MOB1
IAP/RAS, Nizhny Novgorod, Russia
The main latest activities in the field of ECR ion sources development at the Institute of Applied Physics (Nizhny Novgorod, Russia) are connected with transition from pulsed to continuous wave operation regime of a high-current gasdynamic sources. The main advantages of such devices in pulsed operation are extremely high ion beam current with a current density up to 600 -700 mA/cm2 in combination with low emittance i.e. normalized RMS emittance below 0.1 pi mm mrad. To continue development of a CW gasdynamic ion source a new experimental facility called GISMO (Gasdynamic Ion Source for Multipurpose Operation) was construction at the IAP RAS. The source utilizes 28 GHz/10 kW gyrotron radiation for plasma heating in a fully permanent magnet system with magnetic field configuration close to simple mirror trap. The first plasma in GISMO was ignited in the 2018. Status of the new source development will be presented.
IAP/RAS, Nizhny Novgorod, Russia
UNN, Nizhny Novgorod, Russia
Formation of ion beams with wide apertures and current at level of tens and hundreds Amperes is required in a wide range of studies. Usually plasmas of arc or high-frequency discharges are used for such applications. In this paper the possibility of using of an ECR discharge sustained by powerful millimetre wave gyrotron radiation for these purposes is considered. A high plasma density is required to solve the problem of obtaining high values of ion beam current density. The use of gyrotron as a source of millimetre wave radiation in the ECR discharge makes it possible to obtain plasma with high density and high ionization rate, close to 100%. Earlier at the IAP RAS the possibility of dense plasma fluxes production on the basis of ECR discharge in a magnetic field of one solenoid was demonstrated. In this paper, the characteristics of the outgoing plasma flux (density and homogeneity) were investigated. Estimations of the prospects for using such systems for high-current ion beams formation are presented.
IAP/RAS, Nizhny Novgorod, Russia
One of the interesting applications of ECR ion sources is their use as a part of neutron generators. The use of high-current gasdynamic sources with plasma heating by high-frequency gyrotron radiation allows to increase neutron yield, and obtain a point-like neutron emission by sharp focusing of a high-quality deuterium ion beam on a target. Such point-like neutron source could perspective for neutron tomography. In the first experiments at SMIS 37 facility the high-current deuterium ion beam was focused by a simple magnetic coil (magnetic field strength up to 2 T) placed behind two-electrode extraction system on a titanium target saturated with deuterium. It was demonstrated that in such system a weakly descending 60 mA ion beam with the convergence of 50 could be focused in 1 mm spot resulting in 8 ' cm-2 of current density at the focal plane. Measured neutron yield from the target placed in the focal region under conditions of the beam energy of 80 keV reached a value of 1010 neutrons per second in 1 ms pulse.
IAP/RAS, Nizhny Novgorod, Russia
JYFL, Jyväskylä, Finland
H− ion sources are in great demand for beam injection into cyclotrons and storage rings utilizing charge exchange extraction or injection. The efficiency of proton beam production with the use of gasdynamic ECR ion source based on ECR discharge in a simple mirror trap has been recently demonstrated. It was then suggested to use the gasdynamic discharge as the first part of a tandem source for volumetric negative ion production. Experiments were performed with 37 GHz / up to 100 kW gyrotron power. Plasma was confined in a dual-trap magnetic system consisting of two equal simple mirror traps. The first trap was used for plasma production under the ECR condition. Dense hydrogen plasma flux from the first trap was allowed to flow into the second trap through a perforated conductive plate, which prevented propagation of the heating microwaves into the second one thus preventing plasma heating in the second chamber and allowing cold electrons to accumulate there. We present recent experimental results on this topic after optimization of the facility. We achieved a negative ion current density of 80 mA/cm2 with a 1 mm plasma electrode aperture.
