학술논문
Kinematically complete experimental study of Compton scattering at helium atoms near the ionization threshold
Document Type
Working Paper
Author
Kircher, Max; Trinter, Florian; Grundmann, Sven; Vela-Perez, Isabel; Brennecke, Simon; Eicke, Nicolas; Rist, Jonas; Eckart, Sebastian; Houamer, Salim; Chuluunbaatar, Ochbadrakh; Popov, Yuri V.; Volobuev, Igor P.; Bagschik, Kai; Piancastelli, Maria Novella; Lein, Manfred; Jahnke, Till; Schöffler, Markus S.; Dörner, Reinhard
Source
Nature Physics 16, 756-760 (2020)
Subject
Language
Abstract
Compton scattering is one of the fundamental interaction processes of light with matter. Already upon its discovery [1] it was described as a billiard-type collision of a photon kicking a quasi-free electron. With decreasing photon energy, the maximum possible momentum transfer becomes so small that the corresponding energy falls below the binding energy of the electron. Then ionization by Compton scattering becomes an intriguing quantum phenomenon. Here we report a kinematically complete experiment on Compton scattering at helium atoms below that threshold. We determine the momentum correlations of the electron, the recoiling ion, and the scattered photon in a coincidence experiment finding that electrons are not only emitted in the direction of the momentum transfer, but that there is a second peak of ejection to the backward direction. This finding links Compton scattering to processes as ionization by ultrashort optical pulses [2], electron impact ionization [3,4], ion impact ionization [5,6], and neutron scattering [7] where similar momentum patterns occur.
Comment: 7 pages, 4 figures
Comment: 7 pages, 4 figures