1. Outline: Current status Active splitter Plan Chris Neu, Daniel Whiteson, Rick Van Berg L2 Upgrade Meeting 11 June 2004 XCES Input Path: Status

2. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 2 XCES Input Path: Status Recall from last time: 48 XCES input channels for L2 Tx downstairs use Taxi  Optical Tx strength varies component-to-component  Weak optical Tx strength rampant – half too weak to split; others marginal or sufficient 16 split channels  16 NetOptics splitters  Housed near bottom of rack 2RR31C (near entrypoint for XCES fibers from CH)  2U chassis, Siemon patch panels on front and rear (thanks to Dervin’s guys for fabrication)  Inputs fed in through back  Half of outputs sent out the back, half out the front (particularly convenient)  Inputs to splitters coupled directly to XCES fibers at original patch panels (to avoid moving input fibers)  Have each output marked with ID # and loss value to facilitate channel swapping

3. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 3 XCES Input Path: Status Staged 16 new 20’ long fibers  feed pulsar board  Left 4 fibers from stage 0 in as spares Installed 16 splitters on 4/15 Chose 16 strongest Tx channels for splitting: Tested with L2 torture  Tev studies time – my favorite time  Script from Masa: allows user to adjust by hand the XCES thresholds to tune occupancy  During studies one can mimic real data  All looked well with Run 2A system Beam tests Pulsar channelXCES channelTaxi Tx loss (-dBm) 00W15.2 10E15.91 212E15.56 315W16 414E15.73 53W14.67 615E15.47 716W15.12 85W13.22 919W15.69 107W15.33 1119E15.68 1220E15.5 139W15.08 1421W14.82 1521E14.97

4. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 4 Results of Beam Tests: Run 2A system ADC counts and turn- on curve for high and low XCES thresholds.

5. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 5 Results of Beam Tests: Run 2A System = split channel

6. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 6 Results of Beam Tests: Run 2A system Same run, restricting attention to events away from threshold to remove turn-on effects

7. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 7 Results of Beam Tests: Run 2B system Two references for Pulsar path, each with their own quirks Compare Pulsar data to simulation of trigger threshold Compare Pulsar data to threshold trigger bits in alpha Rare differences CESD simulation as reference TL2D as reference

8. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 8 Results of Beam Tests: Run 2B system Using absolute reference: L2Torture test with patterns in the SMXR thresholds so that the bits were predictable. In 1 million bits: Run 2B: TP2D: Zero errors! Run 2A: TL2D: Rare errors Plots like these to be available in PulsarMon!

9. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 9 Commissioning Plan: Timeline Made Before Tx Power Problems ID’d 3/15: Stage0 splitter box complete DONE 3/16: Install Stage0 splitter box DONE 3/15-3/22: Perform optical measurements on all 48 XCES signals coming from downstairs DONE 3/22: CDF power back 3/22-4/1: L2 Torture testing: debug/use/refine monitoring code DONE 3/23-4/10: Beam tests after understanding L2 Torture DONE 4/10: Stage0 complete DONE 4/10-5/1: Develop DAQ code for XCES readout DONE 5/1: Stage1 splitter boxes complete DONE 5/7: FW for driving out over SLink complete DONE 5/1-5/7:Install Stage1 splitter boxes in system DONE 5/7-6/1: L2 Torture and beam tests of split system; DONE L2T of Slink output … Progress Made – BR, SP, Frans et al. 5/7-6/1: Install and test XCES Merger link Progress Made 6/1: Stage1 complete 6/2004: Build and install Stage2 splitter boxes …. complicated by active splitter End of 6/2004: Have N Taxi Rx boards in hand ready for system (N = 2 + #spares) READY – thanks to others 7/2004: Install 2 more Taxi Rx boards in system; test with L2 Torture, beam 8/2004: Burn-in time in beam; readout by default; monitor for errors 8/24/2004: Stage2 complete 8/25/2004: 10-week shutdown begins

10. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 10 The Virtues of Splitting All 48 Channels Commissioning of system possible with only 16 split channels  But painful Turn-on of XCES path cannot be parasitic-gradual  would need to be threshold moment  this is not optimal Future: would like to have a “hot spare” Pulsar system ready  being fed parasitically with upgrade in place Will make things “clean”  each channel treated equivalently

11. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 11 Design of Active Splitter RVB and I came up with this design at Penn a couple weeks back: -5V Variable Resistor To set Comparison Voltage Taxi Rx HFBR 2416 Taxi Tx HFBR 1414 AD96687 MC10H115 Prototype has been built at Penn; will be here at FNAL for testing next week.

12. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 12 Two Possible Paths and Timelines Delay getting prototype here from Penn  Atlas test beam work required significant attention  Things calmer now Once the hand-made prototype is here we can test it using Taxi Tx-Rx setup in teststand crate Those tests will determine if basic circuit logic is working and whether we can proceed Would like to solicit help getting testing off the ground and ultimately testing all boards once they arrive Need 48 channels split + spares: so let’s say we need 60 split channels Choices to consider: 2 channels-per-board x30, or 1 channel-per-board x60 Two possible paths:  Use PCB  Make all splitters by hand Timeline estimates are different…

13. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 13 Two Possible Paths and Timelines PCB: 6/14-6/18: test prototype here at FNAL work on layout (4 layer, at Penn) 6/19-6/25: finalize layout and determine mechanical issues 6/28: submit design for fabrication 7/12: delivery of boards 7/12-7/18: stuffing of parts at Penn boards start to arrive at FNAL on daily basis en-masse testing begins 7/14-8/1: testing in situ 8/1: all 48 channels split Assemble by hand: 6/14-6/18: test prototype here at FNAL finalize circuit determine mechanical issues 6/19-7/1: assemble at Penn using vector boards (2 students x several per day) boards start to arrive at FNAL on daily basis testing as they arrive 7/1-7/18: assemble boxes, install test in situ 7/18: all 48 channels split Schedule complicated by honeymoon in Spain and Italy – leaving in 7 days. But I will have time to test the prototype and look into mechanical issues before leaving.

14. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 14 Logistical Issues Splitting 48 Channels Input fibers from CH come into the rear of the rack Prefer to leave them in place – do not want to disturb these So input to splitters should be at rear of rack Output fibers (for convenience) should come out the back as well Have ~18 inches vertical space for splitter chassis Thinking about 2 rear-facing chassis on shelves looking like this: Power comes from a 5V supply plugged into power strip; boards get power across a simple backplane or jumpered together…need to talk to Bob DeMaat. ~17in ~7in

15. June 11, 2004 L2 Upgrade MeetingChristopher Neu Penn/CDFPage 15 Summary Stage 0 and Stage 1 splitting completed ahead of schedule Stage 2 splitting complicated by need for active splitters Have an active splitter design and prototype built Needs testing - will be done next week Decision on path needs to be discussed Cost issues? Will need help testing boards Lots of things need to be done.