High voltage, cross-field, gas switch and method of operation
A high voltage gas switch includes a gas-tight housing containing an ionizable gas at a preselected gas pressure. The gas switch includes a gas-tight housing containing an ionizable gas at a gas pressure selected based upon a Paschen curve for the ionizable gas, where the Paschen curve plots breakdown voltages of the ionizable gas as a function of gas pressure multiplied by grid-to-anode distance, and where values of gas pressure multiplied by grid-to-anode distance increase over at least a portion of the Paschen curve in conjunction with increasing breakdown voltages. The gas switch also includes an anode disposed within the gas-tight housing, a cathode disposed within the gas-tight housing, and a control grid positioned between the anode and the cathode, where the control grid is spaced apart from the anode by a grid-to-anode distance selected based upon a desired operating voltage.
1. A high voltage gas switch comprising:
a gas-tight housing containing an ionizable gas at a gas pressure selected based upon a Paschen curve for the ionizable gas, wherein the Paschen curve plots breakdown voltages of the ionizable gas as a function of gas pressure multiplied by grid-to-anode distance, wherein values of gas pressure multiplied by grid-to-anode distance increase over at least a portion of the Paschen curve in conjunction with increasing breakdown voltages, and wherein values of gas pressure multiplied by grid-to-anode distance increase over a portion of the Paschen curve beyond a threshold breakdown voltage;
an anode disposed within said gas-tight housing;
a cathode disposed within said gas-tight housing; and
a control grid positioned between said anode and said cathode, said control grid spaced apart from said anode by a grid-to-anode distance selected based upon a desired operating voltage.
2. The gas switch of claim 1 , wherein the threshold breakdown voltage is 300 kilovolts (kV).
3. The gas switch of claim 1 , wherein the grid-to-anode distance is in the range of 2-15 centimeters (cm).
4. The gas switch of claim 1 , wherein said gas-tight housing contains helium.
5. The gas switch of claim 1 , wherein the grid-to-anode distance is selected to prevent vacuum breakdown between said anode and said control grid at the desired operating voltage.
6. The gas switch of claim 1 , wherein the gas pressure is selected to prevent gas breakdown between said anode and said control grid at the desired operating voltage.
7. The gas switch of claim 1 , wherein said control grid comprises a perforated electrically conductive surface.
8. The gas switch of claim 1 , wherein said cathode comprises at least one of i) gallium, ii) an alloy of gallium, iii) indium, iv) tin, v) aluminum, tungsten, molybdenum, and tantalum.
9. The gas switch of claim 1 , wherein said gas switch is operable in the range of 50-1,000 kilovolts (kV).
10. A high voltage, cross-field, gas switch containing an ionizable gas at a gas pressure selected based upon:
a distance between electrodes of said gas switch; and
a Paschen curve for the ionizable gas, wherein the Paschen curve plots breakdown voltages of the ionizable gas as a function distance between electrodes multiplied by gas pressure, wherein values of distance between electrodes multiplied by gas pressure increase over a portion of the Paschen curve in conjunction with increasing breakdown voltages, and wherein values of gas pressure multiplied by distance between electrodes increase over a portion of the Paschen curve beyond a threshold breakdown voltage.
11. The gas switch of claim 10 , wherein the distance between electrodes is a distance between an anode and a control grid spaced apart from the anode.
12. The gas switch of claim 10 , wherein the threshold breakdown voltage is 300 kilovolts (kV).
13. The gas switch of claim 10 , wherein the distance between electrodes is in the range of 2-15 centimeters (cm).
14. The gas switch of claim 10 , wherein the ionizable gas is helium.
15. The gas switch of claim 10 , wherein the distance between electrodes is selected to prevent vacuum breakdown between a first electrode and a second electrode at the desired operating voltage.
16. The gas switch of claim 10 , wherein the preselected gas pressure is selected to prevent gas breakdown between a first electrode and a second electrode at the desired operating voltage.
17. The gas switch of claim 10 , wherein said gas switch is operable in the range of 50-1,000 kilovolts (kV).
18. A high voltage gas switch comprising:
a gas-tight housing containing an ionizable gas at a gas pressure in the range of 0.01-1.0 torr, the gas pressure selected based upon a Paschen curve for the ionizable gas, wherein the Paschen curve plots breakdown voltages of the ionizable gas as a function of gas pressure multiplied by a grid-to-anode distance, wherein values of gas pressure multiplied by grid-to-anode distance increase over at least a portion of the Paschen curve in conjunction with increasing breakdown voltages, and wherein values of gas pressure multiplied by grid-to-anode distance increase over a portion of the Paschen curve beyond a threshold breakdown voltage;
an anode disposed within said gas-tight housing;
a cathode disposed within said gas-tight housing; and
a control grid positioned between said anode and said cathode, said control grid spaced apart from said anode by the grid-to-anode distance in the range of 2-15 centimeters (cm), the grid-to-anode distance selected based upon a desired operating voltage.