Development of Pellet Target Tracking Systems in Uppsala Main - - PowerPoint PPT Presentation

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Development of Pellet Target Tracking Systems in Uppsala Main activities autumn 2010: Time and position correlation studies. Velocity measurements. Tracking section with two measurement levels for a prototype system at UPTS. Simulation

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Panda CM GSI 2010-11-29 Hans Calén

Development of Pellet Target Tracking Systems in Uppsala

Hans Calén, Kjell Fransson, Carl-Johan Fridén, Elin Hellbeck, Marek Jacewicz, Pawel Marciniewski IFA & TSL, Uppsala University

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Main activities autumn 2010:

‐ Time and position correlation studies. Velocity measurements. ‐ Tracking section with two measurement levels for a prototype system at UPTS. ‐ Simulation studies. ‐ Design ideas for PANDA.

Goals for 2011 ‐ 2014:

‐ Close to 100% efficiency pellet detection. ‐ Pellet track processing and optimization of pellet detection points. ‐ Multi‐camera readout system. ‐ A tracking section for PANDA (tested at UPTS). ‐ Feasibility of laser‐induced droplet production.

Project supported by JCHP-FFE, EC FP7 and SRC

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Panda CM GSI 2010-11-29 Hans Calén

UPTS April/May 2010 Synchronized LS cameras at two levels

2 Laser Camera Upper Laser Camera Lower Distance ≈ 30cm Droplet chamber VIC exit

Time and position correlation studies

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Panda CM GSI 2010-11-29 Hans Calén

3 Studies of pellet signal correlations were used to get a hook on pellet velocity distributions …

Pellet velocity estimate at UPTS May 2010 The good agreement with MC indicates that a “big” fraction of the pellets have a velocity v ≈ 80 m/s …… with a small spread σv /v ≈ 1%.

MC simulation 60m/s Velocity 100m/s

Time difference

ΔT (Lower-Upper) for all combinations

f pellet time signals

Time difference Pellet generation conditions fdroplet ≈ 50kHz p(H2) ≈ 400mbar, p(droplet.ch.) ≈ 25mbar droplet velocity 25 m/s pellet diameter 20-30 micron (guess ) Time and position correlation studies

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Panda CM GSI 2010-11-29 Hans Calén 14 16 18 20 22 24 26 28 30 250 350 450 550 Droplet velocity (m/s)

Driving pressure P_H2 (mbar)

f=40227 Hz f=47616 Hz f=65732 Hz

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Measurements at UPTS September 2010

Higher driving pressure ⇒ faster (and bigger droplets) ⇒ slower pellets

Droplet velocity vs driving pressure and generation frequency

Pellet generation conditions p(droplet.ch.) ≈ 25mbar pellet diameter 25-35 micron (guess ) Time and position correlation studies

14 16 18 20 22 24 26 28 30 30000 80000 130000 Droplet velocity (m/s)

Frequency (Hz)

P_H2=320mbar P_H2=360mbar P_H2=400mbar P_H2=440mbar P_H2=480mbar

70 75 80 85 90 95 100 250 350 450 550 Pellet velocity (m/s)

Driving pressure P_H2 (mbar)

f=40227 Hz f=47616 Hz f=65732 Hz

Pellet velocity from LS‐camera measurement

Δφ/φ ≈1% ⇔ σv /v ≈ 1.5%

(at these conditions)

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Panda CM GSI 2010-11-29 Hans Calén

Placed below a skimmer for possibility to reduce pellet rates to below 20 k/s, which allows tracking of individual pellets. Tracking (i.e. measured pellet velocity and direction) can be checked by measurements one meter away at the existing levels at the pellet generator … and by the well defined beam position at the VIC exit (2 m above).

UPTS tracking section

5 The chamber is designed for measurements with 2‐4 cameras at two levels separated by 80 mm.

UPTS bottom floor

Pellet tracking system prototype at UPTS

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Panda CM GSI 2010-11-29 Hans Calén 1 2 3 4 5 6 5 10 15 20 25

Relative velocity spread (%)

Generation frequency (kHz)

Distance 300 mm

Gauss below curve

Trunk. Gauss

below curve Exp above curve

Case: 1) Short distance / low vel. spread Gaussian ! 2) Longer dist. / higher vel. spread Gauss (trunkated) 3) Longer dist. / higher vel. spread Gauss (tail) / Exp ? 4) Long dist. / high vel. spread Gauss (tail) / Exp !

6 Gauss upper and Exp lower curve 1. 2. 4. 3. 1. 2. 3. 4.

Time between pellets

Curve = Exp w. slope ⇔ 17 k/s

UPTS measurement

300 mm below VIC exit. f≈40kHz, p(H2) ≈ 400mbar, p(DC) ≈ 25mbar (total loss = camera deadtime + illumination ineff. + lost pellets)

Time between pellets Time between pellets σv/v=0.3% σv/v=1% σv/v=2.5% σv/v=5% Simulation Studies for the Pellet Tracking System Pascal Scheffels (Erasmus project report)

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Panda CM GSI 2010-11-29 Hans Calén

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Target thickness fluctuations

Number of pellets in accelerator beam vs time (during 5 ms) for pellet occurence frequencies, 15 & 150 k/s, and different pellet velocity spreads:

MC results for pellet v=60 m/s and accelerator beam Φ=4 mm. (Pellet crossing duration ≈70 μs) .

f = 15 k/s σv /v=1% f = 15 k/s σv /v=0.1% f = 150 k/s σv/v=1% f = 150 k/s σv /v=0.1% f = 150 k/s σv /v=0.01% f = 15 k/s σv /v=0.01%

Simulation studies

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Panda CM GSI 2010-11-29 Hans Calén

Number of pellets in ion beam vs pellet generation frequency

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Target thickness fluctuations MC results for pellet v=60 m/s and ion beam Φ=4 mm.

Simulation studies

0.2 0.4 0.6 0.8 1 1.2 1.4 50 100 150 200

Sigma/Average

no. of pellets

Pellet rate (k/s)

Thickness fluctuations in 20 μs time bins for passage through a 4 mm slot, 2.7 m below VIC

dv/v=1% dv/v=0.1% dv/v=0.01% poisson

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Panda CM GSI 2010-11-29 Hans Calén

Fraction of “primary” pellets that collides vs beam divergence for different velocity spreads σv /v = 0.05, 0.1, 0.5, 1, 2 %. 0 - 700mm 700 – 2700 mm

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Intra-beam pellet-pellet collisions

Simulation studies

PR=100 k/s

Divergence (rad) Divergence (rad) Divergence (rad) Divergence (rad) WASA ? WASA ?

PR=200 k/s

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Panda CM GSI 2010-11-29 Hans Calén

Design idea: Multi‐camera pellet tracking section for determination of velocity and 3‐d direction for individual pellets

10 Four levels for measurements, each with two lasers and two LS‐cameras. ‐ Distance for velocity determination 60 – 260 mm. ‐ Distance for direction determination 200 mm (…internally… one can use VIC exit also).

Design Masih Noor, CAI (Center for Accelerator and Instrument Development), Uppsala University

Total height 400 mm. Space requirement radially: rmax = 500 mm. Laser Camera Frame for alignment

Planned activities: Multi‐camera system

PTR for PANDA

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Panda CM GSI 2010-11-29 Hans Calén

Multi camera readout and synchronization

11 Adapter cards (1 per camera)

Camera links 120 Mbytes/s each Optical links 2 Gbytes/s for 16 links

Convert data to

ptical links

Synchronize all cameras

16 optical receivers 1.6 Gbits/s 64 Mbyte of DDR ram 8 Mbyte of Flash rom USB, Ethernet VME-64x or LVD –bus readout Pellet identification and storage with time stamp Experiment triggers stored with timestamp

Experiment trigger Timestamp to DAQ A few Mbyte/s output data rate for 16 cameras Up to 16 cameras Virtex5-FXT data processing board

Planned activities: Multi‐camera readout system

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Panda CM GSI 2010-11-29 Hans Calén

Multi camera readout development prestudies

12 Planned activities: Multi‐camera readout system

CameraLink bus Signal converter card “Serial” ⇒ parallel bus Virtex-5 development board Study of camera signal behavior Pixel signal monitoring for 22.5 μs camera cycle Signal amplitudes 2 x 256 pixels Readout idle time ( exposure) 22.5 μs

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Panda CM GSI 2010-11-29 Hans Calén

Status and Conclusions November 2010

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Synchronized operation with two cameras works ! Illumination/detection conditions good … but should be improved Desired transverse (x,z) position resolution reachable with present

cameras. Solution for good time (⇒ y position) resolution and high

camera efficiency exists

Clear indication that pellet velocity spread σv /v ≤ 1% can be obtained

⇒ Effective pellet tracking possible !!!

Preparation of a first prototype PTR system for UPTS in progress:

Tracking chamber with two levels of pellet detection
2-3 LS-cameras with lasers

Design & preparation of tracking systems with more LS-cameras.

A design idea of a system for PANDA exists ⇒ TDR. Preparing simulations for the design of a full scale system. New readout system planned (prototype work)