Meeting on Front End Electronics (Zeuthen)
             ------------------------------------------


      Participants: H.Kolanoski, M.Pohl, Y.Jia, Z.Zhu, , U.Uwer, M.Walter
      Date: 30-Sep-98, 13:30 - 14:30


            Agenda:
            -------

         1. Status of recent orders:
         2. ASD8 power distribution boards and testpulse board:
         3. ASD8:
         4. HV Feedthrough Boards:
         5. HV Boards:
         6. First shipment to China:
         7. AOB
         Appendix A
         Appendix B
  


      1. Status of recent orders:
      ---------------------------

      a) Prototype  of the new HV feedthrough board
         Order went out on Monday afternoon.

      b) Coax-Cable (4km):
         Bidding procedure started.
          
      c) Soldering Stations (for China)
         Bidding procedure started.



      2. ASD8 power distribution boards and testpulse board:
      ------------------------------------------------------     
      
      a) Test results: 

         The timing of the testpulse board is currently studied.
         The measurement requires a detailed calibration of the 
         used TDC.  
 
         As a next step the time stability of the power distribution
         boards is tested. 

         Results on both measurements are expected for the Hera-B week.


      b) Redesign and the order of 60 cards:

         The current time schedule does not allow for another design 
         iteration and another prototype batch.

         The currently known modifications and improvements will be 
         implemented until Friday and 60 distribution boards will
         be ordered next week.


      3. ASD8:
      --------
 
      a) Production

         Until today Zeuthen has produced 6260 ASD8 boards. From which about
         4000 boards are foreseen for the OTR. The production is currently
         slowed down. Reason is the preparation of the HV board cables for
         China.

      b) Test: 

         U.Schwanke will be the physicist in charge for the tests.   
         See Appendix A for more information.         
    
      
      4. HV Feedthrough Boards:
      -------------------------

      In order to speed-up the design iteration Mario will provides
      the drawings of the new board.                
          
      The PCBs of a few "connection cards" will be done by the Zeuthen 
       workshop.

      
      5. HV Boards:
      -------------

      a) Spark-catcher:
         The spark-catcher for the test of the HV boards is designed. 
         Drawings for the PCB and a list of the components are given to 
         Mario. The PCbs will be done in Zeuthen. The parts are ordered
         in the coming days.
 
         2 devices will be build for Zeuthen. The remaining components 
         (4 devices) are send to Bejing.

      b) Zeuthen HV Board production: 
         The boards for mini SL2 are ready. The boards for mini SL3 
         and MC2+ are ready by end October.
    
       
      c) Preparation of cables for Bejing:
         Zeuthen is currently producing 1000 cables per day. 
         The particular effort of our Chinese colleagues must be 
         acknowledged: They have produced 2000 cables over the last
         week-end.

      d) Test TC chamber:
         The need of HV boards for the test TC chamber is not clear.

     
      6. First shipment to China:
      ---------------------------

      A first box will be shipped tomorrow to Hamburg to prepare
      the custom formalities. The contents is specified in Appendix B.          

      7. AOB:
      -------

      a) Mario is absent from  08/10 until 22/10
      b) Uli is in Hamburg until 14/10.
      c) Zian will bring on Tuesday 2 Distributuion Boards, 1 Testpulse
         Board and cables to Hamburg



     Appendix A
     -----------
 
     The final test for ASD amplifier cards
     ======================================

(U. Uwer, U. Schwanke)

The objective of this test is to show the full functionality
of the ASD8 amplifier cards before taking them to the experimental
area at DESY Hamburg. It will use the existing test facility for
the ASD8 chip test which has to be modified for this purpose.

The following tests are proposed

(1) Show that all channels respond with ~100% efficiency and good
    time resolution to test pulses at a standard threshold voltage
    (0.7/0.8 V) 

(2) Demonstrate that there is no inacceptable noise at a threshold
    of 0.4 V. 

    ( test environment (long cable, ...) needs to be discussed )

(3) Apply a standard pulse ( 5 fC, 0.7 threshold voltage ) and show
    that all channels deliver a signal at ~100% efficiency.

(4) Measure time differences on channels for large pulses and
    a low threshold.

    ( definition of actual values required )

(5) Measure the threshold voltage for 50% efficiency on all channels
    using test pulses.


What needs to be done
=====================

a) Do a time calibration of the test facility. (M. Pohl)

b) Modify the existing software to actualize (1) - (5) (U. Schwanke)
   This includes the saving of the following information about
   each board on a file:
        o a 16 bit word which summarizes test (2)
          (channel noisy or not)
        o efficiency from test (3)
        o time difference with respect to the calibration
          from test (4) for each channel
        o mean value of U_th^50% of all 16 channels
          and the relative deviation of every single channel 

   Furthermore some tools for reading in the ascii-files and 
   doing the chip statistics are needed.

c) Based on the experience with the first boards the test software
   should include some advises for the person running the test.
   This includes
        - sorting criteria
        - under which circumstances a board should be discarded
        - ... 

d) Documentation & guidance for the people doing the test in the
   electronics lab.

----------------------------------------------------------------------------



   Appendix B:
   -----------


   Material to be shipped to China:
   ================================

Pos    Material         Amount          Price
-------------------------------------------------

1.     HV Boards      5mm RC:  80       approx.
                      5mm LC:  80       1DM / channel
                     10mm RC:  90
                     10mm LC:  90

        

2a.    Coax Cable       6000 (??)       2DM/m
                        pieces

2b.    HV Cable         1km             ????

3.     Connectors        600            ???

4.     Adapter Boards    600            ???
        

5.     Capacitors        300            0.60 DM/piece


6.     Soldering        2 rc, 2 lc      ????
       Templates        6(??) connector

9.      Solder Tin       5 Rolls        ???


11.     HV Power Supply     1           ????
        (Gleisberg)

12.     Testing Setups:
           gas-boxes        4           ????