-
2
-
-
5544290247
-
-
L. Spielberger, O. Jagutzki, B. Krässig, U. Meyer, Kh. Khayyat, V. Mergel, Th. Tschentscher, Th. Buslaps, H. Bräuning, R. Dörner, T. Vogt, M. Achler, J. Ullrich, D. S. Gemmell, and H. Schmidt-Böcking, Phys. Rev. Lett. 76, 4685 (1996).
-
(1996)
Phys. Rev. Lett.
, vol.76
, pp. 4685
-
-
Spielberger, L.1
Jagutzki, O.2
Krässig, B.3
Meyer, U.4
Khayyat, K.5
Mergel, V.6
Tschentscher, T.7
Buslaps, T.8
Bräuning, H.9
Dörner, R.10
Vogt, T.11
Achler, M.12
Ullrich, J.13
Gemmell, D.S.14
Schmidt-Böcking, H.15
-
3
-
-
85037249769
-
-
X-ray and Inner-shell Processes, edited by P. Lagarde, F. J. Wuilleumier, and J. P. Briand, special issue of J. Phys. (Paris) Colloq. 48, C9-48 (1987)
-
X-ray and Inner-shell Processes, edited by P. Lagarde, F. J. Wuilleumier, and J. P. Briand, special issue of J. Phys. (Paris) Colloq. 48, C9-48 (1987).
-
-
-
-
4
-
-
0003581579
-
-
AIP, Woodbury, NY see section written by Bernd Crasemann, p. 701
-
Atomic, Molecular and Optical Physics Handbook, edited by G. W Drake (AIP, Woodbury, NY, 1996);see section written by Bernd Crasemann, p. 701.
-
(1996)
Atomic, Molecular and Optical Physics Handbook
-
-
-
6
-
-
4243218044
-
-
A. Belkacem, H. Gould, B. Feinberg, R. Bossingham, and W. E. Meyerhof, Phys. Rev. A 56, 2806 (1997).
-
(1997)
Phys. Rev. A
, vol.56
, pp. 2806
-
-
Belkacem, A.1
Gould, H.2
Feinberg, B.3
Bossingham, R.4
Meyerhof, W.E.5
-
7
-
-
0000896395
-
-
K. Rumrich, K. Momberger, G. Soff, W. Greiner, N. Grün, and W. Scheid, Phys. Rev. Lett. 66, 2613 (1991).
-
(1991)
Phys. Rev. Lett.
, vol.66
, pp. 2613
-
-
Rumrich, K.1
Momberger, K.2
Soff, G.3
Greiner, W.4
Grün, N.5
Scheid, W.6
-
11
-
-
11644317942
-
-
R. Dörner, H. Bräuning, J. M. Feagin, V. Mergel, O. Jagutzki, L. Spielberger, T. Vogt, H. Khemliche, M. H. Prior, J. Ullrich, C. L. Cocke, and H. Schmidt-Böcking, Phys. Rev. A 57, 1074 (1998).
-
(1998)
Phys. Rev. A
, vol.57
, pp. 1074
-
-
Dörner, R.1
Bräuning, H.2
Feagin, J.M.3
Mergel, V.4
Jagutzki, O.5
Spielberger, L.6
Vogt, T.7
Khemliche, H.8
Prior, M.H.9
Ullrich, J.10
Cocke, C.L.11
Schmidt-Böcking, H.12
-
21
-
-
85037183130
-
-
This assumption may seem somewhat questionable, in particular, since, as is well known, screening plays an important role in moderating pair production at high energies, that is, in preventing an unlimited logarithmic growth of the cross section with increasing photon energy, cf. Eq. (11). The fact that screening is important at high photon energies means that distances of the order of the Thomas-Fermi screening length (Formula presented) are of importance at such energies. In an attempt to improve on the distribution in direct space, the distribution in recoil momentum could be inverted. We shall not embark on such a procedure. Instead we note that if we integrate the pair creation cross section (for screened nuclei) as given by Ter-Mikaelian
-
This assumption may seem somewhat questionable, in particular, since, as is well known, screening plays an important role in moderating pair production at high energies, that is, in preventing an unlimited logarithmic growth of the cross section with increasing photon energy, cf. Eq. (11). The fact that screening is important at high photon energies means that distances of the order of the Thomas-Fermi screening length (Formula presented) are of importance at such energies. In an attempt to improve on the distribution in direct space, the distribution in recoil momentum could be inverted. We shall not embark on such a procedure. Instead we note that if we integrate the pair creation cross section (for screened nuclei) as given by Ter-Mikaelian 23 only over recoil momenta larger than (Formula presented) where (Formula presented) is the K-shell radius, then we obtain (Formula presented) and (Formula presented) at energies of (Formula presented) and (Formula presented) for impact on a lead target. So even at such high energies and for such a heavy target we expect our estimate (19) for the density factor to be good within a factor of, roughly, 2.
-
-
-
-
22
-
-
85037236488
-
-
H. A. Bethe and J. Ashkin, in Experimental Nuclear Physics, edited by E. Segrè (Wiley, New York, 1953), Vol. I, p. 166
-
H. A. Bethe and J. Ashkin, in Experimental Nuclear Physics, edited by E. Segrè (Wiley, New York, 1953), Vol. I, p. 166.
-
-
-
-
33
-
-
0003851731
-
-
Dover, New York
-
Handbook of Mathematical Functions, edited by M. Abramowitz and I. A. Stegun (Dover, New York, 1965).
-
(1965)
Handbook of Mathematical Functions
-
-
-
36
-
-
84913289526
-
-
J. H. Hubbell, W. J. Veigele, E. A. Briggs, R. T. Brown, D. T. Cromer, and R. J. Howerton, J. Phys. Chem. Ref. Data 4, 471 (1975).
-
(1975)
J. Phys. Chem. Ref. Data
, vol.4
, pp. 471
-
-
Hubbell, J.H.1
Veigele, W.J.2
Briggs, E.A.3
Brown, R.T.4
Cromer, D.T.5
Howerton, R.J.6
|