``FFT``: The Forward Scattering Fixed Target Chamber
====================================================

The forward-scattering fixed-target (FFT) chamber hosts the coherent
diffraction imaging experiments, which are the baseline experimental
studies to be performed at the SCS instrument. In the initial design,
a forward-scattering geometry has been considered.  Furthermore, the
sample environment has to allow changing samples without breaking the
vacuum. The latter is realized by means of a fast sample changer
system connected to a load lock.

A cubic chamber with an outer dimension of 500 mm and a height of
700 mm is the base of end experiment station. The cubic shape was
chosen to provide enough space to allocate a linear stage for the
sample movement as well as THz in-coupling mirrors and diagnostic
tools. The linear stage and the mirrors sit on top of a bread board
that separates the chamber into two parts (upper and lower part). This
configuration improves accessibility during installation and
commissioning. An additional advantage of the cubic shape is that it
allows to minimize the sample to detector distance. The 700 mm height
is mainly determined by the flange (DN 350) for the DSSC detector.

There is :download:`extensive documentation <square-one.pdf>` on the
mechanics.

.. _experimental-3d:
.. figure:: experimental-3d.svg

   The motorized axes and their names of the experimental platform. Extracted
   from `experimental platform file`_.

The clearance mechanism to move the steel frame with respect to the inner
experimental platform is partly described in `clearance mechanism file`_.

Components inside the ``FFT``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. toctree::
   :maxdepth: 2

   guard/index.rst
   THz/index.rst
   reflectometer/index.rst
   diag/index.rst
   electromagnet/index.rst
   FSSS/index.rst
   loadlock/index.rst
   TZPG/index.rst
   EP.rst
   SmarAct/index.rst

Flanges on the ``FFT``
~~~~~~~~~~~~~~~~~~~~~~

.. toctree::
   :maxdepth: 2

   upstream/index.rst
   downstream/index.rst
   top/index.rst
   left/index.rst
   right/index.rst
   bottom/index.rst

.. _experimental platform file: https://docs.xfel.eu/share/page/site/xfelwp86/document-details?nodeRef=workspace://SpacesStore/e5833a18-bd96-4ea1-8311-d09085e4166b
.. _clearance mechanism file: https://docs.xfel.eu/share/page/site/xfelwp86/document-details?nodeRef=workspace://SpacesStore/02f8acf7-d5aa-4d17-8c9b-755df7b0814d

How To ``FFT``
~~~~~~~~~~~~~~

.. toctree::
   :maxdepth: 2

   boz_align.rst
   ventpump.rst
   interlock.rst
   airpads.rst