PhoENiX

Physics of Energetic and Non-thermal plasmas
in the X (= magnetic reconnection) region
Noriyuki Narukage (NAOJ)
and PhoENiX WG member

2021/03/09

20th HEAPA meeting1

Science Goal

Understanding of particle acceleration during magnetic reconnection• Science Objectives
1. To identify
particle acceleration sites
in reconnection-associated structures insolar flares
2. To investigate
the timing of particle acceleration
during reconnection-associatedphenomena in solar flares
3. To characterize
the properties of accelerated particle
populations in solar flares
2Particle acceleration

Accelerated particles are deviated from equilibrium.

Thermal equilibrium= Maxwell distribution
Number of electrons

Accelerated particle＝ power-law spectrum

1 keV

10 keV 100 keVEnergy of electrons

1 MeV

3

Particle acceleration

Accelerated particles are ubiquitously detected in the universe.

The universe is filled withHigh Energy (Accelerated) Particles!!

“What is the origin ofHigh Energy Particles?”4Particle acceleration

The energy of accelerated particles achieves up to 1020 eV.
Accelerated particles are ubiquitously detected in the universe.

××

Makishima (1999)5

Particle acceleration

How are particles accelerated? It is not fully understood.

Super Nova Remnant(long time acceleration)

Gamma-ray Burst(short time acceleration)

SN 1006

Gamma rays

Credits: eCUIP and ISDC

Balbo+ 2011

1st order Fermi-acceleration
Statistical acceleration

How are particles accelerated
in very short time?
6Particle acceleration
Magnetic reconnection is a key.

Gamma-ray Burst(short time acceleration)
Uzdensky+ 2011
Magnetic reconnection
Magneticene
rgyèèoushoctfkloKin
The eticrm ene
al e rgynergycush rreee n ttw

plasmoid

Courtesy of Dr. Kaneko

Gamma rays

Credits: eCUIP and ISDC

Balbo+ 2011

How are particles accelerated
in very short time?
7

Magnetic Reconnection

MR is fundamental plasma process and ubiquitously occurs in the universe.

Lundquist number

𝑆𝑆 ≡𝜇𝜇! 𝑉𝑉" 𝐿𝐿#$𝜂𝜂

Solar Flare

Heatedplasmas+Accelerated
particles（X-ray is best）

Cf. Reynolds number

Re = 104

Ji & Daughton 2011

Re = 1.54

Effective
plasma size

𝜆𝜆 ≡𝐿𝐿𝑑𝑑%8

Significance of solar flare study[Plasma physics]

Natural laboratory of plasma• Magnetic reconnection• Particle acceleration[Unique observation target]
The closest star•

Solar phenomenon can beobserved with wide field of view andwith spatial and temporal resolutions[Impacts on the Earth and social environments]
The mother of the Earth• Evolution of life (cosmic rays)• Space weather[As a star]• Reference of other astrophysical objects

9Magnetic Reconnection in Solar Flare

Observation

Model10

Particle Acceleration is one of the major puzzles
in solar physics
By hard X–ray observations, it is known that theparticles are accelerated by solar flares.
But particle acceleration site is still puzzle.
This is caused by poor observations of energy
release regions in X-rays.
DC acceleration?

?

Collapsing magnetic traps?

?

Shocks?

Turbulence?

Aschwanden (2002)

Karlicky & Kosugi (2004)

Tsuneta & Naito (1998)

Liu et al. (2008),
Petrosian, (2012)

?

?

11

New observational
approach

Focusing Imaging-Spectroscopy
in soft and hard X-rays

x, t, E, po l

Numerical
approach

AsSp
tracopLa
SeolhyboPhasiraryscstoPhicrysysics

Spectro-Polarimetry
in soft Gamma-rays

Interdisciplinary
approachParticle Acceleration
Magnetic Reconnection

Science Objectives of PhoENiX mission
1. Identify particle acceleration sites
in solar flares [where]
2. Investigate temporal evolution ofparticle acceleration [when]
3. Characterize properties ofaccelerated particles [how]planned to be realizedin Solar Cycle 26 (2030’)
12

Experiment to investigate the mechanism of accelerator
A certain experimental equipment

A preferable experimental equipment

Probe~~ ~~Accelerated electrons

Probe~~~ ~Accelerated electrons

Acceleratorwhose mechanism is unknown

Liu+ 2013

2-dimentional target(spectroscopy)

Transmission type target(spectroscopy)
Thick target (spectroscopy)
Block electrons

RHESSI

Block electrons

Thick target (spectroscopy)(+polarimetry)

PhoENiX
13

Observational Approach for Scientific Objectives• Science Objectives
1.

To identify particle acceleration sites in reconnection-associated structures in solar flares

2.

To investigate the timing of particle acceleration during reconnection-associated phenomena in solar flares

3.

To characterize the properties of accelerated particle populations in solar flares

14Instruments and Key technologies of PhoENiX
The basic developments of these technologies have been completed.

Soft X-ray Imaging Spectrometer（0.5 keV ~ 10 keV）

Soft Gamma-ray SpectroPolarimeter（20 keV ~ > 600 keV）

Large effective area X-ray mirror
Resolution: < 8 arcsec (FWHM)~2.0m

High-speed soft X-ray camera
Back-illuminated CMOS sensor~3.0m

High-precision X-ray mirror
Resolution: < 2 arcsec
Low scatter: 10-4 @ 20 arcsec

Hard X-ray Imaging Spectrometer（5 keV ~ 30 keV）

High-sensitivity hard X-ray cameraFine-pitch CdTe detector

Si/CdTe Compton camera
Polarization measurement: > 60 keV

15

Demonstration of Observational Approach= FOXSI (Focusing Optics X-ray Solar Imager) sounding rocket• US-Japan collaborative sounding rocket experiment.
• Objectives:• Study small scale energy release in the solar
corona• Demonstrate the new technology for X-ray imagingspectroscopy• Method: X-ray focusing imaging spectroscopy• Observation time : about 6 min / flight

2012

2014

2018

FOXSI 2nd launchWhite Sands Missile Range
New Mexico - USA
Dec 11, 201416

HXR focusing imaging spectrograph of FOXSI

This is planned to be used as PhoENiX HXR instrument.

Existing instruments (RHESSI etc.)

New instruments（FOXSI）

Modulation collimator + detector

Grazing incidence mirror + CdTe detector
Credit: Chandra telescope

CdTe detector

Furukawa et al. 2019

RHESSI 4-15 keV

Wolter-I geometry

FOXSI-1( 4-12 keV)FOXSI-1 4-15 keV

930

940

950

960

970

980

990

17

FOXSI-2 result was published from Nature Astronomy（Ishikawa et al. 2017）a7–9 keV

22DEM (cm–5 K–1)

10Hinode10201018∝ T –12FOXSI

1016
1014
2

3

51020
Temperature (MK)18

SXR focusing imaging spectrograph of FOXSI-3

This is planned to be used as PhoENiX SXR instrument.

• US-Japan collaborative sounding rocket experiment.
è FOXSI-3 was successfully launched on September 7th, 2018.
• Objectives:
1. Study small scale energy release in the solar corona
2. Demonstrate the new technology for X-ray imaging spectroscopy• Method:
1. Hard X-ray imaging spectroscopy
2. Soft X-ray imaging spectroscopy (for the first time in the world) with ahigh-speed X-ray camera        

See
http://foxsi.umn.edu/
andhttps://hinode.nao.ac.jp/
en/news /topics /foxsi-3180907/

     

19

FOXSI-3 Soft X-ray data

250 FPS data (4 ms continuous exposure)time profile

image (like pointillism)

spectrum

20

This full sun image is drawn by dotting
about 10 million individual X-ray photons.

21

FOXSI-3 (the 3 flight of Focusing Optics X-ray Solar Imager)rd  !"!%$  ! #   #
 

200
100

3.90•104
3.85•104
3.80•104

3.75•1040200

400

pixels

600

800

1000

photons

photons

pixels105
104

3.95•104300

0 # 

0

20

40

60
time [sec]

80

100

103
102
101

100
10-1
0

1000

2000
3000
energy [eV]

4000

5000

FOXSI-3 PhoEnIX full Sun soft X-ray image
1500• FOXSI-3 successfully performed the focusing imaging
spectroscopic observation of the solar corona in soft Xrays (from 0.5 keV) for the first time in the world!!

pixel

1000

500

00500

1000
pixel

1500

22FOXSI-4 sounding rocket project :It’s time to observe a flare!!
First sounding rocket to observe a solar flare• Science objectives:
1. Determine how much particle acceleration occurs in thegradual phase of a flare

FOXSI-4

Hi-C Flare

2. Produce images and spectra of flare footpoints from thermal tonon-thermal energies

FOXSI-4

3. Determine where non-thermal sources and heated plasma arelocated in a given coronal configuration
4. Measure the spatial distribution of superhot sources in a flare
5. Identify locations of energetic electrons in an erupting CME

Hi-C Flare• Method: Focusing imaging spectroscopy in X-rays (update ofFOXSI-3 observation)

Solar Flare Campaign White Paper:https://rscience.gsfc.nasa.gov/keydocs/SolarFlareCampaign.pdf

July, 2020
Schedule

Proposal was

accepted byNASA

2021

2022

2023

2024

Design &Development

Fabrication &TestIntegration &Test

Launch!!
23

FOXSI-4 sounding rocket project
High-precision electroformed
X-ray mirror  !"!%$  ! #   # photonspixels

300
2001000 # 
105
104

3.95•104
3.90•104
3.85•104
3.80•104
3.75•104
0200400

pixels

600

800

1000

photons

Paraboloid

CMOS detector (cf. FOXSI-3)
25 um depletion layer thickness (ç 4 um) for• Higher sensitivity to high-energy X-rays• Higher robustness against X-rays

Goal (cf. FOXSI-3)• <10” HPD (ç 30” HPD)
• <4” FWHM (ç 5” FWHM)

Hyperboloid

200 mmWolter type I mandrel (left) and circumferentialerrors (right)

Updated CMOS (for soft X-rays) & CdTe (for hardX-rays) detectors

0204060
time [sec]80100

103102101

100
10-101000

2000
3000
energy [eV]

2440005000

New observational
approach

Focusing Imaging-Spectroscopy
in soft and hard X-rays

x, t, E, po l

Numerical
approach

AsSp
trac
op
La
Seol
hyboPhasi
ra
r
ys
cs
to
Ph
ic
rys
ys
ics

Spectro-Polarimetry
in soft Gamma-rays

Interdisciplinary
approachParticle Acceleration
Magnetic Reconnection

Science Objectives of PhoENiX mission
1. Identify particle acceleration sites
in solar flares [where]
2. Investigate temporal evolution ofparticle acceleration [when]
3. Characterize properties ofaccelerated particles [how]planned to be realizedin Solar Cycle 26 (2030’)
25

Numerical Approachλ ~ 10 (Hoshino et al. 2001)

λ ~ 100 (Guo et al. 2015)
Model of
Shibata & Tanuma
2001

Lundquist number

𝑆𝑆 ≡𝜇𝜇! 𝑉𝑉" 𝐿𝐿#$𝜂𝜂

Cf. Reynolds number

Dynamical Petschek
S < 106(Shibayama et al. 2015)

Re = 104b.
aL

MHDPIC

Plasmoid chain MR
104 < S < 106
Ji & Daughton 2011

Re = 1.54

Effectiveplasma size

𝜆𝜆 ≡

𝐿𝐿𝑑𝑑%

Sweet-Parker modelS < 10426

Numerical Approach

MHD for understanding of ambient plasma
MHD simulation of a solar flare (magnetic reconnection)
calculated by Kaneko

Takasao et al. (2012)

Possible acceleration sites

ntrr e etcu h e
stou

flow

plasmoshoidck

Chen et al. (2015)27

Numerical Approach

MHD + GCA for understanding of particle acceleration
calculated by Kaneko

28

Numerical Approach

MHD + GCA for understanding of particle acceleration
calculated by Kaneko

29

Numerical Approach

PIC for understanding of particle acceleration

30Numerical Approach

Emission model for comparison
between observation and numerical simulation
calculated by Nagasawa

electronemi@ed gamma ray

interacting point
40000 km

Input Electron spectrum
H$ = H$% I !&Normalized Counts

Normalized Counts



40000 km

Solar corona modelin ComptonSoft
Photon Spectrum

2.0!!"# = 100 keV

4.0

3.0
Energy [keV]

Energy [keV]

31

New observational
approach

Focusing Imaging-Spectroscopy
in soft and hard X-rays

x, t, E, po l

Numerical
approach

AsSptracopLaSeolhyboPhasirar
yscstoPh
icrys
ysics

Spectro-Polarimetry
in soft Gamma-rays

Interdisciplinaryapproach
Particle Acceleration
Magnetic Reconnection

Science Objectives of PhoENiX mission
1. Identify particle acceleration sites
in solar flares [where]
2. Investigate temporal evolution ofparticle acceleration [when]
3. Characterize properties ofaccelerated particles [how]planned to be realizedin Solar Cycle 26 (2030’)
32

Interdisciplinary approachwith strength and heritage of each research field• Space Physics• Observation in interplanetary space(trace of plasmas from the sun)
• PIC simulation• Astrophysics• X-ray & gamma-ray observations• X-Ray Spectral Fitting Package(Xspec)• X-ray emission model• Key technologies

Common Physics• Particle Acceleration• Magnetic Reconnection• Laboratory plasma physics• Laboratory experiment of MR• Solar Physics• Solar observations• MHD simulation• Key technologies

33

Science Objectives of PhoENiX mission
The universe is filled withHigh Energy (Accelerated) Particles!!

“What is the origin ofHigh Energy Particles?”1. Identify particle acceleration sites
in solar flares [where]
2. Investigate temporal evolution ofparticle acceleration [when]
3. Characterize properties ofaccelerated particles [how]The sun is unique in that:ü A natural laboratory of high energy plasmas
ü Mother of lifeü Impact on earth and social environments

ü Energization of space plasmas
ü Formation and evolution of lifeü Influence on planetary environments

Sounding Rocket FOXSI series

2012

2014

2018

NASA DRIVE Science Center

Solar Flare Energy Release
https://solfer.umd.edu/

planned to be realizedin Solar Cycle 26 (2030’)

New observational
approach

Focusing Imaging-Spectroscopy
in soft and hard X-rays

x, t, E, po lSpectro-Polarimetry
in soft Gamma-rays

2024
Flare campaign

Numerical
approach

AsSptracop
LaSoehyboPhlasiraryscstoPhic
rys
ysics

Interdisciplinary
approachParticle Acceleration
Magnetic Reconnection
34