Beamline setup

Beamline transmission:

Transmission of the pump branches of the beamline Plot of the beamline transmission for the pump branches, considering that pump A counts one reflection more than pump B due to the splitting mirror and assuming both splitting mirrors (M1 and M2) inerted.

Transmission of the probe branches of the beamline without the delayline Plot of the transmission of the probe beam without the delayline as function of wavelength, assuming that the splitting mirror of the probe (M1) is inerted.

Transmission of the delay line (current setup) Transmission of the delayline for the four currently mounted sets of multilayers tuned respectively at 8.34 nm, 13.4 nm, 16.8 nm and 20.8 nm. Note that the transmission at 8.34 nm is multiplied by a factor 10.

Intensity ratio between pump A and pump B Plot of the intesity ratio between pump A and pump B. Unbalanced intensities of the two pumps decreases the TG visibility and adds to it a spatially uniform distribution of light intensity; an intensity ratio of 0.5 reduces the visibility by about 10% and adds a 10% of uniform intensity, a ratio of 0.2 has an effect as large as 50%.

Possible TG periods in exemplificative cases Plot of the EUV TG period as a function of the excitation wavelength for given values of the crossing angle (2θ) and probe wavelength (λpr), this is our preferred choice for changing the TG period.

Transmission of the delay line (additional settings) Transmission of the delayline for the three currently dismounted sets of multilayers, tuned respectively at 6.7 nm, 17.8 nm and 22.8 nm. They can be installed upon request, but this cannot be done during a running experiment since it requires several days.

Filters along the pump A and pump B branchlines Transmission of the filters along the pump A and pump B branchlines, indicated as Filter-A and Filter-B in the beamline layout (see page "Beamline setup"). These filters are often used to compensate for the lower intensity in pump A, due to its additional reflection. Filters can be changed during the experiment. We are in the process of rearranging some filtering items, so please contact us for confirmation. If you need other filters please contact us.

Filters along upstream the pump A / pump B splitting   Transmission of the filters placed upstream M2, in the location indicated as Filter-AB in the beamline layout (see page "Beamline setup"). Since this filter is placed before thes pump A and pump B splitting, it equally affects the intensity of both pumps. Filters can be changed during the experiment. This filter should block the photons at the probe's wavelength that co-propagate in the pump branchlines, it is often very important. We are in the process of rearranging some filtering items, so please contact us for confirmation. If you need other filters please contact us.

Filters in front of the detector Transmission of the filters placed in front of the detector; "Pary" means Parylene-N; thicker filters of the same materials (except niobium) are available. The main scope of this filter is to suppress as much as possible the diffuse light from the pump and maximize the transmission of the probe. Sometimes this filter plays a critical role, in particular if the sample surface is rough. Changing these filters takes several hours, so we suggest to not plan changing them during the experiment. If you need other filters please contact us.

Beamline specifications:

SOFTWARE and DATA ANALYSIS: