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.  Facility   Inside the experimental chamber |
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