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Sinaia, September 6-10, 2005 1
Berndt Klecker
Max-Planck-Institut für extraterrestrische Physik, 85741 Garching, Germany
Workshop on
Solar Terrestrial Interactions from
Microscale to Global Models
Sinaia, Romania, September 6 - 10, 2005
Heavy Ion Charge States in
Solar Energetic Particle Events
Sinaia, September 6-10, 2005 2
• Introduction
• Measurement Techniques
• Ionic Charge State (Fe , Ne, Mg, Si) in IP Shock /CME Related SEP
Events
• Ionic Charge States (Fe, Ne, Mg, Si) in 3He-rich and Heavy Ion-rich Events
• The Energy Dependence of Ionic Charge States - Mechanisms
• Summary
OUTLINE
Sinaia, September 6-10, 2005 3
ENEGETIC PARTICLES IN THE HELIOSPHERE
Sinaia, September 6-10, 2005 4
• Information on the Source
i.e. Solar (Solar Wind, Corona); Interstellar, e.g. He+ Pickup Ions
For Solar Source: Source Location (Temperature, Density)
• Important Information on Fractionation, Acceleration and Propagation
Processes
Injection, Acceleration and Propagation generally depend on Rigidity,
i.e. particle velocity v and M/Q
INTRODUCTION
Why are Ionic Charge States Important?
Sinaia, September 6-10, 2005 5
WHERE DO SOLAR ENERGETIC PARTICLES COME FROM ?The Historical Development
Forbush, 1946
Phase 1:
Everything comes from Flares
Phase 2: ~ 70s to 90s
Flares and CMEs / Shocks
Impulsive and Gradual SEPs
Phase 3: Present
Flares and CMEs / ShocksRelative Contribution to SEPs under Debate
Classification of 2 distinct types of SEPs events in question.
IMPULSIVEFLARES
GRADUALFLARES
DurationSXR < 1 h < 10 hγ SXR < 10 min < 10 min
Height ≤10 km ~5 ⋅10
Volume 10 -10 cm 10 -10 cmenerg y density high LowHa size small LargeDuration HXR < 10 min > 10 minDuration m < 5 min > 5 minMetri c Radio (I )I , III II,(III),IV
Lin, 1970; Pallavicini et al., 1977, Reames 1999
He-rich gradualparticles electron rich proton rich
He/ He ~ 1 ~0.0005Fe/O ~ 1.23 ~ 0.15H/He ~ 10 ~ 100Q ~ 20 ~ 14Duration hours Days
Long. Distrib < 30° ≤ 80°Metric Radio III, V II,III,IV,VSolar Wind - Ipl. shockEvent Rate ~ 1000/a ~ 10/a
1st measurement of 2 GLEs
in 1942
Sinaia, September 6-10, 2005 6
Average of 20 Events
Energy: 385 keV/nuc
IMPULSIVE EVENTS Average Elemental Abundances
• Mason et al., 2002, 2004
• Reames, 1999
NEW
Sinaia, September 6-10, 2005 7
Results from early measurements at ~1 Mev/nuc:
Qm(Fe) ~12 -16
-> Te ~ 1.5-2 106 K
Coronal Temperatures
Q ~ Solar Wind, but somewhat larger (Fe)
EARLY RESULTS
for Large (gradual) IP-Shock Related SEP Events
Gloeckler et. al., 1976, Hovestadt et al. 1981, Luhn et al., 1984
Sinaia, September 6-10, 2005 8
Qm (Fe) ~ 19-20, Qm (Si) ~14
-> Te ~107 K
EARLY RESULTS
for 3He-, Fe-rich (Impulsive) SEP Events
Klecker et al., 1984, Luhn et al., 1987
Sinaia, September 6-10, 2005 9
EARLY RESULTS
Puzzle:
Gradual: Q at ~1 MeV/n similar to Solar Wind, but for some
ions (e.g. Fe) higher than in Solar Wind
Impulsive: Si fully ionized, i.e. M/Q=2
How can abundances be enhanced relative to C or O
(M/Q=2 for C - Si)
Question: Measurement only in small energy range at
~1MeV/nuc. How is Q at other energies?
Sinaia, September 6-10, 2005 10
1) In-Situ Measurement (e.g. by Electrostatic Deflection)
Energy range from Solar Wind energies to a few MeV/amu
Advantage: Direct Measurement of E, M, Q, Q Distribution,
Energy Dependence Q (E)
2) Measurement of the Rigidity Cutoff in the Earth’s Magnetic Field
Measurement of M, E, Rcutoff > Determination of average Q
Advantage: Q Determination to High Energies of 10s of MeV/amu
3) Indirect Methods using information on Energy Spectra, Composition, or time-
intensity profiles
Disadvantage: Model dependent
IONIC CHARGE DETERMINATION
Measurement Techniques
Sinaia, September 6-10, 2005 11
We want: E, M, Q Measurement of E/Q (electrostatic defl.)
E/M (e.g. time-of-
flight)
E (SSD)
Solar Wind: SWICS / Ulysses, SWICS/ACE, CTOF/SOHO
Suprathermal: STOF /SOHO, SEPICA/ACE
~ 0.2 - 0.6 Mev/nuc: SEPICA/ACE
~ 0.5 - 2.0 Mev/nuc: IMP-7/8, ISEE-1/3
IONIC CHARGE DETERMINATION
(1) In-Situ Measurements
Sinaia, September 6-10, 2005 12
1) In-Situ Measurement (e.g. by Electrostatic Deflection)
Energy range from Solar Wind energies to a few MeV/amu
Advantage: Direct Measurement of E, M, Q, Q Distribution,
Energy Dependence Q (E)
2) Measurement of the Rigidity Cutoff in the Earth’s Magnetic Field
Measurement of M, E, Rcutoff > Determination of average Q
Advantage: Q Determination to High Energies of 10s of MeV/amu
3) Indirect Methods using information e.g. on Energy Spectra, Composition, or
time- intensity profiles
Disadvantage: Model dependent
IONIC CHARGE DETERMINATION
Measurement Techniques
Sinaia, September 6-10, 2005 13
IONIC CHARGE DETERMINATION
(2) Rigidity Cutoff of the Earth’s Magnetic Field
10 1
10 2
55 60 65 70 75
Sampex/Lica0.85-1.25 MeV/nuc
Flux (particles/cm
2
-sec-sr-MeV/n)
Adjusted invariant latitude
normalization:average flux between 75-85degrees invariantlatitude
1H4He
16 O
Fe (group)
97311 0005 - 97313 1156
Mason et al., 1995; Mazur et al., 1995;
Leske et al., 1995; Oetliker et al., 1997
• Determine c(Rc) with ions of known charge (H+) on an orbit-by orbit bases
• Determine c for other ions
• Compute Qavg from Rc, c and E, M
Advantage:
Large Energy Range
Energy Dependence
Disadvantage:
Intensity needs to be large
SAMPEX
(polar Orbit, ~ 600 km altitude)
Sinaia, September 6-10, 2005 14
IONIC CHARGE DETERMINATION
(2) Rigidity Cutoff Variations During SEP Events
Leske et al., 2001
• c(Rc) can vary by several degrees
during an event• Determine c for H+ or He2+ on an orbit by
orbit basis• Compute adjusted c from time variation
• Use c(Rc) or linear fit: cos4(c) = a Rc+b
to derive Qavg from Rc, c and v, M
Qavg = (M v) / (Rc e)
SAMPEX
Sinaia, September 6-10, 2005 15
3) Indirect Methods using information e.g. on Energy Spectra, Composition, or
time - intensity profiles
Disadvantage: Model dependent
• Energy Spectra: M/Q dependent roll-over of spectra (Tylka et al.,
2000)
• Composition: M/Q-dependent fractionation effects (Cohen et al.,
1999)
Rigidity dependent interplanetary propagation:
• Time to maximum intensity (O’Gallagher et al, 1976, Dietrich & Tylka, 2003)
• SEP decay phase (Sollitt et al., 2003)
IONIC CHARGE DETERMINATION
Measurement Techniques
Sinaia, September 6-10, 2005 16
IONIC CHARGE DETERMINATION
(3) Indirect Methods
1. FeX(E) ~ Eγ exp(-E/E0X)
2. E0X =E0H*(Q/M) 1
April 20-24, 1998Tylka et al., 2000
• Determine E0X, γ from spectral fit
• Determine M/Q from (2)
17
IONIC CHARGE DETERMINATIONExperiments and Energy Range
EEARLY MEASUREMENTS FROM IMP-7 / 8, ISEE - 1/3
RECENT MEASUREMENTS FROM SAMPEX - SOHO - ACE
0
4
10-1 100 101 102 103 104 105
ENERGY (keV/nucleon)
Solar Wind
SWICS / ACE
Suprathermal and Energetic Particles
STOF / CELIAS / SOHO
SEPICA / ACE
LICA+HILT+MAST / SAMPEX
ULEZEQ / ISEE-1/3
Sinaia, September 6-10, 2005 18
NEW RESULTS (SAMPEX-SOHO-ACE) Gradual Events: Mean Ionic Charge Varies With Energy
SAMPEX: Mason et al., 1995; Leske et al., 1995, Oetliker et al., 1997)
Systematic Increase of Q with Energy above ~10 MeV/amu, in particular for Fe
Oct. 1992
Sinaia, September 6-10, 2005 19
NEW RESULTS (SAMPEX-SOHO-ACE) Gradual Events: Large Variability of Q (E)
Möbius et al., 1999, 2000, 2003; Bogdanov et al., 2000, Klecker et al. 2000, 2001, 2003; Popecki et al., 2000, 2001, 2003; Bamert et al., 2002; Labrador et al., 2003
Large Variability of Q (E) for Heavy Ions, in particular for Fe
At energies above ~200 keV/nuc:
Large VariabilityQFe(E) increasing at E > 10 Mev/nuc - often
QFe (E) increasing at ~ 1 MeV/nuc - some cases
At low energies of up to ~ 250 keV/amu:
Q similar to Solar Wind
0
10
20
30
40
50
60
0 5 10 15 20 25
Q STOF (x3)Q SEPICA (0.18-0.25 MeV/n)
IONIC CHARGE
1998, Day 121
Day 121, 1998 CME / IP Shock Event
0.01 - 0.1 MeV/n
SW: 10.1
Sinaia, September 6-10, 2005 20
NEW RESULTS (SAMPEX-SOHO-ACE) Gradual Events: Mean Ionic Charge Varies With Energy
SAMPEX ResultsMason et al., 1995; Leske et al. 1995; Oetliker et. 1997; Mazur et al., 1999;Leske et al., 2001; Labrador et al., 2003
ACE ResultsMöbius et al., 1999, 2000, 2003; Bogdanov et al., 2000, Klecker et al. 2000, 2001, 2003; Popecki et al., 2000, 2001, 2003
Sinaia, September 6-10, 2005 21
NEW RESULTS (ACE+SOHO) Impulsive Events: Mean Ionic Charge Increases ALWAYS with Energy
YEAR DATE Qm (Fe)0.18-0.43
Q
1998 252 00:29-253 23:45
17.5 0.60
1999 184 21:36-186 06:00
14.9 0.60
1999 201 02:19-202 22:19
16.5 0.60
2000 122 04:05-122 23:54
15.2 0.55
Möbius et al., 2003; Klecker et al, 2005
8
10
12
14
16
18
20
22
24
0.01 0.1
Event 1
Event 2
Event 3
Event 4
STOF-AVG (2-4)
Averge Charge of Fe
Energy (MeV/nuc)
Sinaia, September 6-10, 2005 22
IMPULSIVE EVENTS Ionic Charge of Ne, Mg, Si, Fe (ACE)
6
10
14
18
22
26
0.1 1
9. September 1998
Q-NeQ-MgQ-SiQ-Fe
Energy (MeV/nuc)
SW / CME related SEP
6
10
14
18
22
26
0.1 1
20. July 1999
Q-Ne
Q-Mg
Q-Si
Q-Fe
Energy (MeV/nuc)
SW / CME related SEP
Sinaia, September 6-10, 2005 23
THE ENERGY DEPENDENCE OF THE IONIC CHARGE Overview of Possible Mechanisms
1) Ionization by e, p in a dense plasma in the low corona
“Stripping Model”
2) Effect of Energy Spectra with M/Q-dependent roll-over
(i.e. Acceleration and Propagation effects)
2) Mixing of 2 Sources: Solar Wind Origin and Flare Origin (i.e Heavy Ion Rich)
Sinaia, September 6-10, 2005 24
Comparison of Ionic Charge States with Stripping ModelI. The Equilibrium Case
The Equilibrium Case
Impact ionization by p + e
Radiative + dielectronic recombination
1. Qm at E < 0.1 MeV/amu depends on Te (electron distribution function)
2) Large Increase of Qm at E > 0.1 MeV/n by (p+e) impact ionization
Electrons: Maxwell distribution
Cross sections and rate coefficients:
Arnaud & Raymond, 1992, Mazzotta et al., 1998; Kovaltsov et al. 2001
4
8
12
16
20
24
28
0.01 0.1 1 10
CONeMgSiFe
Energy (MeV/nuc)
Te = 1.2 10
6
Te = 2 106
Te = 1 107
Ostryakov et al., 1999; Barghouty & Mewaldt, 1999; Kocharov et al., 2000
Klecker et al., 2005
Sinaia, September 6-10, 2005 25
Comparison of Ionic Charge States with Stripping ModelII. The Non-Equilibrium Case
The Non-Equilibrium Case
Impact ionization by p + e
Radiative + dielectronic recombination
1) Qm depends on N*t
2) Equilibrium will be reached for
N * t ~ 1-10 * 1010 cm-3 s
(for E ~ 0.1 - 10 MeV/n)
3) Equilibrium N*t is energy
dependent
Kocharov et al., 2000
Q
24
20
16
12
8
Sinaia, September 6-10, 2005 26
Comparison of Fe Ionic Charge State Datawith Stripping Model
The Equilibrium Case
1. Qm at E < 0.1 MeV/n consistent with Te 1.2 - 1.4 106 K
2) Large Increase of Qm at E > 0.1 MeV/n
N * t ~ 1 * 1010 cm-3 s
t ~ 1 - 100 s: N ~ 108 - 1010 cm-3
-> Acceleration low in Corona
3) Increase of Qm with E larger than
in equilibrium stripping model
What is missing?
Klecker et al., 2005
8
10
12
14
16
18
20
22
24
0.01 0.1 1
Event 1Event 2Event 3Event 4STOF-AVG
Te=1.2 106 K
Te=1.4106 K
Averge Charge of Fe
Energy (MeV/nuc)
Sinaia, September 6-10, 2005 27
INTERPLANETARY TRANSPORTINCLUDING THE EFFECTS OF
Model, including acceleration Kartavykh et al., 2005
DIFFUSION CONVECTIONADIABATIC
DECELERATIONSOURCE
Energy Loss by Adiabatic Deceleration
1/E dE/dt = 4/3 Vsw / r s-1
Integrated (0.01 AU -> 1AU) energy loss depends on scattering mean free path and particle velocity.
Sinaia, September 6-10, 2005 28
A MODEL FOR ACCELERATION AND TRANSPORT
Acceleration Model, including
At the Sun: Spatial and Momentum Diffusion,Ionization, Coulomb Losses
Interplanetary Space: Transport, including Spatial Diffusion, Convection, Adiabatic Deceleration.
Simultaneous fit of: Energy Spectra Intensity-time
profile QFe (E)
(Kartavykh et al., 2004, 2005)
Sinaia, September 6-10, 2005 29
MODEL FITS FOR Ne, Mg, Si and Fe
July 3, 1999 Event July 20, 1999 Event
Sinaia, September 6-10, 2005 30
THE ENERGY DEPENDENCE OF THE IONIC CHARGE 2. Effect of Energy Spectra with M/Q-dependent Roll-Over
Klecker et al, 2001
10-8
10-6
10-4
10-2
100
102
104
10-2 10-1 100 101 102
61014186101418
Fe Flux (relative units)
Energy (MeV/nuc)
Eo (Fe10+) = 0.2 MeV/n
Eo (Fe10+) = 2.0 MeV/n
Fe Charge
0
5
10
15
20
10-1 100 101
Q (E0=0.2)
Q (E0=0.5)
Q (E0=1)
Mean Ionic Charge
Energy (MeV/nuc)
= 1.0
Assumed Energy Spectra J(E) ~ E−γ ex p (-E/E0)with E0 (A/Q) = E0 (proto )n * (Q/ )A
(Ellison & Ramaty, 1985, Tylka e t a., l 2000)
Fe Mean Ionic Charge computed with sample SW-Fe ionic charge distribution
Sinaia, September 6-10, 2005 31Mixing SW with QFe> 16+ from Impulsive EventsTylka et al. 2001
THE ENERGY DEPENDENCE OF THE IONIC CHARGE
3. Mixing of 2 Populations
Sinaia, September 6-10, 2005 32
SUMMARY-1Impulsive Events
• All non Interplanetary Shock related 3He-rich, Fe-rich events investigated so
far show
Qm (Fe) ~11 - 13 at 10 - 100 keV/n with a steep increase of Qm (Fe) to
Qm (Fe) ~14 - 20 in the energy range 180 - 550 keV/n.
• For several events, the increase above ~200 keV/n is steeper than expected for
charge stripping equilibrium conditions. Interplanetary transport effects
(adiabatic deceleration) are important and can explain the steeper increase.
• Homogeneous models provide good fits, if Q(E) is not too steep
• Inhomogeneous models are required to explain observations of steeper charge
spectra
Sinaia, September 6-10, 2005 33
SUMMARY-2
• The steep increase of Q with E for E < 1 MeV/nuc requires acceleration low
in the corona
N * A ~ 1-10 * 1010 cm-3 s
• For A ~ 10-100 s this corresponds to N ~ 108-1010 cm-3, i.e. altitudes < 2 Rs
High Charge States (e.g. Fe+20) observed at energies of ~ 1 MeV/n
can be used as Tracer for a Source Low in the Corona
Sinaia, September 6-10, 2005 34
SUMMARY-3Gradual Events
• High Charge States (and abundance enhancements) of Fe at Energies of
~ 1 MeV/nuc
Acceleration low in the corona
• High Charge States (and abundance enhancements) of Fe at Energies
> 10 MeV/nuc
Option 1: Injection and acceleration in the contemporary flare
Option 2: Injection and acceleration of 2 components by CME driven
coronal shock
(1) ~ solar composition, SW charge states
(2) ‘flare’ composition (heavy ion rich, high charge states)
Recommended