Discharge characteristics of the spherical inertial electrostatic confinement (IEC) device

Abstract

The University of Illinois inertial electrostatic confinement (IEC) device provides 10 7 2.5 MeV D-D neutrons/second when operated with a steady-state deuterium discharge at 70 kV [1]. Being compact and lightweight, the IEC potentially represents an attractive portable neutron source for activation analysis applications [2]. The plasma discharge in the IEC is unique, using a spherical grid in a spherical vacuum vessel with the discharge formed between the grid and the vessel wall, while the 070 kV grid (cathode) also serves to extract high-energy ions. Two key features of the IEC discharge are discussed: 1) the breakdown voltage characteristics as a function of pressure-grid/wall distance (pd pd pd), and 2) the formation of ion "microchannels" that carry the main ion flow through grid openings.

Instrument reflections and scene amplitude modulation in a polychromatic microwave quadrature interferometer

“…The second experimental device was a spherical IEC chamber, which creates a plasma by static discharge in a neutral gas and confines the plasma using a radial electrostatic field [7]. A sketch of the IEC device is given in Fig.…”

“…[6]. The low-density device is a spherical Inertial Electrostatic Confinement (IEC) chamber operating in a sustained discharge mode [7]. A total of 3685 phase shift measurements are included in the database, $ken from 312 experimental runs in plasmas from three species.…”

Optimizing the Electrode Configuration of a Cylindrical Discharge-Type Fusion Device by Computational and Experimental Analysis

“…Therefore, they circulate in the chamber. This contributes to the generation of new pairs of ions and electrons via ionization, resulting in discharge at lower pressures relative to the solid cathode [4]. The low-pressure operation is considered effective for achieving higher neutron yield owing to the discharge characteristic of such devices (lower pressure makes the discharge voltage higher) and the cross section vs energy curve for the D-D fusion reaction.…”

A portable neutron/tunable X-ray source based on inertial electrostatic confinement

“…This can be explained since the larger grid allows a lower neutral background pressure cf. Paschen theory of breakdown [3], reducing charge exchange losses. In conclusion, these preliminary results suggest pulsed operation of the IEC can be very attractive and provides an important compliment to conventional steady-state operation.…”

“…A wide range of geometric dimensions are possible. However, once the electrode spacing is selected, the voltage and pressure are fixed by the Paschen breakdown relation [3]. …”