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( HTRA: ~ 100 ms -- 1μs )

- To develop the most promising technologies for HTRA- Assess relative strengths/areas of application in astronomy

JRA3: Technology development

for high-time-resolution astronomy

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- Indicative budget 1.2 M€- 3 main technology WPs- 4 ‘connective tissue’ WPs

JRA3

Partners Max-Planck-Institut für Extraterrestrische PhysikInstitute of Astronomy, CambridgeNational University of Ireland, GalwayUniversity of WarwickSheffield UniversityUK Astronomy Technology Centre, EdinburghLandessternwarte HeidelbergMax-Planck-Institut für Astrophysik European Southern Observatory

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JRA3

1. Rapidly varying astronomical objects

2. Rapidly varying earth atmosphere (adaptive optics)Key requirement for high time resolution astronomy: single photon detection

Need for high time resolution

GX 339-4 13/5/04 FORS2 HITI

1 2 3s

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JRA3

WP4 Avalanche photodiode arrays

WP2 EM-CCDs (L3CCDs)

WP3 Avalanche amplified pn-CCDs

WP5 CCD controllersWP6 SoftwareWP7 TestbedsWP1 Management

Contractors and workpackages

NUIGSheffieldWarwickUKATCMPG/MPEESOIoA, NOTSA

MPG/MPA, LSW

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JRA3

Projected JRA3 spending by technology

Avalanche photodiodes

Electron multiplied CCDs

Avalanche amplified PN CCDs

‘connective tissue’

17%

40%

30%

13%

~ 1985

2004

2008

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JRA3 WP4 APD-array developmentNational University of Ireland

in collaboration with University College Cork

Array elements haveto be spatially separated (crosstalk)

- to be fed with- lenslet arrays or- fibers

Single detectors in use for HTRA and AO

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JRA3

nFibre fed APD array¨Fibres epoxied by UV curing to APD devices¨Elimination of cross talk issue due to ¨separated APD elements

Individual fibres aligned on to APD dies in ceramic packages

On-chip arrays

APD arrays (WP4)

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JRA3 APD arrays (WP4)

Summary and perspective APD technology

- known technology- limitations: cross-talk, dark current non-uniformity.- close to its technological limit- CCD-based technologies encroaching on its territorybut ...- still the only technology for highest time resolution

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● Conventional CCDs: spurious electrons on readout● ‘EM’: On-chip electron multiplication● Available now (E2V, TI)

● JRA3 activities:

1 Controller development for high time resolution applications - up to 60 Mpix/s 2 Application tests: - ‘Lucky images’: cheating the seeing limit - HTRA: rapidly varying objects

- (photon counted spectra)

L3CCDs (EM-CCDs) WP2, WP5, WP7

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JRA3 ‘Lucky images’

E2V EM-CCD+

fast controller(WP5,6,2)

10% best framesall frames

M13

Cat’s Eye

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pulsar in crab nebula P=30 ms

exposures 2 ms

‘Lucky images’

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Spectra with single-photon detection

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JRA3 WP5 controllers for EM-CCDs

Controller boards, vacuum interface & chip support

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JRA3

Summary and perspective EM-CCDs

● Best currently available technology● Advances in controllers & data processing technology ● Shows the potential of photon counting CCDs for - high time resolution observations - angular resolution improvement by ‘lucky imaging’ - wavefront sensors for AO

● technology still developing rapidly

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Avalanche-amplified pn-sensors (AA-pn)

● Alternative silicon technology for same purpose● Developed at the semiconductor laboratory of the MPG, ● Initiated by JRA3● Technology elements produced and tested (Aug 2007)● Prototype device by end of 2008● elements: - thick detection layer (0.5mm) - avalanche amplifier - AR coatings

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JRA3 Avalanche-amplified pn-CCDs (WP3)

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JRA3 Avalanche-amplified pn-CCDs (WP3)

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JRA3 Avalanche-amplified pn-CCDs (WP3)

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JRA3 Avalanche-amplified pn-CCDs (WP3)

Differences ↔ E2V EM-CCD 1. Parallel readout + slower clock → lower readout noise → lower amplification factor →● higher dynamic range and● no internally generated photons 2. Deep depletion layer →● near-IR wavelength sensitivity 3. AR coating technology:● broader wavelength range

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JRA3 Avalanche-amplified pn-CCDs (WP3)

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JRA3 Avalanche-amplified pn-CCDs (WP3)

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JRA3

Summary and perspective AA-pn CCDs

● represents next generation electron-multiplied CCD technology - photon counting accuracy - wavelength range - IR sensitivity - time resolution (<1 ms)● development on schedule● full-scale CCD currently ‘in the oven’, functional tests mid-2008● prototype device and controller expected by end 2008

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JRA3

‘connective tissue’

- camera head development (WP7, completed)- higher level software interfaces (WP6, under construction)- management (WP1)

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JRA3

UKATC high voltage clock (WP5)

JRA3

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WP 7 Cooled camera head (in ESO cryostat)

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JRA3

Management

Main events since start of contract - Transfer of management from LSW Heidelberg to MPA (July 05)- Redefinition of technology contribution MPE (Feb 05)- Common hardware platform for comparison of technologies replaced by software procedure (Feb 05)- Definitive finance plan JRA3 approved by OPTICON board (Oct 05)

Status August - 95% of work on track- Technologies successful beyond expectation- Major innovations achieved in high time resolution CCDs

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Miles and deliverables (as of Aug 2007)

achieved/deliveredWP1 M1, M2, M3 WP2 M1, M2, D1 WP3 M1, M2, D1 WP4 M1 WP5 M1,M2,M3,D1 WP6 M1 WP7 M1, D1WP8 M1

remainingD2 D2 M3, D2 M2, D2D2D1completedD1

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JRA3