Within ATLAS both TILECal and LAr are planning upgrades to the readout systems - current systems will reach limits on radiation exposure aging of components – connectors - higher luminosity will require a better trigger than the current analog tower sums - improve reliability Both systems are looking at bringing out full digizations to the counting room where a digital trigger could be derived Kelby Anderson

Current system has 3 layers of boards and many signal and power interconnects. 2 ATLAS Tilecal

3in1 MainBoard PMT Block PHOTOTUBE Each Tilecal cell is read out by 2 phototubes on opposite sides of the mainboard. The board is split to mitigate against single point failure. 2 components to the system 1. MainBoard (size of current motherboard) - independent operation - no board to board interconnects 2. Electronics in the PMT block (3in1 card) Electronics in the PMT block – looking at 2 options 1.passive shaper – discrete component version ( update to the current 3in1 card) 2.ASIC design that incorporates the ADC’s is being considered (new version of QIE) 4 Main Boards in a drawer NEW DESIGN 4

PMT shaper Integrator charge injection PMT shaper Integrator charge injection PMT shaper Integrator charge injection PMT shaper Integrator charge injection PMT shaper Integrator charge injection PMT shaper Integrator charge injection ADC logain ADC higain ADC logain ADC higain ADC logain ADC higain ADC logain ADC higain ADC logain ADC higain ADC logain ADC higain FPGA Data Organizer & Control MAIN BOARD READOUT STRUCTURE (1/2) SNAP12 12 bit ADCs DATA TO USA15 +5V -5V +3.3V discrete component version of PMT block electronics Integrator multiplexer Integrator ADC SNAP-12 TTC-GBT control ~60GB/s 5

H SC TTC ID ADC1ADC2ADC3ADC4ADC5FEC H SC TTC ID ADC6ADC7ADC8ADC9ADC10FEC H SC TTC ID ADC11ADC12FEC Intg ID - DATA - spare bits - 120bits/25ns  4.8GB/s for each link GBT 12 fibers to send both gains on 2 separate fibers 4.8GB/s x 12 = 57.6GB/s for each Mainboard 256 drawers x 4 Mainboards/drawer So we need about 1024 ~60GB/s links for ATLAS Tilecal One gain (high or low gain) for 12 tubes => 3 fibers at 4.8GB/s (GBT protocol)

ATLAS LAr

Can we find something better than commercial Snap12 transmitters … assuming they will work in the ATLAS environment? Avago Reflex Photonics 12 fiber cable