太陽風を起源とする軟 X 線観測への原子物理の寄与

dpc.nifs.ac.jp

太陽風を起源とする軟 X 線観測への原子物理の寄与

Laboratory Experiments of SWCX

- 太 陽 ⾵を 起 源 とする 軟 X 線 観 測 への

原 ⼦ 物 理 の 寄 与 -

⾸ 都 ⼤ 学 東 京 ・ 理 ⼯ 学 研 究 科 ・ 物 理 学 専 攻

原 ⼦ 物 理 実 験 研 究 室 ⽥ 沼 肇

Hajime TANUMA

Department of Physics, Tokyo Metropolitan University


Activity of Atomic Physics Group in TMU

E-ring

(electrostatic

ion storage ring)

10 - 30 keV

GeV

城 丸 春 夫 , 松 本 淳 ( 化 学 )

東 俊 ⾏ ( 理 研 )

間 嶋 拓 也 ( 京 ⼤⼯)

RCE @HIMAC / GSI

(resonant coherent

excitation)

東 俊 ⾏ ( 理 研 )

Drift Tube

(ion swarm in He gas

at 4.3 K, etc.)

0.5 - 100 meV

⼤ 槻 ⼀ 雅 ( 電 通 ⼤)

井 上 洋 ⼦ (PD)

ECRIS

(electron cyclotron

resonance ion source)

1 - 100 keV

阪 ⼤レーザー 研 / UCD (Dublin)

宇 宙 実 験 (⾸ 都 ⼤)/ IAPCM ( 北 京 )

2


Contents of this talk

• Motivation – What’s SWCX ?

• Features of CX of multiply charged ions

• Principle of the measurements

• Preliminary results

• Comparison with theoretical calculations

• Future plans

3


Solar Wind = extremely thin plasma

- Negative : e - ~ 10 cm -3 around the Earth

- Positive : H + ~ 90%, He 2+ ~ 4%

C q+ , O q+ , Si q+ , Fe q+ , Ni q +, etc.

- Velocity : 250 - 400 km/s, 2x10 8 cm -2 s -1

(320 - 830 eV/u, 8 cm -3 )

400 - 800 km/s, 4x10 8 cm -2 s -1

(0.83 - 3.3 keV/u, 3 cm -3 )

Solar-Wind Charge-eXchange emission :

O 7+ (1s) + H → O 6+ (1snl ) + H + 4

O 7 (1s) + H → O 6 (1snl ) + H

→ O 6+ (1s 2 ) + h (≥ 561eV)


Chandra's image of Jupiter shows bright polar caps associated with

auroral activity on Jupiter. X-ray spectra revealed that this activity is

caused by highly charged ions of oxygen and other elements crashing

into the atmosphere above Jupiter's poles. The charged particles were

primarily ions of oxygen and other elements that were stripped of most

of their electrons, which implies that the ions were accelerated to high

energies in a multimillion-volt environment above the planet's poles. 7


3/4 keV diffuse background map from the ROSAT all-sky survey.

At 3/4 keV, the sky is dominated by the relatively smooth extragalatic

background and a limited number of bright extended Galactic object.

8


Luis Mendez

Dennis Bodewits

Scot Porter (EBIT, LLNL)

Elmar Träbert

Charge Exchange Madrid

29 September -1 October, 2010

European Space Astronomy Centre, Madrid, Spain

http://www.sciops.esa.int/index.php?project=CONF2010&page=CX2010 9


Suzaku ( 朱 雀 ) the 5th Japanese X-ray astronomy satellite

(July 10, 2005 -)

10


SUZAKU papers on SWCX

11


The Soft X-ray background observed by Suzaku

O VII : 1s 2 -1s2p p( (570 eV)

O VIII : 1s-2p (654 eV)

Low resolution ~ 100 eV

121


Transition Edge Sensor (TES) X-ray Micro-Calorimeter

Absorber

Heat sink

Size of the absorber :

200x200 µm 2

High resolution < 5 eV

13


Collaboration with

Astrophysics Groups (TMU and JAXA)

who are working for the development of TES

micro-calorimeter

Goal : “ High resolution spectroscopy of SWCX

using the TES micro-calorimeter in Lab.”

ex. O 7+ (1s) + H → O 6+ (1snl ) + H +

→ O

6+ (1s 2 ) + h (≥ 561eV)

Test measurements using Si(Li) detector

14


Charge Exchange :

Charge Transfer :

Electron Transfer :

Electron Capture :

電 荷 交 換 , 荷 電 変 換

電 荷 移 ⾏, 電 荷 移 動

電 ⼦ 移 ⾏, 電 ⼦ 移 動

電 ⼦ 捕 獲

Single electron capture, SC :

A q+ + B A (q -1)+ + B +

“True” double electron capture, TDC :

A q+ + B → A (q -2)+ + B 2+

Transfer ionization, TI :

A q+ + B → A (q -1)+ + B 2+ + e -


Some features of CX of MCI

• Very large cross sections ( > 10 -16 cm 2 )

• Single capture is usually dominant.

• Almost constant CS at keV range

• Increase/ decrease at very low energies

• Strong capture state selectivity

• Simple scaling rules for cross sections

• Emission lines are generally polarized.

16


Historical Works on CX in Japan

•NICEproject @ NIFS in Nagoya (1970s-80s)

(Naked Ion Collision Experiments)

Prof. Y. Kaneko and many guest researchers

• Classical l over the barrier model

H. Ryufuku, S. Sasaki, and T. Watanabe :

Phys. Rev. A 21 (1980) 745.

• Strong state selectivity in electron capture of

multiply charged ions

17


Classical over-the-barrier model

I B : 標 的 のIP

(q 1)2

E A


2

2n A

R C

2

←このときの 核 間 距 離 が 重 要

( A. Niehaus, 1986 )

主 量 ⼦ 数 :

n A


1 2 q



2I B

(q 2 q)

標 的 によって 捕 獲 準 位 が 異 なる

1

2

q


Scaling rules for the constant cross section region

Empirical scaling rule :

Mueller-Salzborn : Phys. Lett. 62A (1977) 391.

q,q1

/cm 2 1.43 10 12 q 1.17

Scaling rules based on COBM :

(I /eV) 2.76

M. Kimura et al.: : J.Phys.B28 (1995) L643.

q

/cm 2 2.6 10 13

q

(I /eV)

2

N. Selberg et al. : Phys. Rev. A 54 (1996) 4127.


r q

/cm 2 2.7 10 13 qr / I 2 2

1

I r


I j

: The j-th ionization energy in eV

N


j1


( j /I 2 j

)


N : # of outer shell e - (2 for He, 8 for Ar and Xe) 19


電 荷 交 換 分 光 法 による 状 態 選 別 断 ⾯ 積

粒 ⼦ 間 ポテンシャルによる 状 態 選 択

性 の 理 解

( Yu. S. Gordeev et al., 1983 ) ( K. Okuno et al., 1983 )


電 荷 移 ⾏ 断 ⾯ 積 のスケーリング 則 :

⼀ 価 イオンでない 限 り,かなり 普 遍 的

少 なくとも, 桁 を⾒ 積 もるのには 使 える

捕 獲 準 位 に 関 する 予 測 :

・ 古 典 的 オーバーバリアモデル

・ポテンシャル 交 差 モデル

定 性 的 には2つのモデルで 説 明 できる 場 合 が 多 い

その 他 の 理 論 :

厳 密 な 理 論 : 緊 密 結 合 法 etc.

古 典 論 :Classical l Trajectory Monte Carlo


電 ⼦サイクロトロン 共 鳴 型 多 価 イオン 源

MW : 14.25 GHz, 100 - 500 W

Coils & Magnets : B = 1 T


Experimental setup (1)

ECR ion source

Analyzing Magnet

He, H 2 gas

aperture : Φ8

target gas

He, H 2

Si(Li)

detector

(30mm 2 )

Faraday cup

23


14.25 GHz ECR

ion source

Analyzing magnet

Switching magnet

Experimental Setup

CORONA

- Cooperative Research On Novel Atoms -

Collision chamber

Liq. N 2 cooled CCD

Grazing Incident Spectrometer

24


Experimental setup (3)

Si (Li) detector

Window-less

E = 160 eV@5.9 keV

E ~ 107 eV @ < 1 keV 25


Preliminary

experimental spectra

in collisions of bare ions

with H 2 and He

26


C 6+ -H /He collisions (1)

2

Relative intensity of soft X-ray emission :

Collision energy dependence is small in the shape of spectrum.

27


C 6+ -H /He collisions (2)

2

The 1s-2p transition is dominant.

2p > 4p >> 3p 2p > 3p > 4p

28


O 8+ -H /He collisions (1)

2

Relative intensity of soft X-ray emission :

Collision energy dependence is small in the shape of spectrum.

29


O 8+ -H /He collisions (2)

2

The 1s-2p transition is dominant.

2p > 4p > 3p 2p > 4p > 3p

30


JPL

( J. Greenwood et al., , 2001 )


Be-window vs window-less

56 keV

O 8+ -H 2

80 keV

O 8+ -He

O 8+

J. B. Greenwood et al. (2001) TMU (2010) 32


Be-window vs window-less

H 2

TMU

Greenwood et al.

1s-2p 69% 80%

1s-3p 17% 9%

1s-4p 7% 11%

1s-5p 7% 0%

He

1s-2p 65% 76%

1s-3p 13% 10%

1s-4p 21% 14%

1s 5p 1% 0%

33


Comparison with theoretical

calculations

l 34


TC-AOCC calculation

35


Partial cross sections (1)

36


Partial cross sections (2)

37


Energy levels of H-like ions

2

S 1/2

2

P 1/2, 3/2

2

D 3/2, 5/2

2

F 5/2, 7/2

n=5

n=4

n=3

n=2 E = 186 meV (O 7+ )

E = 653.5 eV (O 7+ )

n=1

38


Statistical weights in cross sections

(nl) (nl)J l 1 (nl) J l 1

J l

2

J l

2



1

1



2

l 11

( 1

( 2 (nl) 2


l 1

2

(nl)





2

l 1 11


1

2

2 l 1 1

2


l

l 1

(nl)

l 2 l 2 (nl)

np 2 P 1/2 : np 2 P 3/2 = 1 : 2

nd 2 D 3/2 : nd 2 D 5/2 = 2:3

Now it is just assumption.

We must confirm it by experiments

with help of theoretical calculations.

nf 2 F 5/2 : nf 2 F 7/2 = 3 : 4

39


Cascade of transitions

2

S 1/2

2

P 1/2, 3/2

2

D 3/2, 5/2

2

F 5/2, 7/2

n=5

n=4

n=3

n=2

Initial state distribution

n=1

40


C 6+ - He collisions

The 1s-2p transition is dominant.

2p > 3p > 4p 2p > 3p >> 4p

41


C 6+ -H 2 collisions

2

The 1s-2p transition is dominant.

2p > 4p >> 3p 2p > 3p ~ 4p

42


O 8+ -H 2 collisions

2

The 1s-2p transition is dominant.

2p > 4p > 3p 2p > 3p ~ 4p ~ 5p

43


O 8+ - He collisions

The 1s-2p transition is dominant.

2p > 4p > 3p 2p > 4p > 3p

44


Experiments vs AOCC

•C 6+ cases – Agreements are very poor.

- Energy calibration of the detector is difficult.

• Atomic target (He) > Molecular target (H 2 2)

- Effect of molecular structure ?

- MOCC should be applied.

45


Preliminary

experimental spectra

in collisions of H-like ions

with He

46


C 5+ - He collisions

Relative intensity of soft X-ray emission :

Collision energy dependence is small in the shape of spectrum.

47


N 6+ / O 7+ - He collisions

The 1s-2p transition is dominant.

2p > 3p >> 4p 2p > 4p >> 3p

48


Bare ions vs H-like ions

Bare ion collisions :

A q+ + T → A (q-1)+ (nl 2 L + +

J ) T

H-like ion collisions :

A q+ (1s) +T→ → A (q-1)+ (1snl 1 L 3 +T +

J , L J ) AOCC method can not treat this issue.

MOCC is necessary for H-like ion collisions.

49


Energy levels of He-like ions

O 6+ 1s2p 1 P o 1

1s2s 1 S 1 1s2p 3 P o J

J = 2

J = 1

J = 0

w : 573.9 eV

A = 3.3x10 12 s -1

1s2s 3 S 1

A 3.3x10 s

z :

561.0 eV

1x10 3 s -1

y :

568.55 eV

x :

568.62 eV

33x10 5 s -1

3.3x10 5 s 1

5.4x10 8 s -1 2 h

1s 21 S 0 50


Future plans

• deceleration of ion speed up to 200 km/s

• absolute capture cross sections

• absolute emission cross sections

• measurements with a TES micro calorimeter

• introduction of an atomic hydrogen target source

• singlet-triplet t i l t ratios of produced d He-like ions

• H/H 2 ratio from the target dependence data

• challenge to observation of forbidden lines

• contribution to the SWCX as atomic physicists

51


Good and Bad News

I. N. Draganić, D. McCammon, and C. C. Havener (2010) 52


⾸ 都 ⼤・ 原 ⼦ 物 理

Collaborators

神 ⽥ 拓 真 , ⽯⽥ 卓 也 , (⼤ 橋 隼 ⼈・ 電 通 ⼤)

⾸ 都 ⼤・ 宇 宙 物 理

⾚ 松 弘 規 , ⽯ 崎 欣 尚 , + 数 名

JAXA / ISAS

篠 崎 慶 亮 , 満 ⽥ 和 久

北 京 応 ⽤ 物 理 与 計 算 数 学 研 究 所

劉 玲 , 王 建 国 , R. Janev

53


Thank you for your attention.

謝 謝

御 静 聴 ありがとうございました。

54

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