Study of hydrogen ECR plasma in a simple mirror magnetic trap heated by 75 GHz pulsed gyrotron radiation

Abstract

Plasma of electron cyclotron resonance (ECR) discharge sustained by millimeter wave radiation is widely used for production of ion beams of different kind. The main trend in ECR ion sources development nowadays is an increase of frequency and power of microwave heating. The most advanced systems use gyrotrons in 24-60 GHz frequency range. In previous studies at IAP RAS it was demonstrated that ECR source SMIS 37 (Simple Mirror Ion Source) with 37.5 GHz heating operating in quasigasdynamic regime of plasma confinement is able to produce proton and deuteron beams with ion current density about 700 mA/cm. As the next step of these investigations plasma properties of the discharge sustained by 75 GHz radiation have been studied. Plasma density and electron temperature were determined using spectroscopic and Langmuir probe techniques. It was demonstrated that plasma density could reach values close to 10 cm and that is of great interest for further development of high current ion sources for various applications.

Wide-aperture dense plasma fluxes production based on ECR discharge in a single solenoid magnetic field

“…Experiments were conducted at the IAP RAS using SMIS 37 facility [5][6][7] (Fig. 1), modified for described experiments.…”

“…As it was mentioned above, plasma density in the ECR discharge is one of the key parameters which determines the maximum value of extracted ion beam current, and it could be enhanced by means of increase of the frequency of microwaves heating the plasma. Similar to [7] a series of experiments on spectroscopy were performed to determine the plasma density according to Stark broadening of the lines of Balmer series of atomic hydrogen [9]. Analysis of hydrogen lines of Balmer series (transition from highly excited electron levels to the level with principal quantum number n = 2) was performed, as this series lies in visible and near-ultraviolet range.…”

“…The ECR discharge with a quasi-gasdynamic plasma confinement in a simple mirror trap was studied in the very first experiments [4]. A possibility to obtain 100%-ionized plasma with low content of molecular ions (at a level of several percent), density on the level of 10 13 -10 14 cm −3 , and electron temperature of 10 -100 eV was demonstrated [5][6][7]. Combination of plasma parameters mentioned above seems to be optimal for light ion production.…”

Еmittance Measurements of a Gasdynamic Electron Cyclotron Resonant Ion Source

“…The results of the development of the accelerator for operation in the continuous mode for the DARIA project are presented in [12]. For the impulse variant, it is planned to develop a design of the accelerator for the parameters of the beam of the Gasdynamic Ion Source for Multipurpose Operation (GISMO) pulsed ion source developed at the Institute of Applied Physics (Nizhny Novgorod) [14][15][16][17][18]. To develop an accelerating channel and determine competitiveness of the pulsed accelerator, measurements of the emittance of a given proton source by the "pepper-pot" method were carried out.…”

Измерения Эмиттанса Газодинамического Электронно-Циклотронного Резонансного Источника Ионов

“…При выборе параметров компактного источника нейтронов DARIA в качестве ориентира послужил исследовательский реактор BER-II в Берлинском центре материалов и энергии им. Гельмгольца (HZB) (Германия), который обеспечивает пучок нейтронов плотностью 2 [14][15][16][17][18]. Для разработки ускоряющего канала и определения конкурентоспособности импульсного ускорителя проведены измерения эмиттанса данного источника протонов методом " pepper-pot".…”