Editing Bremsstrahlung (section)

== Polarizational bremsstrahlung ==
Polarizational bremsstrahlung (sometimes referred to as "atomic bremsstrahlung") is the radiation emitted by the target's atomic electrons as the target atom is polarized by the Coulomb field of the incident charged particle.<ref>''Polarization Bremsstrahlung on Atoms, Plasmas, Nanostructures and Solids'', by V. Astapenko</ref><ref>''New Developments in Photon and Materials Research'', Chapter 3: "Polarizational Bremsstrahlung: A Review", by S. Williams</ref> Polarizational bremsstrahlung contributions to the total bremsstrahlung spectrum have been observed in experiments involving relatively massive incident particles,<ref>{{cite journal | last=Ishii | first=Keizo | title=Continuous X-rays produced in light-ion–atom collisions | journal=Radiation Physics and Chemistry | publisher=Elsevier BV | volume=75 | issue=10 | year=2006 | issn=0969-806X | doi=10.1016/j.radphyschem.2006.04.008 | pages=1135–1163| bibcode=2006RaPC...75.1135I }}</ref> resonance processes,<ref>{{cite journal | last1=Wendin | first1=G. | last2=Nuroh | first2=K. | title=Bremsstrahlung Resonances and Appearance-Potential Spectroscopy near the 3d Thresholds in Metallic Ba, La, and Ce | journal=Physical Review Letters | publisher=American Physical Society (APS) | volume=39 | issue=1 | date=1977-07-04 | issn=0031-9007 | doi=10.1103/physrevlett.39.48 | pages=48–51| bibcode=1977PhRvL..39...48W }}</ref> and free atoms.<ref>{{cite journal | last1=Portillo | first1=Sal | last2=Quarles | first2=C. A. | title=Absolute Doubly Differential Cross Sections for Electron Bremsstrahlung from Rare Gas Atoms at 28 and 50 keV | journal=Physical Review Letters | publisher=American Physical Society (APS) | volume=91 | issue=17 | date=2003-10-23 | issn=0031-9007 | doi=10.1103/physrevlett.91.173201 | page=173201| pmid=14611345 | bibcode=2003PhRvL..91q3201P }}</ref> However, there is still some debate as to whether or not there are significant polarizational bremsstrahlung contributions in experiments involving fast electrons incident on solid targets.<ref>{{cite journal | last1=Astapenko | first1=V. A. | last2=Kubankin | first2=A. S. | last3=Nasonov | first3=N. N. | last4=Polyanskiĭ | first4=V. V. | last5=Pokhil | first5=G. P. | last6=Sergienko | first6=V. I. | last7=Khablo | first7=V. A. | title=Measurement of the polarization bremsstrahlung of relativistic electrons in polycrystalline targets | journal=JETP Letters | publisher=Pleiades Publishing Ltd | volume=84 | issue=6 | year=2006 | issn=0021-3640 | doi=10.1134/s0021364006180019 | pages=281–284| bibcode=2006JETPL..84..281A | s2cid=122759704 }}</ref><ref>{{cite journal | last1=Williams | first1=Scott | last2=Quarles | first2=C. A. | title=Absolute bremsstrahlung yields at 135° from 53-keV electrons on gold film targets | journal=Physical Review A | publisher=American Physical Society (APS) | volume=78 | issue=6 | date=2008-12-04 | issn=1050-2947 | doi=10.1103/physreva.78.062704 | page=062704| bibcode=2008PhRvA..78f2704W }}</ref><ref>{{cite journal |title=Measurements of electron bremsstrahlung double-differential cross sections for solid targets down to low photon energies: No polarization contribution |journal=Physical Review A |url=https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.L020802}}</ref>

It is worth noting that the term "polarizational" is not meant to imply that the emitted bremsstrahlung is polarized. Also, the angular distribution of polarizational bremsstrahlung is theoretically quite different than ordinary bremsstrahlung.<ref>{{cite journal | last1=Gonzales | first1=D. | last2=Cavness | first2=B. | last3=Williams | first3=S. | title=Angular distribution of thick-target bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on Ag | journal=Physical Review A | volume=84 | issue=5 | date=2011-11-29 | issn=1050-2947 | doi=10.1103/physreva.84.052726 | page=052726| arxiv=1302.4920 | bibcode=2011PhRvA..84e2726G | s2cid=119233168 }}</ref>