laboratory astrophysics using intense x-ray from free...
TRANSCRIPT
Laboratory Astrophysics
using Intense X-ray
from Free Electron Lasers (FELs)
2018. 3. 8. 1st CHEA Collaboration Meeting
Moses Chung*, Chae Un Kim, Kyujin Kwak, Min Sup Hur, and Dongsu Ryu
(UNIST Dept. of Physics and Center for High Energy Astrophysics)
J. R. Crespo López-Urrutia (Max-Planck-Institut fü r Kernphysik, Heidelberg)
Sung-Nam Park, Kyoung-Hun You (UNIST)
Hyock-Jun Son (IBS/RISP and Handong University)
Contents
Laboratory Astrophysics using Intense X-ray from FELs 2
Background
Strategy
Status
Laboratory Astrophysics using Intense X-ray from FELs 3
Background
Galaxies consist of:
90% ionized hydrogen
10% stars
0.01% planets
J. R. Crespo López-Urrutia, MPIK: X-ray astrophysics… 1st UNIST XFEL Science Workshop Ulsan 2016
In the Universe, Elements are Mostly “Ionized”
Laboratory Astrophysics using Intense X-ray from FELs 4
CircumGalactic Medium (CGM)
InterCluster Medium (ICM)
“Compilation of current observational measurements of the low redshift baryon census“
(Shull, Smith, & Danforth, ApJ 2012)
Warm-Hot Intergalactic
Medium at 105 to 108 K
In the Universe, Elements are Mostly “Ionized”
Laboratory Astrophysics using Intense X-ray from FELs
In the Universe:
• Interior of the Sun (15 MK)
• Solar corona (2 MK)
• Solar wind (MK)
• Supernova remnants (초신성 잔해)
• Active galactic nuclei (100 MK)
• Warm-hot intergalactic medium (0.1-10 MK)
In the laboratory:
• Fusion machines (50 MK)
• Accelerator, Laser produced plasmas (1 MK)
• Electron beam ion trap/source, ECR ion source
5
• Atoms lose many electrons at high temperatures due to collisions.
• The incomplete electronic shell does not compensate the positive
nuclear charge. The electronic structure of such positive ions with few
electrons behaves like that of an atom.
• Highly Charged Ions (HCI) constitute a dominant fraction of the visible
matter in stars, supernovae, near-stellar clouds, shocks, and jets from
active galactic nuclei.
Highly Charged Ion (HCI, 고전리(고가) 이온)
Laboratory Astrophysics using Intense X-ray from FELs 6
Example: Fe XXV = Fe24+ Ion
From 26 electrons to only two electrons: Helium-like 1s2
Z (Atomic number) = 92 for Uranium
Highly Charged Ion (HCI, 고전리(고가) 이온)
Laboratory Astrophysics using Intense X-ray from FELs 7
Atom: • size: 100 pm (Å ), • outer electrons weakly bound (~10 eV)
HCI: • size: few pm, • positive charge • few strongly bound
electrons (~keV) • strong electron-
nucleus overlap
Highly Charged Ion (HCI, 고전리(고가) 이온)
Laboratory Astrophysics using Intense X-ray from FELs 8
1
H
2
He
3
Li
4
Be
5
B
6
C
7
N
8
O
9
F
10
Ne
11
Na
12
Mg
13
Al
14
Si
15
P
16
S
17
Cl
18
Ar
19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
37
Rb
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
55
Cs
56
Ba
* 71
Lu
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
87
Fr
88
Ra
*
*
103
Lr
104
Rf
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Ds
111
Rg
112
Cn
113
Uut
114
Uuq
115
Uup
116
Uuh
117
Uus
118
Uuo
• Binding energy Z2 10 eV 140 keV
• Relativistic fine structure Z4 eV keV
• QED Z4 eV 300 eV
• Hyperfine structure Z3 eV 5 eV
• Nuclear size effects Z5 eV 200 eV
• Forbidden transition probabilities Z10 up to a factor 1018
Detailed properties of HCI states
are mostly unexplored. Why ?
* lanthanide, ** actinide
X-ray Spectroscopy of HCI
Laboratory Astrophysics using Intense X-ray from FELs 9
• Spectral lines are essential for diagnostics: – Plasma composition and charge state
– Doppler shift for velocity, cosmological redshift, rotation velocity
– Line ratios for plasma collision rate, density and temperature
– Line profiles for density, photoabsorption, temperature, relativistic boosting
– Magnetic fields…
• The strongest lines in HCI appear in the VUV and X-ray domain.
HCI regime: from 50 MK to 0.1 MK
X-ray Spectroscopy of HCI
Laboratory Astrophysics using Intense X-ray from FELs 10
Accuracy of X-ray spectroscopy of HCI is ~10 orders of magnitude worse than in
frequency metrology (도량형).
~140 keV
20.7 keV
1.24 keV
276 eV
PAL-HX1
PAL-SX1
Lasers
Laser spectroscopy has been
severely limited beyond the UV
and Vacuum UV range due to the
lack of appropriate light sources.
XFELs open an unexplored
photon energy range to laser
spectroscopy. (with 4~5 orders
of magnitude better resolution
than synchrotrons)
X-ray Astronomy
Laboratory Astrophysics using Intense X-ray from FELs 11
• Precise knowledge of the line spectrum of HCI is indispensable for the
understanding of astrophysical objects through space observatories.
Chandra’s
Wolter telescope
(NASA)
X-ray Multi-Mirror Mission (XMM-Newton)
European Space Agency
Athena (Advanced Telescope for High-ENergy Astrophysics):
Launch in 2028 by ESA (~ € 1B)
X-ray Astronomy
Laboratory Astrophysics using Intense X-ray from FELs 12
Soft X-ray
Spectrometer
of Astro-H
(Hitomi)
Fe XXV He a
in space and laboratory
plasmas
Launched on 17 February 2016,
contact was lost on 26 March 2016
(about $360 million)
Laboratory Astrophysics using Intense X-ray from FELs 13
Strategy
Laboratory Astrophysics using Intense X-ray from FELs
PAL-XFEL Overview
14
PLS-II
(3GeV/400mA)
0.1 nm Hard X-ray using 10GeV XFEL
(Max photon flux: >1.0x1012 photons/pulse)
• Project Period: 2011 ~ 2016
• Total Budget: 400 M$
PAL-XFEL
(10GeV/3kA)
1.1 km
170 m
Time resolve: ~picosecond
1024 1034
PSL-II PAL-XFEL Sun
> >
Peak Brilliance
Time resolve: ~femtosecond
280 m
PAL-XFEL Layout and Parameters
Laboratory Astrophysics using Intense X-ray from FELs 15
Undulator Line HX1 SX1
Wavelength [nm] (20.7 keV) 0.06 ~ 0.6 1 ~ 4.5 (0.276 keV)
Beam Energy [GeV] 4 ~ 10 3.15 (2.55)
Wavelength Tuning [nm] 0.1 ~ 0.06 (Undulator Gap)
0.6 ~ 0.1 (Beam Energy)
3 ~ 1 (Undulator gap)
4.5 ~ 3 (Beam Energy)
Undulator Type Planar Planar + APPLE II
Undulator Period [mm] 26 34
Undulator Gap [mm] 8.3 8.3
+ scanning plane
grating
monochrometer
30/10 Hz
CXI + XPP
2018~: Self-seeding, 60 Hz operation, Fast kicker (Hard/Soft simultaneous operation), Higher energy (~15 keV, Moessbauer)
How to Prepare HCI Samples ?
Laboratory Astrophysics using Intense X-ray from FELs 16
Electron beam ion trap (EBIT) Compact in size and can produce uniform
and steady-state HCI plasmas
Electron impact ionization
Selective ion production by election beam
energy
Photonic excitation by XFEL suppresses
uncertainties arising from collisional excitation
Most of the EBITs are not designed for FEL
50 eV ~ 30 keV to cover all ionic species of astrophysical interest
Experimental Station
Laboratory Astrophysics using Intense X-ray from FELs 17
XPP CXI
+ Additional
Plasma/AMO
physics station ?
(~ a few M$)
Transportable
EBIT design for
easy access
X-ray
Milestone Experiment at LCLS (2012)
Laboratory Astrophysics using Intense X-ray from FELs 18
The Fe XVII (Fe16+) spectrum is poorly fitted
by even the best astrophysical models. (40 year
old problem)
Controversy over whether this discrepancy is
caused by incomplete modelling of the plasma
environment or by shortcomings in the treatment
of the underlying atomic physics.
Inaccurately predicted
oscillator strengths are
the cause of
discrepancies
between collisional
radiative codes and
astrophysical/
tokamak observations
Measured ratio disagrees with theory by more than 3
Preparation of the Experiments
Laboratory Astrophysics using Intense X-ray from FELs 19
Take a few boxes, a Boeing 747 and a
big track (~ 30 k$ one way)
Soft X-ray beamline SXR
at LCLS
X-ray photoexcitation at 1 keV The EBIT itself is typically operational within 2-4 days after shipping
Center for High Energy Astrophysics (CHEA)
Laboratory Astrophysics using Intense X-ray from FELs 20
Stage1: Delivery and Experiments with mini-EBIT Stage2: Design and Development of a new mini-EBIT (UNIST-EBIT, 유니빛)
Compact Transportable EBIT: mini-EBIT
Laboratory Astrophysics using Intense X-ray from FELs 21
Ion cloud: - 0.05~0.5 mm diameter - 16 mm long - 1010 ion/cm3
Highly Charged Ions are extremely sensitive to charge transfer in collisions with the neutrals of residual gas ( < 10-11 mbar)
- Low-maintenance, table-top - Magnet structure: 72 permanent magnets - 0.86 T at trap center - Tunable electron beam energy to 8 keV,
limited by high voltage power supplies - Electron beam current up to > 80 mA - Excellent optical access, opening angle of 58o
along 16 mm
(in keV)
O Fe
Collaboration with MPI-K
Laboratory Astrophysics using Intense X-ray from FELs 22
MOU 체결 및 mini-EBIT 실험에 직접 참여
On-going Experiment / Analysis
Laboratory Astrophysics using Intense X-ray from FELs 23
X-ray
EBIT (He-like and H-like Oxygen)
570 ~712 eV
Ionization Chamber (Auger effect)
Off-axis e-gun
Silicon drift detector
YAG screen image
MPIK+NASA+LLNL+UNIST
Possible Experiment by CHEA #1
Laboratory Astrophysics using Intense X-ray from FELs 24
30% uncertainties in atomic data
XFEL + EBIT could reduce down to ~1% level
(Fe24+)
Possible Experiment by CHEA #2
Laboratory Astrophysics using Intense X-ray from FELs 25
Microcalorimeter X-ray spectrum of the Perseus cluster of galaxies. Top: Measured (black) and modelled (red) spectra in the 1.8–9.0 keV band. Bottom: Magnified 7.4–8.0 keV band showing He-like Fe and Ni transitions in comparison with XMM-Newton CCD data. From: Ref. [1], “Solar abundance ratios of the iron-peak elements in the Perseus cluster”, Hitomi Collaboration, Nature (2017). Hitomi collaborators (NASA Goddard, LLNL) are part of our team.
Possible Experiment by CHEA #3
Laboratory Astrophysics using Intense X-ray from FELs 26
Soft X-ray beam line
Possible Experiment by CHEA #4
Laboratory Astrophysics using Intense X-ray from FELs 27
Newly-discovered 3.5 keV line by Charge Exchange (CX)
Laboratory Astrophysics using Intense X-ray from FELs 28
Status
Laboratory Astrophysics using Intense X-ray from FELs
Mini-EBIT Part List Investigation
29
Laboratory Astrophysics using Intense X-ray from FELs
Student Training
30
RISP EBIS project
GBAR antiproton trap project
Thank you for your attention !
Laboratory Astrophysics using Intense
X-ray from FELs 31