~keV 暗黒物質 by 宇宙観測 & AXION実験~keV

Astronomical searches of dark matter &microcalorimeter ground experiments
満田和久，JAXA宇宙研
Kazuhisa MITSUDA, ISAS, JAXA
ダークマターの懇談会2019
5-6 July 2019, at Waseda Univ.

Outline•••

Story of the 3.5 keV line,
and astronomical searches of keV dark matter• Sterile neutrinos• Where to observe?
• 3.5 keV line from clusters of galaxies• XMM-Newton (and Chandra) results• Suzaku results• ASTRO-H SXS results• Emission from the Milky-way halo by Suzaku
Axion and ALP search using the earth’s magnetic field
Monochromatic solar-axion search• TES microcalorimeter development and ground applications• Signal multiplexing (MUX) for large format TES• TES microcalorimeter for solar-axion search

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

2

K. Mitsuda, ISAS, JAXA

Sterile neutrinos
Right-handed neutrinos• Neutrino oscillation• N1 (~keV) can be a dark mattercandidate• Production scenarios exist• Warm dark matter• may solve sub-halo and corecusp problems• Radiative decay modes exist in
addition to dominant decay mode
N1 → ν + γ•(e.g. Boyarsky 2009)
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

3

http://wwwhome.lorentz.leidenuniv.nl/~boyarsky/

Astronomical search
Monochromatic emission

E = mN1 /2(Abazajian+ 2001)
K. Mitsuda, ISAS, JAXA

Where to observe?
Dark matter column density-2

DM column density, log10[S/Msun pc ]

6

•
•
•

Clusters of galaxies
Dwarf and/or spiralgalaxies
Milky-way halo

All observations so far arebackground limited (and not photon limited).
Baryon aurface brightness

Figure of
merit

29

Spirals20

13

Clusters

4

50.00
89.13
223.87794.33
DM
3
20
300
4E+04
emission
Assuming that the object is extended all over the field of view
Unit is

4

3

2

1

Boyarsky+2010
10

8

9

10

10

11

12

13

M⊙ pc−2

10

10

15

10

16

10
10
10

5
4
3
2

10
1
10

-1

Sekiya2010
1

0.5

2

5

photons cm−2 s−1 sr−1 keV−1 @2keV

XDB

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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10
10
10
10
10
DM halo mass M200 [Msun]

6
Baryonic
emission surface brightness
10

DM column density

MilkyDwarfs
way halo

5

0
7
10

Speciﬁc Intensity[Counts cm 2 s 1 sr 1 keV 1]

Figure of merit =Subhalos from Aquarius simulation
Isolated halos from CDM N-body simulations
Predictions from the Secondary infall model
Clusters of galaxies
Groups of galaxies
Spiral galaxies
Elliptical galaxies
dSphs

4

M31 center

10Energy [keV]
Perseus center

K. Mitsuda, ISAS, JAXA

暗黒物質輝線探索に用いる X 線天文衛星 / 検出器の検討

Instruments
to useWhy Suzaku?

「Chandra/ACIS」「XMM-Newton/PN, MOS」「すざく/XIS」の性能比較

Suzaku observation of
Milky-way halo is the best
combination.
Suzaku(ISAS)
Suzaku(ISAS)
2
視野 [amin ]Chandra/ACISXMM-Newton/MOS+PN

Suzaku/XIS

Chandra(CXC) XMM-Newton
XMM-Newton(ESA)!
(ISAS)
Chandra(CXC)(ESA)! Suzaku
8.3 × 8.3 × (4FI + 6BI)

~700 × (2MOS + 1PN)

17.8 × 17.8 × (3FI + 1BI)

エネルギーバンド [keV]

0.3 − 120.15 − 15

0.2 − 12エネルギー分解能 [eV]50 − 200

50 − 200

50 − 200

有効面積 @ 1 keV [cm2]200 (4FI), 400 (6BI)

800 (2MOS), 1200 (PN)

660 (3FI), 320 (BI)Chand

−1 sr−2 keV−1] 10 − 1000 (不安定)NXB 輝度 [cm-2 s暗黒物質輝線探索に用いる
5 −X100(不安定)
1 − 10 (安定)線天文衛星
/ 検出器の検討

有効面積 × 視野の比較

NXB 輝度の比較

10

輝度 [Counts cm 2 s 1 sr 1 keV 1]

有効面積 × 視野 [cm2 sr]-1
輝線放射の計数を稼ぐために重要な性能である有効面積× 視野の面で10
ペルセウス銀河団中心
105
10は XMM-Newton/PN
が最も有利-2
Suzaku6

4

X 線背景放射の観測の障害となる非X 線バックグラウンド(NXB) の低
3
アンドロメダ銀河中心-31010
さと安定性の面ではすざく/XISが最も有利102
10
10

-4

-5

0.5

From Yamasaki+ 20171

2
5
光子エネルギー [keV]

10

Suzaku/4XIS Chandra/ACIS-I XMM-Newton/2MOS
Chandra/ACIS-S XMM-Newton/PN

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

p 5

10

10
1
10

Suzaku-1

X 線背景放射2105
光子エネルギー [keV]
Suzaku/4XIS Chandra/ACIS-I XMM-Newton/2MOS
Chandra/ACIS-S XMM-Newton/PN

0.5

2
4
2
⹨⹺岔䄍؄⨑⃫⺀泴‫إק‬㚃‫ڋْٱقڋٓا‬䫵䵗؊䛟䖗؄⼶㧼1EV"撲㾃1

K. Mitsuda, ISAS, JAXA

4

sin2 2Present astronomical constraints on sterile
neutrinos
10
10

-5

Sekiya+2016 (MWH., LEE corrected, 3σ)Sekiya+2016 (MWH., LEE uncorrected, 3σ)-6(DM overproduction)

Accepted
10
10
10
10

-7
-8

Boyarsky+2013(MWH+Dwarfs,
LEE uncorrected)-9

Accepted

-10

10
10

Excluded-11

Bulbul+2014 (Perseus cluster)
Bulbul+2014 (stacked clusters)

Excluded-12

Excluded-13

10 1(Not enough DM)

2enough DM)

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

510m s [keV]
6

K. Mitsuda, ISAS, JAXA

Cluster 3.5 keV line (Bulbul+2014)
Bulbul after
et al. z correction
78 clusters stacked(XMM-Newton)

The Astrophysical Journal, 789:13 (23pp), 2014 July 1

Perseus cluster (XMM-Newton MOS)

Perseus cluster (Chandra ACIS-S)

Figure 7. 3–4 keV band of the stacked MOS (left panel) and stacked PN (right panel) spectra of the Perseus Cluster. The figures show the energy band, where a newspectral feature at 3.57 keV is detected. The Gaussian lines with peak values of the flux normalizations of K xviii and Ar xvii estimated using AtomDB were includedin the models. The red lines in the top panels show the model and the excess emission in both spectra. The blue lines show the total model after a Gaussian line is
added, indicating that the unidentified spectral line can be modeled with a Gaussian.
(A color version of this figure is available in the online journal.)

However, the fluxes of the nearby K xviii line at 3.51 keV andthe Ar xvii DR line at 3.62 keV were at their allowed upper
limits predicted from AtomDB. Relaxing the upper limits has
ダークマターの懇談会2019, 5-6 +0.01
July 2019, at Waseda Univ.
shifted the line energy higher, to 3.59 −0.03 (+0.02−0.04 ) keV, with a

7

K. Mitsuda, ISAS, JAXA

Caveats and issues of 3.5 keV line••

Caveats discussed in Bulbul+ 2014:• The equivalent width of the line is only ~ 1 eV, while
the energy resolution is ~100 eV. Thus the excess isonly ~1% of continuum spectrum. Uncertainties incontinuum model significantly affects the results.
Issues found in their results• Two different sets of sensors, MOS and PN, of XMMNewton gives inconsistent intensities of the Perseus
cluster residual emission.
• Centroid energies of MOS and PN for stacked spectra
are inconsistent within the statistical errors.
• Residual intensity of Perseus cluster is ~10 times
larger than that of the stacked spectrum.

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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K. Mitsuda, ISAS, JAXASuzaku Perseus results (Tamura+2015)

XIS FBXIS FB

XMM-Nweton 3.5 keV line
deliberately added to the model“Line search”
1-σ sensitivity is ~1 eV EW level.

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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K. Mitsuda, ISAS, JAXAPerseus results compared– 17 –XMM

60

MOS (710)

40

XMM

ChandraSuzakuACIS−I (290)
XMM vs. Suzaku
XIS (320)
PN (710)in expectedACIS−S
photoncounts(47)

20

2017-10 Kanazawa 

Flux (10−6 photons cm−2 s−1)

80Perseus78 clusters stacked0

Table 6: Suzaku XIS and XMM-Newton EPIC observations. Areas are for the enrgy of
Tamura+2015
3.5 keV. EPIC exposures are thoseof
Bulbuletal.
(2014).
The
MOS
and FI exposures are
Bulbul+2014
sums of CCD.
Detector Area FOV
exp Area× exp Area× exp × FOV(cm2 ) (arcmin2 ) (ks) ()
()
MOS
300
710
317 95.1K
67.5M
PN
PM
700
710
38
26.6K
18.9M
XIS/FI 260
320
1040 270K
86.5M
XIS/BI 260
320
530 138K
44.1M
total
408K
131M
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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In terms of exposure x area (photon

K. Mitsuda, ISAS, JAXAASTRO-H SXS Perseus•••

Improves energy resolution by a factor of 20.
Energy resolution (5eV) becomes the same order ofthe equivalent widths (~1eV), which makes
uncertainty of continuum much less important.
X-ray microcalorimeter
Major draw backs are smaller effective area and field operating at 50mK
Kelley+2017
of view; sensitivity is limited by photon statistics

Suzaku XIS
ASTRO-H SXSFigure from
Tamura 2017
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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K. Mitsuda, ISAS, JAXAASTRO-H SXS Perseus

Hitomi collaboration 2017

XMM-Newton MOS Perseus intensity was excluded at a 3σ confidence limit.
However, intensity of stacked clusters is not excluded.

3σ

180 km/s: thermal velocity of a proton
1300 km/s: velocity dispersion of galaxies
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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Intensity of XMM stacked clusters
K. Mitsuda, ISAS, JAXAPerseus results compared

XMM

ChandraSuzakusmall uncertainty
in continuum
Astro-H

ACIS−I (290)4060

MOS (710)

XIS (320)

PN (710)ACIS−S (47)20

XMM

Flux (10−6 photons cm−2 s−1)

80Perseus

SXS (9)3σ

078 clusters stacked

Tamura+2015 Hitomi col.+2017

Bulbul+2014(FOV arcmin2)

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

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Small FOV is corrected for this data.
K. Mitsuda, ISAS, JAXAThe redshifts of the three APEC models were fixed to zero.
In the power-law emission models for the CXB (powerlaw in
XSPEC), their photon indices were permitted to vary around
すざく/XIS アーカイブデータ (2005−2013)
1.4. In Suzaku XIS observational data, an O I fluorescent line
Step
1.the
データ選択
from
Earth’s exosphere was sometimes found especially af2011, at the time of Solar maximum, despite the fact that its
全天 187ter
方向のX 線背景放射データ
contamination was mostly removed by applying the elevation
angle criteria as described above (Sekiya et al. 2014b). When
we found a discrepancy in the spectral fitting result below 0.6
keV, we added a Gaussian with a centroid of 0.525 keV for O I(gaussian in XSPEC). To summarize, the following modelfor the spectral fitting was
adopted: [“APEC1 ”+“Galactic
銀河中心
反銀河中心
銀河中心
Anti
G.C.
absorption”×(“APEC2 ”+“APEC3 ”+“CXB”)+“O I”]
where“Galactic absorption” was for a photoelectric absorption by
the interstellar medium of the Milky Way (phabs in XSPEC)
which were able to estimate from accurate observational data of
the neutral hydrogen column density NH (Kalberla et al. 2005),
APEC1 , APEC銀河系座標、マップ中心は反銀河中心
2 and APEC3 correspond to the H-SWCX +LHB, the MWH and the UHTP, respectively.

Milky-way halo: Suzaku resultsSekiya+2016
Counts s 1 keV 1

10 1

90.00060.00030.0000.000

315.000

270.000

225.000

180.000

135.000

90.00045.000Data
Model (total) Response
H-SWCX + LHB + MWH+ UHTPCXB
Instrumental lines

10 2

10 3
Al-K Si-K

Au-M

4-30.000

Mn-K , K
2/dof = 1.05 (dof = 3693)

0-90.000

0

100

199

300

400

500

600

700

800

900

1000

• 187
fields with faint sources
We fitted the stacked XDB spectra with the model for eachperiod. The results of the XDB spectral fitting and the best-fit
removed.
parameters of the XDB model are shown in Fig. 2 and Table 2.
As thegoodnessof fit, χ /dof (dof)was 1.05 (3693), and the• 31
Ms
integrationtime
hypothesis probability was 2.5 %. The deviations between~null
20% of total Suzaku
the data and model were about 1.6, 2.9 and 4.0 % in the rootmean-square at 0.5 – 2,time.
2 – 5 and 5 – 7 keV, respectively.
observation2

5 Search for a keV signature of DM
ダークマターの懇談会2019,
5-6 July
WasedaUniv.with the14
We simultaneously fitted
the 2019,
stackedat XDB
spectraData/Model Ratio-60.000

4
1.1
1
0.9
4/10
0.5

1

2

5
Energy [keV]Spectrum is modeled well with
• Non X-ray background• Heliosphere + Local Bubble• Hot ISM in Milky-way halo
• Faint extragalactic sources

Fig. 2. Exposure-time-weighted average of the 25 stacked XDB energy
spectra from 2005 to 2013 and its best-fit model convolved with thecorrected response. Sub-components of the model are represented by blue
dashed (XDB in the Milky Way (1)+(2)+(4)), green dashed (CXB (3)) andorange dotted (instrumental origin) lines.

K. Mitsuda, ISAS, JAXA

Line search and Look elsewhere effect (LEE)
Number of independent searches acrossthe spectrum determines the final upper
limit, which is determined with MonteCarlo simulations

0.04

0.4

0.02

0

0

0.4

0.02

0.8

0.04

0.5

1
Local
Significance [ ]

(b)

0.5

local 3σ upper limit

1

2

3

5
Energy [keV]

2
1
0.5

1

2

5
Energy [keV]

10

-1

1

10

-2

2

10

-3

3

-4

10 2.53

3.5
4
LEE-uncorrected Significance [ ]LEE-corrected Significance [ ]0.8Probability of Occurrence (p-value)(a)Line Intensity [LU]Line search(local significance)Lines with ≥2.5σ local significance are expected to appear with
~40% probability at some energies in the spectrum. This isconsistent with the observational results.
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

15

K. Mitsuda, ISAS, JAXAComparison of Suzaku MW result with 3.5 keV line

sin2 2

Intensity of stacked clusters Bulbul+2014 is statistically excluded at a 3σ confidence.
However, because of uncertainty in column density, we cannot perfectly ruled it out.

10
10

-5

Sekiya+2016 (MWH., LEE corrected, 3σ)Sekiya+2016 (MWH., LEE uncorrected, 3σ)(DM overproduction)-6

Accepted
10
10
10
10

-7
-8
-9

-11

Accepted
Bulbul+2014 (Perseus cluster)
Bulbul+2014 (stacked clusters)

Excluded-12

Excluded-13

10 1

Boyarsky+2013(MWH+Dwarfs,
LEE uncorrected)

excluded by ASTRO-H

-10

10
10

Excluded(Not enough DM)

2

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

5
16

10

[keV]
ISAS, JAXA
mK.s Mitsuda,

Axion and ALP search using the earthmagnetic field
The inverse Primakoff effectB−21

Pa→γ ∼ 2 × 10

γ

ALP

−6

ma < 10

for

L

B⊥L
( 10−10 GeV−1 ) ( T m )
gaγγ

2

2

1
2

− 12

Ea
L
eV
( 1 keV ) ( 104 km )Ground experiments

Low-earth orbits or line sight through the earthsuperconductor magnet + cavity

106

B 2 L 2 = 105 to 106 m2T2

CAST

>>

B 2 L 2 = 6.4 × 103 m2T2

106

5

5

(B⊥ L)2 [T2m2]

10(B⊥ L)2 [T2m2]

10

104

Large BL
Sensitive mass range limited by large L

4

10

103

0

103

1

0

2

3

Time [hour] 1

2

3Time [hour]

Figure 1. Left: Schematic view of the position and observation direction of Suzaku satellite relative2
ダークマターの懇談会2019,
5-6Right:
July Time2019,
at Waseda
Univ.
to the Earth magnetosphere.
dependenceof (B? L)in a Lockman17
hole observation.
Figure 1. Gray
Left:hatched
Schematic
viewperiodsof thepositionand observation
directionof Suzaku
regions showof theEarth occultation,i.e. the Earthexists between
a target satellite relative

K. Mitsuda, ISAS, JAXA

Search for ALP from keV dark matter
The inverse Primakoff effect
2
B
L⊥
Pa→γ ∼ 2 × 10−21( 10−10 GeV−1 ) ( T m )2gaγγ(B⊥L)2 = 104 − 105 (T m)2
106

5(B⊥ L)2 [T2m2]

10

104

6

10
103

at z

0

1

2

3

Time [hour]
52]Figure 1. Left: Schematic view of the position and observation direction of Suzaku satellite relative2
to the Earth magnetosphere. Right: Time dependence of (B? L) in a Lockman hole observation.
Gray hatched regions show periods of the Earth occultation, i.e. the Earth exists between a target
4and Suzaku
10
(B ⊥

2

m
2 [T
L)

χ + χ̄ → a + a

10No bright sources (i.e., the original observational purpose was a study of blank sky
Integrating over z, ALP spectrum will1. fields)
be or maskable faint compact sources are in the XIS FoV;
2. Galactic latitudes of |b| > 20 in order to avoid the X-ray emission peculiar to the
Galactic disk [17];

3

10

0

rva
e
s
b
d o ce onan
3. Separate from the region occupied by the emission from North Polar Spur and other tion ende ltaios dep occu
local X-ray diﬀuse emission;p
the me rthof : Ti e Eatw
4. Total exposure time is more than 200 ks.
vie Righ of th
c
s
ti e.
od
r calibrationima hefor
The Lockman hole is a famous HI hole, and annually observed with hSuzaku
bs
r
e
e
o
p
p
c
l
s
S to alsoowused for the
purpose. South Ecliptic Pole (SEP) and North Ecliptic Pole (NEP)
ina urceK. Mitsuda,
ft: gnare
h
ISAS,
JAXA
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.
g
18
e
s
i
r
o t soblank sky study,MBM 16 is one of the nearby molecular cloud.
. L ma ionsge 1 ththe acdN∝ E +0.5 (e.g. Asaka+1998)
dE

Search for ALP

Yamamoto+2019

2 0.5

Search for a spectral component which is ∝ (B⊥L) E
Data-NXBSWCX+LHB
CXB
MWH
ALP

10-3

50
45
40

Exposure Time [ks]Photons cm-2 s-1 keV-1

10-2

-4

10

10-5

35
30
25
20
15
10
5

-6

10

0.7

00
1

2

5

Energy [keV]

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

19

00

20000

4

40000

4
2

60000

4

80000 5

1000006

2 2] 2⊥L)2 [T(B(BL)[Tm2m]

K. Mitsuda, ISAS, JAXA

2 0.5Upper limit of ∝ (B⊥L) E

2.5×10−8
3×10−8
Surface brightness of CXB in 2−6 keV [erg/s/cm2/sr]

3.5×10−8

MBM16

0

2×10−9with assumptions of dark matter
mass, density & decay rate(somewhat unusual assumptions)−2×10−9

Surface brightness of ALP in 2−6 keV [erg/s/cm2/sr/104(Tm)2]

3×10−910−92×10−9Lockman hole0Surface brightness of ALP in 2−6 keV [erg/s/cm2/sr/104(Tm)2]

Four blank sky directions

emission-610

2.2×10−8 2.4×10−8 2.6×10−8 2.8×10−8
3×10−83.2×10−8
Surface brightness of CXB in 2−6 keV [erg/s/cm2/sr]

3.4×10−8-8

2.5×10−8

2×10−9-1gaγγ [GeV ]4×10−9

NEP
-10

10

-12

10

0

−2×10
−4×10

1.5×10−8
2×10−8
Surface brightness of CXB in 2−6 keV [erg/s/cm2/sr]

Surface brightness of ALP in 2−6 keV [erg/s/cm2/sr/104(Tm)2]

0

2×10

−9
−9

SEP

−9

Surface brightness of ALP in 2−6 keV [erg/s/cm2/sr/104(Tm)2]

4×10

−9

10

QCD axion
ADMX prospects
ADMX
IAXO
CAST
Suzaku(Gal. monochromatic)
Suzaku(Univ. continuous)

-14

10

1.5×10−8

2×10−82.5×10−8
Surface brightness of CXB in 2−6 keV [erg/s/cm2/sr]

3×10−8

10-16
10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

101

ma [eV]

Figure 4. ALP parameters constrains in this paper in Universal continuous ALP (cyan) and Galacti
monochromatic ALP (yellow) see details in text. Limits of other experiments are taken from [32]

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

20

K. Mitsuda, ISAS, JAXA

[2] T. Asaka, J. Hashiba, M. Kawasaki, and T. Yanagida, Spectrum of background x-rays frommoduli dark matter, Phys. Rev. D vol 58 (1998) 023507.

The best target is solar axion
Staying in the sun shade (atL2), no power generationfrom solar cells
Pointing to the sun only
while the satellite is in
the sun shade, requires
attitude maneuvers.
Pointing to the sun, closing
a shutter while the satellite
is under the sun shine(dedicated mission)
50-kg class small satellite, carrying light-weight X-ray
optics and X-ray spectrometer, e.g. ORBIS (Ezoe+2018)
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

21

K. Mitsuda, ISAS, JAXAA solar-axion space mission
Pointing to the sun, closing
a shutter while the satellite
is under the sun shine(dedicated mission)

ultra-light X-ray optics

50-kg class small satellite, carrying light-weight X-ray
optics and X-ray spectrometer, e.g. ORBIS (Ezoe+2018)

Advantages over Suzaku results• higher source flux
• longer exposure (~5 days = a Suzaku
obs. of single direction)• background subtraction by image
Disadvantages• Shorter L (~6x103 km, smaller BL)• less sensitivity but wider mass range• smaller collecting areaby a factor of ~10
Fig 9 (Top and bottom left) Concept and photo of Pt-coated MEMS X-ray optics, (Top right) a transmission electron
microscope image of a sidewall, and (Bottom right) X-ray reflectivity curves at Al Kα 1.49 keV of the sidewalls. The
photo and electron microscope image are for the Plasma Pt ALD sample, while the reflectivity curves are for both thethermal and plasma Pt ALD samples. Numbers indicate micro roughness estimated from the reflectivity curves.

-6

10

addition to removing the edge structure, this process allows us to leave the flat mirror surface.

-8

10

Thus, we can expect not only a large effective area at small reflection angles but also a better

In addition to the angular resolution, we tested a new ALD process to increase the effective area.37

Coating of the sidewalls with high Z materials is necessary in the MEMS X-ray optics. Since a-1

3.5 Effective area

gaγγ [GeV ]angular resolution.

-10

10

10-12

standard coating process such as sputtering or evaporation do not allow conformal coating of thehigh aspect sidewalls, we selected the ALD as a new coating method. We have tested Ir ALD
in the early stage of our development.38 Although the coating was successful in terms of X-ray

QCD axion
ADMX prospects
ADMX
IAXO
CAST
Suzaku(Gal. monochromatic)
Suzaku(Univ. continuous)

-14

10

18

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

10-16
-8
10

-7

10

-6

10

-5

10

-4

-3

10

10

-2

10

-1

10

0

10

1

10

ma [eV]

Figure 4. ALP parameters constrains in this paper in Universal continuous ALP (cyan) and Galactic
monochromatic ALP (yellow) see details in text. Limits of other experiments are taken from [32]22

K. Mitsuda, ISAS, JAXA

Microcalorimeters
ETF (Electro-thermal feedback)Energy quanta

E

T
E/C

C

T
G

TB

E

PJ

TB

T0

R

V

G
C, T

0

t

•Sensitive to any energy input → DM
•High energy resolution

FWHM

This figure is ford ln Rα≡> 0. ETF
d ln T
works for α < 0.

X-ray absorber of a few 100µm square x a few µm thickness：C ~ 1pJ/K@100mKΔE = 5.4ξ eV
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

ξ∼1
23

K. Mitsuda, ISAS, JAXA

Towards large-format arrays
ThermometerSi thermistor

TES

TES

Signal MUX

none

FDM/TDM/CDM

Microwave FDM

max possible #pixels in space~100

a few k~ 1MSpace mission

ASTRO-H SXSXRISMAthena X-IFU

S-DIOS# pixels

363168~ 300 k2016/2021

2032

203X

Launch year

Ground application: HOLMES (Nucciotti+2018)• End point spectrum of 163Ho EC decay to constrain
neutrino mass,• 1024 TES microcalorimeters with microwave FDM readout
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

24

K. Mitsuda, ISAS, JAXA

15 series SQUID
array Array X 8

800 nm

5mm

105
10

?

Si abs edge

1004

Fe Kα

Mg Kβ

Si Kβ
Si abs edge

K Kα

Mg abs edge

Fe Kα

Mg abs edge

SDD

1000

K Kα

−10
1000
0.2

10

0.5

1

5

Energy (keV)0
C = 3.6 (pJ/ K)−10

C = 4.0 (pJ/ K)

102

0.2

C = 0.7 (pJ/ K)

0.5

1

5

E (eV)

Energy (keV)

21 eV∆ E (eV)TES microcalorimeter array &Detector head with SQUID array amp.

TES

Cu Lα

106

Hayashi 2018, Hayashi+2019
229Th experiment

O Kα

104

Si Kβ

Olivin TEM image & EDX spectrum

Si Kα

?

Mg Kβ

105

Mg Kα

SDD

Cu Lα

both utilize TES+DC readout

Fe Lα

8x8 TES array

TES

Fe Lα

STEM TES EDX(data−model)/error
counts s −1 keV −1(data−model)/error
counts s −1 keV −1

106

Si Kα

O Kα

Mg Kα

TES ground applications of our group~18 eVTES for 229Th

101

Muramatsu 2019
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

25

4.8 eVTES for STEM EDX
101

30
Energy (keV)(keV)
Energy50

K. Mitsuda, ISAS, JAXATES-microcalorimeter fabrication
All in-house process mostly using JAXA facilities(a)

TES membrane sputtering(b)

Photo mask alignment

Tokyo Metro. Univ.
(e)

Al sputtering deposition(c)

Wet etching(d)Dry etching (ICP, DRIE)JAXA nano clean room (Building D, Sagamihara )(f)

EB vapor deposition

Mitsuda/Yamasaki laboratory clean booth(Building A, Sagamihara)
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

Cryogenic readout
electronics (SQUID array
amplifiers) in the previous
page were designed by ourgroup and fabricated by
CRAVITY of AIST
(Sakai+, IEEE 2015)

26

K. Mitsuda, ISAS, JAXA

Microwave FDM development
collaboration with AISTHEMT amp

Feedline

Port1

Port2

-wave tones

Capacitor

S21

Resonator
TES

RF-SQUID

Variable inductor=

L( )SQUID Modulation Signal

MUX chipfabricated at CRAVITY of AIST

example of de-MUXed signal

Kohjiro+2017
Nakashima+2018

pixel 1
pixel 2
pixel 364 pix/ch MUX is expected
be realized soon

pixel 4

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

27

K. Mitsuda, ISAS, JAXA

x!

a

„,

p,

C exp( —PT), (7)=2o.oyI /I

op

Search for monochromatic
Solar axions)„,—D + 25'
(3F
—
—
=
1.19!
C(D, F, 5, z)!

+(D+F) 1+ z'

(8)

(12)

where o.oy
26 + 10 ' cm is the maximum res= 4.7 X
onant cross section of y rays [14], and I
10 ' keV is the total decay width of the first excitedstate of Fe. The factor 2 in Eq. (12) represents thedifference of the spin multiplicity between photons and»Monochromatic
axion emissionaxions.
predicted by Moriyama (1995)
Semiconductor experiments by Namba (2007) and others.

where
1 is assumed
in the solar interior.
Our• Pr
estimation differs slightly from that of Ref. [11], because
value of Fe abundance in the Sun is used [9].
a different•
Equation (7) provides an estimation of the differential
axion Aux at the Earth,d&b(E, )

1

dE

4m RE

$2vr rr(T)

exp

z-

(E. —E, )'2o(T)Center ofBE(T)the sun:X

p(r)4vrr dr,

10 13
10 12

(9)

γ+57Fe → 57Fe* → 57Fe + axion

where R~ is the average distance between the Sun and theEarth. Ro denotes the solar radius. T(r) and p(r) are
the temperature and the mass density at the radius r, respectively. o(T) = E~(kT/m). '~ represents the Doppler
is the mass of the Fe nucleus. It should
broadening.
noted that the on
be Detector
numberof iron atoms per unit mass isground:assumed to be uniform as in the framework of the stan57Fe+γ(9%)
dard57solarof
Fe +model
axion(SSM)→ 57[8],
Fe*i.e.→, that N is independentr. In addition, the SSM provides the mass density andthe temperature as a function of the radius r, which arenecessary for calculating Eq. (9). The values of the functions are taken from Table XVI in Ref. [8]. Thus Eq. (9)can be evaluated if one fixes D, F, S, 57
and+ + e.- →
The
z, Fe

I

f,

~10
%10
10

'.

—

0

FIG. 1. Differential

s»

I

5

Aux

28

I

i

I

I

I

&

&

s

10
15
20
axion energy (keV)of the axion fromthe Sun.
The
Moriyama(1995)

Fe
sharp peak corresponds to the axion emission from the57
deexcitation. The broad part of the differential Aux corresponds
to the axion generated through the Primakoff effect.

Fe + n e + e

57Fe + γ + n’e-+ e-

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

s»

3223

K. Mitsuda, ISAS, JAXA

Search for monochromatic Solar axions
Microcalorimeter• pros• Better efficiency because microcalorimeters are sensitive
to conversion electrons and low energy X-rays. (~95%)• Sensitivity will be limited by signal Poisson fluctuation
rather than background fluctuation because of goodenergy resolution (~10eV@14.4keV)• Axion converter mass can be increased by utilizing alarge format array with microwave FDM readout.
• cons• TES performance will degrade with magnetic fields fromthe converter material, 57Fe.
• Yet small converter mass
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

29

K. Mitsuda, ISAS, JAXA

Sensitivity prediction
Assumptions
200 eV3−σ upper ilmit (events day−1kg−1)

R for S/N = 3

150 um pixels
100 eV5

100 um pixels
104

1000

100 um pixels, 20% BGD

50 eV

30 eV

100

1000

104
Number of pixels

105

106

Maehisa 2017

S + bΔEη

S: total signal events
b: background events/eV
ΔE: energy resolution
η: fudge factor = 2.5

106

10

S/N =

S

S = RTMα
R: event rate
T: integration time
M: converter mass
α: detection efficiency
b: estimated from experiments
without anti-cowith anti-co (20% of above)
ΔE: pulse height position dependency
assuming Fe thermal conductance inliterature at low temperature
L
ΔE = 7 eV( 100μm )L
1+( 100μm )6

L: one side length of converter
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

30

K. Mitsuda, ISAS, JAXATES design and development status
What we have done so far.
order
• Design• Thermal strap was introduced to avoid magnetic field
1• Thermal simulations with different strap lengths
4• Iron membrane fabrication process• High-yield converter deposition process2
collaboration with
• Electro deposition was selected and tested
Waseda Univ.
• Material properties at low temperature• Thermal conductance of iron
• Measurement of low temperature electrical3
conductance of iron membrane made by electro
deposition. Then Wiederman-Frantz law applied.
• Degradation of TES due to magnetic field from iron
• Magnetic field was estimated by using electro3
magnetic field simulations
we are• R-T measurements of TES with and iron converter
5 here now
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

31

K. Mitsuda, ISAS, JAXAExample of magnetic field
simulations

Concept design of a pixel
180 um
140 um
100 umFe

Au

200 umMagnetization

TES

5 um
1 um

Si

150nm

SiNx/SiO2

Si

Condition: B⊥ < 1 μT at TES

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

32

K. Mitsuda, ISAS, JAXA

Thermal̲desktopによる

Thermal conductancemeasurement
エッチング後、基板全面

1

FEM simulationsof TES
57Fe
先行研究より、吸収体に
response2

3

5
Iron4membranes deposited andpatterned on Si substrate.
(collaboration with Homma groupat Waseda university)

6
Position sensitivity to TES response was studied.
大きさ[μm3]

Electrical conductance was measured
at low7temperature. Then the8Wiedemann–Franz was applied toestimate thermal conductance.
ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

Fe

100 100 5

Au(1,2)100 100 5

Au3

140 140 5

TES

180 180 0.159熱伝導Degradation of ΔE < 5 eV

33

K. Mitsuda, ISAS, JAXA

アクシオンTES 冷却試験

Resistance-Temperature relation of TES

・RT測定素子
MU532
RT特性 結果
1,前回測定した素子からFeを剥がした素子 （熱パス 60 um）
2,使用する冷凍機配線を変更した素子
electrodes
TES iron
Fe吸収体成膜後（熱パス 100 um）
Fe成膜前との比較（同条件:1uA)
1

1
2

With iron
Fe吸収体剥がし2

Without irongreen parts: lift-off
photo resist was not・遷移特性に変化が見られた？
removed perfectly.
Superconducting phase transition is affected by iron!

6/16(日) 昇温：Fe成膜までの蒸着、電析などの熱負荷がかかるプロセスによって遷移特性がWe need to make the distance larger.
6/18(火) 基板取り出し、Fe剥がし、組み込み、真空引き、GM冷凍機 ON
変化したか、Fe吸収体の有無が原因か切り分けは出来ない。
6/21(金)4K到達 抵抗チェックの際に１本配線が使えない状態に（ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

34

K. Mitsuda, ISAS, JAXA

I talked about•••

Story of the 3.5 keV line,
and astronomical searches of keV dark matter• Sterile neutrinos• Where to observe?
• 3.5 keV line from clusters of galaxies• XMM-Newton (and Chandra) results• Suzaku results• ASTRO-H SXS results• Emission from the Milky-way halo by Suzaku
Axion and ALP search using the earth’s magnetic field
Monochromatic solar-axion search• TES microcalorimeter development and ground applications• Signal multiplexing (MUX) for large format TES• TES microcalorimeter for solar-axion search

ダークマターの懇談会2019, 5-6 July 2019, at Waseda Univ.

35

K. Mitsuda, ISAS, JAXA