Search arXivSearch

arXiv · 2601.10694

Increasing the opening speed of the plasma opening switch on an direct action accelerator with an inductive energy storage device

Abstract

To increase the voltage multiplication factor in a small-sized direct-acting electron accelerator DIN-2K with an inductive energy storage and a plasma opening switch, it is necessary to ensure an increase in the rate of change of the current and its amplitude during the POS opening for the purpose of obtaining an explosive electron emission with the formation of an electron beam and a virtual cathode. However, the opening process depends on many electrical parameters of the plant, and it re-quires determining their joint and individual effect on its dynamics. The purpose of this research is to study and determine the effects of electrical parameters, including those of the discharge voltages of the entire electrical circuit of the accelerator on the dynamics of the plasma opening switch, in particular opening speed, current amplitudes, and opening time, as well as to give recommendations on optimizing the operation of accelerators of this type and highlight possible ways to increase the voltage multiplication factor. Methodology. A method for determining the induced voltage according to experimental current oscillograms has been proposed. The methodology was verified by the coincidence of its data with the results of measurements by a capacitive voltage divider with the data spread of less than 20%. Scientific novelty. The rates of change in the current at the plasma switch opening stage were determined depending on the main electrical parameters of the DIN-2K accelerator. The diagnostics of the voltage induced during the POS opening were provided using no capacitive voltage divider in the internal volume of the accelerator, which enabled the removal of some diagnostic tools from the working volume of the chamber. Practical significance.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D. V. Vinnikov, O. M. Ozerov, V. V. Katrechko, V. I. Tkachov, O. V. Manuilenko, I. N. Onishchenko. 2026-01-15. Increasing the opening speed of the plasma opening switch on an direct action accelerator with an inductive energy storage device. https://arxiv.org/abs/2601.10694

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

High-power attosecond X-ray free-electron lasers: physics and design strategy

Attosecond pulses from X-ray free-electron laser (XFEL) have opened new opportunities for probing ultrafast electronic dynamics on the Angstrom--attosecond spatiotemporal scale. Most attosecond XFEL concepts rely on generating an ultrashort high-current spike through either external laser modulation or accelerator-based beam manipulation. Despite their different implementations, these approaches share the same essential physics, namely that the XFEL amplification is confined to a short effective lasing window within the electron beam. However, existing studies are often scheme-specific and do not yet provide a unified quantitative picture of how fundamental electron-beam properties constrain high-power attosecond performance. In this work, we investigate the general physics and scheme-independent requirements for generating high-power attosecond X-ray pulses from a short current spike. From the perspective of post-saturation superradiant evolution, we show that the effective lasing length of the electron beam governs both the attainable peak power and the pulse duration. We further examine the distinct roles of slice energy spread, slice emittance, energy chirp, undulator tapering, and transverse beam tilt. Our results reveal the trade-off between peak power, pulse shortening, and single-spike probability, and provide facility-independent guidelines for optimizing electron-beam phase-space manipulation toward terawatt-class attosecond XFEL operation.

physics.acc-ph

Bayesian Optimization of The Relativistic Heavy Ion Collider Luminosity via $s^*$ Control

Maximizing luminosity at the interaction point (IP) requires the collision location $s_{IP}$ to coincide with the longitudinal position of the minimum beta function, $s^$. Accurate optics measurements and control of $s^$ are therefore essential for luminosity optimization. At the Relativistic Heavy Ion Collider (RHIC), average horizontal beta-beat measurements between operating IPs are approximately $20%$, with significant variation in measured $s^*$. Precise control of the beam waist position $s^$ is particularly challenging for modern high-energy colliders with short bunch lengths and large crossing angles. We present an online Bayesian optimization (BO) application using the GPTune framework to optimize sPHENIX luminosity through $s^$ control at RHIC. GPTune was first validated at the RHIC Electron Beam Ion Source (EBIS), where it achieved up to a $70%$ increase in beam intensity over the baseline, although experienced operators could reach similar performance with longer manual tuning. The framework was subsequently deployed during sPHENIX operations. Using an intensity-normalized Zero-Degree Calorimeter (ZDC) signal as the optimization objective, due to the unavailability of the live sPHENIX MVTX signal, GPTune identified local luminosity maxima, recovered from intentionally degraded $s^$ configurations, and revealed residual horizontal and vertical waist offsets in the interaction region. These results demonstrate the robustness and efficiency of Bayesian optimization for real-time collider tuning under noisy, time-varying conditions. The $s^$ control methodology provides a promising tool for precision luminosity optimization and is particularly relevant to next-generation short-bunch colliders such as the Electron-Ion Collider (EIC).

physics.acc-ph

Ultralow Mean Transverse Energy and High Quantum Efficiency Cryogenic Bialkali Photocathode for MHz-Repetition-Rate Electron Sources

Simultaneously achieving high quantum efficiency (QE), ultralow mean transverse energy (MTE), and robust long-term operation under conditions relevant to continuous-wave (CW) X-ray free-electron lasers (XFELs) remains a central challenge for semiconductor photocathodes. This challenge arises from the trade-off between QE and MTE, as well as the difficulty of maintaining stable operation in high-field CW electron guns. Here we demonstrate a cryogenic K2CsSb photocathode that simultaneously achieves high QE, ultralow MTE, and robust long-term operation in a CW gun under XFEL-relevant operating conditions. Under cryogenic operation, the photocathode achieves an MTE of 50 meV while sustaining a QE of 5.4%. Milliampere-level CW current, including operation at 5 mA, was demonstrated together with an approximately 20-day operational history. The observations are consistent with improved carrier survival and/or surface escape in photocathodes prepared using the optimized recipe. These results show that the practical QE-MTE trade-off can be substantially mitigated in cryogenic bialkali photocathodes and provide a practical pathway toward high-brightness electron sources for CW XFELs and energy-recovery linacs.

physics.acc-ph