1992PH.D. UCLA/CERN (UA8 Experiment discovered hard diffraction) 1992-1999 Post-doc and Wilson Fellow at Fermilab -Discovered hard color singlet exchange JGJ -Discovered diffractive Z -1997 PECASE Award for contributions to diffraction -Proposed and built DØ Forward Proton Detector

(with collaborators from Brazil) -QCD and Run I Physics Convenor -Trigger Meister, QCDTrigger Board, Designed Run II Trigger List 1999-2004 UTA Assistant Prof 2004-2010; Assoc. Prof 2010; Prof. -OJI, MRI, ARP awards for DØ FPD -2005 started fast timing work (ARP, DOE ADR) -2008 sabbatical on ATLAS

•ATLAS Forward Protons+Timing•ATLAS Trigger•DØ Diffractive Physics + MSSM Higgs?

AGB Background

ATLAS Forward Proton Upgrade

AFP concept: adds new ATLAS sub-detectors at 220 and 420 m upstream and downstream of central detector to precisely measure the scattered protons to complement ATLAS discovery program.These detectors are designed to run at a luminosity of 1034 cm-2s-1 and operate with standard optics (need high luminosity for discovery physics)

AFP Components1) Rad-hard edgeless 3D silicon detectors with resolution ~10 m, 1rad2) Timing detectors to reject overlap background (SD+JJ+SD)3) New Connection Cryostat at 420m4) “Hamburg Beam Pipe” instead of Roman Pots

beam

p’

p’AFP Detector

LHC magnets

420 m 220 mH

Andrew Brandt, University of Texas, Arlington

2

• 2000 Khoze, Martin, Ryskin (KMR): Exclusive Higgs prediction Eur.Phys.J.C14:525-534,2000, hep-ph/0002072

• 2003-2004 Joint CMS/ATLAS FP420 R&D collaboration forms

• 2005 FP420 LOI presented to LHCC CERN-LHCC-2005-0254 “LHCC acknowledges the scientific merit of the FP420 physics programme and the interest in exploring its feasibility”

• 2006-7 Some R&D funding, major technical progress, RP220 formed

• 2008 AFP formed, cryostat design finished, LOI submitted to ATLAS

• 2009 “AFP year in review”, FP420 R&D document published

“The FP420 R&D Project: Higgs and New Physics with Forward Protons at the LHC,” FP420 Collaboration, arXiv:0806.0302v2, published in J. Inst.: 2009_JINST_4_T10001,

http://www.iop.org/EJ/abstract/1748-0221/4/10/T10001.

• 2010 AFP LOI approved, physics case acknowledged, encouraged to prepare Technical Proposal for 2011, UK funding cancelled,

adopt staged approach: 220 m in 2013, 420 m in 2016 3

AFP Evolution

4

What does AFP Provide?

5

Allows ATLAS to use LHC as a tunable s glu-glu or colliderwhile simultaneously pursuing standard ATLAS physics program

420-420

420-220

220-220

Acceptance >40% for wide range of resonance mass

Combination of 220and 420 is key to physics reach!

• Mass and rapidity of central system, assuming central exclusive production (CEP) process, where momentum lost by protons goes into central system

• Mass resolution

of 3-5 GeV per event

“+” “=”

How does CEP work?

• Extra “screening ” gluon conserves color, keeps proton intact (and reduces your )

• CEP defined as ppp+X+p , where protons are scattered at small angles, but remain intact, with all of their lost energy going towards production of the system X

• Central system produced in Jz=0++ (C-even, P-even) state, this results in di-quark production being suppressed

• Process observed by CDF: exclusive dijets PR D77, 052004 (2008) and exclusive χc PRL 102, 242001 (2009)

pp gg H +x pp p+H+p

TypicalHiggs Production

CEPHiggs

6Find a CEP resonance (for ex. Higgs) and you have

measured its quantum numbers (0++ )!!

7

For the MSSM and related models, AFP is likely to provide the only way to determine the Higgs quantum #’s and the coupling to b-quarks, and will provide an excellent mass measurement

MSSM and CEPModels with extended Higgs sectors, such as the MSSM, typically produce a light Higgs (h) with SM-like properties and a heavy Higgs (H) which decouples from Gauge boson. This implies:• no HVV coupling (V=W, Z)• no weak boson fusion• no HZZ• big enhancement in

• pseudoscalar A does not couple to CEP

H bbH

R=(MSSMH)/(SMH)tan

mA (GeV)

R=300H→bb, mhmax, μ = 200 GeV

•AFP manpower primarily dedicated to detector R&D and technical studies, however… • We (Brandt, Pal, et al.) performed studied over last few years to validate the theory predictions , using 120 GeV for and 160 GeV for • We validated the exclusivity cuts needed to reduce the overlap background, including tracking rejection with full detector simulation• In the bb channel Standard Model Higgs without forward protons is believed to be impossible. With FP’s it is really, really hard. We obtain a signal to background including a believable trigger (using Phase I calo upgrade and 220 m proton tag) of near 1 up to 2x1033, but with only about 1 signal event/ 30 fb-1 after cuts to control the overlap background . With the x8 MSSM enhancement factor, we get comparable significance as JHEP 0710:090,2 007•We produced a luminosity model that showed that we can obtain comparable significance/fb-1 for a store starting at 1x1034 as we could with continuous 5x1033 • So 120 GeV , requires a 5-10 “MSSM factor” for 4 observation in 100 fb-1

• For we showed that the backgrounds are easily controlled at 160 GeV, and this looks like a promising channel (4 observation in 100 fb-1 ) down to ~130 GeV or so [Note smaller bkgd, easier trigger >1034 operation]

AFP Studies

H bb *H WW

H bb*H WW

8

10 picoseconds is design goal(light travels 3mm in 10 psec!)gives large factor of background rejection;Stage I: 2013 220 m lum up to several 1033 t < 20 ps Stage II: 2016 add 420 m 1034 t < 10 ps (<4 years)

Use time difference between protons to measure z-vertex and compare with tracking z-vertexmeasured with silicon detector

Pileup Background Rejection

Ex: Two protons from one interaction and two b-jets from another

Forward Proton Fast Timing

WHY?

How?

How Fast?

Timing System Requirements• 10 ps or better resolution• Acceptance over full range of proton x+y• Near 100% efficiency• High rate capability• Segmented : for multi-proton timing and L1 trigger• Robust: capable of operating with little or no intervention

in radiation environment (tunnel) - PMT’s, detectors, cables, and electronics must be able to

tolerate radiation levels (for PMT’s this includes tolerance to external radiation damage, as well as to internal photocathode damage)

- Backgrounds from other particles must not impair operation

Andrew Brandt (UTA) AFP Workshop Prague

10Sep. 6, 2010

4x8 array of 5x5 mm2 fused silica bars

QUARTIC is Primary AFP Timing Detector

Multiple measurements with “modest” resolution simplifies requirements in all phases of system1) We have a readout solution for this option 2)We can have a several meter cable run to a lower radiation area where electronics will be located3)Segmentation is natural for this detector4)Possible optimization with quartz fibers instead of bars

proton

phot

ons

Only need a 40 ps measurement if you can do it 16 times: 2 detectors with 8 bars each, with about 10 pe’s per bar

11

UTA, Alberta, Giessen, Stonybrook (w/help from Louvain and FNAL)

MCP-PM

T

12

Micro-Channel Plate Photomultiplier Tube

Burle/Photonis 64 channel 10 and 25 m pore MCP-PMTs have been tested extensively with test beam and laser and would be default for first stage except for lifetime issues

MCP-PMT RequirementsExcellent time resolution: 20-30 ps or better for 10 pe’s High rate capability: Imax ~ 3 A/cm2

Long Lifetime: Q ~ 30 C/cm2/year at 400 nmMulti anode: pixel size of ~6 mm x 6mm Pore Size: 10 m or better Tube Size: 40 mm round, 1 or 2 inch square

Need to have capability of measurements in different parts of tube between 0-2 ns apart, and in same part of the tube 25 ns apart 13

Photek240 (1ch)

HamamatsuSL10 (4x4)

Dt

QUARTIC Timing 2008 CERN TB

56.6/1.4=40 ps/bar using Burle 64 channel 10 mpore tube including CFD!

Time difference between two 9 cm quartz bars after CFD implies a single bar resolution of 40 ps for about 10 pe’s (10 pe’s from simulations/Test Beam).

Npe=(area/rms)2

14

2 21 2 1

1

( ) ( ) 2

so if 1 2 then / 2

t t t t

t t

6 mm

6mm

Eve

nts

Strip #

Eff

icie

ncy

(a) (b)

(c)

QUARTIC Efficiency CERN TBAll tracks(Bonn SiliconTelescope)

Tracks witha Quartz bar on

Use tracking (b)/(a) to determine that QUARTIC bar efficiency is high and uniform

Shape due to vetocounterwith 15mmdiameterhole

15

LeCroy Wavemaster 6 GHz Oscilloscope

Laser Box

Hamamatsu PLP-10 Laser Power Supply

Andrew Brandt UTA1610/14/2009

laserlensesfilterMCP-PMT

beam splittermirror

Established with DOE ADR, Texas ARP funds, some supplemental support for UG’s

- Ian Howley (Ph. D. student), Ryan Hall (was UG, now in UTA Ph. D. program), both students moving on soon…- Monica Hew, Keith Gray, James Bourbeau (UG)+…

Beam Mode Fiber Mode

(a)

(b) (d)

(c)

17

UTA Laser System

Timing vs. Number of PE’s10 m Planacon

55 10peN G If then timing independent of HV/gain

10 pe Time Resolution from Laser Tests

19Laser tests of Photonis 10 µm tube show that with sufficient amplification there is

no dependence of timing on gain (low gain operation extends lifetime of tube)

10/14/2009 Andrew Brandt UTA 20

No rate dependence on number of pixels hit (that’s a good thing!)

Saturation from Laser Tests

Saturation refers to the reduction in amplitude of the output signal due to the pores becoming busy at the rate increases (typically 1 msec recovery time/pore). This plot shows that saturation is a local phenomena, and is unaffected by multiple channels being on at the same time.

10/14/2009 Andrew Brandt UTA 21

Current/area for 10 m Tube

Last point is 2.0 μA/cm2 ~meeting the high luminosity goal. Photonis has made Planacon with 10x higher current capability which exceed meet our rate requirements(Note: even with saturation we still obtain the same time resolution!!!)

Beam vs Fiber

Fiber timing not as good, but allows us flexibility for some characterization tests

If single fiber gives 35 ps then 4 fibers should give 17 ps; but note that with many fibers plugged in, individual pixel gets light leaking from neighboring channel, need to test that this effect is reproduced in test beam

SQRT(N)?

From averaging time of four measurements on event-by-event basis

Cross Talk

• Initial PE’s “bouncing” into nearby channels, or cascade electrons hitting a neighboring anode

• Results in a false signal in the adjacent channel, which may distort measurements of the real time value

Anode 2

Photons

Anode 1

Electrical Crosstalk

Photoelectron Rebound

Optical Crosstalk

24

Protons in Adjacent Pixels

• The amount of light sharing affects ability to measure two adjacent rows/columns independently

• As one proton enters some time before the other, the second timing measurement shifts due to cross talk

Top View

25

Cross Talk Results

• Tested a prototype Burle Planacon tube using variable length fibers

• Examined both row and column effect of spillover light 100, 250 and 500 ps before the target pulse

• About10% of the pulse is detected in adjacent, empty pixels

• Data shows that early light is not significantly affected by late light

• Late light mean time is shifted, but is not totally dominated by the early pulse

• Late time measurement degrades significantly as Δt increases

• Exploring ways to reduce this effect

26

27

Electronics Layout

t~25ps t~5ps

t~5ps

t~15ps

ZX60 4 GHz amplifier

CFD Louvain,Alberta

HPTDC Alberta

Stony Brook

Sep. 6, 2010 Andrew Brandt (UTA) AFP Workshop Prague

28

Reference TimingReference timing is needed to connect two arms ~1km apart; what we want is TL-TR, what we measure is (TL-Tref)-(TR-Tref), so need small jitter in Tref

This setup has just been tested at SLAC to give <10 ps with 1000 ft cable

The reference system uses a phase lock loop to maintain a constant number of wavelengths in a 100m cable. This synchronizes the phase of the RF at each end of the cable. A voltage controlled oscillator (VCO) launches a signal down the cable where it is reflected and sent back. The returned signal is then interfered with an external RF reference to synchronize it with the reference. At the end of the 100m cable the signal is sampled with a directional coupler which mixes the signal to produce a DC level. That DC level is fed back to the VCO to maintain a constant number of wavelengths in the cable.

Lifetime IssuesLifetime due to positive ions damaging the photocathode is believed to be proportional to extracted charge: Q/year = I*107 sec/year Q for 3 A/cm2 is 30 C/cm2/yr

Can reduce this requirement with fiber detector but still off by at least a factor of 20, so developed an R&D plan to pursue this

Andrew Brandt (UTA) AFP Workshop Prague

29Sep. 6, 2010

Options for Improved Lifetime MCP-PMTIon barrier, already demonstrated, this promises a factor 5 to 6 lifetime

improvement (Hamamatsu SL10 may be better than this)

Electron scrubbing demonstrated by Photonis gives a factor of ~5 lifetime improvement

Z-stack promises a factor of 10 lifetime improvement (A.Yu. Barnyakov, et al., Nucl. Instr. and Meth. A 598 (2009) 160)

Arradiance coated MCP’s, to be demonstrated, this promises a factor of 10 or more lifetime improvement

Various combinations of these factors are possible and should give multiplicative improvement factors, except for the electron scrubbing and Arradiance coating, which would be expected to be orthogonal

30Sep. 6, 2010 Andrew Brandt (UTA) AFP Workshop Prague

Pursuing funds to develop and test longer lifetime tubes. Photek will build tubes to our specification (no funding for this yet!). Photonis will insert Arradiance modified MCPs into their tubes (just received notification of NSF SBIR funding with Arradiance)

31

MCP-PMT Alterntive: SIPM

Ronzhin, AlbrowAt FNAL have been studying

32

SIPM (4 pe average)

16 ps for 25 pe(expectedamount ofLight using quartz radiatorin front of SiPM)

CERN/FNAL Test BeamQUARTIC: New quartz bar prototype test (Alberta 8 long-bar prototype), use scope to measure raw signal

and compare to laser, pulse height, number of pe’s, timing resolution 8 channel electronics test AMP->CFD->HPTDC [sqrt(N) test] study coherent noise effects and 8-channel timing compare 25 um and 10 um Burle tubes (single channel and also 8 channel) Color dispersion tests with long bar and filter

FIBER: Giessen fiber detector with Giessen readout Alberta fiber bundle comparison tests

SiPM Tests

338/18/2010 Andrew Brandt UTA Test Beam Planning

Analysis of CERN Aug 23-30 TB in progress, some of tests to be repeated at FNAL Nov. 16-21 with UTA students, better trigger,amplifier shielding and protection

2011 UTA Laser Plan• Goals:

- Finish cross talk and multi-proton studies

- Submit results of these and other laser studies over the past 1.5 years to J. Inst (this also includes detailed studies of timing of Burle 10 and 25 m tubes, saturation, rates, Photek tube, etc. )

- Lifetime and characterization of Arradiance/Photonis tubes from SBIR

- Buy/Borrow Hamamatsu SL10? Photek tube(s)

5/26/2010 Andrew Brandt UTA 34

35

We have developed a fast timing system for AFP that seems to be capable of ~10 ps resolution, still some loose ends to address

Work in progress:

1) final optimization of detector (quartz fibers could lower maximum rate by 2-3 by more sensible binning)

2) developing final HPTDC board (Alberta) and trigger circuit (Stony Brook)

3) test beam and laser tests

4) developing and testing long-life MCP-PMT (new funding)

5) evaluating radiation tolerance of all components and upgrading as needed

6) SiPm alternative

Writing up results for Technical Proposal

Timing Conclusions

October 20, 2009 AFP Andrew Brandt UTA DOE Review

36

UTA Role in AFP•Brandt:

has been co-leader/deputy leader of AFP since its inception was primary editor of LOI, major editor of FP420 docleads the fast timing effort for AFP with Pal studied/strengthened the physics case developed L1 trigger detector prepared PMT lifetime note, L1 trigger detector/latency note, co-edited response to referee questions prepared Barcelona talk key to LOI acceptance worked with Steve Watts and now Christophe Royon on approval/funding strategyCo-author and editor of Technical Proposal

37

LOI approved, Technical Proposal being prepared

UK groups funding cut leaves a big hole

ATLAS Management has been encouraging, is developing a plan with us for Stage I installation in 2012/2013, including TP approval in 2011, TDR/LHCC approval in 2012

R&D funds still needed

HPS at CMS has similar plans will be added officially to CMS Upgrade in December (just received US CMS Upgrade funding)!

AFP Status

38

Backup Slides

January 28, 2010 Andrew Brandt Clermont-Ferrand 39

Fourier Transform of Signal

-whole signal is in first GHz: rule of thumb BW=1/3*risetime=1/3*400ps=0.8 GHz-scope bandwidth is 6 GHz-cell phone/wireless noise contributions visible-we use high bandwidth amp because of low noiseand then add filtering. A 1 GHz low noise amplifier would likely be preferable, but we couldn’tfind one so we filter (1.5 GHz filter helps a little,1 GHz starts to cut into signal degrade performance)

10 m planacon, 40 pe’s

Lecroy 8620AWavemaster6 GHz20 Gs/s

1 GHz

40

Photek 210 Single Anode 3 µm Pores

41

Photek 210 Single Anode 3 µm Pores

Photek 210 with 8 GHz amp 10 pe’s

8.7 ps with CFD vs 11.6 ps for raw pulse (compared to 23 ps for Burle tube) 80 ps rise time

1 GHz

Some signal out to 3-4 GHz

Photek With Ortec VT120 amp

Amplitude Rise Time Time

Ortek 9306 (1 GHz)

603.62 mV 146.69 ps 12.8 ps

Vt120 (X200-350 MHz)

618.10 mV 395.10 ps

29.0 ps