Beam Phase and Intensity Monitor for LHCb

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Augustine Mills
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AB/BI Greg Kasprowicz, AB/BI Thilo auly,

1 ERN Beam hase and Intensity Monitor for LHb Zbigniew Guzik, IJ, Warsaw, oland Richard Jacobsson, ERN Acknowledgements: Eva alvo Giraldo, AB/BI Rhodri Jones, AB/BI Greg Kasprowicz, AB/BI Thilo auly, ATLAS LE 2006, September, Valencia, Spain

Motivation 1 z Global clock stability ¾ ¾ ¾ z ERN LHb: 14 km of fibre between SR4

seasonal drift 8ns Aid in the coarse and fine time alignment of the experiment ¾

fibres (Source: Asservissement en phase d'une liason fibre optique, rapport de

2 Motivation 1 z Global clock stability ¾ ¾ ¾ z ERN LHb: 14 km of fibre between SR4 and A8 at a depth of ~1m Estimated max. diurnal drift 200 ps Estimated max. seasonal drift 8ns Aid in the coarse and fine time alignment of the experiment ¾ Measure bunch phase bunch-by-bunch Effect of temperature variations on distribution fibres (Source: Asservissement en phase d'une liason fibre optique, rapport de stage, Avril-Juin 2002, Abdelhalim Kelatma (AB/RF)) LE 2006, September, Valencia, Spain 2

3 Motivation 2 ERN Monitor individual bunch position Bunch structure LHb off nominal I with 7.5m See single bunch (-gas) crossings Ghost or displaced bunches (compare LE) Bunch intensity bunch-by-bunch Trigger conditions heck trigger/detector timing alignment Interface the measurement directly with the data taking Bunch information in the event data Bunch crossing trigger/gate LE 2006, September, Valencia, Spain 3

4 Experiment Beam ick-ps ERN 146 m to the I 1158 Beam osition Monitors (BMs) in the LH of the Button Electrode type Two per I for exclusive use by the experiments Located ~146m on either side of the I on the incoming beam in LHb LE 2006, September, Valencia, Spain 4

Button Electrodes (BTX) ERN Sum voltage from all

position Beam intensity (ppb) BTX output [V] 200

2-1.7 3.7-0.6 1.2 Year 1 (4*10 10 ) 10 18-14 30-4.

15*10 11 ) -29 51-39 85-12 28 Σ V button σ beam

5 Button Electrodes (BTX) ERN Sum voltage from all four buttons Signal amplitude ~independent of position Beam intensity (ppb) BTX output [V] 200 m MA5 450 GeV 7 TeV 450 GeV ilot (5*10 9 ) Year 1 (4*10 10 ) Nominal (1.15*10 11 ) Σ V button σ beam (450 GeV) = 375 ps σ beam (7 TeV) = 250 ps LE 2006, September, Valencia, Spain 5

6 Signal transmission ERN Signal cables installed between BTXs and the LHb LH rack in counting houses ½ Nexan MA50 coaxial cable Approximately 200m (to be measured precisely), 4.2ns/m Attenuation 3.3dB/100m(160 MHz), 5.9dB/100m(450MHz) MA m ulse from single button with nominal beam at 7 TeV LE 2006, September, Valencia, Spain 6

Expected Signal ERN Beam intensity (ppb) BTX output [V] 200 m MA50 cable [V] 450 GeV 7 TeV 450 GeV 7 TeV ilot (5*10 9 ) -1.3 2.2-1.7 3.7-0.6 1.2-1.2 2.4 Year 1 (4*10 10 ) 10 18-14 30-4.4 9.

7 Expected Signal ERN Beam intensity (ppb) BTX output [V] 200 m MA50 cable [V] 450 GeV 7 TeV 450 GeV 7 TeV ilot (5*10 9 ) Year 1 (4*10 10 ) Nominal (1.15*10 11 ) Σ V button σ beam (450 GeV) = 375 ps σ beam (7 TeV) = 250 ps ulse from single button after 200m with beam at 7 TeV Signal from BTX on SS compared to simulation (4.2*10 10 and 100m cable) LE 2006, September, Valencia, Spain 7

Developing custom made acquisition board Beam hase and Intensity Monitor (BIM) 6 VME, one per beam Acquisition Board ERN Summary

Triggered via controls interface <100 ps precision Measure continuously bunch intensities bunch-by-bunch 12-bit resolution

for full turn Output bunch crossing trigger on G outputs Interfaced directly to LHb Timing and Fast ontrol system Bunch

8 Developing custom made acquisition board Beam hase and Intensity Monitor (BIM) 6 VME, one per beam Acquisition Board ERN Summary of functions: Measure time between bunch arrivals and LH bunch clock locally Bunch-by-bunch for a full turn filled in FIFO Triggered via controls interface <100 ps precision Measure continuously bunch intensities bunch-by-bunch 12-bit resolution Output intensity on front-panel at 40 MHz (8/4-bit resolution) Triggered via controls interface, fill in FIFO with intensities for full turn Output bunch crossing trigger on G outputs Interfaced directly to LHb Timing and Fast ontrol system Bunch information fed into event data May be used in the trigger control Readout via Experiment ontrol System LE 2006, September, Valencia, Spain 8

9 Input stage ERN onfigurable attenuator to normalize the amplitude range for pilot/nominal(ultimate) beam Two selections using a special RF relay from Omron Output of the attenuator is buffered with an ultra-fast gain device Board is driven with the LH bunch clock and orbit signal The phase and the intensity measurement circuits are adjusted with only one programmable delay on the incoming clock which covers entire 25ns range LE 2006, September, Valencia, Spain 9

10 Full wave rectifier Active integrator circuit Differential 12-bit A/D conversion Integrator charge reset using an RF MOSFET BNH LOK Intensity Measurement Beam Bunch clock Attenuator FGA Threshold DA FGA Level adapter Analog buffer rogrammable delay FGA Rectifier (positive) Rectifier (negative) Threshold comparator Zero-crossing comparator lock fanout Delay + Delay Data EL F/F lock Reset Integrator Delay LVEL/EL 8:1 Divider LVEL/EL Oneshot Oneshot ERN Sample Stop Start AD TD BEAM LSE DELAYED BNH LOK Master lock AD sampling point INTEGRATOR OTT RESETTING HARGE 2 ns TD START ( every 8-th bunch ) TD STOS FIFOS WRITE LOK LE 2006, September, Valencia, Spain 10

11 hase Measurement ERN Based on ultra-high performance TD-GX from Acam R-Mode: 27 ps resolution over 10 μs at 40MHz ulse is discriminated with programmable threshold First version based on zero-crossing detector Zero-crossing moves with varying bunch size/shape 450GeV/7TeV: ~100 ps Measurements with respect to every 8 th bunch clock edge Discharge BNH LOK BEAM LSE DELAYED BNH LOK Master lock AD sampling point INTEGRATOR OTT RESETTING HARGE 2 ns TD START ( every 8-th bunch ) TD STOS FIFOS WRITE LOK LE 2006, September, Valencia, Spain 11

12 Digital rocessing ERN Large FGA : Readout and control interfaces for AD/TD ontrol of attenuator selection ontrol of threshold DA rogrammable clock delay Linearization of converter characteristics Output compressed 8/4-bit intensity data on F roduce bunch crossing trigger or gate ommanded via control interface, FGA starts filling FIFOs with phase and intensity measurements of a full orbit upon the following orbit pulse LE 2006, September, Valencia, Spain 12

13 Board ontrol ERN Main control interface based on on board redit-ardsized with Ethernet. Board busses (Local Bus,I2,JTAG) produced from I bus in a Glue Logic FGA on separate mezzanine MAIN FGA LVDS Drivers BX Info G outputs Alternatively, board may be controlled via a standard 32-bit VME interface implemented in an FGA FIFO hase FIFO Intensity FGA programming FGA may be programmed directly from the onfiguration device may also be programmed directly from the or onboard header. VME interface FGA is programmed via a header Glue ard redit ard Ethernet Local Bus VME interface (FGA) Drivers VME Bus LE 2006, September, Valencia, Spain 13

14 TF Interface ERN Bunch crossing information is used in the Timing and Fast ontrol system and information is put in the ODIN Data Bank which is appended to the event data LH clock RF2TT lock receiver/fanout L0 (LVDS) Trigger splitter ME Req. (GbE) L0 TRIGGER VELO Detector ST OT RIH EAL HAL MON BIM ODIN Readout Supervisor ODIN data bank Event Building BIM L0 trigger LH clock TF SYSTEM L0 FE L0 FE L0 FE L0 FE L0 FE L0 FE L0 FE TELL1 TELL1 TELL1 KL1 TELL1 TELL1 TELL1 Front-End ME Requests Readout Network MNIN Throttle Switch THOR TF Switch SWITH SWITH SWITH SWITH SWITH SWITH farm TT system TTtx Optical transmitter TToc Optical splitter TTtx Optical transmitter TToc Optical splitter TToc Optical splitter TTtx Optical transmitter TTtx Optical transmitter TToc Optical splitter TTtx Optical transmitter TTrx TTrx TTrx VELO TTrx L0 VELO VELO FE L0 VELO L0 FE L0 FE FE TTrx TTrx TTrx EAL TTrx L0 VELO VELO FE L0 VELO L0 FE L0 FE FE FREJA TT monitoring TTrx TTrx VELO TELL1 VELO L1 FE HGIN Throttle OR TTrx TTrx EAL TELL1 VELO L1 FE HGIN Throttle OR Event Building Event Building LE 2006, September, Valencia, Spain 14

15 onclusions ERN First prototype of Beam hase and Intensity Monitor developed for the LHb BTXs Variable attenuator for pilot/first year/nominal beam Measuring beam intensity per bunch contrinuously Outputting intensity measurement at 40 MHz via LVDS interface Outputting bunch crossing trigger/gate or whatever based on intensity/timing Resolution of intensity measurement - 12 bits Measuring phase between incoming bunch signal and bunch clock continuously Resolution of phase measurement better than 100ps Accumulates data from full turn triggered by control interface redit ard based control interface and VME interface 6 VME board Directly interfaced to the Timing and Fast ontrol system in LHb Bunch crossing information in event data Board is being mounted and will hopefully be tested on beam in Oct-Nov Improvements: Zero-crossing detection replaced with bunch size/shape independent method Interest in the other experiments? LE 2006, September, Valencia, Spain 15

Features of the 745T-20C: Applications of the 745T-20C: Model 745T-20C 20 Channel Digital Delay Generator

Features of the 745T-20C: Applications of the 745T-20C: Model 745T-20C 20 Channel Digital Delay Generator 20 Channel Digital Delay Generator Features of the 745T-20C: 20 Independent delay channels - 100 ps resolution - 25 ps rms jitter - 10 second range Output pulse up to 6 V/50 Ω Independent trigger for every