Generation and Focussing of Intense Pulsed Light-Ion Beam at Nagaoka–ETIGO Project–

Masugata, Katsumi; Nakayama, Tadao; Inazumi, Yoshinori; Konno, Kohji; Nakabaru, Mitsugu; Takano, Shinya; Matsui, Masayuki; Irisawa, Juichi; Yatsui, Kiyoshi

doi:10.1143/jjap.20.l347

Cited by 17 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ion-current density in the IIB may be focused ballistically to increase J i , using an inward tilt of the AK electrodes, as shown in figure 2. This method has produced 50 × radial compressions to a final beam radius of the order of, r 0 ≃ 0.025 m [33]. Downstream-magnetic coils have also been used (as lenses) to focus the IIB.…”

Section: High Density Ion Sources Used To Produce Iibsmentioning

confidence: 99%

Neutralized, intense-ion beams for fusion

Wessel,

Egly,

Rogers

2024

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

- A charge- and current-neutralized, intense-ion beam (IIB) will propagate undeflected in a magnetized plasma by the $\bf{E}\times\bf{B}$, or diamagnetic, drift for a distance large compared to the beam-ion gyro-radius. This propagation occurs because of collective plasma effects when the beam-energy density is sufficient to sustain the polarization-electric field, or diamagnetic-screening currents. Our principal interest is the \exb, with $\beta = \mathcal{E}_\text{beam}/ \mathcal{E}_\text{field} < 1$. IIBs are characterized by parameters in the range: 0.1-2 MeV ion energy, 1-100 MA/m$^2$ ion-current density, and 17 - 350 kW average power produced on repetitively-pulsed systems. Multi-MW average-beam power is possible with appropriate modifications to the power supply and ion-source/accelerator. IIBs can be focused geometrically, and/or magnetically, to spot sizes of the order of a few cm's and their angular divergence is typically, $\sim$15 mRadians, suitable for long-range propagation in a vacuum beam-line. IIBs lose energy and momentum in the same manner as particles injected by a neutral-beam injector (NBIs), hence could be useful for fusion applications, including: heating, current drive, fueling, profile modifications, etc., and such applications have yet to be thoroughly studied. Summarized here are the physical principles accounting for IIB propagation; ion-source designs used to produce the IIB; and pulsed-power methods for energizing the IIB accelerator. This technology base informs scalable metrics for the ion-source/accelerator (excluding the HV power supply and interconnects) used in a conceptual injector that provides the same ion energy and injected power (1 MeV, 17 MW) as NBIs used on ITER. A comparison indicates that the IIB injector would be much smaller in size, lower cost, and have much greater efficiency, while also providing for real-time modulation of the beam energy and intensity and the use of small-diameter injection ports that could minimize fuel contamination and magnetic-field leakage between the IIB injector and tokamak.

show abstract

Section: High Density Ion Sources Used To Produce Iibsmentioning

confidence: 99%

Neutralized, intense-ion beams for fusion

Wessel,

Egly,

Rogers

2024

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

show abstract

“…The cathode is separated into two parts with a forked connection to two symmetrically installed transformers powered by the magnetic field power system. The special configuration sets up a virtually ''close'' coil around the anode to produce the external-magnetic field, and then overcomes the disadvantages of the conventional cathode as a one-turn theta-pinch coil, 10,11 in which a nonuniform magnetic field led to loss of electron flow and the notable penetrated magnetic field in the propagation region of the ion beam to obvious deflection of the ion beam. The magnetic field power system is charged in parallel with the Marx generator by the same dc high-voltage supply up to 10 kV, which can provide a maximal magnetic field strength of about 0.5 T in the A -K gap.…”

Section: Unipolar-mode Pulsed Ion Beam Apparatusmentioning

confidence: 99%

“…A maximal output of ion current density has been achieved with the magnetic field at 8 kV. Therefore, the efficiency of ion beam generation, defined as the ratio of total ion current to diode current, 7,11 was relatively higher at about 8 -9 kV. The result is consistent with the theoretical calculation on the magnetic insulation for MID, where the ion current grows above the spacecharge limit only in the neighborhood of B crit ͑with a value of about 0.3 T in this diode͒ and reaches its maximum at about 1.2B crit .…”

Section: A Effect Of External Magnetic Fieldmentioning

confidence: 99%

Characterization of a high-intensity unipolar-mode pulsed ion source with improved magnetically insulated diode

Zhu

Lei

Dong

et al. 2003

Review of Scientific Instruments

View full text Add to dashboard Cite

A magnetically insulated ion diode (MID) with an improved external-magnetic field system has been developed and installed onto a TEMP-6-type high-intensity pulsed ion source in order to produce a high-intensity pulsed ion beam (HIPIB) for surface modification of materials. The external-magnetic field MID is operated in unipolar mode based on dielectric high-voltage flashover, and a double coaxial pulse-forming line (PFL) powered with a Marx generator is used to form the unipolar pulse of nanosecond width. A specially designed cathode has been constructed with a forked connection to two symmetrically installed transformers to improve the effect of the magnetic field and thus increase the stability of generation and propagation of the ion beam. It was found that the efficient generation of HIPIB mainly depended on the magnetic field strength, the gas pressures in reverse and output switches of PFL, and the anode–cathode (A–K) gap of the external-magnetic field MID. A proper magnetic field strength was found with magnetic field power system at dc charging voltage of 8 kV. The proper A–K gap distance is not uniform with the value varied from 6 to 8 mm. Suitable gas pressures for reverse and output switches were about 1.2 and 2.4 atm, respectively, at a charging voltage of 40 kV to the Marx generator. The most efficient plasma generation and ion extraction led to a maximum output of HIPIB with a peak ion current density of 300 A cm−2 and a beam pulse width of 80 ns (full width at half maximum), at an accelerating pulse of 300–350 kV with a pulse width of 70 ns.

show abstract

“…Diode" (Masugata et al 1984;Takahashi et al 1986;) A new and simple ion diode of self-magnetically-insulated type has been successfully developed. Since the shape is similar to a Mather-type plasma-focus device, we have named it "Plasma-Focus Diode" (PFD).…”

Section: Development Of Self-magnetically-insulated "Plasma-focusmentioning

confidence: 99%

“…The experiment has been carried out using a pulse-power machine, "ETIGO-I" (Yatsui et al 1985;Masugata et al 1981). The anode is made of brass (inner diameter 40 mm), inside which a flashboard made of acrylic is attached.…”

Section: Development Of Self-magnetically-insulated "Plasma-focusmentioning

confidence: 99%

Recent progress of studies on intense particle beam at Nagaoka—ETIGO Project

Yatsui¹,

Shimotori²,

Ikeda³

et al. 1987

Laser Part. Beams

Self Cite

View full text Add to dashboard Cite

Recent experimental and theoretical research on intense pulsed particle beams involving the ETIGO Project at the Technological University of Nagaoka is reviewed. Experimentally, we review the following: (1) studies on local divergence angle in parameter space, (2) development of self-magnetically insulated "Plasma-Focus Diode," (3) beam focusing by z-discharged plasma channel, (3) measurement of ablation process of beam-target interaction, (4) time-resolvable measurement of energy and species, (5) inductive postacceleration of highly neutralized ion beam, (6) construction of new pulse-power machine, and pulse-compression experiment by plasma erosion opening switch. A brief summary is also given on the development of 2.5-dimensional particle-in-cell computer simulation code.

show abstract

Generation and Focussing of Intense Pulsed Light-Ion Beam at Nagaoka–ETIGO Project–

Cited by 17 publications

References 6 publications

Neutralized, intense-ion beams for fusion

Neutralized, intense-ion beams for fusion

Characterization of a high-intensity unipolar-mode pulsed ion source with improved magnetically insulated diode

Recent progress of studies on intense particle beam at Nagaoka—ETIGO Project

Contact Info

Product

Resources

About