I. Reinhard

A MEASUREMENT OF THE 1S-2S TRANSITION FREQUENCY IN MUONIUM

Doppler-free two-photon laser spectroscopy has been employed to measure the 12S12−22S12 transition in the muonium atom (μ+e−). A value of 2 455 529 002(33) (46) MHz has been obtained, which agrees with QED calculations within two standard deviations. The Lamb shift contributions are tested to the level 8×10−3. The corresponding measurements in hydrogen and deuterium using the same apparatus and laser system provide a test of the applied systematic corrections and have verified the systematic error of 46 MHz quoted. The mass of the positive muon has been derived from the isotope shift in this transition and yields a value of 105.65880(29)(43) MeVc2.

Measurement and compensation of frequency chirping in pulsed dye laser amplifiers

Rapid changes of the refractive index in the active medium of a pulsed, excimer laser pumped dye laser amplifier were investigated with an optical heterodyne technique. Time-dependent shifts in the phase of optical light waves could be observed which for Coumarin 102, 153 and 307 dyes at wavelengths of 488 and 550 nm depend predominantly on the thermal properties, in particular, on the expansitivity of the dye solutions. A fast Electro-Optic Modulator (EOM) using LiTaO3 crystals has been designed for compensating these phase perturbations. With appropriately shaped voltage pulses applied to the EOM the resulting changes in the instantaneous frequency of the pulsed laser output could be lowered by a factor of 4 with respect to the values measured in the uncompensated light.

Spectroscopy of the 1S-2S energy splitting in muonium

A new measurement of the 1/sup 2/S/sub 1/2/-2/sup 2/5/sub 1/2/ energy splitting in muonium (/spl mu//sup +/e/sup -/) by Doppler-free two-photon laser spectroscopy yields a value of 2 455 529 002 (33) (46) MHz, where the 33 MHz error arises from statistics and the 46 MHz uncertainty is due to systematic line shifts. The experiment agrees with quantum electrodynamics theory within two standard deviations. The mass of the positive muon can be derived as 105.65880 (29) (43) MeV/c/sup 2/ from the measured muonium-hydrogen and muonium-deuterium 1S-2S isotope shifts. The measurement may alternatively be interpreted as a test of the equality of the electric charges of muon and electron with a precision of 1.4 (1.2) l0{-8}. >

Pressure dependence of the Mg 3s4s3S1 ! 3s3p3P0;1;2 transition in superfluid 4He

The pressure shifts of the

Measurement of the muonium 1S‐2S transition frequency

3s4s^3S_1 to 3s3p^3P_{0,1,2}

A sensitive search for Muonium‐Antimuonium‐Oscillation

transition of magnesium atoms immersed in superfluid helium have been measured at

Pressure dependence of the Mg \(\) transition in superfluid \(\)He

(1.3pm0.1 )

Pressure dependence of the Mg

K between saturated vapour pressure and

3s4s^3S_1 \to 3s3p^3P_{0,1,2}

24

transition in superfluid

bar. The wavelength is blue shifted linearly by