Illustration
Physicists at Chalmers present a way to generate an ultrafast “attosecond betatron radiation pulse train”. High-intensity X-ray sources are essential diagnostic tools for science, technology and medicine​.​​
​Illustration:  Vojtěch Horný 

Generating an ultrafast train of promising X-ray pulses

High-intensity X-ray sources are essential diagnostic tools for science, technology and medicine. Such X-ray sources can be produced in laser-plasma accelerators, where electrons emit short-wavelength radiation due to their betatron oscillations in the plasma wake of a laser pulse. 
In a recent paper, published in Scientific reports,​ Vojtěch Horný and Tünde Fülöp at the Department of Physics at Chalmers, present a way to generate an ultrafast “attosecond betatron radiation pulse train”. 

​“It improves the resolution of diagnostics techniques based on betatron radiation by an order of magnitude. The promising applications include the X-ray absorption spectroscopy of warm dense matter or the scanning of fundamental processes such as chemical reactions and phase transitions occurring at the timescale of femtoseconds,” says researcher Vojtěch Horný at the Department of Physics at Chalmers.

Betatron radiation is the hard X-rays which are emitted by electrons accelerated at the plasma wave after the intense laser interaction with a gaseous target. The researchers modified such a scheme by adding another delayed laser pulse, which separates the accelerated electron bunch into a series of equidistant micro-bunches.

As a result, the emitted betatron radiation is modulated as well and can thus be interpreted as a train of the attosecond X-ray pulses - separated by the half of the modulator pulse wavelength
The new results are published in collaboration with colleagues in the Czech Republic and China. 

Text: Mia Halleröd Palmgren​

For more information, please contact: 

Vojtěch Horný , Researcher, Department of Physics, Chalmers University of Technolgy, vojtech.horny@chalmers.se ​

Tünde Fülöp,​ Professor, Department of Physics, Chalmers University of Technology, tunde.fulop@chalmers.se

Published: Mon 28 Sep 2020.