planar-gem trackers bernd voss helmholtzzentrum für schwerionenforschung gmbh (gsi)

Planar-GEM Trackers

Bernd VossHelmholtzzentrum für Schwerionenforschung GmbH (GSI)

2Planar-GEM Forward Trackers PAND -FE-DAQ Workshop April, 23rd 2009B. Voss et. al.

Outline

Basic assumptions Task & Set up

Internal structure Basic design & Detector assembly

Simulations Particle flux & Tracks

PadPlane Design & Consequences

Front End Electronic The XYTER Family

Higher Level Readout SysCore / Exploder

First Results Noise figures

The Future FAIR-XYTER

http://wwwires.in2p3.fr/


Figure of Merit: Momentum resolution dp/p(p,θ,z,r)

• particle momentum p• scattering angle θ• vertex coordinates z, r

Basic assumptions: 3..4 GEM-Tracker stations

GEM-TPC ‘short’ version? (1,5 m 1,2 m)

Maximize shape-conformity

Full angular (phi) coverage not possible

Radiation hardness 100krad

Planar GEM-Trackers Basic assumptions

Target spectrometer@PANDA ‘V833’



Planar GEM-Trackers Acceptance

Longitudinal positions: 810,1170,1530,1890 mm

Diameters: Ø900,900,1120,1480 mm

Inner bore: Ø50..100 mm

Active area: 0,6..1,7 m2

Angular range: ~ 5..18° (2..26)°

Material budget (active area): ~ 0.5% X0 (per GEM station)

Position resolution: < 0.1 mm

Double track resolution: 10 mm, 5° Target spectrometer@PANDA ‘V833’

Still discussing where to but the detectors Preliminary: Low B-field region, low curvature tracks



Planar GEM-Trackers Detector assembly

Window

Drift electrode

GEM stackPad Plane

Support &

Media-Distribution

Cooling Support &

LV- Distribution

Front-End Electronic

Shielding Cover

& Read-out

Plane

Possible cabling hooks: central bar & circumference



Hit Rate Simulation assumptions

Assumptions:! 4 GEM stations

! 4 projections per station (4 coordinates, 2 tracklets per detector)

Ar/CO2 tcoll=nx10ns

Standard physics run 2·107 annihilations / s



GEM-Trackers Simulation results@15GeV/c

Ralf Kliemt

(TU-Dresden)

Radoslaw Karabowicz

(GSI)

Mean 1,5 mm

Structure size

Inner | Outer area…

Beam pipe…

Mean 0,15 °



PadPlane Basic design concepts

Simulation results: HIT-rate 5..50(140)k particles/cm2/s (r)

Track lengths: radial 0,5..8 mm (mean 1,3..1,6 mm) angular 0..0,8° (mean 0,15°)

Cluster sizes <1mm (single-cluster HIT to be avoided)

Purely resolution driven

Patterning structure under investigation

1. Strips

1. Circular/polar + Radial

2. Cartesian

2. Pixels – regular polygon shapes

3. Hybrid readout structures



PadPlane Pattern ‘concentric’

Assumed in simulations: 1571,1571,1571

Required for constant resolution: 5888, 9600,13440

Problems with Patching (GEM4)

Patching process

Signal routing Dead areas

Increased material budget

Support

Additional routing layers



PadPlane Pattern ‘radial’



Problems Patching (GEM4)

Cut channels (iso-centric)

non-uniformity

iso-centric

acentric



PadPlane Pattern 60° ‘tilted’



Problems Patching (GEM4)

Cut channels Unequal length non-uniformity



PadPlanes (3..4 GEM-Ts)

FEE system ‘Division bar’ not sufficient nor feasible Circumferential

arrangement FEE-Ring width ≤ 50 mm ≈ 7..11% of total detector area

(n-)XYTER-based FEB cards 180..900 cards (2 ASICs à 128 channels each, 100x65mm2)

overall operating power 21 mW/channel 2,7 W/chip ! ≈ 1..5 kW power/cooling requirements, Axial cooling structure,

≈ 30% of weight

Front-End Electronic General ideas

Structure size Resolution evolution Channel no.

0,3..0.5 mmdecreasing 20..26 kch

constant 96..116 kch

1 mm constant 80..95 Kch



Front-End Electronics (n-)XYTER

• AMS CMOS 0.35 m technology

• 128 channels / chip

• Charge-sensitive preamp• Fast (30ns)& Slow (150ns) Shaper• Peak detector

• Time-stamping with 1 ns resolution

• Data driven, autonomous hit detection

• Token ring readout @ 32 MHz

de-randomizing, sparcifying • expected noise:

370 e-@10pF, 550e-@20pF



Front-End Electronics XYTER testing board

Simple hybrid PCB with signal fan-in

ADC

interconnect to DAQ chain (SysCore,Exploder)

CBM beam time September 2008: whole signal chain operative

‘Chip-In-Board’ avoids space eating vias

allows pitch adaptation: 50,7 μm on chip

101,4 μm on PCB (two levels)

10 Rev. C boards, fully functional



Front-End Electronics XYTER TPC Prototype board

42 4-layer PCBs for PANDA TPC prototype

2 XYTER chips / card chip-in board glued to aluminium backing step-down & staggered bonding

2 x 128 channels / card 300 pins / connector

~350 Watt power dissipation passive heat pipe system cooling liquid HFE-7100 (3M)

PCB lab-tested awaiting in-beam test (@CB-ELSA)

Higher integration level (1:1): SysCore Boards (KIP Heidelberg) Exploder+… (GSI-EE, MBS) Others …?

2 XYTERsADC

Power regulators

Gold plated edges



System Integration Issue Global Timing

SysCore generates 48 to 64 bit data elements: n-XYTER provides

14 bit time stamp @ 1ns resolution 7 bit channel number

FEB provides 10 bit peak height

SysCore adds chip number epoch counter some diagnostic

SysCore provides data FIFO

The serialized event number with successive time stamp could be fed into auxiliary inputs.

This event header would be added to the data elements Such synch scheme should be fine up to about 50 kHz event rate

Relate local time stamps to global events:Feed a global epoch marker or event strobe into SysCore



Test Setup Complex Multi-layer Data Chain

Detector n-XYTER-FEB

n-XYTER FEB and Bonding Technology Documentation (Manual)

ADC Interconnect SysCore / Exploder

Firmware Embedded software Soft configuration

Ethernet-Interconnect PC and DAQ

KNUT GUI DAQ System

Ongoing:

Realize software design freeze to be packaged

Still missing:

Diagnostic toolbox for system analysis to make successful deployment in other labs feasible



Experimental data Energy-Output (preliminary)

Si Detector 300μm strip-pitch

DC coupled

40V

Pulse-height spectra on one strip ‘as is, on the table’

Enhanced low-energy part: -electrons & other scattering

Sr90

Energy [ADC digits]

Am241 60keV ~2/3 MIP

Photo escape? Pedestal ?



Experimental data Energy-Output (preliminary)

Pulse-height spectra with internal test pulse

Cdet not determined (5-10 pF)

Peak-to-peak distance ~5560e-

FWHM ~1000e-, σ ~425e- (370e-expected)

2780e- (CAL = 10)

Analog read out chain operative

Temperature coefficient spoils the effort

Sr90

Energy [ADC digits]

Am241 60keV ~2/3 MIP

Pedestal ?Photo escape?



n-XYTER Engineering Run

Preparations by Hans Kristian Soltveit (Physikalisches Institut Heidelberg)

Several thousand chips@110k€

Issues addressed: Temperature coefficients on three amplifiers

Pad arrangement, input-ESD-pads, LVDS in/out arrangements

Shielding (in particular mono stable cross-talk)

Choice of process

Epoch marker output

Time line (03/2009): Current: Extensive corner analysis on new schematics

Until end of April: finalize schematics & Review on modifications

May & June: Layout modifications

End of June: Submission readiness review and successively submission to AMS



The Future: FAIR-XYTER …for gaseous detectors

GEM-Tracker GEM-TPC Others

Channels/chip 32-128 64-128

Power limit/channel 10mW

Noise limit 500e@5pF 500e@5pF, 900e@25pF

Max. rad dose 100 krad

Avg. det. capacity 7 pF7..150 pF

Max. det. capacity 2...150 pF 7 pF

Rate/channel 4..11/200kHz 250 kHz 250 kHz

Ampl. 94 ke 25 ke above 25 ke

Signal distribution Landau

Measured feature Spatial resolution + Hit-time

Signal shape 30..40ns

Max. possible signal 200ke = average*2 750ke=average*30 1000ke, 3000ke, Dual range

ADC res./ampl. 7 bit, 5 ke 8-9 bit linear, 4 ke

Time resolution 10ns/hit 4ns/hit 4ns

Special tasks Spark protection + baseline restoration +forced neighbor readout



Detector Control & Monitoring Structure

Current concept: Modular, expandable, flexible

Same structure for all GEM-Detectors

Hierarchical interlocking

Failsafe operation

Hard- & software limits

Integration into PANDA-DCS database started Identified 45 parameters so far


GEM-Projects: TPC1 & Tracker2 GSI crew-members & tasks

Jörg Hehner1 Aging tests Andreas Heinz1 PadPlane, GEMs, sensors, WebInfoMarkus Henske1 Material tests, sensors, infrastructure, purchaseRadoslaw Karabowicz2 Root-SimulationsVolker Kleipa1 Front-End Electronics (XYTER)

Jochen Kunkel1,2 Mechanics, drawings, simulations, assemblyRafal Lalik1 Front-End Electronics (XYTER)Christian Schmidt1 Front-End Electronics (XYTER)

Sandra Schwab1 Part production, tooling , FOPI environmentDaniel Soyk1 FEM-Simulations

Eduard Traut1 GEM generals Ufuk Tuey1 General mechanics, drawings Bernd Voss1,2 ‚All & nothing‘, ideas & concepts, project & logisticsJan Voss1 General mechanics, material testsJoachim Weinert1 Part production, tooling

Backup slides


Benchmark channels

ChannelFinal state

Related to

Arguments / Aimspp pA MVD CT FT

(n)π+π- (n)π+π- X

ψ(3770) D+ D-

2K 4π

X XSecondary vertex tagging capability

Special consideration of the slow π coming from the D* decays

K, π tracking and momentum measurement ψ(4040) D*+D*- X X

ΛΛ pπ-pπ+- X X X Λ reconstruction, partly only with CT (~15%) tests vertexing capabilities of CT

Incorporates also cascade decays outside MVD ΞΞ pp 4π X X X

ηc ΦΦ 4K X PID studies and V0 reconstruction with CT

J/ΨX 2l X X X

High pT lepton tracks in multi-track environment CT important for momentum measurement nd tracking

pp pp X X Ximportant for FT background studies for CT and MVD


n-XYTER Architecture as Realized and Under Test Today


Cooling Motivation Simulations

Backside view Parameters:

NXYTER(2) + ADC + voltage regulators on board

FR4 + Alu backing, single sided mounting

10°C cooling media temperature

25°C backflow temperature

Results: Chips reasonably cool


Analogue Pulses, Peaking Time, Front-End Noise

FAST channel SLOW channel

ENC26.9 e/pF + 200 e

12.7 e/pF + 233 epeaking

timea (1% to 99%)

18.5 ns 139 ns

Engineered for 30 pF, giving 1000 e 600 e

power consumption: 12.8 mW per channel; OK for neutrons!


Context FP7 JRA ‘JointGEM’ Projects

Name … prototype detector systems of … …as planned for…

P-1 TPC-GEM… a high-rate Time Projection Chamber

(TPC) with GEM readoutInner tracker of

PANDA@FAIR

P-2 Cylindrical-GEM… a multilayer self-supporting cylindrical

GEM (C-GEM) structureAMADEUS & KLOE2

P-3Large-Area Planar-GEM

… large-area planar GEM detectors capable of withstanding

very high beam rates

Forward tracking system of PANDA@FAIR and for the muon system

of CBM@FAIR

planar-gem trackers bernd voss helmholtzzentrum für schwerionenforschung gmbh (gsi)

Documents

gem stations

voss et

daq workshopapril

kch slide

uniformity slide

patching gem4 slide

weightkg203040 slide

panda v833 slide