Electromagnetic wave propagation in a fast pulse line ion accelerator
Autor: | Brian D. Kavanagh, Reza A. Behbahani, Quentin Diot, David C. Westerly, Moyed Miften, Natalie J. Serkova |
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Rok vydání: | 2019 |
Předmět: |
Resistive touchscreen
Materials science business.industry Pulse generator Capacitive sensing Cyclotron General Medicine Spark gap 030218 nuclear medicine & medical imaging law.invention 03 medical and health sciences 0302 clinical medicine Optics law Electromagnetic coil Positron-Emission Tomography 030220 oncology & carcinogenesis Particle Accelerators Transformer business Electromagnetic Phenomena Voltage |
Zdroj: | Medical Physics. 46:5714-5721 |
ISSN: | 2473-4209 0094-2405 |
Popis: | Purpose The pulse line ion accelerator (PLIA) is a low-cost accelerator concept originally designed to accelerate heavy ions. Our group has been investigating the use of PLIA to accelerate light ions and believe a multi-stage PLIA could be useful for short half-life PET isotope production. The goal of this work was to develop a single prototype fast PLIA structure and demonstrate electromagnetic wave propagation using a high-voltage pulser. Materials and methods A 1.6 m fast PLIA structure (wave speed > 107 m/s) was constructed along with a high-voltage, sinusoidal pulse generator. The latter uses capacitive voltage doubling and spark gap switching. A step-up transformer couples voltage from the pulser to the PLIA coil. Voltage measurements on the coil were made in air using a high-voltage resistive probe, while capacitive probes placed along the length of the PLIA were used to measure wave propagation with the PLIA structure filled with transformer oil. Results Voltage measurements acquired on the primary and secondary coils of the transformer coupler in air demonstrated a peak-to-peak voltage step-up of 4.2 relative to the pulser DC charging voltage. The maximum voltage time-rate-of-change on the PLIA coil was 0.76 × 1013 V/s. Capacitive probe measurements indicated voltage oscillations on the PLIA coil with half-period equal to 43 ± 0.9 ns and wave speed (with oil) of 1.2 × 107 m/s. Average and peak accelerating gradients were conservatively estimated to be 0.44 and 0.60 MV/m, respectively, with a charging voltage of 55 kV. Wave propagation was demonstrated at these gradients without flashover at a vacuum pressure of 9 × 10-6 Torr. Submerging the pulser in oil would allow for charging voltages up to 150 kV and produce accelerating gradients >1.2 MV/m. Conclusions Use of a multi-stage, fast PLIA for light ion acceleration could provide a low-cost complement to cyclotrons for the production of short half-life isotopes used for PET imaging, including carbon-11, nitrogen-13, oxygen-15, and fluorine-18. |
Databáze: | OpenAIRE |
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