1南極30m級テラヘルツ望遠鏡用電波カメラ
新田冬夢（筑波大学）

中井直正, 久野成夫, 永井誠, 村山洋佑, 服部将悟, Guangyuan Zhai, Pranshu Mandal (筑波大学)
関本裕太郎, 福嶋美津広, 三ツ井健司, 都築俊宏, 野口卓, 松尾宏, Agnes Dominjon, Wenlei Shan, 長谷部孝 (国立天文台)
関口繁之, 清水貴之 (東京大学)
瀬田益道（関西学院大学）
成瀬雅人 (埼玉大学)

2017/3/2：南極30m級テラヘルツ望遠鏡によるサイエンス発表概要
1. 南極10m望遠鏡搭載に向けた超伝導カメラ- カメラシステムの概要- 機械設計, 熱設計, 検出感度など

2. 多画素カメラ実現のkey technology- Microwave Kinetic Inductance Detector- レンズアレイ & ホーンアレイの開発- 極低温における反射防止コーティング- 野辺山45m望遠鏡搭載に向けたMKIDカメラ

3. 南極30m望遠鏡に向けて
4. まとめ2]tzhzzmz 90/150-GHz45 m

南極10m/30m鏡による広視野探査

mt
10 m3sh m✴ サブミリ波銀河のサーベイ観測t]・サブミリ波銀河は天空のどこにあるかわからないため、広視野観測が重要
h m
A.W. Blain et al. / Physics Reports 369 (2002) 111 – 176→南極望遠鏡＋電波カメラによるサーベイ観測

一素子による観測
電波カメラ：多素子
tm

Blain et al., 2002

南極テラヘルツ望遠鏡

14010+0253

cD galaxy14011+0253

mc

14009+0252

14010+0252

t

同時に観測が可能[

1. A comparison of deep optical and submm views of the sky. The background image is a 3-color optical image ofch cluster of galaxies Abell 1835 at the low=moderate redshift z = 0:25 (Smail et al., 1998b) taken using the 5-m
telescope, overlaid with the 14-arcsec resolution contours of a SCUBA 850-!m submm-wave image of the same(Ivison et al., 2000a). North is up and East to the left. The brightest SCUBA galaxies at (−45; −15), (65,0) and	 1 9=9 cD galaxy( ((Edge et al., 1999), all have clear radioz detections at a frequency of 1:4 GHz in−60),
and the central
es with higher spatial resolution than the SCUBA contours, obtained at the Very Large Array (VLA), supporting theiry. The bright SCUBA galaxy at (−45; −15) is associated with SMM J14011+0253, an interacting pair of galaxies
dshift z = 2:56 in the background of the cluster (Frayer et al., 1999). Spectacular fragmented structure appears in therly red component of this galaxy in Hubble Space Telescope (HST) images (Fig. 18).

© NAOJ© NAOJt ms
SCUBA-2 ts

詳細構造などはALMAを用いてフォローアップ観測

em 350-GHz
SCUBA-2 tz（相補的な役割）

南極10m望遠鏡：全体光学系
視野 : 1° @ F/6 focus

観測周波数→ 広域サーベイ観測・400 / 850 / 1300 GHz
副鏡(1.5 m)

designed by H. Imada

主鏡(10m)

観測装置：カメラシステム

ヘテロダイン受信機
望遠鏡焦点 (F/6)(dia. 1m)

冷却光学系
( T < 4K)
信号の伝送
ミラー or レンズ

電波カメラ(T < 0.2K)
集光系
信号の結合検出器

4カメラシステムの伝送光学系✴ ミラーによる反射系 (e.g. SCUBA-2)✴ レンズによる屈折系 (e.g. APEX-SZ)

Schwan et al., 2012

Holland et al., 2013
Zotefoamwindowmesh LP filter
stack
HDPE imaging
lens

LP shader

HDPE aperturelens

Horn array
280 mK stage
370 mK stage
Vespelstrut~3K stage
Pulse tube
cooler・視野1度で伝送するとミラーが巨大化

mirror to the detector arrays inside the cryostat. The beam envelope, shown
mes of the field-of-view for this projection of the optics. The arrow shows thenside the cryostat window, whilst mirrors N4 and N5 relay the optical beam
al plane units (FPUs).

ngthsm for5

・複数枚の組み合わせではアライメント調整が困難

・ミラーの配置を工夫することで冷却部をscientific potential of SCUBA-2 with a selection of early results.
コンパクトにできるG10 strut
4 K thermallink
Vacuum port

RF seal・屈折率が高いSi等のレンズを用いることで冷却部をコンパクトにできる

FIG. 11. Drawings showing two orthogonal sections of the APEX-SZ cryostat.
shown looking upward in the orientation used in the laboratory for work on th
can be removed for access to the focal plane and readout components. The alum
separates the optical and readout sections of the cryostat. Optical componentsorange, 380 mK in yellow, and the 4 K SQUID card housing and readout wirin
the cryostat is downward-looking, with the window pointed at a mirror on the・低温での反射防止対策が必要

10mカメラ：クライオスタット

6✴ 光学ー構造設計• 1°の視野を７モジュールに分割• 直径1 mのF/6焦点の先に配置• Siレンズ２枚を用いたシンプルな冷却光学系
8.3 Design of 850 GHz-bands Camera

1• 3000 pixels × 7モジュール = ~ 20000 pixelsが目標

4 K Si Lens
1 K Si Lens
(dia. = 400 mm) (dia. = 110 mm)

レンズアレイ

副鏡(1.5 m)
FoV : 10.65m

1.3THztelescopefocus@F/6
0.4THz0.85THz ホーンアレイ

Figure 8.8: A module design of 850-GHz band camera. (Left) Green part showed t
1.3THzsiliconsubstrate, and the bottom space is used for the carbon based absorber. (RigThe camera module with the 2977 pixel silicon lens array and the springs for fixing t
camera module and the lens array.

1.4m

0.85THz

0.4THz

主鏡(10m)望遠鏡焦点 (F/6)(dia. 1m)

dB. These parameters were summarized in chapter 5, Fig. 5.1.

1.3THzThe optimized parameters of the extension thickness, the gap height and the lediameter were L/R = 0.34, H/R = 0.604 and D = 2.4λ (λ = 353 µm; the wavelength

・ 7モジュール
HDPE window
図 2: 37 個のホーンが並んだホーンアレ
Figure 8.7 shows the simulated
beam patterns →of integrated
silicon lens arr
cold baffle~ 20000素子(dia. = diameter.
340 mm)850 GHz), respectively. In this simulation, the detector spacing was equivalent to the le10mカメラ：クライオスタット✴ 熱設計

Sekiguchi, D-thesis (Univ. of. Tokyo), 2017

• GM冷凍機1台で4 Kまで冷却

66

CHAPTER 3. WIDE FIELD COMPACT COLD

• 冷却能力：30 W＠40 K• 冷却能力：1.5 W＠1.5 K• 4 K以下は希釈冷凍機で0.1 Kまで冷却• Loading : 大気からのloadingが支配的
Stage

740K

4K

1K

0.1K

WmW

mW

uW

Shield

5.8

48

0.003

0.004

Conduction

3.4

320

0.31

0.3

280

Dissipation
Dilution

5500

Window

3.2

30

0.015

2.4

Total

17.4

1178

0.33

2.7

Capacity

30

1500

120

Margin

42%

21%

67%

86%

8

感度予想
✴ 10 m 望遠鏡
400 GHz
Lens

850 GHz
Lens

coupling
No. of module
2318005600
total beam
bandwidth [GHz]4085
10-18, ~ 0.3 K
10-18, ~ 0.3 K
detector sensitivity (NEP [W/Hz0.5], Trx
4.3 × 10-16
5.5 × 10-16
photon noise NEP [W/Hz0.5]
南極0.530m
テラヘルツ望遠鏡－諸元－
single beam NEFD [mJy・Hz]
41.8
43.2
3.6
Sensitivity (5σ, Tint = 1h) [mJy/beam] （2015.11.2） 3.48
Sensitivity
1.10
1.14
〇感度等 (5σ, Tint = 10h) [mJy/beam]
confusion limit [mJy/beam]~21.45(1) 連続波観測（注 1）

1300 GHz
Horn0.65m

2
9000
9010-18, ~ 0.3 K
1.4m
5.5 × 10-16
137.5
11.5
3.620.26✴ 30 m 望遠鏡（冬季 50%レベル＠新ドームふじ）感 度 (5σrms) （τ=積分時間）

周波数帯

角分素子数

Mapping speed[deg2 hr-1 mJy-2]

τ=60sec

1 hour10 hours

confusion

解能350GHz0.80mJy

0.10mJy

0.033mJy

0.22 mJy

7.1”

4800×2

44×2

400

1.12

0.15

0.046

0.20

6.2”

6300×2

22×2

650

1.68

0.22

0.069

0.052

3.8”

16600×3

9.8×3

850

2.45

0.32

0.10

0.011

2.9”

27000×2

4.4×2

1300

13.6

1.76

0.56

0.00035

1.9”10800×2

0.024×2 (注 3)

1500

46.4

5.99

1.89

0.000091.7”

14400×3

0.0022×3 (同)9Key Technologies
広視野観測を実現する多素子カメラを開発する✴ 重要となる開発技術(1) 多素子の効率的な読み出し、高い歩留まりを実現する検出器•

Microwave Kinetic Inductance Detector(2) 限られた焦点面に多素子を効率良く配置•

誘電体レンズアレイ／ホーンアレイの開発(3) 誘電体レンズを用いたコンパクトな冷却光学系•

屈折率の高い誘電体を利用する ( Si : ~ 3.4, HDPE ~ 1.5 )•低温でも使用可能な反射防止コーティングの開発•

0.1 Kへの冷却A promising new approach to the detection of photons is by using supercondu
10ing resonators [16]. The steady stream of incoming photons (with photon enerlarger than 2¢) breaks up Cooper pairs into unpaired excitations, changing th
respective densities, aÆecting the high frequency response of the superconduct
Day et al., Nature, 2003

✴ MKIDの動作原理

マイクロ波 (3 - 9GHz)

E・マイクロ波帯で動作する超伝導共振器
quasiparticles

C・入射光子によりクーパー対が解離→ 超伝導に由来する力学インダクタンスが変化ћ"#$!
→ 共振周波数 (f0) が変化→ f0の変化量 = 入射光子の強度に対応
!

N(E)

C
Lm+Lk

transmission (dB)Microwave Kinetic Inductance Detector (MKID)

Cooper pairs

超伝導ギャップエネルギー以上の光子を検出

0-10-20-30-10!"0/"0-50

51/2
δf105 ("-"f0)/"(LC)0500 umex ) Al : > 90 GHz

入射前

入射後

金：超伝導体(Al)黒：シリコン基板

Figure 1.2: Left: A photon with energy ~! is absorbed and breaks a Cooper p✴ MKIDの利点 creating quasiparticle excitations on top of the thermal background. Middle: Tvariation in the Cooper pair and quasiparticle densities leads to a change in the kine
・共振器の長さをわずかに変えることで共振周波数が変化し、周波数方向に多重化が可能
inductance. Right: Subsequently
the resonance frequency of the circuit shifts.
・1つのアンプで1000素子程度を読み出せる→ 他の超伝導検出器にはない特徴
MKID246

MKID344

S21 [dB]

MKID1

マイクロ波

MKID1 MKID2

MKID3424038

低雑音アンプ366.376

6.378

6.38

6.382 6.384 6.386
Frequency [GHz]

6.388

6.39

11

Microwave Kinetic Inductance Detector (MKID)Power Response at 220 GHz

The external radiation
4 power at 220 GHz was controlled by gate voltage of a poweret al.,Amp
Nature,plifier, which was shown in the right panel of Fig.Day
4.7. Powerの Gate2003
Voltage✴ 高感度検出器御することで 0.3uW から 500uW までパワーを変化させた。
10-2

各 KID のパワーレスポンスを測定

感度を表す指標 ：雑音等価電力 (NEP)

10-15

大気ゆらぎによる制限
雑音帯域1 Hzで信号対雑音比 (S/N) が1となる入射電力
The resonance frequencies of MKIDs are measured from the S21 spectrum take

雑音を温度換算： Trx ~ 1 [K]10-16

NEP (W Hz-0.5)

・electrical NEP : 6 × 10-18 [W/Hz1/2]

τqp (sec)

10-3

a vector network analyzer as shown in the left panel of Fig. 4.9. The shift of reson
10-4

frequency and the change of the amplitude of resonances correspond to detected pin an MKID. The detected power is recorded as a function of the position of10the ext-17

τ qp (measured)
source, which is controlled by a XY θ scanner in frontτqpof(theory)the vacuum window oelectrical NEP (amplitude)
10-5

高感度検出のためには、T < 0.2 Kが必要

cryostat. The incident power to the MKID is adjusted by the gate voltage of the p
0.1

0.15

0.2

0.25

0.3

amplifier. The beampatternwascalculated from the obtained data.
Naruseet al.,
2013

0.35

T (K)

Fig. 2 Measured ⌧qp (blue open circles) and electrical NEP (red filled
ミリ波に対する応答例circles) of a MKID made of epitaxially-formed
Al film as function of tem-1
0perature. The thoretical curve of ⌧qp [29] is also shown as dot-line. datafit✴ 高いダイナミックレンジ

Frequency Shift [kHz]-2Magnitude [dB]-3-20-40

300
K/kB T [29] (dashed line inlowering
temperature
as⌧
/e-60
qp・ダイナミックレンジが高い
Fig. 2), there is a saturation
below 230 mK (⇠ T c /5-5-80 of ⌧qp77
K: > 105
withT
representing
criticaltemperatureof superconducc-6-100tor). This characteristic is quite universal for MKID made of-7~40toKexplain
any material, and there -120
are several models trying
・300 K loadでもサチュレーションしない-8-140the saturation limits the sensitivit [20],
[24],
[30]
Although
5.526
5.528
5.53
5.532
5.534
5.536
5.5380100200300400500→ hot loadを用いた強度較正が可能
Frequency[GHz]220 GHz Input
Power[µW]even
ity of MKID, it can reach the fundamental
noiselimit
the saturation [21], [31]. Therefore, the requirement for
入力パワーを増加with= 共振周波数がシフト-4Frequency Shift [kHz]0dataf(x)-10-20-30-40-50-60

050

100150Input Power [µW]200

12Kiuchi et al., IEEE TST, 2015
MKIDの読み出し also
developed by M. Nagai
・ 各素子を同時に, 独立して読み出しを行うことが可能
263.5 LO の周波数掃引第 3 章 多素子読み出し回路 (FSP4000) を用いた MKID の読み出し

25・ 1 GHz の帯域内に周波数 comb 信号を発生し変調・復調することにより、3.6 FSP による読み出しセットアップ

高周波数分解能・広帯域測定が可能

本章で述べた FSP の機能を用いて, MKID の読み出しを行うための基本的なセットアップは図 3.8 の通りである.

FSP 搭載の DAC から出力したコムは, LO からの CW 信号と周波数ミクサにより, 図中の RF にアップコンバートさ

3.2 FSP4000 の機能

19

図 3.7: 共振周波数に対するコムの設定
図 3.8: FSP を用いた読み出しセットアップ

れる. ハイパスフィルタにより低周波成分を除いた後 *6, MKID に入力する. その後ダウンコンバートを行い, ローパスフィルタを通した後 *7, ADC に入力, FSP による集録が行われる.

FSP により 4 素子を同時測定したデータを図 3.9 に示す. この測定では, 各素子 1 MHz の帯域を 64 チャンネルのスペクトル, サンプリングレート 1024 Hz で集録している.

3.7

本章のまとめ本章では, 多素子読み出し回路の性能を提示, 共振をトレース, 且つ多素子を同時に読みだせることを確認し,• 複数の素子を 1024 Hz のサンプリングレートで同時に読みだす.
• LO の周波数掃引により, 周波数分解能を自由に調整, 正確な共振周波数の決定が可能という MKID カメラでの観測に用いるための条件を満たせることを示した.

*6 ミクサによるアップコンバートを行う際, fcomb − fLO の信号も発生するため, ハイパスフィルタにより取り除く*7 *6 と同様

Nitta et al., J. Low Temp. Phys., 2014 13
Okada, M-thesis, 2015

Lens-coupled MKID

Chapter 7. Development of a Wide-Field Camera System for M✴ 高い集積度を持つレンズアレイ

134→ 望遠鏡焦点面の大きさには制限があるため、集積度の向上が重要
レンズ内の電界強度608画素220-GHzカメラ

レンズアレイ(dia. 1.6 mm)

Z

レンズ表面X平面アンテナ.2 Height Dependence of Small-Diameter Silicon Lens

・電界が集中するのはレンズ上部→レンズの上部のみを使用
有効部分

3.5. DESIGNOF WIDE FOV CRYOGENIC OPTICS FOR ANTARC
エンドミルによる直接加工(国立天文台ATC)

50

cuttingmachine
Fig 2.㻌 The ultra-precision
Figure
7.21:
A photograph of 608-pixel MKID camera with AR-coated sil

46

83 machine (Toshiba Machine ULG-300)(a) A photograph of the ultra-precision cutting(b) A photograph of the high speed spindle(Toshiba Machine ABC-20M)
and approximately
1 mm-size silicon-carbide-grains act as scattering suS21 [dB]Y~ 50 mm

42(c) A photograph when cutting
the honeycomb
frequency
rangegroovefrom millimeter-wave to terahertz.

A large nested baffle (left of Fig. 7.20) mounted on 4 K consists of co38

four reflective plates (Sekiguchi, 2014). The shape of reflective plates is sp

and its curvature radius is 80 mm. The length and diameter of the ne34
30

approximately
T(stage)=0.1120Kmm and 155 mm, respectively. The carbon based bla
44

applied to the back side of the reflective plates. Therefore, the front side a

4.5 plates act 5as reflector and5.5absorber, respectively.
6reflective

6.5Frequency [GHz]・0.4 / 0.85 THz で検討（レンズ直径〜1mm）to the MKIDs. In a future experiment the amount of straylight can be reduced by a better design of the sample box14
and using intermediate optics to improve the coupling efficiency from the source to the lens-antenna. Here we takeadvantage of the fact that the background signal is common
for all channels and use it first to calibrate the responsivity
variation between the MKIDs. Then we flatten the spectra bynormalizing each spectrum on the background signal. As aresult, we obtain a spectrum for each channel which has a

30 mテラヘルツ望遠鏡に向けて032601-2

Endo et al.

14Appl. Phys. Lett. 103, 032601 (2013)✴ MKIDを用いた面分光測定
・ MKID + narrow band filterを用いた

on-chip上での分光・ FTS等に比べてコンパクト・ 焦点面に搭載しているイメージング用のカメラと交換
・ R = f0/Δf ~ 1000

FIG. 1. (a) 3-port network model of a single submillimeter wave filter. kSM and kMW indicate the submillimeter wave and microwave wavelengths, respectively, which are reduced by the dielectric medium and also by the kinetic inductance of the superconductor. (b)FIG.
Networkmodel of phasea singlechannel,
which
is a behind consecutive filters
2. Normalized
responseof theMKIDs
combination of a submillimeter wave filter and a microwave resonator (MKID). The channel is capacitively coupled
to theofsignal
lineGHz.
on theend andin the range
600–700
Allfilter
5 curves
havetobeen normalized so that thethe readout line on the MKID end. (c) Micrograph of a small area on the filter bank chip. The image captures theaverageantennabackgroundand 5 channelsof thefilter banknearresponse
outsidethe filter
band is equal to unity, andest to the antenna. (d) Double-slot antenna etched into the NbTiN ground plane. The horizontal line is the signal
MSL
whichisconnectedtothefilterbank.
each curve has been given an offset for clarity. The stepped plots indicate(e) Submillimeter wave MSL filter, shaped like the character U. (f), (g) Sections of the MSL-MKID. (h), (i) Microwave
couplerthe MKID
reading
the measured
data, ofwhere
the solidforcurves
are out
Lorentzian fits to each set ofthe response. (j) Block diagram of the experimental setup.
data. (Inset) Example of spectra for two channels before dividing out the~3m✴ 30m望遠鏡に向けた電波カメラ

At f ¼ f0 , the transmission reaches its maximum of

・10 mテラヘルツ望遠鏡の焦点面- F/6 focus (dia. ~ 1m)

jS31 j2 ¼

2Q2i
ðQc þ 2Qi Þ2:- 同じF値の場合、焦点面面積は約3 m

10m望遠鏡で開発したクライオスタットを更にモジュール化(3)

The configuration of a single spectroscopic channel,
which is a combination of a filter and an MKID detector, ispresented in Fig. 1(b). At the top of the diagram is the submillimeter wave filter that we discussed in the previous paragraph. The signal line and the filters are made of NbTiN,
which typically has a gap frequency of %1.1 THz (Ref. 9)
and should therefore behave as a superconductor for a signalof 600–700 GHz. Now P3 is connected to the center of an
MKID which is open-ended on both sides. The MKID isitself a half wave resonator for a microwave readout tone in
the range of 6–7 GHz and is capacitively coupled on one ofits open ends to a through-line made of a NbTiN microstrip
line for probing the microwave response. For the prototype
device we have chosen Ta as the material for the top wire,
while the ground plane is the same NbTiN film continuingfrom the filter. Inferring from the measured Tc of the Ta filmof 4.4 K and assuming the BCS relation of 2D ¼ 3:5kB Tc ,the gap frequency of the Ta film is %320 GHz, and therefore
forms a lossy stripline for the signal at 600–700 GHz.

・30 mテラヘルツ望遠鏡の焦点面-Endo et al., APL, 103, 032601, 2013

common stray light component. The vertical axis shows the phase responseof the MKIDs in units of milliradians. One of the spectra (solid blue curve)a filter with a frequency within the measured band at 614 GHz, whereetched using electron has
beamlithography and dry etching.
the other one (dashed black curve) has, by design, a filter centered at
Then a 1lm-thick layer 759of GHz,
amorphousdepositedusing band. The spectrum ofx isthe
which is SiN
outsidemeasured frequency
the614GHz
channelafter
dividing
outthestrayat
light component is included
plasma-enhanced chemical vapour deposition (PECVD)
also in the main figure, as indicated by the arrows.
&300 C. We subsequently deposit a 200 nm-thick layer of Ta
on top of a 7.5 nm-thickseedlayer asofindicatedNb, followed
by Reuse of AIP content isThis article iscopyrighted
in the article.
electron-beam lithography and dry etching to define the 133.40.220.81 On: W
MKIDs. Finally, we deposit 85 nm of NbTiN and define thesignal line, the filters, the readout through line, and via-lessbonding pads to connect to the sample box. All wires have awidth of 3 lm, except at the feed point of the antenna, where
it decreases to 1 lm. The top NbTiN layer has a resistivity of
160 lX cm and a superconducting transition temperature ofTc ¼ 14.2 K.
The microwave losses of the transmission lines havebeen measured using a vector network analyzer while thechip was cooled to 350 mK using a 3He sorption cooler. All30 Ta/SiNx /NbTiN microstrip MKIDs have a resonance frequency in the range of 6–7 GHz as designed and have anunloaded quality factor of Qi ¼ 1–5 '105 . We have also fabricated a single microwave resonator with a NbTiN wire tomeasure the microwave losses of the NbTiN/SiNx /NbTiN
microstrip line. This resonator showed an unloaded quality
factor of 2:5 ' 105 . These values show that the SiNx dielectric has a microwave loss in the range of tan d ¼ 2 ( 10まとめ
1. 南極10m望遠鏡搭載に向けた超伝導カメラの開発- Microwave Kinetic Inductance Detector- シリコンレンズを持ちた屈折式光学系- レンズアレイ & ホーンアレイの開発- 極低温における反射防止コーティング- 野辺山45m望遠鏡搭載に向けたMKIDカメラ

2. 南極30m望遠鏡に向けて- MKID + on-chip filterを用いた面分光観測- 10m望遠鏡用に開発したカメラを更にモジュール化15