detector$and$controller$requirements$for$$ …€¦ · · 2016-01-15•...

GMT

Detector and Controller Requirements for GMT Science Instruments

Materials provided by: Sagi Ben-‐Ami (SAO/Harvard – G-‐CLEF) Luke Schmidt (Texas A&M – GMACS) Rob Sharp (Australia Natl Univ – GMTIFS) Dan Jaffe (Univ Texas – GMTNIRS)

10/22/15 1 ELT Detector Workshop -‐ Pasadena

Wavefront Sensor Requirements Presented by Antonin Bouchez

GMT

•  GMT Overview (Las Campanas, Chile) –  24.5m diameter –  7 primary mirrors (8.4m) –  20 arcmin Field of view –  Start of science 2022 (4-‐5 primary segments)

•  Iniàl Instrument Suite (in delivery order) –  G-‐CLEF: high resoluòn op`cal spectrograph (Entering final design) –  GMACS: medium resoluòn mul`-‐object spectrograph (Star`ng

conceptual re-‐design acer de-‐scope) –  GMTIFS: medium resoluòn, diffracòn-‐limited ZJHK IFS / Imager (in

preliminary design) –  GMTNIRS: high resoluòn simultaneous JHKLM AO-‐fed spectrograph

(prototyping key technologies)

10/22/15 2

GMT Instrument Program Overview

ELT Detector Workshop -‐ Pasadena

GMT

•  Asymmetric white pupil design (like HARPS, ESPRESSO) •  Two channels (red/blue) – CCDs coa`ngs selected (one CCD each) •  Cross dispersion with volume phase holographic (VPH) gra`ngs. •  Three observing modes with resoluòns of 20,000 – 100,000:

-  Ultra-‐stable precision radial velocity – 10 cm/s (high full well, low residual image) -  High throughput for faint objects (low read noise, high QE esp blue/red ends) -  Mulòbject spectroscopy (minimal pixel/channel cross-‐talk)

10/22/15 3

G-‐CLEF Op`cal High Resoluòn Spectrograph


PI: Andrew Szentgyorgyi (SAO/Harvard University) Local Reps: Sagi Ben-‐Ami, Brian McLeod

GMT

•  Array size: approx 9K x 9K, 10 μm pixels •  Read Noise / readout speed:

-  RO noise < 2.5e (goal of 2.0e) at 50 kHz to achieve required S/N. -  Full array must be able to read out in 15 sec (higher RN is ok)

•  Full well / linearity: 110,000 e-‐ •  Dark current: <3 e-‐/hr/pix •  QE: See table

10/22/15 4




GMT

•  MTF: measured at frequencies up to ~70 lp/mm •  Residual imaging: none, up to full well •  Binning: >2x2 without full-‐well loss or added read noise •  Thermal stability: <5 mK/hr

-  Packaging: physical size change < 20 Å/pix (0.02%) -  Implies SiC, CE6, Invar op`ons

10/22/15 5




GMT

10/22/15 6

GMACS Op`cal Mul`-‐Object Spectrogtaph


PI: Darren DePoy, Jennifer Marshall (Texas A&M University) Local Reps: Luke Schmidt

•  Slitlet mask MOS: approx 4’ x 8’ FoV (large pixel array) •  Simultaneous wavelength coverage:

-  Required: 370-‐950 nm -  Goal: 340-‐1050 nm

•  Dual channel: red / blue (dual focal plane arrays) •  Direct feed through mul`-‐slit mask (~24 mask capacity) •  Secondary feed via facility fiber feed (20’ FoV)

GMT

10/22/15 7

GMACS Op`cal Mul`-‐Object Spectrogtaph


•  Wavelength coverage: wider than 370-‐950 nm, with goal of 340-‐1050 nm •  QE goals:

-  > 80-‐85% (370-‐950) -  > 25-‐30% at 340, 1050 nm

•  CCDs coaFngs: Selected for each channel (red/blue) •  Array Size: 8K x 12K, 15 μm pixels (2 x 3 of 4Ks; or 2 x 2 of 6Ks if cheaper,

though excess area) •  Read noise < 2 e-‐ •  Flatness berer than 30 μm per CCD and mosaic array •  Full array readout < 60 sec (goal < 20 sec)

Auxiliary cameras •  Flexure control sensors: 4 CCDs of 1K x 1K, 15 μm pixels •  Acquisi`on sensors: 4 CCDs of 1K x 1K, 15 μm pixels

PI: Darren DePoy, Jennifer Marshall (Texas A&M University) Local Reps: Luke Schmidt

GMT

•  Instrument AO modes: NGS, LTAO and GLAO (small pixels, low read noise) •  Imager FoV – 22 x 22 arcsecond (pixel scale 5 mas for 4K x 4K; mosaic OK) •  Integral Field Spectrograph (Single 4K x 4K array)

-  Aspect raò 2:1 for improved sky subtracòn -  FoV: 4 x 2 arcseconds with 50 mas spaxels -  Spaxel scales: 50, 25, 12, 6 mas -  Spectral resoluòn: R ~ 5,000 and ~ 10,000 -  Wavelength range: 0.9 -‐ 2.4 μm

10/22/15 8

GMTIFS Near-‐IR Integral Field Spectrograph


PI: Rob Sharp (Australia Naònal University) Local Reps: Rob Sharp, Annino Vaccarella

GMT

•  Imager: Background limited AO modes -‐-‐ NGS, LTAO and GLAO •  Integral Field Spectrograph

-  Typically read-‐noise limited (esp at fine spaxel scale, high res, blue) -  Fixed spectral format (large array rather than mosaic) -  Fast Cameras (~15 μm pixels or larger)

•  On-‐Instrument wavefront sensors (2-‐3 detectors) -  High frame rate (or windowing) ~ 500-‐1000 Hz -  Low noise (< 1 e-‐) -  256 x 256 pixels or larger

10/22/15 9

GMTIFS Near-‐IR Integral Field Spectrogtaph



GMT

10

Cri`cal High priority Neutral Limited impact

Detector property Priority Chart for Imager, Spectrograph, and Wavefront Sensors Detector property Imager IFS WFS(s)

Quantum Efficiency

CDS read-‐noise

FS noise reducFon

Dark current

Dynamic range

Windowing

Cosmic ray sensi`vity

Frame rate

On-‐detector guide windows

Bias stability

Persistence

Pixel size (15 µm)

Array size, 4kx4k

Array size, 4x 2kx2k

Bad pixel frac`on

Bad region size

Linearity

Cross-‐talk/ghos`ng


GMT

Controller electronics •  Common system desired for Imager, IFS, wavefront sensors •  Cryogenic environment (cold preamps for long signal lines) •  Fast readout (many channels for simulataneous readout)

-  Imager: high contrast imaging -  IFS: many Fowler samples -  Wavefront sensors: `p/`lt correc`ons

•  Windowing for fast subregion sensing (e.g., quad-‐cell sensing, guiding)

10/22/15 11




GMT

10/22/15 12

GMTNIRS JHKLM High Resoluòn Spectrogtaph


PI: Dan Jaffe (University of Texas) Local Reps: Dan Jaffe, Phillip MacQueen

•  Simultaneous JHKLM high resoluòn spectra (low noise, high QE) -  1.1 -‐ 2.5 μm at R=50,000 -  3 -‐ 5.5 μm at R=100,000

•  Near diffracòn-‐limited: 65 mas slit •  103 to 104 gain over exis`ng spectrographs

-  Bigger telescope -  Berer detectors -  Silicon immersion gra`ngs

•  Fixed format (single arrays) -  Single 2K x 2K for each of JHK (3 total) -  Single 4K x 4K for each of LM (2 total)

•  Auxiliary sensors: slit viewer (2-‐5 μm & wavefront sensor 1.6 μm) -  1K x 1K and 256 x 256

GMT

13

Cri`cal High priority Neutral Limited impact

Detector Property JHK LM Slit Viewer WFS

Quantum Efficiency

CDS Read noise

FS noise reducFon

Dark Current

Dynamic Range

Windowing

Cosmic Ray SensiFvity

Frame Rate

On-‐detector guide windows

Bias Stability

Persistence

Pixel Size (15 µm)

Array Size 4kx4k

Bad Pixel Frac`on

Bad Region Size

Linearity

Cross-‐Talk/ghos`ng

Detector property Priority Chart for Imager, Spectrograph, and Wavefront Sensors

GMTNIRS JHKLM High Resolu`on Spectrogtaph

GMT

10/23/15 14

GMT Science Detector Summary -‐ Op`cal


Number Format Pixel Size μm

Minimum QE RN, e-‐

Need By, yrs

Comment

2* 9-‐10K 9-‐10 55% @ 340 2.5 Q4 2017 Blue op`mized

1 9-‐10K 9-‐10 34% @ 950 2.5 Q4 2017 Red op`mized

7* 4K x 4K 15 25% @ 340 2 Q2 2018 Or 5 x 6K, Blue op`mized

7* 4K x 4K 15 25% @ 1050 2 Q2 2018 Or, 5 x 6K, Red op`mized

8** 1K x 1K 15 75% (400-‐800) 3 Q4 2018 Acq & Flexure Control

* Includes spares (1) ** Includes spares (2) First 4 instruments only

GMT

10/23/15 15

GMT Science Detector Summary -‐ IR


Number Format Pixel Size μm

Minimum QE RN*, e-‐

Need By, yrs

Comment

6** 4K x 4K 15 High as Possible

<3.5, 5

2019 Cutoffs at 2.5 μm (2) and 5.5 μm (2)

4*** 2K x 2K 18 High as Possible

<3.5 2019 Cutoff at 2.5 μm

1 1K x 1K ~15 High as Possible

5 2019 Acquisi`on camera

* Read noise floor acer mul`-‐sampling techniques ** Includes spares (2) *** Includes spares (1) First 4 instruments only

GMT

10/22/15 16

GMT Wavefront Sensor Detector Summary


Number Min. Format

Pixel μm QE Readout

rate Read Noise

Needed by Comment

10 240x240 ≥ 16 ≥ 80% 650-‐800 nm

≥1000 Hz ≤ 0.5 e-‐ Q3 2017 CCD-‐220 ok, ≥360x360 ideal

14 780x780 ≥ 24 ≥ 90% 589 nm ≥ 700 Hz ≤ 3.0 e-‐ Q2 2018 E2V NGSD ✔

Number Min. Format

Pixel μm QE Readout

rate Read Noise

Needed by Comment

11 256x256 ≥ 16 ≥ 80% 1.1-‐2.3 µm ≥ 1000 Hz ≤ 2.0 e-‐ Q3 2017 Selex Saphira ✔

Visible Arrays

Infrared Arrays

Numbers include spares

GMT

•  Noise floor (acer many samples) •  QE •  Readout rate •  Persistence (in astronomical context) •  Dynamic range •  Bad regions (clumpy vs distributed) •  Pixel size (bigger is berer, usually) •  Pricing (lower is berer, always) – enables more instruments

across more astronomical facili`es

10/23/15 ELT Detector Workshop -‐ Pasadena 17

Other Driving parameters for IR Science Sensors

GMT

•  Must be capable of delivering the detector requirements.

•  General Criteria –  Available without development (e.g. commercial product) –  Low heat dissipa`on –  Configurable for all/most instruments –  Source code available –  Modern design (component availability) –  Compact

10/22/15 ELT Detector Workshop -‐ Pasadena 18

Controllers

detector$and$controller$requirements$for$$ …€¦ · · 2016-01-15•...

Documents