近赤外線撮像分光装置
IRIS(InfraRed Imager andSpectrograph)

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副鏡
第三鏡
高度角ベアリング
補償光学系

観測装置

観測装置
主鏡
ナスミス台

ナスミス台
基礎

方位角ベアリング

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IRIS Installedon the Bottom NFIRAOS PortIRIS Electronics

IRIS

IRIS Handling Cart
IRIS Cable Wrap

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IRIS Main Components

OIWFS
Mass estimate: 6150 kg
Instrument Rotator

4.2 m

Instrument Support Structure

Science Cryostat

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IRIS: First light facility-class instrument
behind NFIRAOS
Diffraction limited spectrograph andimager to work with NFIRAOS

OIWFS

Wavelength Range 0.81 - 2.4 μm
WFE < 40nm for fine scales

On-Instrument deployable wavefront
sensors (OIWFS)
Three sensors to measure tip/tilt, focus
and distortion across field.

“Wide-field” Imager
34”x34” field of view
0.004 “ per pixel
Parallel observations with IFS

Integral Field Spectrograph

ImagerIFS

R = 4000, 8000, 10000
Four Plate Scales: 0.004, 0.009, 0.025,0.050” per spaxel5Incoming F/15 Beam from NFIRAOS
2 Arcmin field diameter3 Pickoff Arms

ProbeArms

OIWFS

2 arcminThree OIWFS Arms patrol 2 arcminute
NFIRAOS output field.

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Incoming F/15 Beam from NFIRAOS
2 Arcmin field diameter
Imager16”.4x16”.43 Pickoff Arms

ProbeArms

OIWFS

1”.2Imager Collimator (TMA)

Imager2 arcminRotating Lyot Stop
ADC
5 Filter Wheels

34”

Imager with 4mas pixels~34 arcsec field.

Imager Camera (TMA)

Converging
F/17.19
Beam from Imager

Imager focal plane
34 arcseconds
4 x H4RG-10

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Incoming F/15 Beam from NFIRAOS
2 Arcmin field diameter
Imager16”.4x16”.4OIWFS

ProbeArms

3 Pickoff Arms

FixedLenslet Pickoff
and max field(1”.01x1”.15)
1”.2Imager Collimator (TMA)

Imager2 arcmin34”

Rotating Lyot Stop

IFS 4 mas or 9 mas modes

ADC
5 Filter Wheels

Imager Camera (TMA)

Converging
F/17.19
Beam from Imager

CommonGratings

Fixed
LensletMirrorImager focal plane
34 arcseconds
4 x H4RG-10

4mas R. I.
Doublet9mas R. I.
DoubletLenslet Reimaging Optics

Micropupil
Foca Planel
Plane

Lensl
et

CommonCamera(TMA)

LensletCollimator(TMA)

H4RG-15
Detector

8Incoming F/15 Beam from NFIRAOS
2 Arcmin field diameter
Imager16”.4x16”.4OIWFS

ProbeArms

3 Pickoff Arms

FixedLenslet Pickoff
and max field(1”.01x1”.15)
1”.2

Imager Collimator (TMA)

Imager2 arcmin34”

Rotating Lyot Stop

Slicer optics along parallel path

ADC
5 Filter Wheels

Imager Camera (TMA)

Slicer Reimaging
OpticsSlicer Assembly

SlicerCollimator(TMA)

25 mas R. I.
DoubletSelectable
SlicerMirrorConverging
F/17.19
Beam from Imager

50 mas R. I.
DoubletFixedLenslet
MirrorImager focal plane
34 arcseconds
4 x H4RG-10

4mas R. I.
DoubletCommon
Stage toselect scale

9mas R. I.
DoubletLenslet Reimaging Optics

Lensl
etArray

Micropupil
Foca PlanelPlane

Lensl
et

CommonGratings

LensletCollimator(TMA)

Selectable
PeriscopeMirror

CommonCamera(TMA)

H4RG-15
Detector

9Incoming F/15 Beam from NFIRAOS
2 Arcmin field diameter
Imager16”.4x16”.4

OIWFS

ProbeArms

3 Pickoff Arms

Deployed
Slicer Pickoff
and max field(4”.4x2”.25)

1”.2Imager Collimator (TMA)

Imager2 arcmin34”

Rotating Lyot Stop

50 mas mode

ADC
5 Filter Wheels
25 mas R. I.
DoubletSlicer Assembly

Imager Camera (TMA)

SlicerCollimator(TMA)

50 mas R. I.
DoubletSelectableSlicer
MirrorConverging
F/17.19
Beam from Imager
FixedLenslet
MirrorCommonStage toselect scale
4mas R. I.
DoubletLensl
etArray

CommonGratings

9mas R. I.
DoubletMicropupil
Foca Planel
Plane

Imager focal plane
34 arcseconds
4 x H4RG-10

Lenslet Reimaging Optics

Lensl
etLenslet
Collimator(TMA)

Selectable
Periscope
MirrorCommonCamera(TMA)

H4RG-15
Detector

10Incoming F/15 Beam from NFIRAOS
2 Arcmin field diameter
Imager16”.4x16”.4OIWFS

ProbeArms

3 Pickoff Arms

Deployed
Slicer Pickoff
and max field(4”.4x2”.25)

FixedLenslet Pickoff
and max field(1”.01x1”.15)
1”.2

Imager Collimator (TMA)

Imager2 arcmin34”

Rotating Lyot Stop
ADC
5 Filter Wheels

Imager Camera (TMA)

Slicer Reimaging
OpticsSlicer Assembly

Modes selected with 2 position stages.
All complex mechanisms and the mostcomplex optics are shared.
SlicerCollimator(TMA)

25 mas R. I.
DoubletSelectable
SlicerMirrorConverging
F/17.19Beam from Imager

50 mas R. I.
DoubletFixed
LensletMirrorImager focal plane
34 arcseconds
4 x H4RG-10

4mas R. I.
DoubletCommonStage toselect scale

9mas R. I.
DoubletLenslet Reimaging Optics

Lensl
et
Array

Micropupil
Foca Plane
l
Plane

Lensl
et

CommonGratings

LensletCollimator(TMA)

Selectable
Periscope
MirrorCommonCamera(TMA)

H4RG-15
Detector

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IRISの開発プロジェクト
段階的（フェーズ）な開発手法
2004-2006 実現可能性検討フェーズ
2006-2011 概念設計フェーズ
2012-2017 基本設計フェーズ
2018-2023? 詳細設計フェーズ、製造前準備フェーズ
2021年5-6月に中間審査会を実施

2024?-2027? 製造フェーズ（撮像系@ATC, NAOJ）
2028?-2030? 組合せ試験フェーズ（撮像系と分光系@カリフォルニア）2030?-2031? 組合せ試験フェーズ（IRISと補償光学＠ヴィクトリア）
2031?-2032? 組合せ試験フェーズ（IRISと望遠鏡）

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IRIS撮像系の仕様（開発課題）
Category
Wavefront Error[REQ-3-IRIS.IMG-2100]
Throughput

Requirement
High order WFE: < 36 nm after correction by two 60 x 60 element
deformable mirrors conjugated at 0 and 11.8 km above theground.
50% in the imaging mode including the detector QE.

[REQ-3-IRIS.IMG-2000, -2010, -2020]
Science Detector

60% in the IFS mode.
Four science detectors with 4096 x 4096 pixels each and pixel[REQ-3-IRIS.IMG-0220, -0230, -3220, - pitch of 10 µm.
Effective median dark current: < 0.020 e-/s.
3221, -3222, -3210, -3244]
Median CDS readout noise: < 12 e-.
Typical readout noise: < 5 e- after (120-second exposure using
multiple readouts and noise reduction algorithm)
Support up to one configurable on-detector guide window(ODGW) per Imager science detector.

Photometry[REQ-3-IRIS.IMG-2800]
Astrometry[REQ-3-IRIS.IMG-2600, 2610, 2620]

Support multiple sub-array readouts, when the on-detector guide
window is not in use.
< 0.3% to differential photometry for point sources with SNR =100 and not fainter than magnitude 24 (Vega) in J band over a 34x 34 arcsec field of view.
Relative astrometry error allocation to the Imager: 8.9 μas.
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NAOJにおけるIRIS撮像系開発
光学設計
機械設計・熱構造解析
機械系の試作・耐久試験
プロトタイプ光学系の評価

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光学設計
公差解析・迷光解析

IRIS撮像系検出器面での波面誤差
設置誤差±0.1mm±1 arcmin

IRISのフィルターによるゴースト解析例

フォーカス
像面傾斜
Col3鏡の位置補正
可変形鏡補正15

機械設計・熱構造解析

検出器マウント＋シャッター＋IFSピックオフの機械設計
38.95Hz87.03Hz114.62Hz

検出器マウントの固有振動数解析

152.18Hz

157.56Hz

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21Linear Stage機械系の試作・耐久試験
TMT.INS.TEC.21.116.REL01

Figure 4. (a) Finished Prototype. The motor and the ball screw for the linear stage are not installedrotational and translational motion are defined as shown. (b) Implementation of the hall e↵ect sensor andthe rotary stage reference position.

Page 6 of 12(PROTOTYPE.IMG) GEARED MOTOR DURABILITY TEST (SUMMARY REPORT) May(b)(a)

Rotary Stage
Motor
GEARED MOTOR PARTIALLY
USING UHMW-PE
GEAR
Reference Position(GEAREDMOTOR)DURABILITYTESTSensor (Linear)

Power Supplyfor Hall Effect Sensor

View Port / Feedthrough Port
Hall Effect Sensor

EST PURPOSE

Laser Autocollimator HeadMagnetCryostat

The opt-mechanical stages in the IRIS imager are required to be operable in a vacuum
and cryogenic temperature condition without any failure for 10 years. The geared motoris planned for use in the filter exchanger for the IRIS Imager, and is required to move
without any failure during its lifetime. Its durability test was conducted in a vacuum andCCW
cryogenic temperature condition in order to confirm thatthe geared motor satisfies theTMT.INS.TEC.21.116.REL01
lifetime requirement.

Temperature
Monitor / Controller+Page 8 of 12(PROTOTYPE.IMG) GEARED MOTOR DURABILITY TEST (SUMMARY REPORT) MayCW

20, 2021

Data Logger
Motion Controller,
Motor Driver andPower Supply

Reference Position
Sensor (Rotary)

EST SAMPLE

The geared motor consists of an original design gear box and a Phytron VSS52 stepper
motor. The gear box consists of two gears with a reduction ratio 2.5. The reduction ratio
between the VSS52 stepper motor and gear box is 6.25. Test sample specifications areLinearlisted in Table
1, Stageand Figure 1 shows the transparent figure of the 3D CAD model ofgeared motor.

Vacuum Pump

Table 1 – Test sample specifications

ron VSS52 stepper

Gear box reduction ratio
6.25

Cryopump

TMT.INS.TEC.21.116.REL01

Gear material
UHMW-PE and AISI304

P(PROTOTYPE.IMG) GEARED MOTOR DURABILITY TEST (SUMMARY REP

Cold stopの試作と性能試験

Figure 4. (a) Finished Prototype. The motor and the ball screw for the linear stage are not installed. Figure
DirectionsofTestequipment. Laser autocollimator is aligned to the top view port of the cryost
20, 5.
2021
Schematic diagram of the test equipment.
otational and translational motion are defined as shown. (b) Implementation of theFigure
hall2:e↵ectsensor and the magnet for
he rotary stage reference position.
Original designgear box

Power Supplyfor Hall Effect Sensor

Laser Autocollimator HeadUHMW-PE gear
Gear ratio is View
2.5 Port / Feedthrough Port
CryostatPhytron VSS52
stepper motor

torque meter and autocollimator. Fig. 5 shows the test equipment with autocollimator. A tempera
maintains the stage at 79 ⇠ 82 K except for the lifetime test that was carried out at 44 ⇠ 46 K.

As described in the tab. 1, the prototype will be evaluated in four configurations; wobbling e
accuracy in rotary motion, drive accuracy in linear motion and lifetime. The first configuration
Gear box
surement of wobbling error, one target mirror was located on the center of the rotary stage and wCryopump
wobble by a laser autocollimator, H350R-C050/F12 from Suruga Seiki co., ltd., through the view p

Temperature
Monitor / Controller
VSS52
stepper motor

Data Logger
Motion Controller,Motor Driver andPower Supply

Temperature
sensorVacuum Pump

Figure 3: Photograph of test equipment inside the cryostat.

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Filter wheelに使うgeared motorの耐久試験
Figure 2: Schematic diagram of the test equipment.

Figure 1: Transparent figure of the 3D CAD model of geared motor.

プロトタイプ光学系の評価
接着保持パッドの冷却時の影響

Figure 4 : Large mirror prototype with bonding pads.

TMT.INS.TEC.21.128.REL01(PROTOTYPE.IMG) MIRROR DEFORMATION MEASUREMENT AND MODELICRYOGENIC TEMPERATURE (SUMMARY REPORT)

TMT.INS.TEC.21.128.REL01

Page 13 of 32(PROTOTYPE.IMG) MIRROR DEFORMATION MEASUREMENT AND MODELING AT
CRYOGENIC TEMPERATURE (SUMMARY REPORT)May 26, 2021

TMT.INS.TEC.21.128.REL01

Page 13 of 32

Figure 6 : (Left) FE model of large substrate. (Right) Worst principal stress on substrate surface.
(PROTOTYPE.IMG) MIRROR DEFORMATION MEASUREMENT AND MODELING AT
Tensile stress is indicated as positive value.
RYOGENIC TEMPERATURE (SUMMARY REPORT)May 26, 2021

Figure 5 : Schematic and picture of test equipment for large substrate.

Figure 4 : Large mirror prototype with bonding pads.

The FE model of this prototype and worst principal stress on the substrate surface are shown in
Figure 6. The print-through effect is shown as the tensile stress on the substrate surface.
Correlation was carried out with the surface figure at 109 K, that was same temperature as theanalytical model was generated. Even though the small substrate model was correlated well, thislarge substrate model requires larger linear expansion. Finally, it was found that temperaturechange of -233 K gave equivalent thermal contraction for good prediction at 110 K as shown in
Figure 7, and simulation parameters are determined as shown in Table 2.

ミラーマウントモデルと変形予測

igure 6 : (Left) FE model of large substrate. (Right) Worst principal stress on substrate surface.

実測とモデルの比較

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Figure 7 : Measured and predicted surface figure of the large substrate at 110 K. Piston, tip/tilt, andpower are subtracted.

まとめ
これまでATCのおいて、設計・解析、プロトタイプ試験、を実施してきた。
IRISは詳細設計フェーズの途中。2021年5-6月に中間審査会を実施する。
詳細設計フェーズの後半は製造前準備フェーズになる。
IRISの組立、調整はATCで実施する。

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