fast readout high performance optical detectors for astronomy · 2004. 10. 15. · jra 3 fast...

JRA 3

Fast Readout High Performance Optical Detectors for Astronomy

Stefan WagnerLandessternwarte Heidelberg

OPTICON Board meeting, Grenoble, October 11-12, 2004

JRA 3

● Outline● Scientific motivation (HTRA, Imaging)● Technological motivation● Structure and organisation● Workpackages, timelines, milestones● The first 7 months● Relations to other I3 initiatives● Bad news and problems● Good news and progress● Redefinitions

JRA 3, Scientific Motivation

Observational astrophysics:Locate sources in space (4 dimensions).

This includes precise timing.

The parameter space of photon detectionhas expanded in many dimensions.

Time resolved astrophysics has not participated in technological advancement

HTRA, Scientific Motivation

Prime role for high resolution in spatial dimension (Adaptive Optics, Interferometry).

High temporal resolution is an indirect way of

achieving even higher spatial resolution.

d alpha = dx/D > dt c/D (causality)nsec (Pulsars) ~ meters ~ femto-arcsec

10 sec (Blazars) ~ R(star) ~ 50 femto-arcsec


Examples 2


Examples 1

JRA3, Scientific Motivation

Overcome seeing limitations:

Seeing: variations on many scales.Short (noise-free) exposures enable selective

imaging and a post-recording selectionof (close-to) diffraction limited images.

(LuckyCam @ NOT)

Scientific Motivation, part II

Wavefront distortions are not corrected.Frames badly affected by those distortions are

ignored.

All frames are recorded. Post-imaging cuts in data-cube for any desired combination of depth

and resolution.

Useful approach in blue bands and for small telescopes. Selective imaging will eventually

involve very little extra cost.

Technical Motivation

Detectors with high QE (CCDs) replaced other detectors with better temporal resolution.

Can modern detectors combine high QE, low noise and high temporal resolution?

The large parameter space (10 ns - 10 s),different fields, etc. may require different detector

technologies.

Identify best solutions, promote development

Technical Motivation

Exploit synergies in electronics, and software.

Many other applications in astrophysics and elsewhere.

European industries play an important role in detector development, and may play the leading role in fast readout detectors in the near future

(European added value).

The past, the JRA, and the future

Teams working independently on single detectors but building complete systems.

Combine expertise (different detectors)Synergies (expert solutions on subsystems)

Common strategies in detector development,common interfaces (electronics, sw, tests),

common test procedures.

Collective cooperation with European industry.

The past, the JRA, and the future

Maximizing efficiencies of detectors within “their“ optimum corners of parameter space.

Common interfaces of camera heads

Common software tools. On-line data evaluation and analysis tools instrumental for HTRA

applications (else 100s GB/night)

Blueprints for HTRA instrumentation

The teams

ATC, Edinburgh, A. VickESO, Garching, D. BaadeIoA, Cambridge, C.Mackay

LSW, Heidelberg, S. WagnerMPA, Garching, H. Spruit

MPE, Garching, G. KanbachNOTSA, Copenhagen, J. Andersen

NUI, Galway, A. ShearerU Sheffield, V. DhillonU Warwick, T. Marsh

Structure and Organisation

Management

Infrastructure Detectors

Electronics L3CCDCamera Head PN SensorsSoftware APD ArraysTestbed, Instrument Design

Structure and Organisation

Organized in eight workpackageshead and deputy

Usually involvement from several teamsin definition phase (~12 months).Duration depending on progress.

Several meetings in year 1KO: March 14-17, 20044 WP meetings since

Work-packages

● 8 Workpackages ● WP1 Management (S. Wagner, H. Spruit) ● WP2 L3CCDs HTRA (V. Dhillon)● WP3 PN Sensors (G. Kanbach)● WP4 APD Arrays (A. Shearer)● WP5 Electronics (C. Mackay)● WP6 Software (J. Andersen)● WP7 Camera Head (A. Vick)● WP8 Testbed (S. Wagner)

WP1: Management

● Coord: S. Wagner, LSW (H. Spruit, MPA)● Home page (pw protected)● www.lsw.uni-heidelberg.de/projects/tra/jra.html ● Tasks: ● Coordination between other WPs● Oversight timelines, milestones, resources● Meetings, reports, deliverables (quality ctrl)● Coordination with other OPTICON activities ● Work started (mostly troubleshooting)

WP2: LLL (L3)-CCDs

●

●

WP2: LLL (L3)-CCDs

● HTRA:● Small array● Photon counting● Drift mode

applications

● Imaging:● Large array● High speed● Multiple ro

WP3: PN Sensors

● PN Sensors:● Operated in X-ray (PN camera on XMM)● Applications in optical and NIR bands● Silicon detectors, operated in full depletion● High QE up to 1200 nm (bridging opt-IR gap)● Little fringing● Large pixels● 1 amplifier/row, hence fast readout● Synergies: AO applications?● New concept (L3PN cameras)?

WP3: PN Sensors

WP4: APD arrays

● APDs probe (sub-)microsec regime ● Operational goals for HTRA: 100 ns● Novel approaches to established technology● Problems: stability, modularity, efficiency● Stability: Improvements

in fabrication and testing● Modularity: Mounting

APDs in small arrays (common base) of ~ 25 pixels (linear, quadratic)

● Efficiency: Feeding microlens-arrays/fibers● Work started (sub-array base, interfaces)

WP5: Electronics, Controller

● L3CCDs/PN CCDs are operated in principle in the same way as classical CCDs.

● Controller requirements similar, adapted to very high frame-rates/pixel rates

● Absolute timing with very high reliability.● Demonstrate feasibility of “HTRA - upgrade“

with standard controllers (e.g. SDSU).● Multiple port controllers for L3CCDs.● Development of common CCD/PNCCD

electronics.● Activities started (complementing labs)

WP6: Common Software

● SW operating detectors in WP5/WP7● WP6: on-line analysis sw ● Data Flow Management

kHz framerates require fast/efficient pre-processing/analysis and archiving.

● Fast Imaging: preselection, quick-look, processing. Ultimate aim: Fast mode on any CCD op'n.

● HTRA: preprocessing, timing, quick-look● Started by 3 partners

WP7: Camera Heads

● Camera (hardware) - detector – controller● Front-end-electronics optimized for MHz-

frame-rates.● Common design elements for different

controllers and different detectors.● Which elements could serve all detectors?● Ultimate goal (beyond JRA): Camera

that can host different detectors Camera that hosts different detectors in parallel.

● No activities planned in first 12 months

WP8: Instrument Testbed

● Design and construct testbed which allows identical tests for different lab-setups to characterize different systems in homogeneous way (possibly beyond JRA)

● Design and construct testbed for realistic tests (on the sky) of different camera concepts (involving common, simple analysers) – proof of concept.

● Design studies of HTRA instrumentation, optimized for 2-4m/8m class telescopes.

● All three activities started, integrating ELT

Timelines, Milestones

● Detectors: Definition Phase (12 months): ● Identify optimum parts of parameter space for

each detector● Compare controller concepts● Explore synergies (electronics, sw)● Define Interfaces● Consider novel ideas:

e.g. deep depletion for L3CCDs, amplification (gain register) in PN Sensors

● Restructuring Work-packages

Months 13-18

Deliverables:

WP2: Test Report L3CCDWP3: Preliminary design Report PN Sensors

WP5: Fast timing controller(s) L3CCDWP7: Prototype Camera Head

Milestones:PDR, CDR for technologies and controllers,

procurement and integration L3CCD, test setup PN Sensor, APD Array Design

Deliverables:



Milestones:

PDR, CDR for technologies and controllers, procurement and integration L3CCD, test setup

PN Sensor, APD Array Design

Deliverables:



Milestones:



The first 9 months

Activities:

March: 1st JRA meeting (Garching)

June: WP5 meeting (Glasgow)June, July: WP3 meetings (Garching)

July: WP2 meeting (Heidelberg)

Deliverables:



Milestones:



Deliverables:



Milestones:



Relations to other I3 activities

● JRA 2: Fast detectors for AO; Related goal but very specific application with different specifications; detector technology may ultimately be similar.

● Common call for tender was not possible (time-scales for specifictions do not match)

● JRA 5: Information on detector development● N3 (WP3): HTRA ● Access Program: HTRA Instrumentation ● ELT: brought forward and will be implemented

as a specific additional AI

Bad news and problems

● Money was late ● Partners in MPG● Coordinating team (the “Landessternwarte

Heidelberg“) may disappear.● First results require redefinition of timeline in

two of the key work-packages.

Money is late

● 2nd collaboration meeting with full team postponed (originally scheduled for July 2004).

● Definition of optimum specs for L3CCD delayed.

● Specifications for work-packages on APD arrays delayed.

● To first order this results in delays wrt the original timeline.

● Common call with JRA2 affected.

Partners in MPG

● Proposal was written with MPE and MPA foreseen as partners in JRA3.

● In late 2003 it was decided that MPE, MPA, MPIfR will not be independent partners but associated labs of MPIA, representing MPG

● MPIA administration was unaware of the implications (acting as a bank and being responsible for auditing)

● Cashflow problems resolved● Auditing/reporting to be clarified

Coordinating partner

● Coordinating partner of JRA 3 is the Landessternwarte Heidelberg (LSW).

● LSW has been an independent research institution of the federal state of Baden/Württemberg under supervision of the state ministery for research.

● As of Jan 1 2005 it shall be merged with other institutes to a Heidelberg center for astrophysics at the University of Heidelberg.

● University administration is not willing to act in accordance with agreements for JRA3.

Current status (LSW)

● Plans for discontinuation of administrational status were announced in April 2004.

● No formal agreement signed yet.● Unclear whether LSW retains independence● Unclear when merger might take place.● Unclear whether university administration

agrees with operations for JRA3.● Plan B: Move coordinating partner (and some

of the associated tasks) to other team.● Obvious alternative (MPA) difficult (see MPG

issues)

Other admin issues:

● One partner suffers from communication problem within its administration

● Reluctance in institutions prior to receipt of contract in June 2004

● Reluctance to start cash-flow in several institutions in early phase

● Overhead problem?

News WP2

● Challenging/exploratory projects● Continuous redefinition required● “Problem“ from management point of view● “Success“ from a technical point of view ● Inherent nonlinearity in EMCCDs● (see recent discussion on ccdworld)● Tests are a spinoff from kick-off meeting● Investigation using different devices, cameras,

etc. by different JRA3 teams

EMCCDs

● Gain adjustment in multiplication register through modulation of amplitude of HV clock phase.

● Large signals lower the voltage at each electrode.

● Charges pass larger potential gap.● The gain is increased due to high signal.● A spatially inhomogeneous non-linearity

results.● Effect can be simulated (MC) and corrected

for (ought to work on-the-fly?)

News WP3

● Design optimisation for PN sensors.● Initial measurements on ron performance are

not satisfactory.● Improvements possible (multiple reads)● Not of interest to HTRA but might result in an

interesting spin-off (improved spectral resolution).

● HTRA: amalgamate PN with EMCCD technology (triggered by 1st JRA3 meeting)

● Columnwise organised avalanche amplifiers.

Timelines, Milestones

● Detectors: definition phase (12 months): ● Identify optimum parts of parameter space for

each detector - ongoing● Compare controller concepts - started● Explore synergies (electronics, sw) - ongoing● Define interfaces pending● Consider novel ideas: ongoing

e.g. deep depletion for L3CCDs, amplification (gain register) in PN Sensors

● Restructuring work-packages started

Good news and progress

● Work for all workpackages started despite cashflow problems (including recruitments)

● WP3: discussions on concepts and initial tests triggered new ideas.

● Proof of concept studies initiated.● If successful, this will open a shortcut to the

initial plan.● WP2: thorough testing of parameter space in

the UK and Germany.● Synergies become apparent.

Redefinitions

● Redefinitions within EMCCD package● Controller and low-level software will require

more effort.● PN sensor modifications very promising but

timeline may require adjustments.● On-the-fly analysis packages require more

effort● Boost ELT planning

Scientific Motivation, part II

Selective imaging compares favorably with other high resolution approaches.

HST – NOT : Similar apertures and resolution.

High resolution not continuously, but very high efficiency (30%) has been reached.

Can be applied to imaging, spectroscopy, etc.Co-add equivalent to classical techniques.

Ultimate goal: All 2-4m astronomy this way?

Lucky Imaging

fast readout high performance optical detectors for astronomy · 2004. 10. 15. · jra 3 fast...

Documents