Pickup Ions and Reservoir for Energetic Particles

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Pickup Ions and Reservoir for Energetic Particles

• George Gloeckler Eberhard Möbius

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PUI Session

• PUI Production RatesDidkowski et al.
• PUI SourcesDrews et al., Schwadron, Bochsler
  Möbius
• Evolution of PUI DistributionsRoelof, Möbius et
  al.
• PUI Generated WavesJian et al., Smith et al.
• Tails and Energetic Particle ReservoirsGloeckler,
  Popecki et al., Lario et al.

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14.5 Years of SEM EUV data
Didkowski et al.
4
SEM-based He Photoionization Rates

• Black this work with SOLERS22 reference
  spectrum
• Magenta same as black but with SOLAR-2000
  spectrum

Rates match those calculated by McMullin et al.
(SOHO 11 Symp) using SOLERS22
This work uses SOLERS22 and SOLAR-2000 reference
spectra
Didkowski et al.
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ISM Ne Cone Inner Source C, N, O, H2O

• STEREO PLASTIC sees ISM Ne He, showing the
  Focusing Cones
• C, N, O, and H2O group ions are identified and do
  not show cone structure-gt Inner Source

Drews et al.
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Prediction vs Observed ENA H

• Roughly constant density outside the ionization
  boundary
• 50 eV ENAs survive inside 0.5 AU, higher energy
  move even closer

nENA-PUI ?i r12nENA/(r u) np1(r1/r)
nENA-PUI 2.3x10-4 cm-3 calculated at 3
AU nENA-PUI 1.7x10-4 cm-3 observed at 3 AU
Schwadron
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Simulation of ENA-Generated PUIs
June 1, 2015
IBEX_GRUSI_4
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Bochsler Möbius
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ENA Generated PUIs vs Inner Source
June 1, 2015
IBEX_GRUSI_4
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Bochsler Möbius
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PUI Sources

• ISM Ne PUI Ions found at 1 AU
• New suggestion for Inner Source from ENAs-
  Fluxes seem to agree- Cant explain molecules-
  Produce suprathermal distribution rather than
  cold Inner Source distribution- Has difficulty
  to explain latitude distribution

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Conclusions for guiding center energy loss in a
Parker magnetic field (applicable to
scatter-free propagation)
Outside Earths orbit rsin?gtV/?1AU ltdlnp/dtgt?
-2V/3r adiabatic cooling Inside Earths orbit
rsin?ltV/?1AU dlnp/dt (1-?2)/2
?lnB/?t-(1?2)(V/2r)(1-cos4?) ?
-(1?2)(?sin?)2(r/V) ? 0 as r ? 0 No adiabatic
deceleration near the Sun!for any nearly
scatter-free particle (PUIs or GCRs)
Roelof
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Influence of Ionization Cooling

• PUI Distribution Determined by Ionization
  Cooling
• ACE SWICS PUI PSDs June 2001 2007- Along
  Inflow Axis- 2001 L 0.85 AU (SolMax)- 2007 L
  0.34 AU (SolMin)
• Use a 2.0, 1.5 1.2in Model
• Looks Tantalizing!Acceptable V/Vsw
• To Do PSD Integration!!

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Evolution of PUI Distributions

• For scatterfree propagation, PUI cooling is
  reduced
• Preliminary observations with ACE SWICS seem to
  support a visible deviation from standard
  adiabatic cooling behavior
• PUI fluxes are highly modulated by SW
  streamsSTEREO ACE data provide excellent
  opportunity for detailed study

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Distribution of LH vs. RH in S/C Frame

• Because all the waves are intrinsically LH in
  plasma frame, the RH waves in s/c frame should be
  due to inward propagation with respect to the
  solar wind
• Both the inward and outward propagating ICWs can
  be carried out by the super-Alfvénic solar wind
• We use the Doppler shift relation to get fsw from
  fsc

LH ( 70)
RH
Jian et al.
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Power Spectrum
Magnetic power spectrum computed for 4.5 hr
interval shown on previous slide. Note broad
spectral enhancement at the proton cyclotron
frequency. Note, too, the added enhancement,
lower in frequency consistent with He
resonance. Both waves are left-hand polarized in
the s/c frame.
fpc/4
Smith et al.
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PUI Generated Waves

• PUI generated waves are preferentially observed
  during radial B
• Event rate decreases with r
• At 0.3 - 1 AU LH RH circular polarization
  observed
• Outside 3 AU events are rare Linear polarization
  is observed

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Gloeckler et al.
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He Suprathermal Tail Jan-Oct 2008 SW speeds lt
VmaxHe in the SW Frame

• PSD averaged over total time with SW speeds lt
  VmaxHe
• SW frame by subtracting Vsw
• Spectral index over the speed range 2 lt V/Vsw lt
  5 -5.2 0.1

Popecki et al.
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Correlation between ACE and Ulysses
Decay Times of SEP Electrons
Fluxes of SEP Electrons
Nearly homogeneous fluxesand decay rates
overwide range of Longitude,Latitude, and
footpoint sep.
Lario et al.
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Suprathermal Tails Energetic Particle Reservoirs

• Common spectra (v-5 high-E Rollover)for H,
  He, and He2observed in different heliospheric
  regions
• Large SEP events populate a spatially extended
  reservoir in the inner heliosphere during the
  decay phase
• Various sources probably contribute to energetic
  particle reservoirssuprathermal tails,
  ENA-generated PUIs, SEP events

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Open Questions

• What are the sources of Inner Source PUIs?
• Why are not more PUI-generated waves observed?
• .?

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Estimating Density of H ENAs

• j0 200 cm-2 s-1 sr-1 keV-1 at E01 keV
  McComas et al., 2009
• jj0 (E/E0)-? with ?2
• Lower energy bound of E150 eV (Survival prob. lt
  60 inside 1 AU)
• nENA4? j0 E0 (E1/ E0) 1/2-?/(?-1/2) v0
• 0.0034 cm-3
• v0440 km/s is the particle speed associated
  with E01 keV