US Government As Represented by the Secretary of the Army

Frederick Rothwarf

Arthur Tauber

Robert L Bergner

Herbert A Leupold

Robert D Finnegan

Raymond L Ross

John J Winter

James T Breslin

A method is disclosed of operating a cold-cathode-cold-reservoir thyratron for laser/radar and other systems employing high voltage and current pulses using ZrVFe as the hydrogen thyratron material. According to the method, a hydride of ZrVFe is first formed and the hydrided material then placed in the cathode structure of the thyratron. The tube is then pumped down to its operating pressure of approximately 10.sup.-3 atmospheres, the hydrided material then acting as a ballast to maintain that partial pressure of hydrogen at room temperature.

Method of operating a cold cathode-cold reservoir thyratron

The reversible temperature coefficient of magnetization of a permanent magnet alloy over the temperature range from -50 degrees C. to +150 degrees C. is lowered by heat treating the alloy in a noble gas atmosphere or in a vacuum by the steps of (a) heating the alloy at about 1150 degrees C. for 1.5 hours (b) quenching the alloy in ice water, (c) heating the alloy at about 940 degrees C. for 2 hours, (d) lowering the temperature to about 700 degrees C. and heating for one hour, (e) lowering the temperature to about 600 degrees C. and heating for one hour, (f) lowering the temperature to about 500 degrees C. and heating for 2 hours, and (g) lowering the temperature to about 400 degrees C. and heating for 10 hours.

Method of treating Sm.sub.2 Co.sub.17 -based permanent magnet alloys

Magnetic alloys of the general formula Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12-x M.sub.x are provided wherein M is Mn or Cr and wherein x is a value greater than zero and less than 2.1.

Magnetic alloys

Compounds of the general formula Sm.sub.2-x RE.sub.x Co.sub.17-y Mn.sub.y are provided wherein RE is a rare earth element selected from the group consisting of erbium, dysprosium and gadolinium wherein x has a value greater than zero and less than 0.7 and wherein y has a value less than 2.1. The compounds are suitable for use as permanent magnet material in microwave/millimeter-wave traveling wave tubes (TWT's).

Permanent magnet materials

The reversible temperature coefficient of magnetization of a permanent magnet alloy is lowered by (a) heating the alloy at about 1200 degrees C. for 2 hours, (b) quenching the alloy in ice water, (c) heating the alloy at about 850 degrees C. for 2 hours, (d) lowering the temperature to about 700 degrees C. and heating for one hour, (e) lowering the temperature to about 600 degrees C. and heating for one hour, (f) lowering the temperature to about 500 degrees C. and heating for one hour, (g) lowering the temperature to about 400 degrees C. and heating for four hours, and (h) lowering the temperature to about 280 degrees C. and heating for 12 hours. The method is particularly effective in lowering the reversible temperature coefficient of magnetization of the permanent magnet alloy Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12.

Method of treating a permanent magnet alloy

A method for determining the state-of-charge for zinc mercuric oxide type primary cells. I-V curves of the cells are plotted and the nearly constant slopes of these I-V curves above 75mA are measured graphically. These slopes are used to define effective differential DC resistance values (.DELTA.V/.DELTA.I).sub.75mA which have a linear relationship to charge expended, Q(A-h), which is graphically produced by plotting (.DELTA.V/.DELTA.I).sub.75mA versus Q(A-h). This relationship is used as a basis for a state-of-charge indicator to determine the remaining charge to about 12%. One can also subtract the internal resistance of the cell (measured with an a-c bridge technique) from (.DELTA.V/.DELTA.I).sub.75mA and obtain a new parameter, R.sub.p, which is related to the polarization resistance of the cell. The maximum uncertainty can be reduced to less than 10% if the linear curve is produced by plotting polarization resistance R.sub.p of the cell versus the charge expended Q(A-h). More significantly, the polarization based state-of-charge graph is linear out to 100% of discharge and is applicable to cells discharged at abnormally high current.

Growing community of inventors

Toms River, NJ, United States of America

Frederick Rothwarf