PRELIMINARY REPORT ON THE INVESTIGATION OF THE FEASIBILITY OF AN ELECTROSTATIC ACCELERATOR FOR ACCELERATING MICRON-DIAMETER PARTICLES. PART I. VAN DE GRAAFF GENERATOR. PART II. CHARGING OF MICRO PARTICLES
I. An electrostatic generator of the Van de Graaff type was built. The generator charges to 600,000 volts and delivers 70 mu a when negatively charged. When positively charged the generator delivers 10 mu a at 475,000 volts. The maximum charge the belt will carry was found to be about 50% of the theoretical value. It was shown, by the use of electric field maps, that the generator voltage has very little effect on the amount of charge lost in transit from the lower to the upper oblate. It was shown that most of the charge is lost before the belt leaves the lower oblate. An equivalent circuit is proposed which predicts the voltage attainable by the generator. All parameters in the equivalent circuit are shown to be a function of belt speed only. Agreement is good between predicted and measured performance values at low belt speeds. At the upper beltspeed limit of 4,000 ft/min, errors of 30% are noted. II. An electrostatic particle-accelerator was built for hypervelocity impact studies. The particles used are carbonyl-iron spheroids having an average diameter of 3 mucrons and a density of 7.8 gm/cm/sup 3/. An injector was built which consists of two parallel plates separated by an insulating washer. The application of 2,000 volts d-c across the plates causes the particles to oscillate between them. This motion injects the particles into the system when their path lines up with a small hole in the lower plate. The particles are accelerated by a large d-c voltage developed between two large oblate spheroids by a Van de Graaff generator. The Yan de Graaff generator produces voltages up to 600,000 volts negative. To measure the charge on the particles and also their velocity, a small section of 1/ 8 in. copper tubing is enclosed in a grounded shield. The passage of a charged particle through the tubing induces a voltage pulse whose height is proportional to the charge on the particle and whose length is a measure of the time required for the particles to travel the length of the tubing. (auth)
- Research Organization:
- Utah. Univ., Salt Lake City
- DOE Contract Number:
- AF49(638)-462
- NSA Number:
- NSA-15-021602
- OSTI ID:
- 4046717
- Report Number(s):
- AFOSR-719; OSR-20
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- United States
- Language:
- English
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