Wakefield Excitation by a Ramped Electron Bunch Train in a Plasma-Dielectric Waveguide

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A theoretical and experimental study of wakefield excitation by a profiled sequence of relativistic electron bunches in the plasma-dielectric structure, the parameters of which provide the conditions for the excitation of a small decelerating field for all driver bunches with simultaneous growth with the number of bunches of the accelerating total wakefield was carried out. Theoretically, the transformation ratio was found for the parameters of the experiment as the ratio of the total wakefield of the sequence to the field that decelerates driver bunches. In the performed experiments, the total wakefield was measured by the microwave probe. The magnitude of the decelerating field is determined by the shift of the maximum of the spectrum measured by the magnetic analyzer before and after wakefield excitation in the structure. The obtained transformation ratio increases with the number of bunches in the sequence and significantly exceeds this one for a nonprofiled sequence.

Section: Numerical Analysismentioning

confidence: 96%

Elaboration of the Plasma-Dielectric Wakefield Accelerator With a Profiled Sequence of Driver Electron Bunches

Onishchenko,

Galaydych,

Kniaziev

et al. 2023

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“…In a structure with collinear motion of bunches, where the drive and accelerated bunch move along the same path, the transformer ratio, defined as the ratio of the maximum increase in the energy of the electrons of the accelerated beam to the maximum energy loss of the particles of the leading beam [8,9], cannot exceed 2. To increase it, it was proposed to use charge profiling inside a single bunch [10], profiling a sequence of bunches (ramped bunch train) [11][12][13][14], or using multi-zone multi-channel dielectric structures [15][16][17][18]. In order to obtain profiling a sequence of bunches, precise synchronization of separated units of the "Almaz-2M" accelerator is necessary.…”

Section: Introductionmentioning

confidence: 99%

Modernization and Adjustment of the Microwave Power Control System of the “Almaz-2m” Accelerator

Zaleskyi,

Pristupa,

et al. 2024

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The microwave power source of the “Almaz-2M” accelerator is controlled by supplying a microwave modulated pulse from the “Rubin” master microwave generator to the KIU-12M klystron. The “Rubin” frequency must be adjusted to the resonant frequency of the accelerator, which may change under the influence of external conditions and aging of the materials of the accelerator elements, so it is necessary to adjust the “Rubin” frequency. At the same time, the “Rubin” frequency meter –“wave meter” also needs calibration. This paper describes a method for calibrating a “wave meter” with an accuracy of 1.5 MHz. For experiments on wakefield acceleration of an electron beam using a profiled sequence of bunches, it is important to synchronize all elements of the accelerator - the gun, the master oscillator, the klystron. For this purpose, a standard accelerator launch system was carried out. This made it possible to obtain trigger pulses with a rise time of about 200 ns. Also, based on modern microcircuits, a new trigger system with a leading edge of less than 100 ns has been developed.

“…In collinear devices, where the drive and accelerated bunch move along the same path, T<2. To increase the transformer ratio in collinear dielectric wake accelerators, it was proposed to use charge profiling inside a single bunch [3] or bunch train profiling [4,5]. The transformer ratio can also be significantly increased by using multizone dielectric structures [6][7][8], where the accelerated and drive bunches move along different trajectories.…”

Section: Introductionmentioning

confidence: 99%

“…To carry out experimental studies on measuring the transformation ratio and the accelerating field in the developed five-zone wake structure [9] and the plasmadielectric structure with a profiled train of drive bunches [5], we created new measuring equipment, which includes the measuring probe described below.…”

Section: Introductionmentioning

confidence: 99%

Probe for Measuring the Longitudinal Component of the Electric Field in a Dielectric Wakefield Accelerator

Zalesky,

Pristupa,

et al. 2023

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To conduct experiments to determine the amplitude of the electric field and the transformation ratio in the wake field accelerator based on dielectric structures excited by electron bunches of the Almaz-2 electron accelerator, a probe was developed and manufactured. The probe consists of a ¼ wavelength antenna (27 mm) and a detection circuit based on a 2A201A microwave diode. To calibrate the probe, a measuring stand was assembled, consisting of a microwave generator and a horn emitter. A SPEKTRAN spectrum analyzer (Germany) was used as a microwave power meter, and a digital oscilloscope was used as a meter of the detected signal from the probe. The results of measurements made on the stand show that at a microwave radiation power of 26 mW/m2 and an electric microwave field strength of 2.6 V/m at the measurement point, the output signal from the probe is 1 mV.