Effects of coherently excited Zeeman transitions on a hydrogen maser hyperfine transition

1979 ◽  
Vol 57 (6) ◽  
pp. 904-916 ◽  
Author(s):  
J.-Y. Savard ◽  
G. Busca ◽  
S. Rovea ◽  
M. Desaintfuscien ◽  
P. Petit
Keyword(s):  
Frequency Shift ◽  
Asymmetry Parameter ◽  
Spin Exchange ◽  
Average Duration ◽  
Low Frequency ◽  
Transition Rates ◽  
Hydrogen Maser ◽  
Hydrogen Atoms ◽  
Zero Crossing ◽  
Exchange Cross Section

The effects of transitions excited within the F = 1 multiplet of the ground state hydrogen atoms while radiating on the ΔmF = 0 transition are analyzed theoretically. The results are valid for low transition rates and unrestricted maser power. The predictions are: (a) an important modification of the well-known spin-exchange frequency shift of a hydrogen maser, due to the imaginary part of the spin-exchange cross section, (b) a frequency shift proportional to the asymmetry parameter between the 2-Zeeman frequencies in the upper multiplet F = 1, and (c) a frequency shift proportional to the polarization of the atoms in the storage bulb.Also shown is a displacement of the zero crossing of the maser detuning vs. the low frequency coherent transition frequency with respect to the dip of the maser absorption. This effect is visible for a maser tuned by spin-exchange and operated at a relatively high magnetic field and nonuniform Zeeman populations.An experimental verification of the theory is presented. A new method for tuning the hydrogen maser is suggested, and a proposal is made to measure the collisional frequency shift proportional to the average duration of hydrogen atom spin-exchange collisions.

scholarly journals Спин-обменные столкновения в системе K-Li

2019 ◽  
Vol 127 (10) ◽  
pp. 639
Author(s):  
В.А. Картошкин
Keyword(s):  
Magnetic Resonance ◽  
Resonance Frequency ◽  
Frequency Shift ◽  
Cross Sections ◽  
Spin Exchange ◽  
Resonance Frequency Shift ◽  
Magnetic Resonance Frequency ◽  
Complex Spin ◽  
Exchange Cross Section ◽  
First Time

AbstractSpin-exchange cross sections and the magnetic-resonance frequency shift in collision of lithium and potassium atoms in the ground state have been calculated for the first time. The cross sections are calculated based on the data on the singlet ( $$X{}^{1}{{\Sigma }^{ + }}$$ ) and triplet ( $$a{}^{3}{{\Sigma }^{ + }}$$ ) interaction potentials of ^39K^7Li dimer. A passage from the energy dependences to the temperature ones of the real and imaginary parts of the complex spin-exchange cross section yields information about both the broadening of the magnetic resonance line of the atoms under study and the magnetic-resonance frequency shift in their collision.

Stimulated Emission in the Hydrogen Maser and the H Spin-Exchange Cross Section

1973 ◽  
Vol 51 (18) ◽  
pp. 1901-1909 ◽  
Author(s):  
J. Vanier ◽  
R. Brousseau ◽  
R. Larouche
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Spin Exchange ◽  
Analog Computer ◽  
Stimulated Emission ◽  
Rate Equations ◽  
Relaxation Rates ◽  
Hydrogen Maser ◽  
Pulse Technique ◽  
Exchange Cross Section

Experiments are described in which the phenomenon of stimulated emission with a delayed maximum of power is observed in a hydrogen maser and is studied in some detail. The results are coupled to measurements of relaxation rates made through a pulse technique in which the hydrogen beam is modulated. A solution of the rate equations describing the phenomenon for a two-level model is obtained on an analog computer and is compared with the experimental data. From the comparison, we conclude that the phenomenon is explained by the assumed theoretical model. It is found also that the published values of the spin-exchange cross section of hydrogen are consistent with our experimental data.

Multistate life tables using Stata

2020 ◽  
Vol 20 (3) ◽  
pp. 721-745
Author(s):  
Jerônimo Oliveira Muniz
Keyword(s):  
Life Table ◽  
Input Data ◽  
Average Duration ◽  
Transition Rates ◽  
Absorbing State ◽  
Multistate Life Tables ◽  
The Mean ◽  
Time Specific ◽  
Number Of Individuals ◽  
Multistate Life Table

The mslt command calculates the functions of a multistate life table and plots a graph of conditional and unconditional life expectancies by time. The command provides linear and exponential solutions to estimate the number of individuals, transitions, probabilities, person-years, and years of life in a given cohort and state of occupancy. The input data are time-specific transition rates (or survivorship proportions) between nonabsorbing and at most one absorbing state. In addition to the mean age at transfer between states, mslt calculates the following summary measures: the mean age, the probability of dying, the average duration, and the proportion of life spent in a specific state.

scholarly journals Hyperfine contribution to spin-exchange frequency shifts in the hydrogen maser

1987 ◽  
Vol 35 (9) ◽  
pp. 3825-3831 ◽  
Author(s):  
B. J. Verhaar ◽  
J. M. V. A. Koelman ◽  
H. T. C. Stoof ◽  
O. J. Luiten ◽  
S. B. Crampton
Keyword(s):  
Spin Exchange ◽  
Hydrogen Maser ◽  
Frequency Shifts ◽  
Exchange Frequency

Measurement of the hydrogen-hydrogen spin exchange cross section

1968 ◽  
Vol 4 (5) ◽  
pp. 327-327
Author(s):  
C. Audoin ◽  
M. Desaintfuscien ◽  
J. Schermann
Keyword(s):  
Cross Section ◽  
Spin Exchange ◽  
Exchange Cross Section
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