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Miller, C. G.

Publications and source records attributed to Miller, C. G..

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

A two-degree Kelvin refrigerator

Open-cycle cryogenic refrigerator maintains temperature as low as 2K for periods up to six months. Designed to cool an infrared detector, refrigerator can be used in cooling Josephson-junction devices, magnetic bubble domains, and superconducting devices.

Stephens, J. B.↗
NASA NTRS1975

Dosimetry of low energy proton beams for use in spacecraft parts testing

Thermoluminescent Dosimeters tes (TLD) were used to measure proton fluences consisting of 5MeV or lower energies. The results were at variance with the corresponding gamma measurements. The results of experiments on low energy proton dosimetry using LiF-in-teflon microrods (TLD-700 or LiF-7), are presented.

Miller, C. G.↗
NASA NTRS1974

Improved dispensing targets for ion beam particle generators

Beam impinges on palladium-silver tube, which is target, and heats impinged surface causing local hot spot. Contained gas diffuses through hot spot to meet incoming beam and produce desired particles. When beam is turned off, target spot cools and stops dispensing contained gas.

Miller, C. G.↗
NASA NTRS1974

Dispensing targets for ion beam particle generators

A target for dispensing high energy protons or neutrons or ionized atoms or ionized molecules is provided which comprises a container for the target gas, which is at atmospheric or higher pressure. The container material can release the target gas in the spot where the container is heated above a predetermined temperature by the impact of an ion beam where protons or neutrons are desired, or by electrons where ionized atoms or molecules are desired. On the outside of the container, except for the region where the beam is to impact, there is deposited a layer of a metal which is imperious to gaseous diffusion. A further protective coating of a material is placed over the layer of metal, except at the region of the ion impact area in order to adsorb any unreacted gas in the vacuum in which the target is placed, to thereby prevent reduction of the high vacuum, as well as contamination of the interior of the vacuum chamber.

Miller, C. G.↗
NASA NTRS1974

Flow properties in expansion tube with helium, argon, air, and CO2

Test flow velocities from 5 to 7 km/sec were generated in a 6-in. expansion tube using helium, argon, air, and CO2 test gases. Pitot pressure profiles across the flow at the test section are presented for the four test gases, and measured flow quantities are compared to computer predicted values. Comparison of predicted and measured flow quantities suggests the expansion to be near thermochemical equilibrium for all test gases and implies the existence of a totally reflected shock at the secondary diaphragm. Argon, air, and CO2 flows were observed to attenuate while traversing the acceleration section, whereas no attenuation was observed for helium.

Miller, C. G.↗
NASA NTRS1974

Shock shapes of blunt bodies in hypersonic helium, air, and CO2 flows

A primary factor governing hypersonic flowfield characteristics of blunt vehicles entering planetary atmospheres is the normal shock density ratio. Hence, a means of duplicating or simulating the high density ratios experienced during planetary entry is needed. One facility having the capability of generating a range of hypersonic-hypervelocity flow conditions in arbitrary test gases is the expansion tube. Preliminary shock shape results obtained in the Langley 6-in. expansion tube at hypersonic conditions are presented. Normal shock density ratios from approximately 4 to 19 were generated using helium, air, and CO2 test gases at freestream velocities from 5 to 7 km/sec. Test models were a flat-faced cylinder and the Viking aeroshell.

Miller, C. G.↗
NASA NTRS1973

Purging means and method for Xenon arc lamps

High pressure Xenon short-arc lamp with two reservoirs which are selectively connectable to the lamp's envelope is described. One reservoir contains an absorbent which will absorb both Xenon and contaminant gases such as CO2 and O2. The absorbent temperature is controlled to evacuate the envelope of both the Xenon and the contaminant gases. The temperature of the absorbent is then raised to desorb only clean Xenon while retaining the contaminant gases, thereby clearing the envelope of the contaminant gases. The second reservoir contains a gas whose specific purpose is, to remove the objectional metal film which deposits gradually on the interior surface of the lamp envelope during normal arc operation. The origin of the film is metal transferred from the cathode of the arc lamp by sputtering or other gas transfer processes.

Miller, C. G.↗
NASA NTRS1973

Improved spatial uniformity of beam-plane interaction by means of inverse rastering

An analysis is presented that shows the desirability and feasibility of conducting irradiations of large test objects by beams of penetrating radiation, by the method of moving the test object back and forth through the beam, rather than by sweeping the beam across the object. An extension of this method of inverse rastering allows the generation of composite beams with any desired intensity-vs-energy spectrum, obviating the need to determine equivalent damage factors for every energy in the spectrum.

Miller, C. G.↗
NASA NTRS1972

Multiple anode arc lamp system

A high-intensity xenon arc lamp having a plurality of separate anodes axially disposed in a symmetrical pattern which spaced a discharge gap from a common cathode is presented.

Miller, C. G.↗
NASA NTRS1972

Design considerations for combined radiation effects facilities for twelve year outer planet spacecraft voyages

The design considerations influencing the choice and utility of environmental simulation methods and facilities are described, insofar as they relate to the requirements imposed on outer planet spacecraft because of radiation environments to be expected. Possible means for duplicating the radioisotope thermoelectric generator radiation environment, and for duplicating the effects of the trapped radiation belt environment are described, together with an assessment of radiation levels to be expected in the vicinity of an environmental testing chamber when in use.

Miller, C. G.↗
NASA NTRS1970

The effects of nuclear power generators upon electronic instrumentation

Radiation sensitivity of electronic instruments susceptible to neutron and gamma radiation is evaluated by means of a radioisotope thermoelectric generator /RTG/. The gamma field of the RTG affects instrument operation and requires shielding, the neutron field does not affect operation via secondary capture-gamma production.

Miller, C. G.↗