Z. Phys. 218 (1969) 245. [28] B. Crasemann, M.H. Chen and V.O. Kostroum, Phys. Rev. A4 (1971) 2161. [29] M.H. Chen, B. Crasemann and V.O. Kostroum, Phys. Rev. A4 (1971) 1. [30] E.J. McGurie, Phys. Rev. A3 (1971) 587. [31] M.O. Krause, C.W. Nestor, Jr., C.J. Sparks, Jr. and R. Ricci, ORNL Report No. 5399 (June 1978), unpublished. [32] W. Bambynek, B. Crasemann, R.W. Fink, H.U. Freund, H. Mark, C.D. Swift, R.E. Price and P.V. Rao, Rev. Mod. Phys. 44 (1972) 716. [33] J.H. Scofield, Lawrence Livermore Lab. Report No. UCRL-51326 (1973), unpublished.