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Electrostatic techniques can be used to keep dust and aerosols from depositing on optical components. The system makes use of a corona discharge and a safety screen, located out of the optical path, to charge the incoming dust and then push it away from the optical surface. The system is effective for the dust particles normally found in the atmosphere, there are no exposed high voltage components or moving parts, and power consumption is quite limited.

Studies of rock drilling with water-based mud have indicated the existence of a current of electrons from the rock to the drill. If this so-called “normal current” is reduced to zero or is reversed by an applied potential, there is a significant reduction in drill wear. The wear rate is enhanced if oxygen is bubbled through the drilling mud and reduced if nitrogen is used, but in any case the electrical effects can still be observed. Observation of the normal drilling current with an oscilloscope has suggested that, when the drill is “sharp”, the normal current is a time-varying d.c. signal with most of the signal levels at frequencies below 25 Hz. As the drill becomes dull, the number of higher frequency signals and the overall signal amplitude increase. We suggest that this change in signal frequency with wear can be used to monitor the condition of an operational drill.

The introduction of sterile collodial carbon into the dermis produces an area of low electrical resistance in the intact skin. The low resistance spot is suitable for long term, dry contact, stimulation or specialized ECG/EEG measurements.

A surface ionization detector for hydrogen has been developed. This device detects hydrogen in the presence of air at one atmosphere. The detector is not sensitive to other atmospheric gases, e.g., O2, N2, and CO2, and operates at H2/air levels as low as 0.1% by volume.

A chemisorption detector for hydrogen has been developed. The device depends upon the change in work function of a palladium filament when it is exposed to hydrogen. The detector is effective over the pressure range of 10−5 to 10−8 Torr. The system has been checked for sensitivity to other gases, i.e., O2 and N2; it responds strongly to O2 and weakly to N2.

The impact of fine particles and organic contamination on device yield is very serious. We have investigated several technologies in this area. They include: 1) Application of thermophoresis for the prevention of surface contamination. 2) The use of electrets for collection of particles that might otherwise settle on surfaces. 3) The use of dry ice snow as a cleaning medium for the removal of particulates and organic contamination.

The theory of the constant‐current hot‐wire circuit for measurement of very high gas temperatures is developed and it is shown that such a system may be used above the melting point of the wire itself.

Hot metal filaments are often used to evaporate another metal for deposition of thin films. If the metal being evaporated can alloy with the filament, a significant number of high‐energy electrons are emitted during the alloying‐evaporation process.

Liquid nitrogen-cooled shield against oil vapor contamination of proton accelerator in vacuum chamber