1. 6mm 【 Development of Readout Electronics for MPPC 】 We report the read out electronics of MPPC( Multi-Pixel Photon Counter ). MPPC is a new photodetector developed by Hamamatsu Photonics. Here, we report Trip-t ASIC chips and those electronics. We report the read out electronics, Trip-t Test Board. MPPC and Trip-t chip have been decided to use in T2K experiment. We now test the basic performances of latest MPPC samples, and check the device-by-device variation about many samples with Trip-t Test Board. Trip-t Test Board can be used for reading out signals from 32 MPPC at the same time. Trip-t chip ・ Developed by FNAL ・ Used in D0 experiment ・ Plan to use in T2K experiment and MINERvA experiment ・ Input 32ch Analog signal ( - ) ・ Output KEK Trip-t Board Blockdiagram Trip-t & MPPC Mount Board MPPC Mount Board with 32 MPPC Labview …with Plastic Connector for connecting MPPC to wave length shifting fiber Trip-t Block Diagram … Distal wave generator  Discri signal of each 32ch  Analog signal proportional to input signal  Analog signal proportional to the time between input signal and gate signal :::: Trip-t Test Board for Measurement Example Histogram by Trip-t For T2K experiment, ~60000 samples of MPPC must be measured. By this test board, we can measure 32 MPPCs at the same time. Now, we construct the system for mass production of MPPC samples for T2K experiment with this 32ch test board. Takeshi.Murakami*,Shinichi.GomiKEK*,Department of Physics, Kyoto University 190mm 65mm 190mm 155mm ±5VIN MPPC Hole 5.3φ （ 32 Mount ） Bias control MPPC Mount Side Trip-t Mount Side 40pin connector×2 ADC;AD9220 VME SIDE J0 FPGA;XC3S400PQ208 DAC;MAX529 CLK BUSY TRG-A TA-A TRG-B TA-B VME IF ;FPGA;XC95144XL-TQ144 VME6U DAQ Board MPPC SIGNAL(CH1) Pre-AMP RESET Pre-AMP after MPPC signal CLOCK(mux) 01232 T_OUT MPPC Signal D_OUT Pipeline Clock time Voltage A_OUT Trip-t readout sequence Trip-t Position MPPC ( Multi-Pixel Photon Counter ) Multi-Pixel Photon Counter ( = MPPC ) is a new type of photo detector developed by Hamamatsu Photonics (HPK). MPPC consists of 100~1600 small avalanche photo diodes( APD ) in 1mm×1mm sensitive region. 1pixel Sensitive region of MPPC MPPC advantages –Compact –Insensitive to magnetic field –High gain( ~10 6 ), low bias voltage( ~70V ) –High photon detection efficiency –Excellent photon counting capability The left figure is MPPC raw signal. MPPC has good photon counting capability. By using Trip-t Test Board, we are now measuring about the basic performances and device-by- device variation of MPPC for T2K experiment. ch2 A_Pipeline 48x32ch T_Pipeline 48x32ch Analog MUX Analog MUX Analog MUX Signal to Stocks （ Deep;1-48 ） 32chIN → Serial out Front End T_OUT (Time) A_OUT (Charge) D_OUT (discri signal) AMP Discri signal ch1 ch2 ch32 ch1 ch32 Trip-t TRIPT Trip-t ･･･ TRIgger and Pipeline with Timing Trip-t Performances LinearityLinearity High Gain Low Gain Input charge versus. ADC count When the gain of Trip-t is high, linearity become wrong at low charge region. Cross-talkCross-talk Check the signal cross-talk to the another input channel. Cross-talk is small enough. Input only No.15 channel 0.4% The injected charge to each channel is amplified by the front-end amplifiers and stored in pipeline before readout. Next the stored signals are serialized to 1 channel by multiplexer which is located at the last stage of Trip-t. Using 1 Trip-t, we can reduce the number of readout channels from 32 to 1. Simply speaking, A_OUT corresponds to the amplitude of input charge, T_OUT corresponds to the timing of input charge and D_OUT corresponds to the digital information of input charge. Serialized Total 128pins Those 2 boards, Labview and VME are connected by flat cable. Trip-t power supplies VDDD(digital)=+2.5V, VDDA(analog)=+2.5V OPAMP power supplies ･･･ ±5V Power supply Trip-tOPAMP Regulator +5V  +2.5V +5V-5V The DAQ(Data AcQuisition) board is a VME standard module and was originally developed for the SciBar detector in K2K experiment. We use this DAQ board for an analog-to- digital conversion of A_OUT from Trip-t. Several modifications are made to the DAQ board in order to adjust it to the readout of MPPCs. 1.Since A_OUT of Trip-t has 1.0V DC offset, we put A_OUT to the outm of the DAQ board and DC+1V to the outp. By subtracting the outp from the outm, A_OUT has no offset. 2.We change the gain of DAQ board from 20 to 1 because the gain of the Trip-t is enough high. MPPC raw signal Input to 10CH VME 1 ･ 2 ･ 3 ･ 4 ･ 5 ･ 6 ･ 7 ･ 8 ･ 9 ･ 10 ･ 11 ･･･ 10 111213 1PE 2PE 3PE Pedestal 1PE 2PE 3PE Pedestal 1PE 2PE 3PE Pedestal Basic performances of MPPC When we use all 32 channel, each output come at each MUX positions as those figure. PD07 International for poster Jun 27-29,2007 Kobe