Accession Number : AD0821581

Title :   EXPERIMENTS WITH TWO AUTOMATICALLY TUNED HYDROGEN MASERS.

Descriptive Note : Technical rept.,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH NJ

Personal Author(s) : Hellwig, H. ; Pannaci, E.

Report Date : AUG 1967

Pagination or Media Count : 22

Abstract : A comparison of four different methods of tuning the hydrogen maser has been made experimentally. This includes the magnetic relaxation, Zeeman transition, Zeeman transition using beam preparation and the pressure variation methods. Of these methods only the last two yield absolute frequency accuracy and were measured to coincide within the experimental error of 5 x 10 to the minus twelfth power. The pressure variation method is preferred for an automatic tuning system because only this method yields a high ratio of linewidth quenching and thus a high tuning accuracy. Experimental difficulties encountered in the application of the pressure tuning were overcome by modulating the pressure by means of varying the power of the hydrogen rf-discharge in the source. A linewidth quenching ratio of more than two was achieved using this method. A servo system based on this method was used to tune two hydrogen masers simultaneously which were only roughly temperature stabilized. The long term stability of 5 x 10 to the minus 12th power observed for the free running masers was thereby improved to 3 x 10 to the minus thirteenth power, which is equal to the short term stability of one maser during the eighty second tuning cycle. (Author)

Descriptors :   (*MASERS, TUNING DEVICES), HYDROGEN, AUTOMATIC, SPINNING(MOTION), ZEEMAN EFFECT, CAVITY RESONATORS, TEMPERATURE, STABILIZATION, EXPERIMENTAL DATA.

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE