Pileup Background Rejection

Ex: 3 interactions, one with hard scatter, and two with diffractive protons

Fast Timing Detectors for FP420

z=c(TR-TL)/2

z (mm) =0.21 t (psec)(2.1 mm for t=10 psec)

WHO?UTA (Brandt), Alberta (Pinfold), Louvain (K.P.), FNAL (Albrow)

+LLNL (Gronberg)

WHY?

How? Compare z-vertex for SVX with TOF

How Fast? 10 psec -> ~x40 rejection

The Detectors : 1) GASTOF

http://www.fynu.ucl.ac.be/themes/he/ggamma/Cherenkov/

(Louvain)

Presents little material to beam, extremely fast

The Detectors : 2) QUARTIC

proton

Segmented, provides multiple measurements

V2

Baseline Plan1 GASTOF Lots of silicon 2 QUARTICs

T958• Fermilab Test beam experiment to study fast

timing counters for FP420 (Brandt spokesman)

• Used prototype/preprototype detector with NIM/CAMAC to test concept in Fall 2006, Mar 2007

• Next run planned July 11-18 2007

Time resolution for the full detector system:1. Intrinsec detector time resolution2. Jitter in PMT's3. Electronics (AMP/CFD/TDC)

First TB Initial Results

<70 psec/Gastof (2500V)>90% efficiency

G1-G2 For QUARTIC bar 110 psec Efficiency 50-60%

For events with a few bars on see anticipated√N dependence

Upgrade for T958 Phase II

• New detector prototypes, electronics,• Improved DAQ, alignment, analysis, tracking• Scope Data

March 7-20

http://indico.cern.ch/conferenceDisplay.py?confId=14046

10:00->12:30    Fast Timing (UTA Workshop)10:00 Fast Timing Test Beam Overview (20') Andrew10:20 Scope Analysis (20') Tomek Pierzchala 10:40  Test Beam Analysis Plans (20') Pedro Duarte11:00 Quartic Geant Simulation (20') Yushu Yao11:20 Ray Tracing MC (20') Joaquin Noyola11:40  Reference Timing (30') Mike

Burle 8x8 MCP-PMT25 um pore

Amplifier :HamamatsuOrtecPhillips

Constant Fraction DiscriminatorOrtec 934(9307)

TDC(Phillips 7186)

T958 Electronics

SMA SMA Lemo

Phase I:

Phase II:

10 um Burle or 6 um Hamamatsu

Custom CFD (Louvain)

Phase III:

HPTDC

LCFD V2, Amp+CFD board (Alberta)New 10 um Burle?

TB Phase II AnalysisI) Pedro Duarte data analysis of CAMAC data (TDC tracking) leads to understanding of coherent

noise, tracking, efficiency, cross talk.

II) Tomek Pierzchala scope data analysis gives data base of pulses, allows separation of

detector/tube response from electronics. Focus on scope analysis for this talk.

Scope (Tektronix DPO70404) AnalysisWaveform2 sample 755 events: Trigger Ch3xCh1CH1 QBE > Ortec9306CH2 G01 > HamamatsuCH3 G02 > ZX60CH4 QBD > 18dB > Phillips2

Using Scope SignalsWhat timeTo use?

Scope Analysis (G1-G2)

(t)=45 ps (t)=35 ps

Threshhold discriminaton CFD algo simulated

time difference using LCFD

23 GASTOFs 35±1ps

14 QUARTICs 63±2ps

12 74±3ps

13 69±3ps

24 64±3ps

43 50±3ps

Overconstrained setup gives G1 = 42 ps G2=24 Q1=59 Q4=40

Scope Analysis: Detector Resolution

Ch4=LCFD output of same bar as ch1 raw pulse

(t)=40 psDifference gives LCFD

resolution

Scope Analysis: LCFD Resolution

Noise?

Saturation

Concerns

Efficiency: From tracking+scope Q about 60%, G2 from tracking 10-30% (CFD threshhold?)

Correlation/cross talk: Track not in row of bar but bar on

Background—not tested

Rad Hardness of electronics

Readout

Extrapolating

Current QUARTIC/PMT resolution ~60psLouvain CFD ~40 ps, software optimizationimplies might reduce this to 20 ps,combined with TDC resolution of 20 ps gives

66 ps/bar60% efficiency implies 10 measurements instead of 16 with two QUARTICs gives

21 ps QUARTICs only resolution

GASTOF/PMT is 24 ps, combined with a single photoncounter with <10 ps resolution would give 25 ps,

which implies an overall system resolution of 15-20 psAnd rejection factor ~30

Q3

Parallel tube to lower background, shorter light guide to increase light

Short kink Long kinkaka

Dogleg

<#p.e.>=5.5 <#p.e.>=3.5

S.K L.K.6 4 2.5Q2-4

TB III: July 11-18

•LCFD v2, better algo dual output for HPTDC tests

•Alberta amp/CFD board

•Scope analysis, more systematic

•Q2 vs Q3

•GASTOF 2 efficiency

•Q correlations

•Compare Phillips 7186 TDC and HPTDC

GOOD NEWS!

• DOE ADR awarded A.B. $75k includes money for fast scope, CAEN HPTDC, electronics, travel to CERN testbeam, etc.

• My sabbatical was approved by UTA, I plan to be at CERN Jan-Aug 2008

Laser stand & irradiations• We resume June 22nd irradiations and tests with picosecond laser (PiLas) using blue laser head PIL040 - 408 nm, 32 ps pulse FWHM and < 3 ps jitter!

Before and after irradiation series of laser pulses measured by Hamamatsu MCP-PMTs will be taken with 3 GHz LeCroy. We will scan Hamamatsu responses as a function of HV, pulse rate and number of photons per pulse.In next step, front-end electronics will be irradiated.

EIG1000D with PIL063SM (fiber coupler and fiber)

• PiLas Digital Control Unit (EIG1000D) • Optical Heads (PILxxx) for 375 nm – 1550 nm)

Optical box, with possibilityof varying light attenuation in wide range

Laser headHamamtsu MCP-PMT