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Soft-X ray characterization facility

The EUV radiation is emitted by a microfocus soft X-ray source. An high energetic electron beam is emitted by a tungsten filament (the cathode) by thermionics effect. The beam is accelerated against a target anode, stimulating the emission of radiation correspondent to the core shell energy levels of the target. The operating anode to cathode voltage have been 5KV, the electronic current 0.2 mA. Target materials are Al ( L -17 nm), Si (L-13 nm), Mg (L-25 nm) etc. In place of the microfocus source, an hollow chatode lamp fullfilled by He gas  can be used to generate radiation at 30 nm). An hollow chatode lamp can be alternatively used for HeII 30.4 nm emission. The wavelength scanning is performed by a grazing incident spherical grating monochromator, provided by a 600 lines/mm spherical grating that focuses the radiation onto the exit slit. The monochromator adopts a Rowland circle configuration, and the acceptance of the optical system is defined by an aperture on the entrance arm. The same aperture prevent direct source radiation from coming out from the monochromator. The refocusing mirror chamber accommodates a toroidal mirror that focus the folded beams at the centre of the test chamber. The test chamber accommodates two rotators guided by external manipulators in q‑2q configuration. A channel electron multiplier (CEM) detector is mounted on the 2q rotator: it detects the direct beam or the beam reflected by the multilayer sample mounted on the q rotator. The CEM works in the photon counting regime, with negligible noise and high sensitivity. 


Inside the experimental chamber