Update and functional test results for SWIM David McCann Solar system physics and space technology

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Update and functional test results for SWIM

David McCannSolar system physics and space technology

IRF, Kiruna

Supervisor: Professor Stas Barabash

David McCann, IRF ([email protected]) Workshop, Estec 14-15/9

Title

mailto:[email protected]

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START plate

Analyzer high voltage plate

e-

e-

1. Incoming ion directed into the aperture by the electrostatic deflector.

2. Ion traversing the analyzer channel.

3. Ion hitting the conversion surface yielding electrons detected by the START CCEM.

4. Scattered neutral hitting the STOP plate yielding electrons detected by the STOP CCEM.

Deflector high voltage plates

START CCEM

STOP CCEM

STOP platen

i+

i+

TDC

TOF


SWIM – Solar WInd Monitor

Low resource ion mass analyzer

Relying on time-of-flight technique

From significant point of view, a little sister to the MIPA sensor included in the SERENA package accepted to fly on-board the ESA BepiColombo MPO mission to Mercury (2014?)

Launch Mar 2008 on the Indian Chandrayaan-1 mission to the Moon


Introduction

mailto:[email protected]

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Two major modules: i) sensor headii) electronics

board housing


Sensor characteristics

Energy range ~10 eV – 15 keV

Energy resolution, E/E 7%

Viewing angleAngular resolution

9o x 180o

9° x 22.5°

Mass resolution H, He, O, Na/Al-group, K/Ca-group, Mn/Fe

Energy–elevation cycle 8 sec

Geometric factor, total 0.14 cm2 sr eV


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Primary objective:

Monitoring of the solar wind to support sputtered/back scattered ENA studies

Secondary objectives:

Investigating the possible occurrence of local magnetic fields on the lunar surface.

Studying sputtered ions from the lunar surface to investigate eg. permanently shadowed areas.

Studying the dynamic structure of the lunar wake.


Scientific objectives


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Tests performed at the calibration facilities at IRF, Kiruna.

Capable of creating ions with energies up to 50keV/q

Various species (H+, H2+, H3

+, O+, H2O+, N2

+/O2+, Ar+)

Pressure ~ 3-4*10-7 mbar


Test setup


6David McCann, IRF ([email protected]) Workshop, Estec 14-15/9

Test setup


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Several issues regarding the HVPS was identified

Ripple on the high voltage outputs Non-zero minimum on high voltages

Mechanical manufacturing error Analyzer channel walls not aligned to the

same origo


Functional test outcome

0.104 mm

0.133 mm

Analyzer high voltage plate

e-

Deflector high voltage plates

START plate

START CCEM

STOP CCEM

STOP plate

i+

i+

TOF


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Different settings to the deflector plates will scan through the azimuthal acceptance angle.

Plot showing pixel size at certain viewing angels.

Bold boxes is from calibrations, hollow markers from simulations.

Pixel size increasing with increasing angle.




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TOF spectra for H+ and H2O+.

Nicely separated primary particle peaks

Ion recoil problem Seems to be unavoidable? Can be subtracted from results by

calibration of occurrence.




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TOF spectra for H2O+ using different post-acceleration settings.

One can clearly see the influence on the TOF-spectra.




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Several issues regarding hardware were identified and corrected for.

The instrument performance meets the specifications in most aspects.

FM calibrations will thoroughly determine performance and prefered sensor settings.

Major point still pending satisfactory solution is the ion recoil problem.

FM calibrations will start during October 2006 Good luck in trying to get hold of David during the fall/winter of 2006.


Functional test summary


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David McCannSolar system physics and space technology

IRF, Kiruna

Supervisor: Professor Stas Barabash


Title

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Update and functional test results for SWIM David McCann Solar system physics and space technology