Current-Iteration Non-Causal Iterative Learning Control for Beam Loading Cancellation in Particle Accelerators

Shahriari, Zahra; Dumont, Guy A.; Fong, K.

doi:10.1109/icsc47195.2019.8950532

Cited by 4 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This alone, however, could not compensate the effect of the long-term fluctuations in the system, such as variations of a klystron gain and amount of the beam loading. At other facilities around the world, the interactive learning control (ILC) algorithm has been proved to be very effective against the iterative errors [4][5][6][7][8][9][10][11]. Therefore, we secondary developed the ILC scheme of the adaptive beam-loading compensation for the J-PARC LINAC [12].…”

Section: Jinst 17 T11002mentioning

confidence: 99%

Development of the novel and superior adaptive beam-loading compensation system calculated in the frequency domain for the J-PARC Linac

et al. 2022

View full text Add to dashboard Cite

The Japan Proton Accelerator Research Complex (J-PARC) is one of the highest intensity proton accelerator facilities in the world. Its accelerator consists of a 400-MeV linac (LINAC), a 3-GeV rapid-cycling synchrotron (RCS), and a 30-GeV main ring (MR) and its beam is provided for wide-ranging applications. The peak current of the beam at LINAC had been increased from 30 mA to the design value of 50 mA in 2018. Therefore, the performance of the beam-loading compensation implementing in the low-level radio frequency (LLRF) system has been more important to satisfy the stability of the accelerating gradient. Although the iterative learning control (ILC) scheme with adaptive ability was demonstrated, the practical use of ILC was not convenient for large accelerators such as the J-PARC LINAC with forty-nine RF stations. Therefore, we developed at novel and superior adaptive beam-loading compensation system that was calculated in the frequency domain. Compared to the scheme of the previous ILC, the newly developed system is useful because it does not require parameter adjustment using the beam. In the experimental results utilizing this system, the optimum tables of FF_BEAM were able to be obtained as a smaller number of iterations. The peak-to-peak stability of amplitude was achieved to ± 0.23% and the peak-to-peak stability of phase was improved to ± 0.036°. In addition, errors such as white noise did not accumulate for the table of FF_BEAM and this system solved the problem of the divergence when the number of iterations was increased. This implementation of the adaptive beam-loading compensation system calculated in the frequency domain will potentially contribute to the improvement of the J-PARC LINAC LLRF, and this system may lead to a stable user operation. This system is so simple in principle and effective that it could be applied to other linear accelerators with the pulsed beam.

show abstract

Section: Jinst 17 T11002mentioning

confidence: 99%

Development of the novel and superior adaptive beam-loading compensation system calculated in the frequency domain for the J-PARC Linac

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Additionally, simulations using the Iterative Learning Control (ILC) algorithm are presented in Section 4 [13]. Such an algorithm is already in use in particle accelerators for RF and beam trasient compensation [14][15][16][17]. The advantage of using ILC is that repetitive un-modeled detuning disturbances can be rejected in an adaptive way.…”

Section: Introductionmentioning

confidence: 99%

Feedforward resonance control for the European X-ray free electron laser high duty cycle upgrade

et al. 2023

View full text Add to dashboard Cite

The High Duty Cycle (HDC) upgrade is a proposed improvement to the existing European X-ray Free Electron Laser (EuXFEL) to extend the pulsed RF duty factor from the actual value of around 1% to more than 5% up to Continuous Wave (CW). To implement this upgrade, the loaded quality factor (QL) of the superconducting cavities will increase by more than one order of magnitude. This will result in shrinking the cavity bandwidth to values as low as a few Hertz. Since the Lorentz Force Detuning (LFD) experienced during the accelerating field buildup is of hundreds of Hertz, the Low-Level RF (LLRF) system has to accurately track and control the cavity resonance frequency to obtain the desired accelerating gradient. Moreover, ponderomotive instabilities have to be suppressed to achieve stability during beam acceleration. Since LFD is a repetitive disturbance in cavity frequency, the correction to its effects can be implemented as a feedforward compensation on the piezoelectric tuners of the cavity. Initial results on the simulation of feedforward resonance control in the HDC regime are discussed in this proceeding.

show abstract

Iterative Learning Control for Beam Loading Cancellation in Electron Linear Accelerator

2021

View full text Add to dashboard Cite

Current-Iteration Non-Causal Iterative Learning Control for Beam Loading Cancellation in Particle Accelerators

Cited by 4 publications

References 12 publications

Development of the novel and superior adaptive beam-loading compensation system calculated in the frequency domain for the J-PARC Linac

Development of the novel and superior adaptive beam-loading compensation system calculated in the frequency domain for the J-PARC Linac

Feedforward resonance control for the European X-ray free electron laser high duty cycle upgrade

Iterative Learning Control for Beam Loading Cancellation in Electron Linear Accelerator

Contact Info

Product

Resources

About