Accession Number:

ADA278478

Title:

Collision and Motional Averaging Effects in Cryogenic Atomic Hydrogen Masers

Descriptive Note:

Final technical rept. 1 Aug 1991-31 Sep 1993

Corporate Author:

WILLIAMS COLL WILLIAMSTOWN MA

Personal Author(s):

• Crampton, Stuart B.
• McAllaster, Donald R.

Report Date:

1993-09-30

Pagination or Media Count:

11.0

Abstract:

Substantial progress has been made toward optimizing the performance of the neon surface cryogenic hydrogen maser, preparatory to measuring the hyperfine induced frequency shifts HIFS in collisions between hydrogen atoms at low temperatures. Self-excited maser oscillation has been achieved at temperatures from 8.5 to 11.5 K. There is little surface relaxation at the higher temperatures. There is substantial collision broadening at the highest achievable atom densities, which is useful for spin exchange cavity tuning and which indicates the presence of measurable HIFS. We have also made significant progress in understanding the Doppler effect in motional averaging systems such as the cryogenic maser.

Descriptors:

• *MOTION
• *HYDROGEN
• *MASERS
• *CRYOGENICS
• *COLLISIONS
• *FREQUENCY SHIFT
• *MICROWAVE AMPLIFIERS
• *ATOMIC STRUCTURE
• DENSITY
• TEMPERATURE
• SURFACES
• RELAXATION
• COLLISION BROADENING
• HYPERFINE STRUCTURE
• DOPPLER EFFECT
• SPIN STATES
• NEON
• EXCHANGE
• OSCILLATION
• TUNING
• ATOMS
• CAVITIES
• LOW TEMPERATURE

Subject Categories:

• Lasers and Masers
• Atomic and Molecular Physics and Spectroscopy
• Thermodynamics
• Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE