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New measurements of the zero-energy elecuon yield in the region of lhe pholodouble ionization threshold in helium are presented. showing for the first time a Wanniertype cusp with a small asymmetry of the excitltiodionimtion wing amplitudes, similar to the el&" impact results in the region of the first ionization threshold. The observed pressure dependence of the cusp amplitude asymmelry a d other second-order effects are discussed in nn attempt to explain the discrepancy with the earlier photoionization results of Hall et al.

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