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.