WINDOWLESS, GEOMETRY-INDEPENDENT, PHASE-MATCHED METHOD FOR THE MEASUREMENT OF THE OSCILLATOR-STRENGTHS OF XE, KR, AND AR

We have developed a windowless, geometry-independent method for measur ing the relative oscillator strengths of gases by observing phase matc hing in the sum-mixing process in a gas jet. The fundamental beams are focused into the gas jet. There is an optimum pressure for gas behind the inlet valve. The inverse of the optimum pressure is proved to cha nge linearly with the inverse of the energy detuning from the measured level, and the slope of the linearity is proportional to the oscillat or strength of the level. Using this method we have measured the relat ive oscillator strengths of some resonance levels of Xe, Kr, and Ar in the vicinity of the cutoff limit of LiF.