======  TT-UT Tests ======


Build test stand to test different types of sensors. Test will be done with a laser (infrared, focus length about 1 cm, beam spot about 50 mum). Laser and modules will be in a light tight box with cooling facilities.

======  Test stand: ingredients ======

 *  **Laser** Federica: collect all material in Zurich, check that it is working (Informations: Marco, Christian) 
  * Federica meets M&Ch in Zurich (17.December 2013)
  * **Stepmotors** Federica: test system in ZH (M&Ch)
  * **Mechanical assembly in box** Federica, Olaf, Katharina: sketch and discuss with workshop (K send mail to Kurt Boesiger) (17.December 2013)
      * Item level of detail for sketch
      *  mount laser on optical beam or rails
      * precision needed 0.6^o - is this realistic
      * ideas for alignment
   * **Installation in box or fridge** Federica: requirements: cooling, light tight, shielded 
      * Box: is it possible to use old big test box on its side?
      * Fridge: is temperature stable enough? Possible installation: discuss with Achim
      * Olaf: find box in ZH
   * **Cooling of electronics**: C_6F_14 in Zurich, mixed water at CERN
   * **Cooling of irradiated sensors** C_6F_14. This is for later
   * **Readout**: CERN test stand and/or Alibava 
      * Alibava (Olaf, Nico): ask Milano: price (7000 EUR for the complete Alibava system, 1500 EUR for the standard daughter board, and 150 EUR for the standard pitch adapter), delivery time (1-2 months)
      * CERN test stand not yet ready, needs about one month of work (Sandra) but is not top priority
   * **LV, bias voltage** Federica: from old test stand in ZH (Marco, Christian, Achim)
====== Questions on mechanical assembly ======

   * Is there a way to make the rod more stable than now?
   * We need a laser beam that is perpendicular to the silicon bulk and that remains perpendicular also when we move it along //x,// //y//, and //z//. Is it possible to mechanically constrain the rails and the support for the module? Or is it better to put something on the rails that allows us to regulate the alignment? We can verify alignment by looking at signal from sensors. Maximum angle of inclination with respect to the silicon bulk is $0.5^\circ$.
   * Do we need a support for the module? Pros and cons? In case, the support at one end must be flexible, since we will have modules of different lengths.
   * How can we minimize vibrations of the module? In the previous test stand: a pre-tensioning plastic block put between the back wall of the test box and the module inhibits these vibrations. The exact pre-tension can be adjusted by placing hard-plastic disks between the block and the wall.
   * What is the precision of the perpendicularity between the //x// and //z// axes? In the previous test stand: the perpendicularity between the two axes of the movable structure was assumed to be guaranteed by the mechanical precision of the construction.
   * What is the precision on the horizontality of the module?

======  Test modules ====== 
   * TT sensor plus Beetle from Milano (Mauro Monti should be available in March)
   * Multigeometry IT plus Beetle (in ZH: test whether it is working)
   * UT plus Beetle (Marina) 
      * check that hybrids can read both polarities (Olaf)
======  Documentation ======
   * [[http://fpmac116.usc.es/twiki/bin/view/Instrumentation/Alibava|Alibava]]