The TOTEM Roman Pot Electronics System G. Antchev * On behalf of the TOTEM Collaboration

1. The TOTEM Roman Pot Electronics System G. Antchev * On behalf of the TOTEM Collaboration * INRNE-BAS, Sofia, Bulgaria Gueorgui.Antchev@cern.ch

2. Outline of the talk • Introduction • On-detector Electronics • Counting Room Electronics • System Overview • Summary

3. TOTEM Detectors Inelastic Telescopes T1:3.1 < |h| < 4.7 T2: 5.3 < |h| < 6.5 T1 Cathode Strip Chambers (CTS) 10m 4m T2 Gas Electron Multiplier (GEM) 147m Roman Pot 220m Same scheme on both sides of IP5

4. Roman Pot Photo of sector 5-6 220m near RP unit Horizontal beam injection stable beams sensors in garage position 10σ beam Beam pipe sensors in data taking position Verticals

5. The Edgeless Sensor • Technology • Very High Resistivity Si n-type <111>, 300um thick • Standard planar technology fabrication • Design • Single sided detector, 512 microstrips (pitch 66 m) strips at 45° • from the “sensitive” edge; • Voltage Terminating Structure (VTS) on non-sensitive edges • Current Terminating Structure (CTS) on sensitive edges • (50 m) Pitch adapter on detector VFAT / APV25 compatible Only 50m from end of strip to end of sensor!!!

6. On-Detector Electronics – 1 • VFAT 2 Readout Chip • 128 channels of tracking front end, digital storage and data transmissions; • 8 programmable trigger outputs; • Radiation hard technology; • ~160 / 8 bit registers controlling the chip are programmable through its I2C interface; • Designed in PH-ESE group CERN. Photo of the VFAT 2 mounted on GEM Hybrid

7. On-Detector Electronics – 2 • Silicon Detector Hybrid • Carries detector and 4 VFAT2 readout chips and a Detector Control Unit (DCU) chip; • Connected to the outside world by means of an 80 pin connector linked to a flat cable; • On the same connector the HV and LV power, clock and trigger signal, and also connections to PT100 for temperature control; • The VFAT2 is biased internally so as to simplify the design of the hybrid.

8. On-Detector Electronics – 3 • Silicon Detector Package • Stack of 10 hybrids; • Flipping the hybrid and mounting it face-to-face with the next one result in orthogonal strips giving the U and V coordinate information; • All electrical components are mounted on one side to avoid losing space between the hybrids.

9. On-Detector Electronics – 4 • Roman Pot Motherboard – Block Diagram

10. On-Detector Electronics – 5 • Roman Pot Motherboard and its Mezzanines

11. On-Detector Electronics – 6 Digital Opto Hybrid (DOHM) – receives optical control data, converts it to electrical form and connects to the RPMB with two 20pin 3M connectors; Communication and Control Unit (CCUM)– decodes the information from DOHM and provides 16 I2C interface channels and one 8 bit parallel control port for use on the RPMB; Trigger VFAT2 Mezzanine – receives trigger information and defines the time reference in the trigger data stream; Coincidence Chips (CC) – make coincidence from the trigger bits, one for U and one for V; Radiation Monitor (RADMON) – carrier card

12. Counting Room Electronics – 1 • The TOTEM Front End Driver (TOTFED) • The TOTFED has to receive and handle the tracking data and trigger building from the TOTEM detectors; • Used in the data acquisition and trigger systems; • Based on the VME64x standard and modular; • Very flexible and programmable to deal with the different TOTEM sub-detectors • - possible evolution of the data treatment and trigger algorithms over the whole duration • of the experiment • Acquires on-detector data from up to 36 optical links and: • - performs fast data treatment (data reduction, consistency checking, etc...); • - transfers to the next level of the system; • - stores data on request for readout via VME64x or USB2.0. • Compatible with CMS: • - permits TOTEM to run both standalone and together with CMS

13. Counting Room Electronics – 2 Block Diagram Gigabit Optical INPUT 640Mb/s/fiber x 12 = 7.68Gb/s VME64x OUTPUT 40MB/s BLT S-Link64 OUTPUT 480MB/s 64bit@60MHz USB2.0 OUTPUT 480Mb/s – high 12Mb/s – full 320Mb/s – effective S_Link64 OUTPUT 480MB/s 64bit@60MHz TOTFED has: INPUT - 3 x OptoRX -> 3 x 7.68Gb/s OUTPUTS - 4 x S_Link64 -> 4 x 480MB/s - 4 x USB2.0 -> 4 x 320Mb/s - 1 x VME64x -> 40MB/s Data Bandwidth TOTEM Experiment Trigger Rate - 1 kHz Event Size - 40 kBytes

14. Counting Room Electronics – 3 • Main Characteristics • 9U VME64x Slave; • Local Bus Master 32bits/40MHz; • 18MB Spy Memory: • - 3x 6MB per 12 optical channels • (1 OptoRX), 96bits at 80MHz; • 3x Main Bridge + Memory Controller; • 3x USB 2.0 Interface; • Merger + 6MB Memory + 4th USB; • TTCrx, QPLL and CCS clocks • (optical or electrical); • TTS copper link; • JTAG controller on board; • Connectors for: • - 3x OptoRX; • - 1x DRM or Trigger Mezzanine; • - 3x S-Link64 + 1x S-Link64 on rear • at 200MB/s; • 2x Optional Board Connectors; • Board t0 measurements

15. Readout Crate TOTFED TOTFED TOTFED CAEN FEC System Overview – 1 Detectors 5-6 4-5 147 220 220 147 RP2 RP5 RP2 RP5 RP2 RP5 RP2 RP5 Patch Panel Patch Panel Patch Panel Patch Panel RP4 RP4 RP4 RP1 RP4 RP1 RP1 RP1 RP6 RP3 RP6 RP3 RP6 RP3 RP3 RP6 8 16 16 8 18 18 18 18 32 Data Data Data Data Control TOTFED TOTFED TOTFED TOTFED FEC Counting Room TTCci • DAQ System • data taking at up to ~ 1KHz over VME64x at ~ 40MB/s; • S-Link64 later within CMS at ~200MB/s; • 240 Si detectors to be read and 122880 channels, which • is covered by 960 VFAT2 chips LV1A

16. Trigger Crate TRIG TRIG GLOBAL TRIG CAEN TRIG TRIG TRIG LV1A System Overview – 2 Detectors 5-6 4-5 147 220 220 147 RP2 RP5 RP2 RP5 RP2 RP5 RP2 RP5 Patch Panel Patch Panel Patch Panel Patch Panel RP4 RP4 RP4 RP1 RP4 RP1 RP1 RP1 RP6 RP3 RP6 RP3 RP6 RP3 RP3 RP6 8 16 16 8 32 12 12 12 12 Trigg Trigg Control TOTFED TOTFED FEC Counting Room TTCci • Trigger System • optical from 12 fibres per station into 4 TOTFED • electrical 12 cables only from 220m stations using • repeaters

17. Trigger Crate TRIG TRIG GLOBAL TRIG CAEN TRIG TRIG TRIG Readout Crate TOTFED TOTFED TOTFED CAEN FEC LV1A System Overview – 3 Detectors 5-6 4-5 147 220 220 147 RP2 RP5 RP2 RP5 RP2 RP5 RP2 RP5 Patch Panel Patch Panel Patch Panel Patch Panel RP4 RP4 RP4 RP1 RP4 RP1 RP1 RP1 RP6 RP3 RP6 RP3 RP6 RP3 RP3 RP6 8 16 16 8 18 18 18 18 32 12 12 12 12 Trigg Trigg Data Data Data Data Control TOTFED TOTFED TOTFED TOTFED TOTFED TOTFED FEC Counting Room TTCci LV1A

18. System Overview – 3 Photo of the RP DAQ crate

19. System Overview – 4 Photo of the Trigger crate

20. Summary The TOTEM Experiment with its Roman Pot detectors has been set up in a relatively short time: TDR in 2004 and first data taking in 2009 with RP@220m; Complete installation of RP@147m and T1 detector done during 2010 winter shutdown; The Roman Pot Electronics System is the result of the joint efforts and participation of several collaborators; The overall performance of the Roman Pot with its edgeless silicon detectors is excellent. The effort spent in the development and construction of the experiment has started to pay off with physics results; The proton-proton elastic scattering has been measured by TOTEM experiment at CERN in special dedicated runs with Roman Pot detectors using the described above electronics system. The results are published in EPL journal:http://cdsweb.cern.ch/record/1361010/files/CERN-PH-EP-2011-101.pdf

21. Thank you