Feb. 2009
Dear Colleagues,
As usual, a few days before the ESRF proposal deadline we send you this
reminder.
The beamline is going very well. Recently we have performed coherent
diffraction experiment on metal nanoparticles and the beamline is
perfectly suited also for this technique in terms of stability and
repeatability. The main difference with respect to ID01 is that they
mainly work in the specular plane while we can mostly look to reflections
outside the specular plane. This has advantages and limitations.
Concerning the experimental set up we have some important improvements:
a) The flow reactor for catalysis studies is now connected to a new
gas line which can be fully controlled by spec. The gas composition is
controlled with the same procedure used for moving motors. The same is
for the sample temperature. The big advantage is that now we are able
to carry out macros giving more flexibility in exploring the
thermodynamic conditions were reactions might occur.
b) In the UHV chamber of EH2 we have replaced the phi and chi circles
normally used for the surface alignment procedure with an hexapod.
This makes the procedure much simpler and faster and also eliminated
all the problems connected with the z movement of the sample. This
gives also the opportunity of centering the sample surface at the
center of rotation of the diffractometer giving the possibility of
studying sample with dimensions smaller than 1 mm.
c) As you know we can carry out simultaneous measurement of surface
diffraction and GISAXS. With this aim we have developed new mask slits
which will greatly reduce the backgorund in the case of GISAXS
measurements. They will be installed during this spring shutdown and
debugged before the summer.
d) We have finally found the way and developed a sample holder
suitable for Si samples. Now we can flash Si wafers with a pressure
remaining in the 10-10 mbar. So far I have been reticent in accepting
proposal on Si because our system was not clean enough for this
samples. Now I am perfectly confident we can do it.
In the case you need more information do not hesitate in contacting us.
Your sincerely,
Roberto