### Abstract

In our previous work, an ideal model is used to describe the dynamic closing plasma channel for a subnanosecond gas switch. The plasma channel current is assumed to be on the surface of a uniform cylinder. Several authors' studies show that the channel conductivity and radius vary dynamically. This variation results in dynamic impedance of the channel, and corresponding current and voltage that vary with time across the gap. All of the above parameters are hard to measure directly because of the small geometry and the high gap voltage and current on a subnanosecond time scale. Therefore, we have to develop a mathematical model to study the switch properties and compare it with experimental result. In this paper, a Braginskii conduction model is used to describe the nonlinear dynamic plasma channel. When a breakdown happens, the plasma channel electrical conductivity remains almost constant, if we assume that the hydrodynamic cooling associated with expansion, together with radiative cooling, is sufficient to keep the temperature of the conducting channel constant. Therefore, the relationship between plasma channel current 7 and channel radius a is determined by the following formula: a ^{2}∝ ∫ I ^{2/3} dt (1) The Braginskii model is simulated by Pspice, and then a switch is driven by the channel current generated by this model. Because the impedance of the switch is different from the Transmission line, the reflected current from the switch, in turn, affects the development of the channel current and radius. An iteration method is used to find the final stable solution of the channel current. In every iteration step, the current drive the switch is simulated by the Finite Element Method in Time Domain (FETD). After that, the channel impedance, the voltage and current across the gap are also studied based on the simulated channel current.

Original language | English (US) |
---|---|

Title of host publication | IEEE International Conference on Plasma Science |

Pages | 149 |

Number of pages | 1 |

State | Published - 2004 |

Externally published | Yes |

Event | IEEE Conference Record - Abstracts: The 31st IEEE International Conference on Plasma Science, ICOPS2004 - Baltimore, MD, United States Duration: Jun 28 2004 → Jul 1 2004 |

### Other

Other | IEEE Conference Record - Abstracts: The 31st IEEE International Conference on Plasma Science, ICOPS2004 |
---|---|

Country | United States |

City | Baltimore, MD |

Period | 6/28/04 → 7/1/04 |

### Fingerprint

### ASJC Scopus subject areas

- Condensed Matter Physics

### Cite this

*IEEE International Conference on Plasma Science*(pp. 149). [1P44]

**A conduction model for subnanosecond breakdown gas switch.** / Chen, J. H.; Buchenauer, C. J.; Tyo, J Scott.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*IEEE International Conference on Plasma Science.*, 1P44, pp. 149, IEEE Conference Record - Abstracts: The 31st IEEE International Conference on Plasma Science, ICOPS2004, Baltimore, MD, United States, 6/28/04.

}

TY - GEN

T1 - A conduction model for subnanosecond breakdown gas switch

AU - Chen, J. H.

AU - Buchenauer, C. J.

AU - Tyo, J Scott

PY - 2004

Y1 - 2004

N2 - In our previous work, an ideal model is used to describe the dynamic closing plasma channel for a subnanosecond gas switch. The plasma channel current is assumed to be on the surface of a uniform cylinder. Several authors' studies show that the channel conductivity and radius vary dynamically. This variation results in dynamic impedance of the channel, and corresponding current and voltage that vary with time across the gap. All of the above parameters are hard to measure directly because of the small geometry and the high gap voltage and current on a subnanosecond time scale. Therefore, we have to develop a mathematical model to study the switch properties and compare it with experimental result. In this paper, a Braginskii conduction model is used to describe the nonlinear dynamic plasma channel. When a breakdown happens, the plasma channel electrical conductivity remains almost constant, if we assume that the hydrodynamic cooling associated with expansion, together with radiative cooling, is sufficient to keep the temperature of the conducting channel constant. Therefore, the relationship between plasma channel current 7 and channel radius a is determined by the following formula: a 2∝ ∫ I 2/3 dt (1) The Braginskii model is simulated by Pspice, and then a switch is driven by the channel current generated by this model. Because the impedance of the switch is different from the Transmission line, the reflected current from the switch, in turn, affects the development of the channel current and radius. An iteration method is used to find the final stable solution of the channel current. In every iteration step, the current drive the switch is simulated by the Finite Element Method in Time Domain (FETD). After that, the channel impedance, the voltage and current across the gap are also studied based on the simulated channel current.

AB - In our previous work, an ideal model is used to describe the dynamic closing plasma channel for a subnanosecond gas switch. The plasma channel current is assumed to be on the surface of a uniform cylinder. Several authors' studies show that the channel conductivity and radius vary dynamically. This variation results in dynamic impedance of the channel, and corresponding current and voltage that vary with time across the gap. All of the above parameters are hard to measure directly because of the small geometry and the high gap voltage and current on a subnanosecond time scale. Therefore, we have to develop a mathematical model to study the switch properties and compare it with experimental result. In this paper, a Braginskii conduction model is used to describe the nonlinear dynamic plasma channel. When a breakdown happens, the plasma channel electrical conductivity remains almost constant, if we assume that the hydrodynamic cooling associated with expansion, together with radiative cooling, is sufficient to keep the temperature of the conducting channel constant. Therefore, the relationship between plasma channel current 7 and channel radius a is determined by the following formula: a 2∝ ∫ I 2/3 dt (1) The Braginskii model is simulated by Pspice, and then a switch is driven by the channel current generated by this model. Because the impedance of the switch is different from the Transmission line, the reflected current from the switch, in turn, affects the development of the channel current and radius. An iteration method is used to find the final stable solution of the channel current. In every iteration step, the current drive the switch is simulated by the Finite Element Method in Time Domain (FETD). After that, the channel impedance, the voltage and current across the gap are also studied based on the simulated channel current.

UR - http://www.scopus.com/inward/record.url?scp=13244258309&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=13244258309&partnerID=8YFLogxK

M3 - Conference contribution

SP - 149

BT - IEEE International Conference on Plasma Science

ER -