Ratio of positron to electron bremsstrahlung energy loss: An approximate scaling law

Journal Article · Thu May 01 04:00:00 EDT 1986 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.33.3002· OSTI ID:5974029

Kim, L; Pratt, R H; Seltzer, S M; Berger, M J

We have calculated the total energy loss of an incident electron or positron due to the bremsstrahlung radiation from various atoms during a scattering. The kinetic energies considered for the incident electrons and positrons were 10, 50, and 500 keV. The calculations were performed with our relativistic partial-wave multipole-expansion numerical code (H. K. Tseng and R. H. Pratt, Phys. Rev. A 3, 100 (1971)). The differences between the radiative energy loss of positrons and electrons are considerable and cannot be disregarded. We observe that the ratio of the radiative energy loss for positrons to that for electrons obeys a simple scaling law, being expressible fairly accurately as a function only of the quantity T/sub 1//Z/sup 2/, where T/sub 1/ is the incident-particle kinetic energy and Z is the atomic number of the scatterer. This scaling law makes it possible to obtain the energy loss for positrons from existing electron bremsstrahlung data. The scaling is exact in the case of the point Coulomb potential, both in the classical bremsstrahlung formula and the nonrelativistic dipole Sommerfeld formula, not only for the ratio of total energy losses but also for the separate energy losses and even for the radiation energy spectrum. In the screened case scaling is significantly broken for the spectrum and for the total energy loss but remains fairly good for the ratio of the total energy losses. We will discuss scaling features of bremsstrahlung radiation energy loss and the behavior for both high and low energies.

• Research Organization: Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
• OSTI ID: 5974029
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 33:5; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOMIC NUMBER
BREMSSTRAHLUNG
COLLISIONS
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ENERGY
ENERGY LOSSES
ENERGY RANGE
HOT PLASMA
KEV RANGE
KEV RANGE 10-100
KEV RANGE 100-1000
KINETIC ENERGY
LOSSES
PLASMA
POSITRON COLLISIONS
POSITRON-ATOM COLLISIONS
RADIATIONS
RADIATIVE DECAY
SCALING LAWS
STOPPING POWER