He and Li beams have been installed and set into operation at the TJ-II stellarator with the aim of measuring electron temperature and density profiles in the edge and scrape-off layer regions of the plasma. The effusive thermal Li beam penetrates up to a normalized effective radius of ρ=0.6–0.7 in typical electron cyclotron heated plasmas. Density profiles deduced from the Li beam are wider than those obtained from extrapolation of the profile measured by Thomson scattering. The He beam is a pulsed supersonic one. Simultaneous detection of three emission lines (667.2, 706.5, and 728.1 nm) is made with a set of three photomultipliers. First He beam measurements of ne and Te in TJ-II are presented and the agreement among results of different plasma edge diagnostics is discussed.

The use of field measurements of attenuation curves of low-energy x-ray beams as a functional description of the beams is presented in this work. The energy fluence carried by diagnostic x-ray beams has been determined from A1 attenuation measurements made with a quality control ionization chamber for diagnostic x-ray equipment and with a low-volume ionization chamber. The obtained values are compared with those obtained from a catalog of spectral data for diagnostic x rays.

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It is shown that the narrow‐beam attenuation curve can be a functional description of a low‐energy x‐ray beam, as is the spectral distribution. Physical quantities, which are usually calculated by integration over the spectral distribution (differential photon or energy fluence), can also be obtained from the narrow‐beam attenuation curve without any need for an explicit knowledge of the spectral distribution.

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