Miniaturized Langmuir probe systems for in-situ ... - IRTG Heidelberg
Miniaturized Langmuir probe systems for in-situ ... - IRTG Heidelberg
Miniaturized Langmuir probe systems for in-situ ... - IRTG Heidelberg
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<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
<strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong> <strong>for</strong> <strong>in</strong>-<strong>situ</strong><br />
space plasma measurements<br />
Tore André Bekkeng<br />
PhD Candidate, Department of Physics<br />
November 5th 2010<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Outl<strong>in</strong>e<br />
1 Goals<br />
2 Theory<br />
3 Instrument design<br />
4 Results<br />
5 CubeSTAR<br />
6 Future work<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Goals<br />
Scope of the thesis<br />
Develop m<strong>in</strong>iaturized <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong> <strong>for</strong> <strong>in</strong>-<strong>situ</strong> space<br />
plasma measurements of electron density and electron<br />
temperature <strong>for</strong> use on both sound<strong>in</strong>g rockets and satellites<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Theory<br />
<strong>Langmuir</strong> <strong>probe</strong>s<br />
<strong>Langmuir</strong> <strong>probe</strong>s have been widely used to analyze plasma<br />
electron density and temperature.<br />
• An exposed conductor is placed <strong>in</strong> a plasma<br />
• It gets biased to a reference potential relative to the<br />
plasma potential<br />
• The collected current is measured<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Theory<br />
<strong>Langmuir</strong> <strong>probe</strong>s<br />
Normal sweep time 1 second<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Theory<br />
m-NLP concept<br />
The <strong>Langmuir</strong> <strong>probe</strong> equation <strong>for</strong> cyl<strong>in</strong>drical <strong>probe</strong>s<br />
I 2 c<br />
kBTe<br />
=<br />
2πm (nq2πrl)24<br />
<br />
1+<br />
π<br />
qV<br />
<br />
kBTe<br />
= 2kBTe<br />
m (nq2rl)2 + 2q<br />
m (nq2rl)2V I 2 c2 −I 2 c1 = 2kBTe<br />
m (nee2rl) 2 − 2kBTe<br />
m<br />
+ 2e<br />
m (nee2rl) 2 V2 − 2e<br />
m (nee2rl) 2 V1<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong><br />
(nee2rl) 2
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Theory<br />
m-NLP concept<br />
∆(I 2 2e<br />
c ) =<br />
m (nee2rl) 2 ∆V<br />
n 2 e =<br />
m<br />
2e(e2rl) 2<br />
∆(I 2 c)<br />
∆V<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Theory<br />
m-NLP concept<br />
ne =<br />
<br />
K ∆(I2 c )<br />
∆V where K = m<br />
2e(e2rl) 2<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Instrument design<br />
Probe design<br />
Probe diameter: 0.51 mm<br />
15 mm<br />
25 mm<br />
Centre conductor<br />
Dielectric <strong>in</strong>sulator<br />
= 1 mm<br />
Braid<br />
Insulation<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Instrument design<br />
Versions<br />
Versions of the <strong>in</strong>strument:<br />
• 4-channel version <strong>for</strong> sound<strong>in</strong>g rockets: Flown on the ICI-2<br />
rocket from Spitsbergen, November 5th 2008<br />
• Modified 4-channel version <strong>for</strong> sound<strong>in</strong>g rockets: To be<br />
flown on three sound<strong>in</strong>g rockets from Andøya Rocket<br />
Range, December 2010<br />
• 8-channel version <strong>for</strong> sound<strong>in</strong>g rockets: To be flown on<br />
ICI-3 from Spitsbergen December 2011, and on the NASA<br />
payload MICA <strong>in</strong> January 2012 from Poker Flat, Alaska<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Instrument design<br />
Mechanical design<br />
Probe placement on F-field booms<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Instrument design<br />
m-NLP electronics<br />
The entire m-NLP <strong>in</strong>strument consists of one Data Acquisition<br />
card, one Power/Interface card and the electronics box <strong>in</strong><br />
alum<strong>in</strong>ium.<br />
Probe<br />
DAQ PCB<br />
P&I PCB<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Instrument design<br />
Specifications, ICI-2<br />
Specifications <strong>for</strong> the m-NLP system, ICI-2 configuration:<br />
• Four 16-bit measurement channels<br />
• Electronics weight: 130 grams<br />
• Samplerate: Max 9 kHz, 5787 Hz <strong>for</strong> ICI-2<br />
• Measurement range: Down to about 100 pA<br />
• Density range (ICI-2 configuration): ne = 10 9 m −3 to<br />
10 12 m −3<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Instrument design<br />
Specifications, ICI-3<br />
Specifications <strong>for</strong> the m-NLP system, ICI-3 configuration:<br />
• Eight 16-bit measurement channels<br />
• Electronics weight: 270 grams<br />
• Samplerate: Max 100 kHz<br />
• Measurement range: Down to about 50 pA<br />
• Density range (ICI-2 configuration): ne = 10 8 m −3 to<br />
10 13 m −3<br />
• Altera Cyclone III/IV FPGA with TMR implemented<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Results<br />
Test<strong>in</strong>g <strong>in</strong> plasma chamber<br />
Current 2 (A 2 )<br />
3.5<br />
3<br />
2.5<br />
2<br />
1.5<br />
x 10 −14<br />
• Electron density <strong>probe</strong> 1:<br />
Probe current <strong>for</strong> <strong>probe</strong> 1 & 2<br />
1<br />
0.5<br />
Probe 1<br />
Probe 2<br />
Probe 1, l<strong>in</strong>ear fit<br />
Probe 2, l<strong>in</strong>ear fit<br />
0<br />
0 1 2 3 4 5 6 7<br />
Bias(V)<br />
• Electron density <strong>for</strong> <strong>probe</strong> 2:<br />
= 6.85·10 10 m −3<br />
ne = 6.83·10 10 m −3<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Results<br />
ICI-2<br />
Some facts concern<strong>in</strong>g the ICI-2 rocket launch:<br />
• Launched at 10.35 UT, December 5th 2008<br />
• Apogee of 330 km<br />
• Sonda VS-30 / Improved Orion motor configuration<br />
• Measuremente range: Down to about 100 pA<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Results<br />
ICI-2<br />
Post-flight analysis from the ICI-2 rocket launch<br />
Collected current (nA)<br />
400<br />
350<br />
300<br />
250<br />
200<br />
150<br />
100<br />
50<br />
Probe 4<br />
Probe 3<br />
Probe 2<br />
Probe 1<br />
0<br />
50 100 150 200 250 300 350 400 450 500 550<br />
Time after launch (s)<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Results<br />
ICI-2<br />
Post-flight analysis from the ICI-2 rocket launch<br />
Collected current (nA)<br />
120<br />
110<br />
100<br />
90<br />
80<br />
70<br />
Probe 4, filtered once<br />
Unfiltered data, 5.787 kHz sample rate<br />
Data, filtered with a band−reject filter from 3.07 Hz to 3.47 Hz, with a transition bandwidth of 0.2 Hz<br />
60<br />
94 94.2 94.4 94.6 94.8 95 95.2 95.4 95.6 95.8 96<br />
Time after launch (s)<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Results<br />
ICI-2<br />
Post-flight analysis from the ICI-2 rocket launch<br />
HF1 HF2 HF3<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Results<br />
ICI-2<br />
Post-flight analysis from the ICI-2 rocket launch<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
CubeSTAR<br />
Vision: Demonstrate a new concept Space Weather satellite<br />
First: Achieve meter resolution <strong>in</strong>stead of km resolution of<br />
electron density structures<br />
PCB board size: 75 x 80 mm<br />
Weight: Approx. 100 g<br />
Power: 0.5 W - 1.0 W (TBD)<br />
LAUNCH: 2013<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Future work<br />
Conclusions of the Present Work<br />
• The first ever measurements of absolute electron density<br />
have been made, with very high spatial resolution<br />
• Post-flight analysis from the ICI-2 rocket verified that the<br />
<strong>in</strong>strument worked as <strong>in</strong>tended, measur<strong>in</strong>g the smallest<br />
th<strong>in</strong>kable structures (limited by the electron gyro radius <strong>in</strong><br />
the order of 10 meters) <strong>in</strong> ionospheric plasma<br />
• New versions of the <strong>in</strong>strument <strong>for</strong> sound<strong>in</strong>g rockets are<br />
under f<strong>in</strong>al construction, <strong>for</strong> absolute electron density<br />
measurements<br />
• New <strong>probe</strong> design (m<strong>in</strong>iaturized spherical <strong>probe</strong>s, 3 mm<br />
diameter) will be done, <strong>for</strong> the 8-channel version<br />
measur<strong>in</strong>g electron temperature <strong>in</strong> addition to electron<br />
density (<strong>in</strong><strong>for</strong>mation is protected by a patent application)<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Future work<br />
Conclusions of the Present Work<br />
• The first ever measurements of absolute electron density<br />
have been made, with very high spatial resolution<br />
• Post-flight analysis from the ICI-2 rocket verified that the<br />
<strong>in</strong>strument worked as <strong>in</strong>tended, measur<strong>in</strong>g the smallest<br />
th<strong>in</strong>kable structures (limited by the electron gyro radius <strong>in</strong><br />
the order of 10 meters) <strong>in</strong> ionospheric plasma<br />
• New versions of the <strong>in</strong>strument <strong>for</strong> sound<strong>in</strong>g rockets are<br />
under f<strong>in</strong>al construction, <strong>for</strong> absolute electron density<br />
measurements<br />
• New <strong>probe</strong> design (m<strong>in</strong>iaturized spherical <strong>probe</strong>s, 3 mm<br />
diameter) will be done, <strong>for</strong> the 8-channel version<br />
measur<strong>in</strong>g electron temperature <strong>in</strong> addition to electron<br />
density (<strong>in</strong><strong>for</strong>mation is protected by a patent application)<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Future work<br />
Conclusions of the Present Work<br />
• The first ever measurements of absolute electron density<br />
have been made, with very high spatial resolution<br />
• Post-flight analysis from the ICI-2 rocket verified that the<br />
<strong>in</strong>strument worked as <strong>in</strong>tended, measur<strong>in</strong>g the smallest<br />
th<strong>in</strong>kable structures (limited by the electron gyro radius <strong>in</strong><br />
the order of 10 meters) <strong>in</strong> ionospheric plasma<br />
• New versions of the <strong>in</strong>strument <strong>for</strong> sound<strong>in</strong>g rockets are<br />
under f<strong>in</strong>al construction, <strong>for</strong> absolute electron density<br />
measurements<br />
• New <strong>probe</strong> design (m<strong>in</strong>iaturized spherical <strong>probe</strong>s, 3 mm<br />
diameter) will be done, <strong>for</strong> the 8-channel version<br />
measur<strong>in</strong>g electron temperature <strong>in</strong> addition to electron<br />
density (<strong>in</strong><strong>for</strong>mation is protected by a patent application)<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
<strong>M<strong>in</strong>iaturized</strong><br />
<strong>Langmuir</strong><br />
<strong>probe</strong> <strong>systems</strong><br />
Tore André<br />
Bekkeng<br />
Goals<br />
Theory<br />
Instrument<br />
design<br />
Results<br />
CubeSTAR<br />
Future work<br />
Future work<br />
Conclusions of the Present Work<br />
• The first ever measurements of absolute electron density<br />
have been made, with very high spatial resolution<br />
• Post-flight analysis from the ICI-2 rocket verified that the<br />
<strong>in</strong>strument worked as <strong>in</strong>tended, measur<strong>in</strong>g the smallest<br />
th<strong>in</strong>kable structures (limited by the electron gyro radius <strong>in</strong><br />
the order of 10 meters) <strong>in</strong> ionospheric plasma<br />
• New versions of the <strong>in</strong>strument <strong>for</strong> sound<strong>in</strong>g rockets are<br />
under f<strong>in</strong>al construction, <strong>for</strong> absolute electron density<br />
measurements<br />
• New <strong>probe</strong> design (m<strong>in</strong>iaturized spherical <strong>probe</strong>s, 3 mm<br />
diameter) will be done, <strong>for</strong> the 8-channel version<br />
measur<strong>in</strong>g electron temperature <strong>in</strong> addition to electron<br />
density (<strong>in</strong><strong>for</strong>mation is protected by a patent application)<br />
Tore André Bekkeng <strong>M<strong>in</strong>iaturized</strong> <strong>Langmuir</strong> <strong>probe</strong> <strong>systems</strong>
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