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Scientific interests in cusp wave phenomena
Laboratoire de Physique des PlasmasPatrick ROBERT, CNRS / LPP
1. The hybrid AC/DC magnetometer team2. Measurement3. Technical interests4. Scientific interests
• Main scientific problem• Requests for the launch
5. Previous rocket results6. Conclusion
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
LPP: Laboratoire de Physique des Plasmas new laboratory since 1/1/2009 emerging from the plasma part of old CETP, and mixed with another plasmas laboratory of the “Ecole polytechnique”.
CETP spatial activities are kept: Plasma physics, Data processing, Magnetospheric physics, Multi Spacecraft missions as CLUSTER, THEMIS
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Scientific CoI : Patrick ROBERT
Experiment : Christophe Coillot EngineerPaul Leroy Engineer Alexis Jeandet EngineerMalik Mansour PhD Amin Rhouni PhDDominique Alison Assistant Engineer
Laboratoire de Physique des Plasmas
1- The hybrid AC/DC magnetometer team
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
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Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
2- Measurements
The hybrid AC/DC magnetometer is split in two parts :
a AC magnetometer (search-coils) of frequency range ~ 0.1 – 10 kHz
a DC magnetometer (based on Anisotropic Magneto-Resistance effect), of frequency range ~ 0. – 100 Hz
(see next talk of Malik Mansour)
The search-coils instrument is an old specialty of LPP, dedicated for wave fluctuations,and already used in space missions (GEOS, CLUSTER, THEMIS…)
The AMR DC magnetometer is a new technology, dedicated for very low frequencies.
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Experiments
AMR sensor (2 x 1 mm)
~15 cm
Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
HotPay-2 rocket
CETP Search-coil kernel
Half kernel
SCM package
(see next M. Mansour talk)
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3- Technical interests
Interest of simultaneous AC/DC measurement into a same package So this is a self-consistent instrument allowing wave polarization computation.
Test of a new technology
In-situ first measurement allow us to check than accuracy & sensitivity will be those expected
Future interest : spatial mission, automatic polarization computation, etc...
Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
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4- Scientific interests
a) Main scientific problems:
Magnetic field fluctuations are they locally created (< proton gyro frequency, ~600 Hz), or are they comes from equator (~a few Hz) ?
We wish to have near the ground the magnetic image of strong magnetic fluctuations recorded onboard spacecraft since 20 years, and we wish to clarify old points :
– Relationship between waves properties & e- precipitation ?– Ions heating ? (~ 0.3 ev in Ionosphere, to ~ 10-100 ev S/C orbit)– Current instabilities ?– Anisotropic instabilities ?
In any cases we need to identify waves modes, so wave polarization, and one more time an AC/DC magnetometer could be a very useful instrument
Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
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b) Request for the launch
Science is possible if there are significant events:
So, launch should be done during a strong magnetic activity (aurora)
During recent previous rocket missions, we had no chance on event detections, except a little bit on CUSP mission:
Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
Find field line from the ground (day/night side direction) may be not easy
Conjunction with THEMIS S/C not easy :3 S/C in equatorial plane, apogee 12 RE above Canada, Rev=24h Conjunction with CLUSTER ? Not easy too, polar orbit... Rev=2.5 days
Possible magnetic conjunctions with spatial missions ??
Others ?
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5 – CETP/LPP previous rocket results
The CUSP rocket was a NASA Black Brant X sounding rocket dedicated to the exploration of the electrodynamic coupling, pulsations, and acceleration processes in the dayside cusp and the boundary layer interface. The launch occured on December 14, 2002, from Ny Åleysund, Spitzbergen (79° N) during Bz negative conditions.
CETP had delivered the Search Coil Magnetometer (SCM) experiment
ICI-1 rocket (2003 ?) : no luck...
CHARM-1 rocket (2007 ?): no luck for the boom...
HotPay2 : The project is part of a EU financed scientific program called eARI. The projects are owned, managed and operated by ARR.The launch occured on January 31th, 2008, from Andøya.
CETP had delivered the Search-Coils and a New AC/DC Hall Magnetometer (ADHM)
CHARM-2 rocket : in preparation (launch about february 2010)
Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
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200 Hz event detection : some monochromatic waves < FH+Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
Possibility of ions anisotropy reduction, and allow precipitation...
CUSP : Search coils
~ 5. 10-5 nT2/Hz
at 200 Hz
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Main Characteristics of the VLF Magnetic Field Waves Recorded by the Search Coil Magnetometer Experiment Onboard the CUSP Sounding Rocket
Pinçon, J.; Krasnoselskikh, V.; de Feraudy, H.; Rezeau, L.; Robert, P.; Pfaff, R. F.
American Geophysical Union, Fall Meeting 2003, abstract #SM12A-1207
The CUSP rocket is a NASA Black Brant X sounding rocket dedicated to the exploration of the electrodynamic coupling, pulsations, and acceleration processes in the dayside cusp and the boundary layer interface.
The launch occured on December 14, 2002, from Ny Åleysund, Spitzbergen (79° N) during Bz negative conditions.
We present the magnetic field waves measurement collected in the frequency range [10 Hz - 10 kHz] by the three axis Search Coil Magnetometer (SCM) experiment onboard CUSP.
The observations reveal the presence of intense field fluctuations corresponding to ELF hiss which is only seen on closed field lines and hence can be used to define the magnetic boundary of the cusp. Several data analysis techniques were applied to the 3 components of the magnetic field fluctuations associated with the ELF hiss to obtain information regarding the wave polarization and the wave vector directions. The magnetic field wave data are compared with simultaneous observations of electric field wave data to further enhance our understanding of these wave phenomena. The main results coming from this detailed study are presented and discussed.
Laboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
CUSP /SCM : no science publication, only a talk...
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CENTRE d'ETUDE des ENVIRONNEMENTS TERRESTRE ET PLANETAIRES CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
HotPay2 / Search Coils Hall / LF 31/January/2008 (Jul. Day 2952)
HOTPAY2_ROPLOT/cospectro/visuspectro.ps - Roproc_Wave V 3.2 Production date : Wed May 14 18:34:42 2008
Log Power Spectral density, (nT) 2 /HzData from B Magnetic field [nT] in Des system
N= 512 dt= 2.045 s df= 0.4891 Hz Fc= 0.00 F1= 0.00 F2= 125.20
Lat. Long.
16.02 69.29
0
20
40
60
80
100
120
Fre
quen
cy (
Hz)
Bx
0
20
40
60
80
100
120
B
y
0
20
40
60
80
100
120
B
z
-0.50.0
0.5
1.0
1.5
2.02.5
Lo
g P
ow
er,
(n
T)2
5
.0 -
12
0.0
Hz
5
.0 -
12
0.0
Hz
19:15 19:20
U.T.
HotPay 2 : Hall LF Spectrograms (DC part)
eARI user meeting, Nessebar,Bulgaria, May 19th, 2008
CENTRE d'ETUDE des ENVIRONNEMENTS TERRESTRE ET PLANETAIRES CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
HotPay2 / Search Coils Hall / LF 31/January/2008 (Jul. Day 2952)
HOTPAY2_ROPLOT/cospectro/visuspectro.ps - Roproc_Wave V 3.2 Production date : Wed May 14 14:36:16 2008
Log Power Spectral density, (TM cnt) 2 /HzData from B Magnetic field [TM cnt] in SSS system
N= 512 dt= 2.045 s df= 0.4891 Hz Fc= 0.00 F1= 0.00 F2= 125.20
Lat. Long.
16.02 69.29
0
20
40
60
80
100
120
Fre
quen
cy (
Hz)
Bx
0
20
40
60
80
100
120
B
y
0
20
40
60
80
100
120
B
z
0
2
4
6
8
Lo
g P
ow
er,
(T
M c
nt)
2
5
.0 -
12
0.0
Hz
5
.0 -
12
0.0
Hz
19:15 19:20
U.T.
Spinning system Despun system
Unfortunately, no natural wavesDuring the covered period
Beating between spin and nutation
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CENTRE d'ETUDE des ENVIRONNEMENTS TERRESTRE ET PLANETAIRES CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
HotPay2 /Magnetometer 31/January/2008 (Jul. Day 2952)
HOTPAY2_ROPLOT/cospectro/visuspectro.ps - Roproc_Wave V 3.2 Production date : Wed May 14 18:47:22 2008
Log Power Spectral density, (nT) 2 /HzData from B Magnetic field [nT] in Des system
N= 512 dt= 2.045 s df= 0.4891 Hz Fc= 0.00 F1= 0.00 F2= 125.20
Lat. Long.
16.02 69.29
0
20
40
60
80
100
120
Fre
quen
cy (
Hz)
Bx
0
20
40
60
80
100
120
B
y
0
20
40
60
80
100
120
B
z
2.5
3.0
3.5
4.0
4.5
5.0
Lo
g P
ow
er,
(nT
)2
5
.0 -
12
0.0
Hz
5
.0 -
12
0.0
Hz
19:15 19:20
U.T.
HotPay 2 : SC Magnetometer data (same conclusion)
eARI user meeting, Nessebar,Bulgaria, May 19th, 2008
Spinning systemCENTRE d'ETUDE des ENVIRONNEMENTS TERRESTRE ET PLANETAIRES CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
HotPay2 /Magnetometer 31/January/2008 (Jul. Day 2952)
HOTPAY2_ROPLOT/cospectro/visuspectro.ps - Roproc_Wave V 3.2 Production date : Wed May 14 14:41:33 2008
Log Power Spectral density, (TM cnt) 2 /HzData from B Magnetic field [TM cnt] in SSS system
N= 512 dt= 2.045 s df= 0.4891 Hz Fc= 0.00 F1= 0.00 F2= 125.20
Lat. Long.
16.02 69.29
0
20
40
60
80
100
120
Fre
quen
cy (
Hz)
Bx
0
20
40
60
80
100
120
B
y
0
20
40
60
80
100
120
B
z
0
2
4
6
8
Lo
g P
ow
er,
(T
M c
nt)
2
5
.0 -
12
0.0
Hz
5
.0 -
12
0.0
Hz
19:15 19:20
U.T.
no natural events…
Despun system
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Some cautions must be taken to avoid saturation encountered on HotPay-2 :
Various solutions are studied to avoid telemetry saturation :
Choose large dynamic for Bmax ~ 50000 nT (to be clarified). So, even if the spin axis of the rocket is orthogonal to the DC Mag. field, telemetry will not be saturated.
This implies a loss of precision on the sampled waveform amplitude, (may be not so important regardless wave events detection, but pity)
Filtering above ~ 10 Hz the AC search-coils, and below 50 Hz the DC mag to keep an overlapping of the two frequency ranges (redundancy for cross calibration)
Use more than 16 bits samples (24 bits ?) In progress ...
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
Laboratoire de Physique des Plasmas
Telemetry range(12, 16,24 bits ?) B┴ DC field up to ~ 60000 nT
(worse case where trajectory is perpendicular to local DC field...)
Waves amplitude~ 1 nT
16 bits: 0 - 65535
Bo DC field
Spin axis
B DC field
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6 – ConclusionLaboratoire de Physique des Plasmas
ICI-3 MIC/DR meeting, Oslo, September 8, 2009
The AC/DC magnetometer is a new kind of self-consistent instrument to study the wave polarization, allowing computation of the K vector of a wave, in the BDC reference frame
But we always need other data to do correct science:Electric field, particles measurement, etc.
In case of wave events detection, scientific LPP team would be happy to contribute to global work with aurora scientists of the rocket community
Science is possible if there are significant events: All Rocket community is certainly convinced of the importanceto choose the best time span launch too catch interesting events for all experiments.
