Litton Systems, Inc.

Tae M Kwon

Charles H Volk

William P Debley

Howard E Williams

An improved microwave cavity resonator for use in vapor-cell atomic frequency standards. The resonator comprises a generally-rectangular hollow metallic body designed to support the TE.sub.101 mode of standing wave. A dielectric element is positioned within the cavity to concentrate electro-magnetic field so that a compact design is achieved and so that a preselected, substantially uniform magnetic field will be coupled into an alkali metal vapor absorption cell within the resonator. Means are provided for mounting elements of an excitation circuit to preferentially excite the desired TE.sub.101 mode.

Cavity resonator for atomic frequency standard

A nuclear magnetic resonance (NMR) cell for use in a gyro is shown which is maintained at a predetermined temperature, established by testing. Testing of each cell is conducted by heating the cell within a gyro to a series of temperatures and plotting the gyro bias (degrees/time) for each temperature within the series. At one temperature the magnitude of gyro bias will no longer increase but will start to decrease. This temperature turning point is the temperature at which the NMR cell should be maintained for zero temperature sensitivity of the gyro.

Nuclear magnetic resonance cell having improved temperature sensitivity

There is disclosed a magnetic alignment device and method for its fabrication in which the aligned magnetic moments of a gas enclosed within a container have an increased relaxation time, hence an increase signal to noise output. One embodiment is a nuclear magnetic resonance gyroscope including a container for gas having a layer of rubidium hydride on its inner surface. Enclosed within the container is rubidium vapor and xenon-131 gas. The layer of rubidium hydride is manufactured by reacting hydrogen gas and rubidium at a temperature between approximately 70.degree. and about 250.degree. C. In one specific method, a layer of rubidium hydride is formed by heating rubidium and hydrogen gas at about 85.degree. for about 7 days.

Magnetic resonance cell and method for its fabrication

There is disclosed a nuclear magnetic alignment device for use in a nuclear magnetic resonance gyroscope and the like. One embodiment includes a container for gas having a layer of rubidium hydride on its inner surface. The container comprising a spherical portion and a tip portion, is rotationally symmetric about an axis of symmetry. Enclosed within the container is a nuclear moment gas having a nuclear electric quadrupole moment, such as xenon-131, and an optically pumpable substance, such as rubidium. A portion of the rubidium is a vapor. The remainder is a condensed pellet which is deposited in the tip of the container such that the pellet is also rotationally symmetric about the axis of symmetry of the container. A layer of rubidium hydride is deposited on the inner surface of the container. The device further includes means for orienting the symmetry axis of the container at an angle to an applied magnetic field such that the relaxation time constant of the aligned nuclear moment gas is substantially at a maximum.

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Thousand Oaks, CA, United States of America

Tae M Kwon