pax detector developmentcollaborations.fz-juelich.de/ikp/pax/public_files/usual... · 2013. 5....

26. June 2012

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PAX Detector Development

| C. Weidemann

26. June 2012 Slide 2

• Requirements

− Future Experiments

− Detector Arrangement

− Simulations

• Design

− Detectors

− Mechanical Design

− Readout Electronics

− Cooling System

• Summary and Outlook

Outline


Future Experiments With The PAX Detection System

1. Polarizing Antiproton Beams

2. Spin Filtering With Longitudinal Polarization At COSY ()

3. Time Reversal Invariance Test

4. Spin Observables in Breakup Reaction

5. Electric Dipole Moment Polarimetry Tests


Experience WithSilicon Tracking Telescopes

• Polarimeter for the PAX depolarization

and the spin-filtering experiment at COSY

(Talk: D. Oellers)

• Spectator and vertex detector for ANKE

experiments

A detector that fulfills requirements for the future experiments can be realized

with silicon strip detectors and we can use our experience of more than ten years!


Aim Of Simulations

• Optimize the system for spin filtering with antiprotons

• Maximization of detector acceptance and measurement performance

• Versatility: - feasability of addititional experiments (pd breakup, TRIC …)

- measurement of all spin observables

• Usage of existing equipment (HERMES detectors, readout electronics)

Detector Arrangement

• Barrel-shaped, φ-symmetric detection system

• 24 double-sided position sensitive silicon strip

sensors in three layers (300 µm, 300 µm, 1500 µm)

• Strip pitch of 0.7 mm results in a vertex

resolution of 1mm

• All spin observables measurable independent

on -dependence ( cos(), cos(2) )

• Application of diagonal scaling methodw = 97 mm

d0 = 80 mm

d1 = 100 mm

d2 = 110 mm


Detector Arrangement


Diagonal Scaling

Yieldi

Y0 0,

Y1 0,

Y2 0,

Y3 0,

Y0 1,

Y1 1,

Y2 1,

Y3 1,

Y0 2,

Y1 2,

Y2 2,

Y3 2,

Y0 3,

Y1 3,

Y2 3,

Y3 3,

:=

Combinations of beam and target polarization

See also: (1) H. O. Meyer. Diagonal scaling and the analysis of polarization experiments in nuclearphysics. Phys. Rev. C, 56(4):2074–2079, Oct 1997.

(2) PAX wiki : Spin Filtering at COSY, Simulations

4 q

ua

dra

nts

(de

tecto

rs)

kkiiYX λε=

• Extraction of all flipping and non flipping components possible

• Luminosities

• Detector Efficiencies

∑=k

iki xr

∑=i

ikk xc

reduced matrixreduced matrix

sum of rows:sum of rows:

sum of columns:sum of columns:

iEιιιε Ω=kDn0σ


Polarizing Antiproton Beams(Talk: P. Lenisa)

• Spin-filtering experiments at AD exploring the systems p bar p, pbard, (pbar He )

(transverse and longitudinal polarization)

• Detector: Measurement of pbar beam polarization using pbarp elastic scattering

• Simulations forpbarp at 43, 120, and 220 MeV kinetic energy including anihilation

processes (G. Macharashvili, M. Tabidze)

• The momentum spectra and thus the energy deposit of secondary particles is

independent on beam energy

Detector setup adequate for all energies

Acceptance for 220MeV

• 26 % of particles hit 1st layer (∆E > 0.2 MeV)

• 23 % of p and 3 % p bar tracks in 2nd layer

• 18.6 % of p and 2.5 % p bar tracks in 3rd layer

• Reconstruction of two tracks for 2 % of events

• Optimal position in z-direction is + 55 mm for the center of the detector


Spin Filtering With Longitudinal Polarization (COSY)

• Buildup of longitudinal beam polarization due to repeated interaction with a

longitudinally polarized hydrogen target

• Tp 45 - 130 MeV kinetic proton energy

• Detector: Measurement of longitudinal beam polarization using pp elastic scattering

– Measurement during filtering with hydrogen target possible

– Spin correlation coefficient (~ 0.5)

– No background σ

ΩΩ

1 ∙ σ

ΩΩ

1 ∙

C!!


Time Reversal Invariance Test(Talk: Y. Valdau)

• Experiment concept uses vector polarized p beam on tensor polarized d target

• Lifetime change in dependence on the target polarization

• Tp130 MeV kinetic proton energy

• Detector: Measurement of transverse beam polarization

a) using pd elastic scattering during lifetime measurement

b) using pp elastic scattering after lifetime measurement

− no background

− large spin correlation

coefficients (0.5 – 1.0)


Simulation Of ppElastic Scattering

• Simulations for various detector configurations for pp elastic scattering

– Teflon cell introduced (10 " 10 mm), 5 µm teflon

– ABS and BRP tube

– 50 µm Kapton covers surface of HERMES detector

• Acceptance: a) 130 MeV

• 14 % of particles hit 1st layer ( ∆E > 0.2 MeV)

• 9.5 % acceptance (tracks in 2nd layer), 8.4 % in 3rd layer

• Reconstruction of two tracks for 5.1 % of events

b) 45 MeV

• 5.9 % of particles hit 1st layer ( ∆E > 0.2 MeV)

• 3.4 % acceptance (tracks in 2nd layer), 2.6 % in 3rd layer

• Reconstruction of two tracks for 2.1 % of events

• Individual shift of layers in z-direction improves efficiency by

< 10%

• Optimal position in z-direction is + 80 mm for the center of thedetector


Spin Observables In Breakup Reaction

• Study of three nucleon continuum in proton deuteron breakup reactions between

30 an 50 MeV proton beam energy

• Detector: Measurement of vector and tensor analyzing powers and spin

correlation coefficients

• Simulations to test the usability of the detection system, which was developed on

the basis of previous studies

• Stopping of protons and deuterons

is required to clearly identify the reaction

3rd layer of 1.5 mm thickness

is needed to stop particles

up to 30 MeV energy deposit


PAX Detector Design

(V. Carassiti, F. Evangelisti)


Detectors - HERMES

• 8 modules available• Suitable for 1st and 2nd layer of detection system• 50 µm polyimide with 5 µm copper traces• Existing Helix front-end has to be removed• Connect new pitch adapter to VA32TA2

Detector HERMES TIGRE300 µm

Coupling AC

Thickness (µm) 300

Active area (mm) 97.3 "97.3

No. of strips 128

Strip pitch (µm) 758

Depl. voltage (V) 50


Detectors

Detector HERMES TIGRE300 µm

PAX TTT300 µm

PAX TTT 1500 µm

Coupling AC DC DC

Thickness (µm) 300 300#15 1500#50

Active area (mm) 97.3 "97.3 100.42"100.42 100.42"100.42

No. of strips 128 128 128

Strip pitch (µm) 758 760 760

Depl. voltage (V) 50 70 300

HERMES withnew pitch adaptor

PAX TTT


Layer Design

1st and 2nd layer:

• Ceramic board with

VA32TA2_2 chips

• HERMES detector

• Replace by 300 µm PAX TTT

3rd layer:

• Ceramic board with higher

dynamic range VATA2_2

chips

• 1500 µm PAX TTT


Layer Design

1st and 2nd layer

3rd layer


Mechanical Design – 1 Quadrant


Mechanical Design – 4 Quadrants + Cooling


Openable Storage Cell


Mechanical Design – Complete Setup

(V. Carassiti, F. Evangelisti)


Self-triggering Front-end Chips

90 mm

90 m

m

VA32TA2_2

No. of channels 32

Power dissipation 3mW/channel

Linear range11MeV

(±500fC)

Slow shaper (PT) 2 µs

Fast shaper (PT) 60-120 ns

Minimum trigger

threshold0.04 MeV

Readout frequency 10 MHz

Trigger threshold

range+/- (1.6 - 50) fC



90 mm

90 m

m

VA32TA2_2

No. of channels 32

Power dissipation 3mW/channel

Linear range11MeV

(±500fC)

Slow shaper (PT) 2 µs

Fast shaper (PT) 60-120 ns

Minimum trigger

threshold0.04 MeV

Readout frequency 10 MHz

Trigger threshold

range+/- (1.6 - 50) fC

• Process migration from 0.8 µm to 0.35 µm

− Larger radiation stability

− Lower power consumption (~ 30%)

• Modification of VA32TA2_2 design required

− configuration register memory

(readback possible)

− Individual switch off of channels (0V)

− 32 independent threshold DACs

item FE-Chip-1 FE-Chip-2

Max. input amplitude +/- 500fC

+/- 2500fC

(linear scale-up of

noise)

Trigger threshold range +/- (1.6 - 500) fC +/- (8 - 2500) fC


Electronic Readout

(S. Merzliakov)


Cooling System (Design And Tests)

• Cooling and temperature stabilization of detectors and electronics is needed

• Survive 450°C NEG activation and 80°C target chamber bake-out :

Temperature shield

• Conductive cooling will be utilized

• Simulations under way

• Prototype design and tests

Test-bench available with diagnostic system

Cooling

Thermocamera and temperature sensors


Summary

• Experiment simulations are almost finalized

• General detector arrangement is fixed

• First design of mechanical support and cooling system

• To be done

Final specification and ordering of chips

Finalizing the design of:

– Openable cell

– Mechanics, cooling system, tooling

– Thermo shield

– Electronic readout

– Capton dimensions

– Low / high voltage power supply

Test of cooling system and thermo shield

Test of detectors: 8 HERMES and 12 + 2 PAX TTT

…


Additional Slides


Input Parameters

• I = stored protons

•

•

•

227104.61 cmtot

−⋅=σ

213 /108.4 cmatomsdt ⋅=

sdfIrate trev /1950tot =⋅⋅⋅= σ200mm 200mm

dx=dy=10mm

l=100mm

d=10mm

target cell dimensions:

10101 ⋅

Cell wall thickness 30μm


Event Reconstruction

• 2 protons in coincidence in opposite detectors

(1 proton with 1 hit in each detector layer)

• Energy loss threshold 0.5 MeV



accepted events

• φ cut -> 59 %

• z cut -> 16.9 % (17.5 %)

• E cut -> 16.9 % (7.3 %)

0

optimal position

200z

beam direction

-200 -10

26. June 2012 Slide 32228,98

Ac

ce

pta

nc

e(%

)

Measurement Time + Acceptance(HERMES detectors)

oz (mm) T (h) Acc

230 12,5 4,78

220 11,0 5,2

210 10,5 5,7

200 9,8 6,2

190 9,4 6,5

180 8,9 6,8

170 8,4 7,1

160 8,3 7,3

150 8,1 7,4

140 8,1 7,4

130 8,1 7,4

120 8,2 7,4

110 8,4 7,2

100 8,9 7,1

70 9,9 6,2

Me

as

ure

me

nt

tim

e (

h)

oz (mm)

T (h)

Acc (%)

Beam storage cell

HERMES



accepted events

• φ cut -> 59 %

• z cut -> 16.9 % (17.5 %)

• E cut -> 16.9 % (7.3 %)

1 PAX TTT 2 HERMES

1 PAX Layer

• E cut -> 28 %

0

optimal position

200z

beam direction

-200 -40


Scenario

BRP calibration

1. Injection of polarized proton beam

2. Measure beam polarization at ANKE (pd: D.Oellers)

3. Target polarization measurement at PAX ( pp )


Design


Detector Specifications


0 45 90 135 180 225 270 315 3600.6

0.8

1

1.2

1.4

Pz Qz

Rate4 30 ϕ, poise, Q, ( )

Rate4 30 ϕ, poise, Q−, ( )

Rate4 30 ϕ, poise−, Q, ( )

Rate4 30 ϕ, poise−, Q−, ( )

Rate4 30 ϕ, 0, 0, ( )

ϕ radeg⋅

Longitudinal Polarization (130 MeV)

• smaller total cross section ( )

• large spin correlation coefficients

• same acceptances• no φ-dependence

mb7.25=τοτσ


Differential Cross Section


Total Cross Section (mb)


`

TA-4

TA-3

TA-1

TA-5

TA-2

TA-6

8 VA32TA2 CHIPSPCB6

8 VA32TA2 CHIPS PCB1

HIGHVOLTAGEPOWERSUPPLY

ZEL DAQ SYSTEM CRATE

FAST ADC

OPTO

XILINX CONTROL

OPTO

FAST ADC

TRIGGER

VACUUM PART

FLANGE PART

2 COAX

I2CADC

Optocoupler

VA-TA IN/OUT

LVDS

ORed TA-OUT

R

TRIGGER

TRIGGER

LVDS

LVDS

LVDS

LVDS

LVDS

I2CADC

VA-TA IN/OUT

Optocoupler ORed TA-OUT

RECEIVER 3 POWER

DACS

TRIGGER

OUTPUTAMPLIFIER

FLOATINGLOWVOLTAGEPOWER

SUPPLIES

TRIGGERLOGIC

DIG.BUFFER

I2C BUSMASTER

I2CADC

VA-TA IN/OUT


RECEIVER 3 POWER

DACS

TRIGGER

OUTPUTAMPLIFIER

DIG.BUFFER

I2CADC

VA-TA IN/OUT

Optocoupler

150 outputs

ORed TA-OUT

RECEIVER 3 POWER

DACS

TRIGGER

OUTPUTAMPLIFIER

2 COAX

DIG.BUFFER

I2CADC

VA-TA IN/OUT

Optocoupler

128 outputs

ORed TA-OUT

RECEIVER 3 POWER

DACS

TRIGGER

OUTPUTAMPLIFIER

DIG.BUFFER

I2CADC

VA-TA IN/OUT


RECEIVER 3 POWER

DACS

TRIGGER

8 VA32TA2 CHIPS PCB2

OUTPUTAMPLIFIER

FAST ADC

DIG.BUFFER

RECEIVER 3

OPTO

8 A32TA2 CHIPSPCB5

DACS

POWER

ZEL DAQ SYSTEM CRATE

8 8 CHIPSVACUUM PARTPCB3

300 umSi stripdetector

96 outputs

8 CHIPSVACUUM PARTPCB4

2 COAX

XILINX CONTROL

TRIGGER

OPTO

96 outputs

OUTPUTAMPLIFIER

2 COAX

FAST ADC

DIG.BUFFER

1.5 mmSi stripdetector

2 COAXTRIGGER 3

300 um Sistripdetector

OPTO

XILINX CONTROL

2 COAX

150 outputs

128 outputs

FAST ADC

TRIGGER 2

FAST ADC

ZEL DAQ

SYSTEM CRATE

TRIGGER 1

OPTO



VA32TA_2 MATE3

No. Of channels 32 16

Power dissipation 3mW/channel 30 mW/channel

Linear Range11MeV

(±500fC)

50MeV

(± 2220fC)

Slow shaper (PT) 2 µs 1µs and 3µs

Fast shaper (PT) 80 ns 22 ns

Minimum Threshold 0,04 MeV 0,4 MeV

Energy resolution

(Cdet=60pF) 890e- ~ 1530e-

Readout frequency 10 MHz 4 MHz

Time resolution

(E>1.5MeV) ≤0.9ns ≤0.3ns

90 mm

90 m

m


R- Card

• 1outside vacuum front-end interface per detector side

• decouples front-end chip electronics which is operated at the detector bias voltage

• control signals to read out chips and to set trigger pattern of the R-card are provided via a flat cable

• 2 voltage inputs allow controlling the thresholds and calibration pulse amplitude

• analogue outputs

Inner Vaccum Part

• Detector strips bonded to Kaptonpitch-adaptor

• Connection to the self-triggeringfront-end chips

• Kapton connection to the flange


• 12 Bit ADCs, up to 10MHz sampling

• One sequencer per detector side

• Hardware common-mode correction

• Hardware zero suppression

Data flow for 2 STTs: event rate ~1000 /s

no zero suppression ~ 5MByte/s

zero suppression ~ 0.1MByte/s

< 50 µs dead-time

ADC + Sequencer Development Completed


HERMES Detectors


Modifications for PAX:

Remove existing Helix front-end

Connect new pitch adapter to VA32TA2

self-triggering front-end chips

fix mechanical constraints / assembly

check Demetrius with atomic hydrogen : cool detectors ?

check each detector with α-source

HERMES Detector


COSY cooling range

Spin filtering at COSY: Low β-section

Beam lifetimes: Why?

calculated beam polarization after 2 beam lifetimes (Q = 0.8; dt = )213105 −⋅ cm

4000

6000

12000

24000

24000

12000

6000

4000

w3

Folie 47

w3 The next point on the agenda for was to achieve longer beam lifetimes (>10000s), which are needed to reach high polarisations.

You can see the expected polarisation after 2 lifetimes filtering for the transversal and longitudinal case.As you can see the transversal pol. is expected to be very low, whereas for the long. pol. one expects about 25 % for good vacuum cond.

So anyway we have to go for longitudinal polarisation in addition.

The vacuum as major lifetime restricting factor had to be improved beforehand.weidi; 12.03.2010

pax detector developmentcollaborations.fz-juelich.de/ikp/pax/public_files/usual... · 2013. 5....

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