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Observational Tests of Suprathermal Particle Acceleration
(Dayeh/Hill Hill/Desai)
WORKING GROUP SUMMARY
SHINE Workshop 2009
10-5
10-3
10-1
101
103
105
107
200 400 600 1000 3000 5000
5.2-5.5 AU 97,98
FW M1/1H1d 5.2-5.5 AU 97,98FW H+ B2_correctedFWtail 25*c3FWPISUM corefw_TAILFWSW bulk SW1FWSW halo
Phase Space Density (s
3 / km
6 )
Proton Speed (km/s)
SWICS Ulysses
Downstream
f(v) = f v –5
o
tail
(in solar wind frame)
core(pickup ions and halo solar wind)
bulk solar wind
pickupprotons
sd su
tutd
cucd
tr
c0=419.3*c1;c2=1.5e30*c3
(1/cm^3) (km/s)
SW-density SW_Vth SW_kappa
1.000000 15.000 20.000
halosolar wind
V1
Suprathermal Ions in the Solar Wind
• Questions
• What are the major source contributors of the suprathermal population?
Not the bulk SW (Everyone agree?)
• How common are the v-5 spectra in the heliosphere?
Jury still out but lots of new data.
• What acceleration mechanisms are responsible for the suprathermal tail distributions?
Unknown but specific, testable, differences in theories are arising.
Gloeckler
SHINE Workshop 200906/23/2008 NAS - SHINE-Suprathermal
Spatial Variation of Suprathermal Ions
Knee from locally produced pickup ions
Tail from stochastic
and/or shock acceleration
Schwadron
Hill et al. ApJ 2009
Must look at how the suprathermals vary with position….local pickup ions vs. larger scale tail ions.
Variation with distance from Sun shows much more He+ and He++ than known models.
Stochastic acceleration explains compositional variation.
He+
He++
He+
He++
Lines = simulatins symbols = measurements
SHINE Workshop 2009
More observations becoming available
Schwadron (see also McComas et al. 2009)
Lepri
10-6
10-4
10-2
100
102
104
106
108
103 104
FWSW 4:36:55 PM 12/6/07
FWSWFWPIFW M1/1H1d CH boundary NorthFWtailTail SouthFW SCH M1/1H1d CH south 1400-1500
Proton Speed (km/s)
Ulysses SWICS
H+
1996North Coronal Hole
<R> = 2.93
Vsw(km/s) 790.0
SOLARWIND: SW_density(1/cm^3) SW_Vth(km/s) SW_kappa0.220000 50.000 20.0000
Edens (dyne/cm^2) = 6.925735E-12
PI Density= 5.5562E-04 Edens= 2.0249E-12
Tail Density= 0.8*6.092255e-7 E+23Edens = 0.8*1.642207e-14 E+16
FILES CAN BE REFERED TO BY ./filename I
Pickup Protonsn = 5.6•10
-4 cm
-3
P = 1.35*10-12
dyne/cm2
Solar Windn = 0.22 cm
-3
Vth = 50 km/s
P = 4.6*10-12
dyne/cm2
f (v) = fov – 5
Tail Protonsn = 4.9•10
-7 cm
-3
P =8.8*10-15
dyne/cm2
1993South Coronal Hole
<R> = 3.39
New Horizons/SWAPData New at SHINE
Data New at SHINE
Wind/STICSat 1 AU
1-9 AU~11 AU
~3 AU
Hill 2009
Gloeckler
New or newly analyzed data are now joining the observations of Gloeckler et al.
SHINE Workshop 2009
Fisk
Physical Picture of Fisk v-5 Theory
Last SHINE Fisk transport equation was criticized as not conserving particle number! This is not so and the misunderstanding was explained: equation applies only to the tail.
A physical picture was described. It requires a pumping mechanism moving particles and energy between the core to the tail. High energy tail particles diffuse out of expansion/compression regions so less energy is returned to the core => tail is accelerated.
These particlesdiffuse
These particles do not diffuse
SHINE Workshop 2009
To be separable or not?
Lee agrees that Fisk’s transport equation is just Parker’s in a different form. An experimentalist agrees also, adding it took him 5 days to show.
Lee also questions whether the solution is separable in space and velocity as Fisk requires? This is a critical difference between the conventional and the Fisk theory. Is it physically justifiable? Lee solves it w/o separating and does not get a power-law form.
Suprathermal ion composition at 1 AU changes with solar cycle (Dayeh et al., 2009) ===> Argues that remnants from solar and interplanetary events are likely to dominate the suprathermal ion population inside Earth orbit
SHINE Workshop 2009
Is the velocity dependence separable?
Lee asks whether the solution is separable as Fisk requires? This is a critical difference between the conventional and the Fisk theory. Is it physically justifiable? Lee solves it w/o separating.
€
∂f∂t+ (V + VD ) ⋅ ∇f + ∇ ⋅K ⋅ ∇f −
1
3∇ ⋅Vv
∂f
∂v= 0
∂fo∂t=1
v4∂
∂v
δu2
9κv∂
∂vv5 fo( )
⎡
⎣⎢
⎤
⎦⎥f v,r, t( )h r,t( )
€
δf (x, t,v) = v3
d 3x' dt'G (x,x' ; t, t' )(∇' ⋅δV' )∂f0∂v−∞
t
∫−∞
∞
∫
€
G(x, t;x ', t ' ) = [4πK (t − t ' )]−3 / 2 exp{− | x − x ' |2 [4K (t − t ' )]−1}
h∂f∂t
+hδu⋅∇f + f∂h∂t
+δu⋅∇h+53∇⋅δu( )h⎡
⎣⎢⎤⎦⎥=∇⋅δu3v4 h
∂∂v
v5 f( )−hδ fτ
Lee agrees that Fisk’s transport equation is just Parker’s in a different form. An experimentalist agrees also, adding it took him 5 days to show.