K-vacancy production in high-energy U+U and U+Pb collisions at small impact parameters

Molitoris, J. D.; Anholt, R.; Meyerhof, W. E.; Baker, O. K.; Andriamonje, S.; Morenzoni, E.

doi:10.1007/bf01290304

Cited by 9 publications

(21 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When we had determined a bin size such that the ratios of the x-rays to particles was constant over at least the three highest energy bins, we summed over these bins to determine the K-vacancy production probability due to atomic excitation. This technique is described in greater detail in [1] and [8].…”

Section: B Methodsmentioning

confidence: 99%

“…A major problem in measuring the ionization probability for symmetric collisions is that in general one can determine only a dominant center-of-mass scattering angle and impact parameter [1]. Each collision involves x-rays emitted from the primary scattered particle (detected in the ion chamber) and x-rays emitted from the collision partner (detected in the PP AC).…”

Section: Data Reductionmentioning

confidence: 99%

“…But, this anticoincidence method does not reject all internal conversion events due to Coulomb excitation. In our previous U + U collision studies [1], with the 7-ray anticoincidence condition in effect, the unrejected x-ray yield from nuclear Coulomb excitation never amounted to more than 17% of the atomic K x-ray yield. In the present work, which did not use the anticoincidence method, the x-ray yield due to internal conversion from Coulomb excitation was as large as 33% of the atomic K x-ray yield at the largest scattering angles.…”

Section: Introductionmentioning

confidence: 99%

“…This increase in the internal conversion contribution to the K x-ray yield is probably due to the absence of the anticoincidence condition. Although the anticoincidence technique helped to eliminate some 7-ray internal conversion effects in our U + U collision studies [1], we determined that a measurement of the K-vacancy 3 production probability in U + U collisions could be made without it.…”

Section: Introductionmentioning

confidence: 99%

“…In previous work [1], we measured K-shell ionization probabilities for U+U collisions at 4.6-, 5.8-, and 7.3-MeV fa.m.u. for impact parameters (b) as large as 85 fm.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

K-shell ionization in 7.5- and 8.6-MeV/a.m.u. U+U collisions at very small impact parameters

Molitoris

Stoller

Anholt

et al. 1986

Z Phys D - Atoms, Molecules and Clusters

Self Cite

View full text Add to dashboard Cite

Section: B Methodsmentioning

confidence: 99%

Section: Data Reductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…In previous work [1], we measured K-shell ionization probabilities for U+U collisions at 4.6-, 5.8-, and 7.3-MeV fa.m.u. for impact parameters (b) as large as 85 fm.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

K-shell ionization in 7.5- and 8.6-MeV/a.m.u. U+U collisions at very small impact parameters

Molitoris

Stoller

Anholt

et al. 1986

Z Phys D - Atoms, Molecules and Clusters

Self Cite

View full text Add to dashboard Cite

Measurements of theK-vacancy production probability in very heavy collision systems at 1.4 MeV/N projectile energy

Liesen

Liu

Warczak

1986

Z. Physik A - Atomic Nuclei

View full text Add to dashboard Cite

The impact parameter dependence of the K-vacancy production probability in 1.4 MeV/N collisions between very heavy ions and atoms has been determined by K x-rayscattered particle coincidence measurements. The results are interpreted in terms of the molecular lso-and 2pa excitation probabilities. From a comparison to two empirical models a connection between these models is obtained and the energy transfers involved are extracted.

show abstract

Angular correlations of electron-positron pairs produced in heavy-ion collisions

Graf

Reinhardt

Reus

et al. 1987

Z. Physik A - Atomic Nuclei

View full text Add to dashboard Cite

We investigate the strength of angular correlations between coincident electron-positron pairs produced in Pb + Pb collisions at 5.7 MeV/u. The angular correlations are predicted to be observable at electron energies above 200 keV, almost independent of positron energy. 25.70; 34.50.F The EPOS collaboration at GSI has recently reported narrow structures in the difference and sum spectra of e + -e--coincidences in heavy-ion collisions [-1-3]. This gives new insight into the nature of peaks in the positron singles spectra observed earlier [4,5]. Various mechanisms have been invoked as explanation of these structures, among them the possible creation of a new, elementary light boson decaying into an e + -e --p a i r [6 9], and the presence of sudden rearrangements in the quasimolecular energy levels [10][11][12][13][14][15]. PACS:In order to determine the source of these structures a thorough understanding of the atomic excitation processes acting at small internuclear distance and producing the structureless spectra [-3, 5, 16] is required. In particular, the knowledge of possible angular correlations between coincident electron-positron pairs, which are expected due to interference between partial waves with different parity and angular momentum [17,18], is of interest.In this letter we present first numerical results based on the formalism developed in Ref. 19 for the system Pb + Pb at 5.7 MeV/u. We investigate angular correlations between electrons emitted with energy E e into the direction ke/[ ke [ and coincident positrons of energy Ep emitted into the direction kv/] kv]. The * We dedicate this work to Prof. J.S. Greenberg (Yale University) on the occassion of his 60th birthday solutions for electronic continuum states 7~,~,, obtained in a basis of spherical waves must be transformed to a basis set of plane wave states 7~k, a, where k describes the momentum and 2 the helicity of the particle. Expanding the second quantized electronpositron field operator ~ in both basis sets, one derives a canonical transformation between the number operators for electrons and positrons in both basis sets. Denoting by d/+ and /~i the creation operators for holes and annihilation operators for particles respectively, and using the label i as abbreviation for the quantum numbers (ki, 2i), the number of pairs consisting of the plane wave states i and j is given by [19]:

show abstract

K-vacancy production in high-energy U+U and U+Pb collisions at small impact parameters

Abstract: Projectile and target K-vacancy production probabilities in 4.6-, 5.8-and 7.3-MeV/a.m.u. U +U and U + Pb collisions are reported for impact parameters between 10 and 85 fm. These probability measurements are compared with available theory.

Cited by 9 publications

References 16 publications

K-shell ionization in 7.5- and 8.6-MeV/a.m.u. U+U collisions at very small impact parameters

K-shell ionization in 7.5- and 8.6-MeV/a.m.u. U+U collisions at very small impact parameters

Measurements of theK-vacancy production probability in very heavy collision systems at 1.4 MeV/N projectile energy

Angular correlations of electron-positron pairs produced in heavy-ion collisions

Contact Info

Product

Resources

About