GroundBIRD
Observation of CMB polarization
with wide-sky survey and fast rotation scanningShunsuke Honda (Astro. Obs.)

2022/06/24

1

INDEX
CMB basics
GroundBIRD overview
Sensitivity calculation for one cosmological parameter
MKID developments
Readout developments
Observation results

2022/06/24

2

Shunsuke Honda (U Tsukuba)

CMB Polarimeter :GroundBIRD
Shunsuke Honda

2022/07/01

5

6

cosmic microwave backgrounddiscovered by Penzias and Wilson

particle data group 2002

taken from wikipedia
taken from https://astronomy.com/magazine/2018/07/decoding-the-cosmic-microwave-background2022/06/24

almost perfect/uniform
blackbody at 2.7 K !

Shunsuke Honda (U Tsukuba)

7Anisotropy
deviation from TCMB

+ after dipole subtraction

linear scale btw -3 and +3 mK

linear scale btw -100 and +100 μK“Extrinsic” dipole
due to our motion

Planck intermediate results LVII. Joint Planck LFI and HFI data processing, A&A 643, A42 (2020)

CMB anisotropy expanded with spherical harmonics
ΔT(n)̂ =

∞

ℓ

∑ ∑

ℓ=0 m=−ℓaℓmYℓm(n)̂
particle data group 2020

power spectrum
ℓ
1
Cℓ =
aℓma*
ℓm
∑
2ℓ + 1 m=−ℓ2022/06/24

Shunsuke Honda (U Tsukuba)

8Polarization

maps taken from “A&A Volume 641, September 2020, Planck 2018 results”

CMB polarization power = O(0.1–1) μK
linear polarization measured with two orthogonal parameters, Q and U

color: intensity
rods: pol. ampl. and direc.

(Ex-Ey)2/2

-160

Ey2

(Ex+Ey)2/2

U = (Ex-Ey)2/2 - (Ex+Ey)2/2 = 2ExEy

2022/06/24

Q

160 µK
PSfrag replacements

U

0.41 µK

Ex2

Q = Ex2 - Ey2

Shunsuke Honda (U Tsukuba)

9

E and B modes
Q(n)̂ ± iU(n)̂ =

∞

ℓ

∑ ∑

ℓ=0 m=−ℓa±2,ℓm ±2Yℓm(n)̂

E mode (even parity)
aE,ℓm = − (a+2,ℓm + a−2,ℓm) /2

B mode (odd parity)
aB,ℓm = i (a+2,ℓm − a−2,ℓm) /2

converted to real space →converted to real space →combination of electron scatteringand temperature isotropy

gravitational lensing: ℓ~O(100-1000)→ leakage from E to B

hotquadrupole
anisotropy
cold

e-

Thomson scattering

W. Hu and T. Okamoto 2002 ApJ 574 566

epolarizationaligned with “hot”

primordial gravitational wave: ℓ<1002022/06/24

primordial gravitational wave: ℓ<100
Shunsuke Honda (U Tsukuba)

10

E and B modes∞ℓAngular scale

0.2m
Q(n)̂ ± iU(n)̂ =a
Y (n)̂
∑ ∑ ±2,ℓm ±2 ℓ10ℓ=0 m=−ℓ
90±

1±

±

0.1±

0.05±

3

CMB- TT

Planck

aE,ℓm = − (a+2,ℓm + a−2,ℓm) /2

10

ℓ

WMAP
ACT
SPT
ACTPol
SPTpolPOLARBEAR
BICEP2/Keck
BICEP2/Keck/
WMAP/Planck

aB,ℓm = i (a+2,ℓm − a−2,ℓm) /2

2

101

D` [µK2]

1
Cℓ =
aℓma*
ℓm
∑
2ℓ + 1 m=−ℓ90Angular scale
±

0.05±

CMB- TT

PlanckWMAP
ACTSPTACTPol
SPTpolPOLARBEAR
BICEP2/Keck
BICEP2/Keck/
WMAP/Planck

102
10°2
101

D`TE [µK2] D [µK2]0.1±

https://www.cosmos.esa.int/web/planck/picture-gallery

100
103

cosmological parameters

0.2±

1

CMB- EE

10°1

10°3

CMB- BB

CMB- EE

expansion rate: H0reionization depth: τ
2022/06/24]

initial condition:
AS, nS107[`(` + 1)]2C`¡¡/2º`densities: Ωbh2, Ωch2

±

1000
10

0

°100
10°1
°200
1.5
°2
101.0

CMB- BB

0.5
0.0
10°3
°0.5
100

2

150

500

1000

Multipole `

2000

3000

4000

Shunsuke Honda (U Tsukuba)

11

Atmosphere and foregroundTo measure CMB precisely, foreground and atmosphericcomponents should be carefully removed from the data.
https://www.cosmos.esa.int/web/planck/picture-gallery
PdCommPsCommsynchroton

Atmosphere contributions→ non-pol. radiationsµKRJ at 30 GHz

10

dust
300

2

10

70 100 143 217

353

10

m

Su

1

n

ro

ot

hr

nc

st

du
mal

re

fo
r

The

0

fsky = 0.52
fsky = 0.27

CMB

10

-1

10

fsky = 0.83

ds

un

o
gr

→ large scale observation is difficult
for the ground experiments…

44

300

evaluate freq. scaling factor
for each componentSy

No realistic sensitivity for intensity at all
Could not be affected so much in pol.
if time scale <10sec

Rms polarization amplitude [µK]30

uKRJ at 353 GHz

3

10

30

100

300

1000

Frequency [GHz]https://www.cosmos.esa.int/web/planck/picture-gallery→ multiple observational freq. bands are essential
2022/06/24

Shunsuke Honda (U Tsukuba)

12GroundBIRD (GB)Compact telescope for large scale CMB-polarization observations
Installed at the observatory in 2019 and achieved the first light with moon
beam size ~0.5° at 145GHz

Selectable elevation from 60° to 90°
Superconducting detector “MKIDs”
faster time response than sampling rate of 1ksps
two observational frequency bands = 145GHz and 220GHz

Continuous azimuth rotation at 20RPM
mitigating effects of atmospheric fluctuation→ Cutting out any 1/f on timescales longer than 3 seconds
70 100 143 217

353

10

2

44

tro

o
hr

nc
Sy

10

1

n
m
Su

ust

r
fo

ld
rma

ro
eg

The

0

fsky = 0.27

CMB

10

-1

10

fsky = 0.83
fsky = 0.52

dsun

Rms polarization amplitude [µK]

30

10

30

100

300

1000

Frequency [GHz] https://www.cosmos.esa.int/web/planck/picture-gallery

2022/06/24

Shunsuke Honda (U Tsukuba)

!ℓ [$%" ]2022/06/24
10-4

10-5

10-5

Unc. of foreground
0.010
2 bands…
multipoleSA,SO,
GB
`

10

inflation theory evaluation

10-3

10
100

Angular scale

B-mode at large angular scaleτ = 0.054→ constraint
on
“r”
0.007
10˚

10
tensor-to-scalar
ratio
-2

10-4

100

9 bands

1˚

E mode2 bands

9 bands

1000

0.009

1000

0.010

0.009

B modeUnc. of foreground600$m# [eV]10-2

sha1_base64="NFC3HezNlusXKsEK/meGoxIs5Ig=">AAACZ3ichVHLSsNAFD2Nr1ofrQpScKMWxVWZVkFxVXTjsg/7gColiaMNnSYhSQu1+AMu3FZwpSAifoYbf8BFP6G4VHDjwps0IFrUO8zMmTP33Dkzo5hCsx3GugFpaHhkdCw4HpqYnJoOR2ZmC7bRsFSeVw1hWCVFtrnQdJ53NEfwkmlxua4IXlRqu+5+scktWzP0fadl8sO6fKJrx5oqOy51wIWoRGIszrxYHAQJH8TgR9qI3OEARzCgooE6OHQ4hAVk2NTKSIDBJO4QbeIsQpq3z3GGEGkblMUpQya2RuMJrco+q9ParWl7apVOEdQtUi5ihT2ze/bKntgD67GPX2u1vRqulxbNSl/LzUr4PJp7/1dVp9lB9Uv1p2cHx9jyvGrk3fQY9xZqX9887bzmtrMr7VV2w17I/zXrske6gd58U28zPHuFEH1A4udzD4JCMp5YjyczG7HUjv8VQSxgGWv03ptIYQ9p5OncKi7QwWWgJ4WleSnaT5UCvmYO30Ja+gSsN4s7</latexit>

E modelatexitτ = 0.054
0.007

1˚

<

10-3

!ℓ [µK "]10˚!ℓ [µK "]SA,SO, …
Angular scale!ℓ [µK "]sha1_base64="NFC3HezNlusXKsEK/meGoxIs5Ig=">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</latexit>

latexit<!ℓ [$%" ]Neutrino mass from CMB…? 0.09
degeneracy in lensing BB: Σmν 0.06τ

B mode$m# [eV]!ℓ [µK "]13

Science Targets

High sensitivity measurements of large angular-scale polarizations
GB
no constrai
τ = 0.054
0.007 0.12

!m! = 0.06 eV

空間周波数 `τ = 0.054

1000
1400
!m! = 0.06 eV

0.03
0

0

σ

CMB-S4 +

0.044

0.03
0.044

0.

#

!m! = 0.12 eV

no constrai

0.007 0.12
0.09

0.06

σ

CMB-S4 +0.

!m! = 0.12 eV
Shunsuke Honda (U Tsukuba)#

14

Science Targets

High sensitivity measurements of large angular-scale polarizations
E-mode at large angular scale→ constraint on “τ”
optical depth of reionization

neutrino mass measurement"m! [eV]

0.12 No constraints
0.09
0.06
0.03
0

B-mode at large angular scale→ constraint on “r”

σ(τ) = 0.01

unfolding correlations: Σmν τCMB-S4 + DESI simulation

0.044

0.060

!

0.076

tensor-to-scalar ratio
inflation theory evaluation

2022/06/24

τ by space missions getting smaller…
(depending on FG systematics)→ good to validate this with other observations
Shunsuke Honda (U Tsukuba)

15

Telescope property: cryogenics

Pulse tube cooler
with three thermal shields
300K
40K
4K
Cold optics withcross-Dragone mirror(FOV=±10° )Sorption cooler(3 stages with He10)
Detector cooled down to 250mK
Focal plane2022/06/24

Shunsuke Honda (U Tsukuba)

16

Telescope property: rotary joint
PTC

Upper part
rotates at 20RPM

PTC
heliumPTCEëĠA×ņŎŲŅĤĵŰŊŲřķŲņ
ņŎŲŅj¹2

ĠA×ņŎŲŅĤĵŰŊŲřķŲņ
heliumheliumA×ņŎŲŅ2ņŎŲŅj¹2

ŲŅ2

Φ~200

HeşŲņ22222↑2HeşŲņ
↓2HeşŲņ22222↑2HeşŲņ
↓2

rotationtableŜūĶţļņ(ŮŲŊūŲŅũ

HeşŲņò#2

A×ņŎŲŅ2#HeşŲņ2ŜūĶţļņ(16C)HeşŲņò#2

2

helium!ģHeļņıµ.

ıµ.






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2022/06/24



electric power
rotary connectorê³ 2ŮŲŊūŲŁœľŊŲ

















compressor






Lower part ŮŲŊūŲŅũĵŰŐrotary joint
fixed to#HeşŲņ2
the groundRotary.Joint.



.

A×ņŎŲ

ê³ 2
ŮŲŊūŲŁ

Eë

groundShunsuke Honda (U Tsukuba)

17

Telescope property: cold mirror and focal plane
300K vacmirror design

40K-LP
sorption

7 wafers on the focal plane
23pix. for each wafer

4K-LP

138 pix. with 145GHz for CMB
23 pix. with 220GHz for dust
145G

350mK-LP

145G

220G

145G

Kevlar small jigs for thermal isolation

145G
145G

145G

spec. of optical filters at focal plane

Thermal isolation well achievedby tensions of Kevlar wires
temp. 1

thermal conductivity~ 0.0064 [mW/K]

temp. 22022/06/24

145G

100

220G

150
200
250
repairingfrequency [GHz]300

Shunsuke Honda (U Tsukuba)

Observation at Teide Mountain18

Teide Observatory at 2400m altitude(GB)

GroundBIRD

2022/06/24

Control house

QUIJOTE

Shunsuke Honda (U Tsukuba)

19

Telescope Installation and First Light

S.Honda et al. (2020) Proc. SPIE

Deployment at Teide Observatory (TO) - 2400m alt. in Tenerife=

Demonstration ofhigh-speed-rotation
scan at 20RPM

Telescope Mount

GB Cryostat

First light (Moon) Sep. 2019
→ Confirmation of optical design
Demonstration of large-sky
coverage→ End-to-end function test

Integration time [ms] indicating how much data wastaken at each sky pixel. Test MKID array took data
during several days with 120º/sec continuous rotation.

Moon image obtainedby test MKID array

Integration time for eachsky pix. after observation
120º/sec azimuth spinning
Elevation angle fixed at 70º
Phase data of 4 pixels plotted* Test MKID for the first-light campaign was borrowed from SRON.

2022/06/24

Shunsuke Honda (U Tsukuba)

20

GroundBIRD and QUIJOTEQUIJOTE
continous azimuth rotation at 2-10 RPM
elevation up to 30°
installed just next to GB
low-frequency bands covered
with two telescopes:• 11, 13, 17, 19 GHz with QJ1• 30, 40 GHz with QJ2QJ2QUIJOTE GB

n
ro
ot
hr
nc
Sy

GroundBIRD + QUIJOTE combined observation= eight freq. bands 10 - 220GHz

QJ1→ widest frequency analysis to accurately
remove foregrounds + extract CMB

2022/06/24

CMB

st
u
D

Shunsuke Honda (U Tsukuba)

21

Forecast of τ with large scale E-mode

K. Lee et al 2021 ApJ 915 88

CMB, synchrotron, and dust simulated maps with cosmological parameters given by Planck
40-50% of full sky

one shot1 sec.

Earth rotation→ 22.8% of full sky in total

Three year observations in GB+QJ
Artificial noises

Result+ 1/f noise to GB not QJ(knee at 0.1Hz)

GroundBIRD + QUIJOTE combined analysis
can provide τ value with similar unc. of Planck.
2022/06/24

Shunsuke Honda (U Tsukuba)

22

Summary
The cosmic Microwave Background is the key to understanding our universe.
To evaluate the anisotropy, the power spectrum is calculated.
GroundBIRD observes CMB polarization at a large angular scale with highspeed rotation at 20RPM- Unique technologies: high-speed rotation scanning at 120°/sec with thecustom rotary joint- Installation at Teide observatory in 2019 → First light achieved- The τ sensitivity is estimated with GB+QJ combined analysis

2022/06/24

Shunsuke Honda (U Tsukuba)

MKID and DAQ system
in GroundBIRD
Shunsuke Honda

2022/07/01

23

24

MKID
antenna

amplitude[dB]
Amplitude [dB]

Al

Transmittance of readout signal

δff0 [Hz]Si

MKID
having resonant frequency fr(determined by the resonator length)

phase[rad]Phase [rad]

2π

δθ

0

NbTiN

f0 [Hz]feedline
2022/06/24

Shunsuke Honda (U Tsukuba)

25

MKID and readout method
antenna

O(GHz)
readout
waves

…

MKID
MKID responses at different fr
can be read out via single feed line…

S21: transmittance of wave

MKIDはGHz帯域の読み出し信号に
光応答情報を載せる→MKIDの共振周波数の信号を同時に入力。
その時系列データで検出器応答を測定。
(図中 )9 different frequency waves injected
then, readout responsess simultaneously
2022/06/24

Shunsuke Honda (U Tsukuba)

26

Developments for GroundBIRD MKIDNew MKID sensor for GroundBIRD developed with SRON
Hybrid MKID with Al-NbTiN for 150GHz band
Systematic method established to maximize the sensitivity with simulations.

noise power spectrum [W/√Hz]

Typical MKID power spectrum

2022/06/24

Photon noise limited should be
btw 0.3 — 1k Hz for GroundBIRD
0.3Hz
1kHz

Optimization for
TLS noise suppression

fn

photon noise(G-R noise, BLIP noise)

1/

oi

se

(T

LS

no

ise

)

thermal noisefrom cold amp.

frequency [Hz]Shunsuke Honda (U Tsukuba)

27

Optimization of TLS noise in Hybrid-MKID

y
r
a

n
i
im

l
e
r
P

ASJ 2022.03 H. Kutsuma
2022/06/24

Shunsuke Honda (U Tsukuba)

28

GB-KID for science observation

Proto-type sensor chip
23 pixels for observations+ 4 pixels without lenslets
antenna and lenslet for 150GHz
Based on TLS suppressed design

Installed to GroundBIRD
in cooling run of 2021.07
SRON MKID: Al-NbTiN MKID 23pix
for tests of our science observations
4/27 pixels with lenslets for performance checks

In the readout, we need to use 32 tones
for MKID + noise measurements.

2022/06/24

Shunsuke Honda (U Tsukuba)

29

GroundBIRD readout system
IQ signal

up to ±100MHz

IQ mixer

GB Readout box

MLIQ-0218, marki

Simple readout system
Generating/receiving RF signals
32 tones demonstrated

RF signal
RF to CRYO.

FPGAKCU105+ RHEA

amp.
amp.

LPF
div.

LO signal

KIDs

2 - 8 GHz

Synthesizer
FSL-0010, NI

cold
amp.

RF from CRYO.

RHEA

IQ mixer

amp.

Synthesizer

KCU105

FSL-0010, NI

div.
2022/06/24

Trigger function implemented
Tones within LO ± 100MHz

amp.

LPF

MLIQ-0218, marki→ could be 128 tones

readout box

Four readout box installed!
Shunsuke Honda (U Tsukuba)

30

GroundBIRD DAQ Board
FPGA evaluation board: KCU105 from XILINX
Analog board for ADC/DAC: RHEA (custom-ordered board)• Tuned for GroundBIRD experimentboard
max. multiplexing
sampling rate
sent to PC
powerdata rate
communication
ADC Spec.
DAC Spec.
sampling rate on
ADC/DACband width2022/06/24

KCU105 + RHEA
128
1kSPS for 128 mux
1MSPS for ~4 mux~23W
1.7MB/s for 1kSPS (120mux)
LAN(TCP/UDP)
2 Vpp, 14bit, 2 lines
1 Vpp, 16bit, 2 lines
200MSPSIQ signal lines (SMA)
from DAC

to ADCRHEA

KCU105200MHz (LO freq. ± 100MHz)
Shunsuke Honda (U Tsukuba)

31

Readout with particle detection

The trigger function was implemented to check the MKID performance originally→ Can be directly usable for the particle detection.

Preliminary

KID response [rad]KID response [rad]sampling rate = normally 1MSPS / DAQ is triggered with OR of all KIDs

multiple triggers with four KIDs.

Preliminarytime [s]time [s]muon eventat 100us
muon eventat 100us

2022/06/24

almost compatible to the PSD fit ~ 41.8us

Shunsuke Honda (U Tsukuba)

32

Measurement of readout performance

S.Honda et al. (2020) Proc. SPIE

Evaluation of readout system performancenoise spectrum of readout system

TOD during the observation

data taken with 32tones → 27 tones evaluated
0.2 rad(チャンネルごとにオフセットをつけて見やすく表示している)

PSD [dBc/Hz]

phase data [rad]noisefrequency [Hz]MKID

time [sec]Low enough noise level rather than a cold amp. noise
Successed simultaneous observations with 32 tones!
2022/06/24

Shunsuke Honda (U Tsukuba)

33

Observation Results

MKID property
PSD of one MKID with lenslet

frequency sweeping (LO ± 100MHz)
with lens with lenswith lenswith lensseeing roll-off shape both in amp. and phase(with sky loading of Tenerife)

observations with 1kSPS dominatedby the photon noise

26/27 pixels in readout band width

Moon observations
with new MKID

: with lens

月の観測

焦点面位置に応じてピクセルごとに別の位置で月が撮像される

20RPM
all responses are normalized to 1

2022/06/24

Shunsuke Honda (U Tsukuba)

34

Current Status

Test sensor upgraded with 23pixels+lenslets→ Performance check all pixels in 2022
cooling run 2021.12
cooling run 2021.07

full array installation 2023.03

Full array installations in 2023.03
compact chip size
antennas with 4 directions for Q and U
AR coating on the lenslet
2022/06/24

Shunsuke Honda (U Tsukuba)

35

Summary
GroundBIRD uses MKID as the focal plane detector- Fast time response, easy to be multiplexed
To suppress 1/f noise given by the detector chip, we developed the simulation
model for hybrid MKIDs.
→ GB-KID was designed based on this evaluation
Proto-type was fabricated and tested in GroundBIRD→ The performances are very niceThis evaluation will be published as the paper after fabricating the first GB-KID chipin this year.
The readout system was given by the FPGA + frequency conversion.
→ Noise level is enough lower than the LNA white noise at 4K.

2022/06/24

Shunsuke Honda (U Tsukuba)