In applications such as driving a discharge laser, there is a need for producing short, high energy pulses at a high repetition rate. For example, a driver for a copper vapor laser or a CO.sub.2 laser may require approximately one joule at 20-30 kv for pulses in a 10-20 nanosecond range and a 10,000 pulses per second repetition frequency. Such lasers may be utilized in uranium isotope separation and in a broad spectrum of other research, industrial, government and other applications. Heretofore, the pulse drivers for such applications have employed thyratrons to discharge energy stored in a capacitor into the laser. This capacitor is charged to the many kilovolts required by the laser. Such supplies are typically both bulky and unreliable, the bulkiness resulting at least in part from the requirement of maintaining adequate spacing between surfaces charged to a very high voltage and the reliability problem stemming from limitations on thyratron performance.
Another serious problem with such drivers is that cooling is generally accomplished by immersion of the driver in tanks filled with Freon.TM. 113. The Freon.TM. performs two functions. First, it is a coolant for elements heated by the high energy passing therethrough. Second, it serves as a high dielectric strength media supporting electric fields which are 3 to 4 times greater than can be supported by air at atmospheric pressure.
However, liquid Freon.TM. has serious negative environmental properties, and as a result, use of Freon.TM. as a coolant is being restricted and may ultimately be banned. Therefore, it is desirable to eliminate Freon.TM. as a coolant for such power sources. However, the few alternative coolants which have been identified and developed do not perform as well as Freon.TM.and are so expensive, both to make and use, that their use in sufficient quantity to permit a pulse source to be immersed therein would cost more than the pulse source itself. Therefore, both from a cost and performance standpoint, the use of such Freon.TM. alternatives is not desirable.
Since an alternative coolant and insulating fluid material is not readily available for such pulse sources, a second alternative is to design a pulse power source which does not require immersion in a coolant bath for electric field isolation or for cooling. It is therefore a primary object of this invention to provide such a high voltage, high energy pulse power source.
USPTO Backgrounds
USPTO Backgrounds