Energetic particle measurements in the magnetosphere
Thank you to
Rob, Fran, Chris
and Barry for
their assistance
JEDI
George Clark
george.clark@jhuapl.edu
JEDI
sun avoidance
JEDI 270
FOV: 160 x12 Deg.
JEDI 180
FOV: 148 x12 Deg.
JEDI 90
FOV: 160 x12 Deg.
witness detectors
J E D I D E S I G N P R I N C I PA L
150
151
Figure 2: Schematic of the Puck EPD. Panel a illustrates a cross sectional mechanical drawing
152
that labels the various components of the sensor and TOF region. Incoming ions are represented
JEDI PERFORMANCE
B.H. Mauk et al.
Table 1 JEDI Level-3/Level-4 Performance Requirements
Parameter
Required
Capability
Comment
Electron Energies
40–500 keV
Ion Energies
(Measured, not
discriminated)
H: 20–1000 keV
He: 30–1000
O: 50–1000
25–1000 keV
H + 10–2000 keV
He: 25–2000
O/S + 45–10000 keV
Abuts JADE
Abuts JADE
Energy
Resolution
Ions < 25% (< 30% for
E < 40 keV); Electron <
larger of 25 % and 15 keV
20 %
Earth aurora spectra driver
Time sampling
0.6 s
0.5 s
Angle resolution
30°
18° using rotation
≤ 30 km auroral sampling/
Resolve loss cone for
R < 2/3 RJ
Pitch Angle (PA)
Coverage
0–360 degrees for whole
orbit
0–360 degrees for whole
orbit
Time for Full PA
near Periapsis
2s
1.25 s
Requires 3 JEDI heads
with 160◦ × 12◦ fans
Ion Composition
H and S/O over required
energies.
He: 70–1000 keV
H above 15 keV
He above 50 keV
O above 45 keV
Electron
Sensitivity:
Measure energy
spectra
I = 3E5–3E9 1/cm2 s sr
Sensor-G: 0.0036–0.00018
Pixel-G: 0.0006–0.00003
Up to 5E5 1/s counting
I = Intensity (1/cm2 sr)
G = geom. factor × eff.
(cm2 sr)
Variable G; 6 pixels/sensor
Ion Sensitivity
Measure energy
spectra
I = 1E4–1E8 1/cm2 sr
Senso-G: 0.002–0.0002
Pixel-G: 0.0003–0.00003
Up to 5E5 1/s counting
I = Intensity (1/cm2 sr)
G = geom. factor × eff.
(cm2 sr)
Variable G; 6 pixels/sensor
For high energy/angle
resolution
Separate S from O for
E > 200 keV
F L AT F I E L D I N G
T0
T1
T2
T3
T4
T5
i e
i e
i e
i e
i e
i e
ion FOV
blockage?
electron FOV
blockage?
electron and ion channels have some blockage due to grid post
Normalized Electron Flux
Uncorrected G-factor
Normalized Electron Flux
Corrected G-factor
CROSS CAL WITH RBSPICE
Cross-calibration efforts with RBSPICE on Van Allen probes proved fruitful
Electrons
Protons
S U P R AT H E R M A L S W I O N S
• Preliminary
analysis suggest
that JEDI can
measure approx.
10 keV/nuc ions in
the solar wind
WITNESS DETECTORS
a
small pixel mode
b
v0
v5
c
v5
e-
6-views:
Ion
v4
v3
v2
v1
v0
e- Ion
witness detector/unshielded detector
Dominated by
penetrators
Dominated by scattering
Identified scattering contribution and developed a method to determine
penetrators exclusively
JEDI-A180
JEDI 180
• Currently not operating HV on the microchannel plate
• Can not distinguish heavy ions from protons
• Will measure incident ion and electron energies
SCIENCE PLANNING
ENA
Med-Rate
HighS
Rate
Mauk et al., 2013
Planetary Equator
Calibration
Med-Rate
Low-Rate
ENA
JEDI has identified regions of scientific interest in the current sheet —> increase
data rates and tailor specific “modes”….WHY?
JUPITER’S MAGNETOSPHERE
How does Jupiter maintain its magnetodisk shape?
anisotropy, one may seek to identify the mechanism that leads to that anisotropy. The cenF O has
R Clong
E SbeenArecognized
CTING
O N Tfor
H the
E confinement
P L A S MofAlow energy
trifugal force
as responsible
plasma to regions close to the equatorial part of plasma sheet flux tubes (see, for example,
Bagenal et al. 1985; Moncuquet et al. 2002). Here I suggest a role for the centrifugal force
not merely in equatorial confinement but also in creating pitch angle anisotropy.
In order to understand the stretched field configuration, one needs to consider all of the
forces acting on the plasma. Equation (2) can be expressed as
!
2
"
#
2$
B
B
+ p∥ − p⊥ −
−∇ p⊥ +
2µ0
µ0
n̂
− ρΩ 2 r sin(ϑ)(ẑ × ϕ̂) = 0
RC
(3)
where (p⊥, p∥ ) are the components of the pressure tensor perpendicular and parallel to B,
ẑ is a unit vector parallel to the spin axis, r is radial distance,
ϑ is co-latitude,
ϕ̂ is a unit
centrifugal
force
pressure
pressure
vector in the azimuthal direction. Mauk and Krimigis (1987) found that on the day side of
gradient
the field configuration differs little from that of a dipole
Jupiter inside
of ∼22 RJ (whereanisotropy
field) the pressure gradient force, −∇p⊥ , is sufficient to balance the magnetic force but this
magnetic
force does not produce
the stretched field configuration that develops beyond roughly 20 RJ .
tension
McNutt et al., 1983
Connerney et al., 1981
Mauk and Krimigis 1987
Paranicas et al, 1991
Nichols et al., 2015
curvature of the field lines where the
of 20 RJ (dashed line)
Rc= 0.174Rj
indicate
P R E S S U R E A N I S O T Rdata
OP
Y a sharpchangein the
Corotation
[•E•
I
[
[
[
,
0 et lx10
Paranicas
al., -•e
1991
magnetic
Total
particle
Anisotropy
Corotation
•D
t
spacecraft
crosses
theneutralsheet.W
andKrimigis[1987]for quantifyin
fielddata,thereby
producing
avalue
incorporatingthe anisotropicpress
equations,
wewereableto achieveap
for the nightsideneutralsheetreg
balanceproblemidentifiedby McN
Krimigi$[1987]for thedaysidereg
thanwastheproblem(withoutthean
soa full accounting
of forcebalanc
remainstobe achieved.Experimen
measure
theanisotropies
onthedays
work,thattheanisotropy
forcetermh
the daysideas well. However,the
alignedflowsof thelower-energy
po
play (for example,seeMauk andKr
I
(b)
R=23Rj
E
0
I
-leet al.
Fig. 5 From5X10
Paranicas
(1991), count rates of the
Voyager 1 LECP detector in the
scan plane and for different
energy channels. The three
columns show measurements
made at 18.0, 23.1, and 35.45 RJ .
For each distribution the counts
per second are indicated and
below are shown the times (in
1979) of the measurements and
the energy range of the detector
assuming that the ions are
protons
Total
Gradient
I
I
I
Rc=
0.301
Rj
I
lx10 -is
2x10-is
Total
Conclusions
magnetic
Accepting the argument that the field distortion is produced dominantly by pressure
anisotropy, one may seek to identify the McNutt
mechanism [1988]).
that leads to that anisotropy. The cenTotal
trifugal force has long been recognized as responsible
for the confinement
of lowfocus
energy ha
We emphasize
thatour
plasma to regions close to the equatorial part of plasma sheet flux tubes (see, for example,
particle
• Parallel pressure is larger than perpendicular
region near the center of the neu
Bagenal et al. 1985; Moncuquet et al. 2002). Here I suggest a role for the centrifugal force
forceconfinement
plays a dominant
rolepitch angle anisotropy.
• Outside of ~20 RJ the pressure anisotropy
not merely in equatorial
but also in creating
Anisotropy
In order to understand
the stretched
field configuration, one needs to consider all of the
• Process that generates these anisotropies
is still an
open topic
Caudal
[1989],w
forces acting on the plasma. Equation (2)and
can be
expressedand
as Connerney
complementary
tosuch
global
mod
Gradient
(c) R = 35Rj
!
−∇ p⊥ +
2
"
B
+
2µ0
thebalance
of forceseverywhere
wi
2$
B
n̂
−
− ρΩ 2 r sin(ϑ)(ẑ × ϕ̂)system.
=0
(3)
p∥ − p⊥Jovian
magnetospheric
The
µ0 R C
#
P R E S S U R E A N I S O T R O P F.YBagenal et al.
Bagenal et al., 2014
Fig. 7 Three selected Juno orbits: early, (PJ3 2016 Nov. 10 16:46), middle (PJ17 2017 Apr. 13 07:27), end
(PJ31 2017 Sep. 13 21:49) showing precession of line of apsides relative to Jupiter’s geographic equator. The
orbits are numbered according to the sequence of perijoves (PJ), where PJ0 is the initial orbit insertion, with
the start/end of a numbered orbit about a day before perijove. The full orbit period is about 11 days. The black
dots indicate
±4 hours
of perijove.
High-cadence
observations
are planned for about
hoursequatorial
near perijove
measure
the ion
PADs
and
determine
composition
in12the
• JEDI will
region
• More complete measurements of the anisotropies
• Also, See J. Nichols
[2015], model of force balance with anisotropies included!
map out longitude structures in the atmosphere and interior, as well as gravity and magnetic
fields (see Connerney et al. 2014, this issue; Anderson et al. 2014, this issue; Janssen et al.
2014, this issue).
Labeling orbits by perijove (where orbit insertion is PJ0), we show the geometry of science orbits 3, 17 and 31 in Fig. 7 to illustrate typical early, middle and late orbits. A time
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• Observational campaign between Galileo and Hubble
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injection
and
perhaps
scatter
particles
into
20
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20
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19
18
Injection time:
day 362, 23h00
Mauk et al., 2002
ARTICLE IN PRESS
AURORAL RESPONSE TO INJECTIONS
D.G. Mitchell et al. / Planetary and Space Science 57 (2009) 1732–1742
Mitchell et al., 2009
1737
Conclusions
• ~50 - 250 keV ENAs measured
by Cassini INCA
• Local time enhancements in
ENAs indicative of injection of
energetic electrons & ions
• Simultaneous observations
from HST and Cassini UVIS
reveal a strong correlation
between transient
magnetospheric phenomenon
and auroral enhancements
C H A R G E S T A T E A N A LY S I S W / I N J E C T I O N S
Clark et al., 2016
Ion injection
⌦ ⇡ E/q
e
r
u
t
a
rv
u
c
t-
n
e
i
d
a
gr
Galileo
L=5
L=10
L=15
Equatorial Plane
• JADE-Ion may be able to tell us
more about the distribution of
O+ & S++ in Jupiter’s
magnetosphere
• Important to understanding
heavy ion dynamics
S O L A R W I N D VA R I A B I L I T Y
Clarke et al., 2009
•
•
Figure
8. infer
Totalcrude
auroralsolar
powerwind
from variations
Jupiter’s north
(crosses)
and south
(filled circles) polar regions
Can
JEDI
from
our TOF
only measurements?
compared with propagated solar wind dynamic pressure in May – June 2007. Arrival times of solar wind
Itforward
wouldshocks
be very
to compare
with
in situ6. data from JADE and remote
are interesting
indicated by shaded
regions as
in Figure
observations from Hasaki & HST
10 of 20
P R E C I P I TAT I N G H E AV Y I O N S
L ION PRECIPITATION AND ACCELERATION AT OUTER PLANETS
a
a
[
Ozak et al., 2010
Q3
Cravens & Ozak
Figure 2. Equilibrium fraction for oxygen charge states in H2 versus
ion energy and very similar to results from the work of Cravens et
al. [1995]. From the work of Ozak et al. [2010].
The O6+* ion is excited and emits soft X-rays. In addition to
these processes, collisional ionization and excitation of the
3. Chandra X-Ray Observatory (CXO) image of Jupiter. Note the disk and the auroral emission regions. From the
atmospheric target gases also take place. Cravens et al. used
f Elsner et al. [2005].
• JEDI will measure several 100 keV/nuc precipitating
ions
chargeheavy
exchange
(CX) and stripping cross sections for Oq+
(q =accelerated?
0 up to 8) collisions with H2 to calculate an equilibrium
•
If
these
heavy
ions
are
present,
then
how
are
they
ded (via the Knight mechanism) [Knight, 1973; current system. Electrons that are accelerated upward to
fraction versus energy (i.e., fraction of ion beam in each
not to produce the highly charged ions but to several MeV could be responsible for the observed QP-40
state), as shown in Figure 2. Note that the O6+ and
sufficiently to provide the observed 1 GW X- radio bursts [MacDowell et al., 1993; Elsner etcharge
al., 2005].
are found near energies of ≈ 1 MeV u!1. These
O7+ ions
was pointed out that the solar wind protons
Bunce et al. [2004] proposed thatQ4
the field-aligned
potenaccelerated to high energies, and the associated tials and associated field-aligned currents needed
forassumed
the
models
that the ions came from the middle magnehave not been observed (to our knowledge).
X-ray aurora are caused by pulsating reconnections at the
Q9
tosphere with the necessary energies.
a
w
tr
K
b
4
K
in
u
4
o
e
X
f
f
a
p
w
[
g
e
[
O
noon-midnight
cut
Previous
work:
Gurnett
et
al.
GRL
O P E N / C L O S E D F I E L D L I N E S 2010
Gurnett et al., 2010
d
Indications for open-closed
field line boundary:
• low-energy electron density
drop
• auroral hiss
• ratio of diff. intensities from
Kruppenergetic
et al., 2011 MOP
field-aligned
electrons with the same
• Ratio
of energetic
electron fluxes
energy
but oppositie
parallel
and anti-parallel
to the
directions
is a proxy
of field
open• What
will the
open
field
line
closed
field
line
configuration:
MOP 2011, BOSTON, MA, USA
July 14, 2011
configuration look like at Jupiter?
How does it compare to Saturn?
ratio = 1 (CLOSED)
JEDI?ratio ≠ 1 (OPEN)
of the similarities between the Earth’s and Jupiter’s beams
mentioned above, we conclude that the Jupiter beams likely
are generated at low altitudes within regions of downward
auroral electric currents. Because the beams at Jupiter are
highly structured and because strong aurora are expected in
regions of upward auroral currents, we also conclude that
the auroral field-aligned currents at Jupiter likely are structured like they are at Earth, with regions of downward
FIELD ALIGNED ELECTRONS
Variability
IAL ELECTRON BEAMS AT JUPITER
A10221
FAC system
Conclusions
Figure 18. A replotting and fitting of the Earth-obser
electron beam data published by Klumpar et al. [1988]
shown in our Figure 1 (left). The high value of m obtai
may more closely represent values expected while
beams actively are being generated and before the be
are degraded over time by scattering.
• Temporal (few mins.)
and/or spatial (< 20
km)
currents
closelyvariability
adjacent to regions of upward currents.
magnetosphere –ionosphere coupling likely is more st
tured and perhaps dynamic than previous large-scale mo
would suggest [Cowley and Bunce, 2001; Hill, 2001]
suggested by Dougherty et al. [1998]. A spatial-temp
averaging of our picture, however, would be qualitativ
consistent with previous large-scale models (Figure
lower).
[48] A key open question concerns the mechanisms
upward field-aligned acceleration. We propose that dif
ences in the details of the broad upward-accelerated spe
observed in both the Earth and Jupiter systems may co
spond to differences in the relative importance of
contributions of coherent and stochastic acceleration p
cesses. Both kinds of processes appear to contribute to
acceleration at both Jupiter and Earth.
• Angular scattering
between source
location and equatorial
magnetosphere
15-40 keV
• Magnetic field
signatures suggest
[49] Acknowledgments. We thank Sven Jacobsen of the Institu
Geophysik und Meteorologie Universität zu Köln for preparing Figur
turbulent
Alfven
waves
lower. Magnetic
field data in Figures
15 and 16 kindly
were provide
Figure 17. (top) A reinterpretation of the concept shown
in Figure 5. The data presented here indicate that the
electron beams are spatially structured. On the basis of our
Earth-derived assumption that such beams are generated in
regions of downward (with respect to Jupiter) electric
currents, this finding implies that the auroral currents
themselves are highly structured with a pattern of strong
upward and downward currents embedded in the broad
region that on average is a region of generally upward
currents. (bottom) Notional sketch of field-aligned electric
currents as a function of radial distance. The red line shows
a highly structured electric current system that we infer in
this paper. We expect a spatial and temporal average of
these currents (black curve) to render the static magnetosphere – ionosphere coupling currents derived by Hill [1979,
M. G. Kivelson, the principal investigator of the Galileo magnetom
experiment. Funding for this research was provided by National Space
Aeronautics Administration (NASA) grants from the Outer Pla
Research Program and from the Geospace Research Program.
[50] Wolfgang Baumjohann thanks Richard Thorne and ano
reviewer for their assistance in evaluating this paper.
References
Anderson, L., et al. (2002), Characteristics of parallel electric fields in
downward current region of the aurora, Phys. Plasmas, 9, 3600 – 36
Bhattacharya, B., R. M. Thorne, and D. J. Williams (2001), On the en
source for diffuse Jovian auroral emissivity, Geophys. Res. Lett.
2751 – 2754.
Carlson, C. W., et al. (1998), FAST observations in the downward au
current regions: Energetic upgoing electron beams, parallel pote
drops, and ion heating, Geophys. Res. Lett., 25, 2017 – 2020.
Cowley, S. W. H., and E. J. Bunce (2001), Origin of the main auroral
in Jupiter’s coupled magnetosphere-ionosphere system, Planet. S
Sci., 49, 1067 – 1088.
Dougherty, M. K., M. W. Dunlop, R. Prange, and D. Rego (1998), C
spondence between field aligned currents observed by Ulysses and
auroral emissions, Planet. Space Sci., 46, 531 – 540.
Ergun, R. E., et al. (1998), FAST satellite observations of electric
structures in the auroral zone, Geophys. Res. Lett., 25, 2025 – 2028
Frank, L. A., and W. R. Paterson (1999), Intense electron beams observ
Mauk & Saur, 2007
UPSTREAM ION EVENTS
Trajectory
3956
KRIMIGIS ET AL.: IONS UPSTREAM OF JUPITER
Data
Conclusions
KRIMIGIS ET AL.' IONS UPSTREAM OF JUPITER
3949
(bottompanel)is quitesoft but showsan overalltrendtoward
lO 2
harderspectraasthe eventprogresses
to its conclusion.Simi:
Voyager-1
LECP 89.1
surface-barrier
(96.5
•m for Voyager
1 (V1),
•m for Voy-
Jupiter inbound
1979
_ depletedsolid-state
February 22,detector
1979 larly, the anisotrophyshowsa decreasingtrend toward the end
ager 2 (V2)), totally
with 10 enerR • 175 Rj
of the event.
gy thresholdsrangingfrom 12 keV to ---7 MeV. The threshold
• Source of ions
appear to originate
differentialenergychannelsfrom - 30 keV to - 7.4 MeV. The
set from 0500 to 0600 UT in the sector of maximum intensity
lowestenergythreshold
is setby the
\ thickness
Towards of
- thealuminum
(sector4), again assumingthat the Z •_ 1 ions are primarily
Jupiter
contactfacingthe incomingflux and
varies
according
to
ion
oxygen.
It isform
evidentfrom
the plot that Z _• 6 ionsin the MeV
• end
of
The spectralbehaviorfor this eventis examinedin more de-__
discriminator
outputsarecombined
electronically
to provide
tail in Figure 13. Here the spectraare plotted during eventonlO 1 -
200
Voyager 1
Voyager 2
lO 0 _---
event
--'_-
UT--:
range were presentduring event onset and that the spectrum
species;
for example,
onVoyager12200-2300
thelowest
energy
threshold
Event
onset
H• sector
5
0500-0600
UT
is depletedof protonsin the rangeof -- 300-500 keV by at least
corresponds
to a proton
incident
energyof - 30 keV, whilethe
a factor of -• 9 (the downward pointing arrow indicatesthat
_ sctor
samethreshold
responds
to oxygen
ionswithincident
energies
10-1
there was
anIons
ambientflux
of protons
in the interplanetarymedi•
are
accelerated
of -84 keVandsulfur
Table1). Fur_-- ionsof - 140keV(see
-__
um at the time of this event). As the event progressedtoward
ther,theefficiencies
at thelowestenergy
thresholds
for oxyits conclusion,the spectrumat higher energiesdid not change
along bow shock
genandsulfurarelessthanunity,andthe generalresponses
substantiallyexceptthat the overall intensitiesof Z •_ 6 ions
are fairly broad
(for an extensivediscussionof instrumentre10--2
were enhancedwhile the slope remained about the same. At
the lower energies,the spectrumbecameharder and flatter besponse,seeKrimigis et al. [1981]). Becausethe detectormea-
ß' ........
60½
__
-
- 0430©
} Z•1
t....
H
"..
•
L
',
•
' ,
•
•_ Jupiter
• First order fermi
measurement.
Channel 39, measuringions
with Z _• 2, was not
acceleration
does
compared
on thebasisof energyper nucleon.Thisproperty
functioningproperly at this time on Voyager 1 and is not plotof thedetector
is discussed
in detailin Krimigiset al. [1981]
ted in the figure. As wasthe casewith Voyager2, the spectrum
not play athatrole
and will not be elaborated on here.
for days53 through 54 suggests
the dominant speciesdur10-4
_.
0430
o
/
Composition
•
6
ing this eventat energies• 300 keV were ionswith Z _• 6; the
The LEPT detector,on the other hand, performstwolow -200 keV. This behavior is reminiscentof the spectralevosurestotal particleenergy,it is possible
that itsresponse
could
(plotted
lution on day 184(Figure10)and of the eventon day 180(Figure
be dominated
by the
heavier
ions,eventhoughrelativeabun2230A
asoxygen)
10--3
6). Note that the Z _• 6 point at --4 MeV is a two-parameter
dances
of suchionswithrespect
to protonsmay
besmallwhen
•6
ß
• LECP
look
directions
22302%
• ',
V2• • ', •V1
I
I
IN, '1 I
100
Rj
105
183
Radialdistance(Rj)
151
118
Feb 22, 1979
83
7
t 060012001800
•0600
4
•- LECPon Voyager2
10-6
continuity of the spectrumover the entire energyrange from
< 100 keV to --5 MeV suggeststhat the dominant composition was oxygen, even at the lower energies.
One count
I I I III111
I I I IIIIII
,
level
SUMMARY
OF OBSERVATIONS
I I I llIT]]
101
51
•E
Ch
•45
2.5
(x
MeV
10
TM)
electrons
101
102
103
104
The results from the analysis of the data presented in the
previous sectionsmay be summarized as follows:
Fig. 13. The energyspectrumof the eventshownin Figure 12 using
1. The ion spectralform at event onsetis describedwell by
the samenotationasin previousfigures.Note that the protonsare rela- a power law in energy (dj/dE - KE-L '• --- 4-7) over the
tively
less
depletedin this particulareventthan in•--'--s-previouscases.
The
1013•
- ..............
-- •-'-•-M
range • 100 keV to • 4 MeV. Toward the end of three of the
one-count level shown at the bottom of the figure refers to the LEPT
events, the energy spectrumwas generally harder and exhibitdetector.
ed a relative flatness at the lower (_• 200 keV) energies.In two
other cases,the spectrumtoward the end of an event actually
As a Consequence,
onlyonelong-lived
eventwasobserved
by becamesofter at low energies(day 178) or remained essentially
Voyager 1 upstreamof Jupiter at the distanceof -- 170 Rs at unchanged (days 182-183).
2. The ion spectrumis depletedof protonsat energies• 300
the time the IMF wasapproximatelyradial [Zwickl et al., 1981;
Baker et al., 1984]. The data from this event on days 53 and keV and of helium at energies• 900 keV and is dominated by
Energy (keV)
Fig. 1. An ecliptic
planeprojection
of theinbound
trajectories
for
Voyager1 and 2 at Jupiter.The labelsV I and V2 illustratethe innermostencounters
of Voyagerl and2, respectively,
withtheJovianbow
shock.
Long-lived
events
arenoted
bythesolidbarsonthetrajectory
line.Theinsetshows
theangularsampling
scheme
of theLECPinstrument,including
theshielded
sector(sector8), thenominaldirectionof
theIMF •, andtheexpected
directionof arrivalof ambientionsunder
theinfluenceof the• x • electricfield(adaptedfrom B•ker et •l.
[]984]).
1011[•h•02(x109
)
I/•Jll'l
rl,
Krimigis
et al., 1985
Haggerty & Armstrong 1999
J U N O ’ S S O L A R PA N E L S
• Juno will be the first spacecraft to use solar panels in Jupiter’s magnetosphere
• Can we learn something about the performance of Juno’s solar arrays in Jupiter’s harsh
radiation environment
• JEDI witness detectors can help diagnose the high energy radiation environment
SUMMARY
• JEDI is in great shape to make energetic particle measurements throughout Jupiter’s
magnetosphere
• Detailed analysis of the JEDI EFB and cruise data are revealing new and interesting
opportunities
• In addition to the high-latitude measurements, we have identified several science
questions that can be addressed with JEDI
• This list is not exhaustive however
• In some ways, JEDI is uniquely positioned to test hypotheses (e.g., Cravens et al., 2003)
Thank you!
PA S T E P D I N S T R U M E N T S
Instrument
CPI
Measurements
> 0.5 MeV protons
> 3 MeV electrons
> 10 MeV/nuc heavy ions
↵
> 10 keV electrons
> 15 keV protons
> 50 keV/nuc heavy ions
LECP
HI-SCALE
EPD
MIMI
✏
PEPSSI
⇣
JEDI
⌘
Region
Discoveries
Periodicities in particle flux
Upstream Jovian ions
Particle trapping
Moon effects
Foreshock
Dawn magnetosheath
Inner/outer magnetosphere
foreshock
dawn magnetosheath
Outer/inner magnetosphere
> 30 keV electrons
> 50 keV ions
> 15 keV electrons
> 20 keV protons
>10 keV/nuc heavy ions
Equatorial inner & outer magnetosphere
Satellite flybys
> 20 keV electrons
> 30 keV protons
>7 keV/nuc heavy ions
charge state 2 < E < 200 keV
Bow shock
Magnetopause on dusk flank
>20 keV electrons
> few keV protons
>10s of keV heavy ions
Flank
Distant magnetotail
>20 keV electrons
> few keV protons
>10s of keV heavy ions
Dawn magnetopause/sheath
Polar magnetosphere
Inner/outer equatorial crossings
↵ Pioneer: Simpson et al. 1975
Voyager: Krimigis et al., 1977
Galileo: Williams et al., 1994
Cassini: Krimigis et al., 2004
⌘ Ulysses: Lanzerotti et al., 1992
✏ New Horizons: McNutt et al., 2008
⇣ Juno: Mauk et al., 2013