Journal Article

PUBDB-2025-02459

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Improved laser-plasma accelerator stability via high-bandwidth longitudinal focal position stabilization of 100 TW-class laser system

Einstein-Curtis, J.DESY* ; Jensen, K. (Corresponding author)Extern* ; Barber, S. ; Cook, N. (Corresponding author) ; Edelen, J. ; Coleman, S. ; Doss, C. ; Kohrell, F. ; van Tilborg, J. ; Berger, C.

2025
American Physical Society College Park, MD

Abstract: Laser-plasma accelerators (LPAs) offer an attractive alternative to conventional accelerators for the development of compact electron sources and next-generation light sources. Due to orders-of-magnitude larger accelerating gradients, LPAs enable the acceleration of high-brightness electron beams to ultra-relativistic energies in millimeter- to centimeter-scale distances. However, LPA stability is limited by shot-to-shot fluctuations of the driving laser system. Specifically, fluctuations in the final-focus longitudinal position result in correlated instability in LPA electron beam qualities, including total beam charge, average beam energy, and energy spread. We demonstrate active stabilization of the longitudinal focal position for a 100 TW-class laser system. This repetition-rate scalable stabilization system leverages non-invasive wavefront monitoring of a copropagating, unamplified kHz pulse train to guide corrective adjustments to the focal position of a 1 Hz amplified drive laser via an upstream telescope on millisecond timescales. In this demonstration, the approach limits standard deviation fluctuations of the amplified drive beam's longitudinal focal position to +- 0.22mm (representing at least a 53% reduction), achieved with a correction bandwidth that reaches the Nyquist frequency limit. Consequently, we observe marked improvements in both long-term and shot-to-shot LPA stability in terms of charge and spectrum.

---

Research Program(s):

1. 621 - Accelerator Research and Development (POF4-621) (POF4-621)
2. 623 - Data Management and Analysis (POF4-623) (POF4-623)

Experiment(s):

1. No specific instrument

---

Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---