cern | RL4AA Collaboration

AWAKE beamline showing location of the matching devices (actions) and the observation BTV.

Towards automatic setup of 18 MeV electron beamline using machine learning

F. M. Velotti1, B. Goddard1, V. Kain1, R. Ramjiawan1, G. Z. Della Porta1 and S. Hirlaender2 1CERN, 2University of Salzburg Machine Learning: Science and Technology Abstract To improve the performance-critical stability and brightness of the electron bunch at injection into the proton-driven plasma wakefield at the AWAKE CERN experiment, automation approaches based on unsupervised machine learning (ML) were developed and deployed. Numerical optimisers were tested together with different model-free reinforcement learning (RL) agents....

Episodes from the best NAF2 agent and the PI controller with the same initial states and with a varying additive Gaussian action noise with zero mean and standard deviation as a percentage of the half action space [0, 1]. (A) 0%, (B) 10%, (C) 25%, and (D) 50% Gaussian action noise.

Application of reinforcement learning in the LHC tune feedback

L. Grech1, G. Valentino1, D. Alves2 and Simon Hirlaender3 1University of Malta, 2CERN, 3University of Salzburg Frontiers in Physics Abstract The Beam-Based Feedback System (BBFS) was primarily responsible for correcting the beam energy, orbit and tune in the CERN Large Hadron Collider (LHC). A major code renovation of the BBFS was planned and carried out during the LHC Long Shutdown 2 (LS2). This work consists of an explorative study to solve a beam-based control problem, the tune feedback (QFB), utilising state-of-the-art Reinforcement Learning (RL)....

Success rate of the various algorithms over initial beam intensity.

Automated Intensity Optimisation Using Reinforcement Learning at LEIR

N. Madysa, V. Kain, R. Alemany Fernandez, N. Biancacci, B. Goddard, F. M. Velotti CERN 13th Particle Accelerator Conference Abstract High intensities in the Low Energy Ion Ring (LEIR) at CERN are achieved by stacking several multi-turn injec- tions from the pre-accelerator Linac3. Up to seven consec- utive 200 μs long, 200 ms spaced pulses are injected from Linac3 into LEIR. Two inclined septa, one magnetic and one electrostatic, combined with a collapsing horizontal or- bit bump allows a 6-D phase space painting via a linearly ramped mean momentum along the Linac3 pulse and in- jection at high dispersion....

Online training of NAF Agent of AWAKE electronline trajectory steering in the horizontal plane.

Test of Machine Learning at the CERN LINAC4

V. Kain1, N. Bruchon1, S. Hirlander1, N. Madysa1, I. Vojskovic1, P. Skowronski1, G. Valentino2 1CERN, 2University of Malta 61st ICFA ABDW on High-Intensity and High-Brightness Hadron Beams Abstract The CERN H−linear accelerator, LINAC4, served as atest bed for advanced algorithms during the CERN LongShutdown 2 in the years 2019/20. One of the main goals wasto show that reinforcement learning with all its benefits canbe used as a replacement for numerical optimization and asa complement to classical control in the accelerator controlcontext....

The RL paradigm as applied to particle accelerator control, showing the example of trajectory correction.

Sample-efficient reinforcement learning for CERN accelerator control

V. Kain1, S. Hirlander1, B. Goddard1, F. M. Velotti1, G. Z. Della Porta1, N. Bruchon2, G. Valentino3 1CERN, 2University of Trieste, 3University of Malta Physical Review Accelerators and Beams Abstract Numerical optimization algorithms are already established tools to increase and stabilize the performance of particle accelerators. These algorithms have many advantages, are available out of the box, and can be adapted to a wide range of optimization problems in accelerator operation....