A Helical-Deflector-Based Radio-Frequency Spiral Scanning System for keV Energy Electrons
Abstract
We present the design, modeling, and experimental validation of a radio-frequency based time-to-position conversion system for keV electrons incorporating a helical deflector operating in the 400-1000 MHz range. The device performs circular deflection of the electrons when driven by a single RF frequency and enables spiral scanning when two phase-locked RF voltages with slightly different frequencies are applied. The superposition of the two phase-locked RF voltages produces an amplitude-beating field whose slowly varying envelope modulates the deflection radius, transforming the circular scan into a controlled spiral on the detector plane. A detailed theoretical model describing the electron dynamics under two phase-locked RF voltages with different frequencies was derived, yielding analytical expressions for the transverse velocity and radius-vector components at the deflector exit. The experimental studies demonstrated good agreement with the model predictions. Spiral scanning will allow measurements with picosecond resolution in a temporal dynamic range 1-2 orders of magnitude larger than the period of the circular scanning.
Keywords
Cite
@article{arxiv.2602.10828,
title = {A Helical-Deflector-Based Radio-Frequency Spiral Scanning System for keV Energy Electrons},
author = {Simon Zhamkochyan and Vanik Kakoyan and Vardan Bardakhchyan and Sergey Abrahamyan and Amur Margaryan and Aram Kakoyan and Hasmik Rostomyan and Anna Safaryan and Gagik Sughyan and Hayk Gevorgyan and Artashes Papyan and Martin Pinamyan and Mikael Ivanyan and Satoshi N. Nakamura and John Annand and Kenneth Livingston and Rachel Montgomery and Patrick Achenbach and Josef Pochodzalla and Dimiter L. Balabanski and Ani Aprahamian and Viatcheslav Sharyy and Dominique Yvon and Hayk Elbakyan},
journal= {arXiv preprint arXiv:2602.10828},
year = {2026}
}
Comments
16 pages, 8 figures