Accession Number:

ADA090805

Title:

Investigation of Noise in Solids at Low Temperatures.

Descriptive Note:

Annual rept. 1 Mar 79-28 Feb 80,

Corporate Author:

MARYLAND UNIV COLLEGE PARK DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s):

• Davis,Wm. S.
• Krack,K.
• Richard,J.-P.
• Weber,J.

Report Date:

1980-08-01

Pagination or Media Count:

121.0

Abstract:

This research is concerned with the theory and observations of fluctuation phenomena. Observations have been made of the thermal fluctuations associated with the normal modes of oscillation of an aluminum cylinder at 4 Kelvin. A summary has been accepted by the Physical Review, and a preprint is included here. Progress has been made in solving the difficult problems associated with noise measurements in high quality factor Q approx. 10 to the 8th power to 10 to the 9th power silicon and sapphire crystals. The present status is summarized, together with a description of a new large Dewar capable of cooling a large volume 35 liters to 20 millikelvin. A new approach has been discovered for increasing the interaction of weak forces with a detection system. This makes use of correlated quantum states. In certain cases transition probabilities are proportional to the first power instead of the usual square of the interaction. This offers possibilities for enormous increases in transition rates. Preprints of two papers submitted for publication are included. Author

Descriptors:

• *CRYSTALS
• *SAPPHIRE
• *SILICON
• *ACOUSTIC PROPERTIES
• THERMAL PROPERTIES
• FREQUENCY
• TIME INTERVALS
• MEASUREMENT
• LOW TEMPERATURE
• DETECTORS
• ENERGY TRANSFER
• SOLIDS
• TEMPERATURE GRADIENTS
• CYLINDRICAL BODIES
• ANTENNAS
• GRAVITY
• TRANSITIONS
• BANDWIDTH
• OSCILLATION
• CRYOGENICS
• PIEZOELECTRIC TRANSDUCERS
• CRYOSTATS
• GRADIOMETERS
• CRYSTAL OSCILLATORS

Subject Categories:

• Acoustics
• Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE