Hints for proposals

  • If you want to use the mini-TIMER setup, you have to ask for the DiPROI beamline (not TIMER!) and to state in the proopsal field "other requirements" that you need mini-TIMER.
  • During the allocation phase we may evaluate the possibility to schedule the experiments on TIMER in place of mini-TIMER or vice-versa. If you need to use a specific instrument please stress the motivations in ypur proposal.
  • The "standard duration" of an experiment is 11 shifts (1 shift = 8 hours), we recommend to try fitting your experimental plan in 11 shifts. The facility usually adds one shift for beamline preparation before each user experiment (in some cases we may add more preparation shifts). Please consider that the time needed to align mini-TIMER or TIMER is roughly one shift and any changes in the experimental geometry (FEL crossing angle, angle of incidence of the probing laser, etc.) require a couple of hours time.
  • It is not possible to operate the FEL1 and FEL2 sources in the same beamtime. If you need wavelengths within the range of both sources please write two proposals. Keep in mind that, in this case the two experiments cannot be scheduled one after the other (most likely there will be some to several weeks in between). Moreover, the whole range of FEL2 cannot be covered within the same beamtime, since it requires different electron bunch energies. Please refer to the FEL2 beam parameters and contact the beamline scientist for more details.
  • We prefer using FEL2 tuned at the desired probe's wavelength, where the first stage (sub-harmonics of the FELoutput) is used for the pump pulses. We also prefer to change the wavelength of the pump rather than the crossing angle for changing the TG period.  
  • Typical pulse energies at the source in order to observe a reasonable TG signal are on the order of ~10-20 uJ.
  • The ML of the TIMER delay line reflect only vertically polarized light. However, we typically request circular polarized light to maximize pulse energy at the source.
  • If you need two-color FEL emission (e.g. when using FEL1 with two different wavelengths for pump and probe) state this clearly in the proposal and consider that the total energy radiated in the two pulses (I1+12) is lower than in single pulse mode. 
  • Always ask for the user laser, even when using the EUV probe, since it is needed to adjust the timing between the FEL pulses (for this activity we prefer the fundamental harmonic: wavelength 785 nm).
  • Typical spot sizes are in the range from 250 x 250 to 80-80 μm. Using mini-TIMER it is possible to tune the focal spot size, at EIS-TIMER not.
  • In general we noticed sample damage for pulse energies larger than 40 uJ at the source, in these condtions you burn very nice permanent gratings on the sample.
  • Typical integration time for having a good signal-to-noise (say about 100) is ~20 seconds per time-delay point. Please consider death times as large as 10 seconds for each time-delay points.
  • If you need sample environments different from those available [ADD LINK] please contact us, we are happy to realize new things but we need time and resouces to do that!
The design of an EUV TG experiment  is not at all easy, there is a number of constraints, so, if you think tha nanoscale TGs can be useful for your research projects, please contact us!
Last Updated on Tuesday, 12 March 2024 17:58