1. An Idea of Next Sci-ECAL Prototype for FNAL Beamtest Feb-7 2008 Sci-ECAL meeting S. Uozumi (Kobe)

2. Tungsten absorber assembly Steel frame (3.54+3+1 mm thick) Thickness of this part should be 3 mm (for readout and monitoring system) Tungsten plate 1 2 34 White acrylic Frame (3 mm thick) Guide rails fit for shelf (not necessary?) 18 cm 20 cm

3. One complete layer flat cable with MPPCs (9 channels) Acrylic bar For gain monitoring

4. Length of the flat cable Not easy to decide, because … – Space to put our detector is limited. – Just behind the Sci-ECAL, AHCAL will be located. – Readout electronics takes some space. (size of 1 board ~ 95.3 x 19 cm, we will use ~23 boards. – Need to know available space for our detector in front of the AHCAL. Ask Erika or someone at DESY ? – Make a touch panel to hook up signal lines? It can change the connector bundle size at the same time, if necessary.

5. AHCAL Beam

6. Readout electronics channels Each flat cable has 9 channel connector. Readout baseboard has 14, 30 or 32 ch connectors. If we connect them directly (as done in the DESY BT), there will be some unused channels. (just 90 channels out of 108 are used.) At the FNAL BT, we will have 23 (+2) baseboards. If we use 90 ch per a board, total available num. of readout channels will be 2070. On the other hand, total detector channels will be – 72 strips x 30 layers = 2160 ch – 32 layers = 2304 ch For case of 30 layers, 24 baseboards will be enough. For 32 layers case, we have to use electronics more efficiently. (In this case converting 9 ch connector to 6 channel bundle will be useful.)

7. Things to concern / discuss … Number of layers ? – How much is the shower leakage with 30 / 32 layers ? – By the way, how many tungsten plates in Shinshu ? Design and cabling of gain montoring system – Also need to have available space Shelf for cal layers / electronics / CMBs – Is the guide rail necessary for the cal layers? – Available space – this also defines the length of flat cable. Is it really possible to make the designed structures? – Ability of machining, mechanical / dynamical issue, machining precision – Need to consult with machining company. – Detailed structure will be modified in that discussion.