STaRBoard Jamal Rorie 5/09/06 Physics 476

Why do we need ToF info? Used to determine species of particle –Central Drift Chamber records path –ToF records time –B = 1.5T –Apply Lorentz Force Law

Why do we need to upgrade? Currently Belle has a luminosity of 1.6x10 34 cm -2 /s New technique: crabbing the beam Belle luminosity will be ~2-3x higher Background will be ~2-3x higher as well Old ToF is not fast enough to handle this; a new technique must be tested

Data Collection TDC Leading Edge Lo Level Discriminator Mean Timer 1:3 Splitter ADC Leading Edge Hi Level Discriminator Leading Edge Lo Level Discriminator TDC 1:3 Splitter Leading Edge Hi Level Discriminator ADC PMT

Timing Scheme What did the PMT know and when did it know it? Hi level - event trigger Lo level - higher time resolution

Readout Scheme Event trigger received by STaR Logic request to TDC TDC polls for “hit” around requested time TDC sends data, Logic queries ADC No TDC data, Logic doesn’t query ADC ADC sends data COPPER I/O carries data downstream Hit No Hit

COPPER COmmon Pipelined Platform for Electronics Readout One standardized card can control up to 4 boards

STaR Layout HPTDC LAB3 XC3S2000 COPPER 16 CLK

The STaR Board

LABRADOR3 8 Input Channels

HPTDC 32 input channels –only 8 used when configured for high precision

Spartan3 456 pin pkg (340 used)

ADC Block ADC –LABRADOR3 STaR takes in differential signal from upstream –lower noise –modifications necessary Shaper to elongate signal –Originally 3 GSPS –Now MSPS

TDC, Logic, and I/O Blocks (not quite as exciting) TDC –ECL-to-LVDS –HPTDC Logic –Spartan I/O –COPPER

Testing Shaper Test –Elongation good –Standard delay confirming

Tasks Currently –Firmware development –Board population Ahead –Software development –Firmware testing –Finalization –KEK observations (mid-July)

Online Documentation –Schematics –Updates –Code –Datasheets