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We discuss the formation of a specified super-Gaussian intensity distribution of a fundamental mode by means of an intracavity controlled mirror, which is a water-cooled bimorph flexible mirror equipped with four controlling electrodes. Analysis has confirmed the possibility to form fourth-, sixth-, and eighth-order super-Gaussian intensity distributions at the output of the stable resonators of industrial cw CO(2) and YAG:Nd(3+) lasers. We present the results of the experimental formation of fourth-order and sixth-order super-Gaussian fundamental modes at the output of a cw CO(2) laser by means of an intracavity flexible mirror. We observed an increase in power up to 12% and an enlargement of the peak value of the far-field intensity by as much as 1.6 times that with a Gaussian TEM(00) mode of the cw CO(2) laser.

Recent electron-impact double ionization (e, 3 − 1e) experiments on helium are investigated theoretically. An ab initio calculation has been performed on the basis of the first Born approximation using different correlated wavefunctions for the initial bound-state and a correlated double-continuum wavefunction which satisfies the exact asymptotic boundary conditions for the final state with two slow electrons. The results of this calculation are compared with those of other theories.

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