Outline:

1. ShowerMax Input Path Status Christopher Neu, Daniel Whiteson L2 Upgrade Installation Readiness Review 27 September 2004 Outline: • Brief review • Splitting of input signals • Status of monitoring • Plan

2. XCES Input Path: Description of Run 2A System • Shower Maximum (CES) data used in L2 to reduce trigger rates for electron and photon triggers • reduces detector background from single-phototube discharge • track-matching to shower max reduces combinatoric background for electrons • CES detector: within CEM calorimetry • 32 wires at |z|<200cm, 32 wires at |z|>200cm for each wedge • CES charged pulse -> digitized -> • 4 neighboring wires are summed in some time slice(4 CDF clocks): 16 wire groups per wedge • Compare sum to low and high thresholds: Tlow = 1.5 GeV, Thigh = 3 GeV (changed in ~May) • Low and high trigger bits are setif wire group sum exceeds threshold • 16 wire groups x 2 thresholds = 32 data bits per wedge/evt (called XCES bits) • Data flow: • SMXR board performs sum and threshold comparison; one SMXR per wedge • Single fiber transmits 32 data + 8 for buffer # = 40 total bitsfrom each wedge/evt • Why 8? Is buffer number transmitted on a 32 bit word? • Fixed length, which is good • Mostly zeroes --- lends itself to zero-suppression to reduce overhead in readout, transmission • 48 total cal wedges => 48 XCES fibers into L2 • 4 RECES boards accept these 48 fibers; use Taxi technology; latch according to L2 buffer • RECES boards are aux cards in L2 decision crate (b0l2de00) • Alpha reads out XCES bits when needed (for L2 decision making and/or when making TL2D) Christopher Neu Penn/CDF

3. Review From 3/12 Meeting • We had an internal mini-review on 3/12 and another in June • The status of each sub-task/input path was reviewed • ShowerMax input path significant issues: • Splitting of incoming optical signals for parasitic commissioning • Need for development of monitoring tools • Much progress has been made on both of these fronts - see below • A few new issues need attention as well • Much remains to be done Christopher Neu Penn/CDF

4. Splitting XCES Input Channels West 1 West 2 East 1 East 2 ch 0 -15.20 dBm -15.50 -15.91 -15.56 1 -16.94 -16.86 -17.01 -15.47 2 -17.74 -19.41 -17.01 -15.73 3 -14.67 -16.00 -16.44 -15.47 4 -19.15 -15.12 -17.62 -18.35 5 -13.22 -17.07 -18.82 -15.52 6 -17.45 -17.21 -16.55 -19.30 7 -15.33 -15.69 -19.07 -15.68 8 -16.42 -18.29 -17.90 -15.66 9 -15.08 -14.82 -16.15 -16.27 10 -17.20 -16.53 -18.20 -18.22 11 -17.89 -17.20 -18.40 -16.80 • Optical splitting problem: • Existing XCES channels driven by TAXI protocol through Agilent optical drivers • Significant spread of optical power across system • Optical splitting easy solution is passive splitter • Simple prism • But incurs 1-to-2 -3dBm optical strength hit (50% reduction in signal power) • Many (about half) of the 48 input channels are too weak to split passively • Need for an optical splitter that drives its outputs without significant loss • Looked for commercial product – but found nothing that matched our needs (somewhat meager compared to bandwidth of typical current applications) Christopher Neu Penn/CDF

5. Active Splitter: Circuit Design This is not a schematic! Just a visualization tool…schematic can be found at http://www.hep.upenn.edu/HEP_INST/OpticalSplitter.jpg For all the gory details see CDF 7152 Taxi Rx HFBR 2416 AD96687 light MC10H115 Taxi Tx HFBR 1414 photodiode light VEE GND LED Taxi Tx HFBR 1414 light VEE LED NB: both +5V and -5V are needed for the circuit. VBB VCC Christopher Neu Penn/CDF

6. Active Splitter: Circuit Design This is not a schematic! Just a visualization tool…schematic can be found at http://www.hep.upenn.edu/HEP_INST/OpticalSplitter.jpg For all the gory details see CDF 7152 820 nm light comes in via optical fiber Taxi Rx HFBR 2416 AD96687 light MC10H115 Taxi Tx HFBR 1414 photodiode light VEE GND LED Taxi Tx HFBR 1414 light VEE LED NB: both +5V and -5V are needed for the circuit. VBB VCC Christopher Neu Penn/CDF

7. Active Splitter: Circuit Design This is not a schematic! Just a visualization tool…schematic can be found at http://www.hep.upenn.edu/HEP_INST/OpticalSplitter.jpg For all the gory details see CDF 7152 Analog voltage is input to comparator 820 nm light comes in via optical fiber Taxi Rx HFBR 2416 AD96687 light MC10H115 Taxi Tx HFBR 1414 photodiode light VEE GND LED Taxi Tx HFBR 1414 light VEE LED NB: both +5V and -5V are needed for the circuit. VBB VCC Christopher Neu Penn/CDF

8. Active Splitter: Circuit Design This is not a schematic! Just a visualization tool…schematic can be found at http://www.hep.upenn.edu/HEP_INST/OpticalSplitter.jpg For all the gory details see CDF 7152 Analog voltage is input to comparator 820 nm light comes in via optical fiber Taxi Rx HFBR 2416 AD96687 light MC10H115 Taxi Tx HFBR 1414 photodiode light VEE GND LED Taxi Tx HFBR 1414 light Refernce is set with variable resistor VEE LED NB: both +5V and -5V are needed for the circuit. VBB VCC Christopher Neu Penn/CDF

9. Active Splitter: Circuit Design This is not a schematic! Just a visualization tool…schematic can be found at http://www.hep.upenn.edu/HEP_INST/OpticalSplitter.jpg For all the gory details see CDF 7152 Analog voltage is input to comparator 820 nm light comes in via optical fiber ECL output is fed to repeater Taxi Rx HFBR 2416 AD96687 light MC10H115 Taxi Tx HFBR 1414 photodiode light VEE GND LED Taxi Tx HFBR 1414 light Refernce is set with variable resistor VEE LED NB: both +5V and -5V are needed for the circuit. VBB VCC Christopher Neu Penn/CDF

10. Active Splitter: Circuit Design This is not a schematic! Just a visualization tool…schematic can be found at http://www.hep.upenn.edu/HEP_INST/OpticalSplitter.jpg For all the gory details see CDF 7152 Analog voltage is input to comparator Dual parallel gate outputs drive 2 optical transmitters 820 nm light comes in via optical fiber ECL output is fed to repeater Taxi Rx HFBR 2416 AD96687 light MC10H115 Taxi Tx HFBR 1414 photodiode light VEE GND LED Taxi Tx HFBR 1414 light Refernce is set with variable resistor VEE LED NB: both +5V and -5V are needed for the circuit. VBB VCC Christopher Neu Penn/CDF

11. Active Splitter: Implementation • Assembled by hand at Penn • Need 12, have 14 in hand • Use vector boards • One side has ground plane • Top side has placement field with isolated pads • Four channels per board • 96 pin connector for power • Current draw: • +5V: 40mA/board • -5V: 700mA/board • This means total power consumed per board is less than 4W • Each input voltage is fused on each board Christopher Neu Penn/CDF

12. Active Splitter: Implementation • Original design of active splitter had significantly higher output power than the Tx’s on TAXI mezzanine cards used in the system • Determined by current across LED inside the Agilent optical Tx part • AS: ~-12dBm • Pulsar TAXI Tx mezz cards: -15 to -19dBm • AS cards designed to be within the specification of the Agilent and TAXI recommended operating points • Some risk in exceeding those limits • Overload downstream Rx parts • Adjusted pull-up resistor on Tx to achieve -16dBm output strength across all AS channels • Amounted to changing a 30ohm to 60ohm • Modification entails changing 96 surface mount resistors • Not hard just takes time - Will be completed in the coming weeks Christopher Neu Penn/CDF

13. Active Splitter: Implementation • The active splitter boards will reside in a custom-built crate • Crate resides in trigger room rack 2RR31C • 15 slots • Power provided by two 5V, 20A Lambda supplies • Per recommendation from B. DeMaat and S. Chappa, crate is completely enclosed, like a black box • Allows us to use unique backplane to provide power • Fully driven (15 boards) current draw and power: • -5V: 10.5A • +5V: 600mA • 55.5W total dissipated • Each supply is fused independently • Power supplies will be monitored with standard CDF tools • Design and implementation approved by DeMaat, Chappa, and Dervin Allen Christopher Neu Penn/CDF

14. Active Splitter: Implementation 48 fibers to Alpha 48 fibers to 3 Pulsar boards • Fiber routing recommendation from Dervin • Need to protect fibers from CH • Need a flexible configuration for commissioning • Recommendation: • Move CH fibers once • Couple them to jumper fibers that feed AS crate • 48x2 output fibers routed to Run 2A and 2B systems • Virtues: • CH fibers untouched • Only local fibers move during AS commissioning • Easy to work on/remove the AS crate from data path during commissioning and down the road • Need to purchase 48 new “jumper” fibers 2RR31C (front) Active Splitter Crate 48 fibers from CH + 16 spares Patch panels Christopher Neu Penn/CDF

15. Active Splitter: Testing • TAXI protocol is just a method of encoding data for optical link • Useful data is packaged in TAXI transmitter side into frames • 5b/4b • The framing is then interpreted on the receiver side and data extracted • TAXI looks for this framing constantly – • an error line is pulled high when missing • VLTN signal • Frames come in at 80MHz • High rate testing • 1hr = 3E11 frames Active splitter cards would endure minimally 1-2 hours of VLTN testing upon arrival at FNAL from Penn as part of checkout. Only 3 out of 56 channels were identified as faulty. Christopher Neu Penn/CDF

16. Active Splitter: Beam Testing • Crate with four active splitter cards installed for beam testing in July • Lack of power supply monitoring restricted tests to data transmission to upgrade electronics only (did not want to endanger the real system) • This obstacle contributed to fully split ShowerMax input path not participating in August commissioning of system (returning real L2 decisions with CPU…) • But some test runs were collected • TP2D v. TL2D • Two pulsar boards receiving copies of split data • Should be identical • Looked at all available events with TP2D and TL2D – in the 10s of thousands • Two failure mechanisms: • Buffer number problem (10 events) • Missing data problem(2 events) Christopher Neu Penn/CDF

17. Active Splitter: Beam Testing • Buffer number problem: • Of the 16 channels coming into the Pulsar Rx, 7 have L2 buffer number that does not match its neighbors (which are correct wrt TL2D). • Dump from PulsarMon: CES_Monitor::validateCESData() - CCN - simbits (portion of 162 CES words): 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CES_Monitor::validateCESData() - CCN - realbits (portion of 162 CES words): 0 3 0 0 0 3 0 3 0 3 0 3 0 3 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 3 0 0 0 3 0 3 0 3 0 3 0 3 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • Problem seen in runs with and without active splitter (same exact channels) • Similar problem reproduced in teststand (Tx-Rx) • Needs attention • This is priority task for ShowerMax path Christopher Neu Penn/CDF

18. Active Splitter: Beam Testing • Missing data problem • CES_Monitor::validateCESData() - CCN - simbits (portion of 162 CES words): 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CES_Monitor::validateCESData() - CCN - realbits (portion of 162 CES words): 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 30000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • Similar problem seen previously • Used CESD info to link this error to Alpha side • Need to verify that this is the culprit in August runs Christopher Neu Penn/CDF

19. Active Splitter: What’s Next • Study and repair L2 buffer number problem • Look deeper into the missing data issue • Get needed jumper fibers • Make modification to AS boards to throttle back current to Tx • As mods are completed, install in system and test with L2 torture • Expect help from Penn • Electronics lab technician coming to participate in the work • 1-2 week commitment • Fix and diagnose three broken channels • Verify the power supply monitoring for crate works • Make sure the monitoring is complete and working well Christopher Neu Penn/CDF

20. ShowerMax Path Monitoring CESD TL2D CDF CESD TP2D TL2D PulsarMon TP2D • Like other Pulsar boards, DAQ buffers in the input and output stage which must be monitored • Can toggle on/off the input and output monitoring depending on task at hand • Must monitor data from multiple boards • System designed to have 3 boards receiving the 48 XCES channels • Can toggle on/off monitoring on each of these boards • Comparison is done between simulated TP2D and real TP2D: • Sources for simulated TP2D: • Upstream bank: CESD • Parallel to TL2D • Nice complimentarity between these two options • Can isolate errors up/downstream of upgrade electronics • Can identify whether discrepancies between Alpha and Pulsar are 2A or 2B problem Christopher Neu Penn/CDF

21. ShowerMax Path Monitoring Using TL2D as reference Number of missinghigh and falsehigh bits • Output of monitoring contains many plots • 1D stats plots for each input and output channel • 2D comparison plots of simulated TP2D versus real TP2D • Global summary histograms • These will be the useful ones for COs • Still developing what exactly will be reported for shift crew • Error messages also sent to ErrorLog • Also still working on the verbosity level • Still some open issues but PulsarMon for ShowerMax is maturing Christopher Neu Penn/CDF

22. Summary • Things are progressing on the ShowerMax input path • Much work remains to be done • Major open issues, manpower and timeline: Present – Oct 15: - understand data integrity issues from beam runs - order jumper fibers Oct 15 – Nov 15: - complete AS modifications - test each card for VLTN and in system with L2 torture - system build-up - finishing touches on XCES portion of PulsarMon and start running XCES monitoring online Nov. 15: - personal deadline for fully split 48 ShowerMax channels - monitoring complete and capable of running online - consistent L2 testing Nov. 22: - beam in the machine Dec. 1: - collisions Christopher Neu Penn/CDF