The principle of laser wakefield accelerators: A high-power laser excites a charge wave in a plasma, which propagates at the speed of the laser pulse and pulls electrons behind it in its "wake", thus accelerating them.

Electron energies in the GeV range have been achievable with this technique for some time. However, the electron bunches produced in this way have so far been too small and too poorly focused to use the synchrotron radiation they emit, an intense, coherent light that is used for research in many different disciplines.

For the further development of the technology, a method is therefore needed to precisely measure and control the cross-section and quality of the electron bunches individually. PTB's storage ring, the Metrology Light Source (MLS), allows the generation of small electron bunches in flexible research operation, which are very similar to those of laser wakefield accelerators, but whose properties can be set and varied very reproducibly and precisely.

A team at HZB and PTB has now developed a method to measure the lateral expansion of the electron beam of a laser plasma accelerator with a resolution in the micrometre range.

"To do this, we use a technique that is successfully employed at the Bessy II storage ring," explains Thorsten Kamps, co-author of the study.

First author Ji-Gwang Hwang had the idea of using the coherent radiation of electron pulses in the visible range via the phenomenon of interference (double slit) and determining the beam cross-section as a deviation from a perfect point source.

With the help of a highly sensitive camera and complex algorithms, the team succeeded in measuring the lateral beam size in the range of a few micrometres. Katharina Albrecht carried out the measurements as part of her bachelor's thesis in physics.

"We worked very closely with our colleagues from the (MLS) at PTB for this project," Kamps emphasises. "There, it is possible to imitate the electron beam from a plasma accelerator on a beamline and thus test the method under realistic conditions," says Kamps.

Research Report: "Monitoring the size of low-intensity beams at plasma-wakefield accelerators using high-resolution interferometry"

Related Links
Helmholtz-Zentrum Berlin
Space Technology News - Applications and Research

Tweet

Thanks for being here; We need your help. The Space Media Network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceMediaNetwork Contributor $5 Billed Once credit card or paypal		SpaceMediaNetwork Monthly Supporter $5 Billed Monthly paypal only

Now we're cooking with lasers
New York NY (SPX) Sep 20, 2021
Imagine having your own digital personal chef; ready to cook up whatever you want; able to tailor the shape, texture, and flavor just for you; and it's all at the push of a button. Columbia engineers have been working on doing just that, using lasers for cooking and 3D printing technology for assembling foods. Under the guidance of Mechanical Engineering Professor Hod Lipson, the "Digital Food" team of his Creative Machines Lab has been building a fully autonomous digital personal chef. Lipson's g ... read more