Title
Update and functional test results
for SWIM
David McCann
Solar system physics and space technology
IRF, Kiruna
Supervisor: Professor Stas Barabash
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
1
Update and functional test
results for SWIM
Introduction
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
Deflector high
voltage plates
i+
2. Ion traversing the
analyzer channel.
1. Incoming ion directed
into the aperture by the
electrostatic deflector.
Analyzer high
voltage plate
i+
TDC
START CCEM
TOF
STOP CCEM
eSTART
plate
n
3. Ion hitting the conversion surface
yielding electrons detected by the
START CCEM.
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
e-
STOP plate
4. Scattered neutral hitting the
STOP plate yielding electrons
detected by the STOP CCEM.
2
Update and functional test
results for SWIM
Sensor characteristics
Energy range
~10 eV – 15 keV
Energy resolution, E/E
7%
Viewing angle
Angular 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
Two major modules: i) sensor head
ii) electronics board
housing
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
3
Update and functional test
results for SWIM
Scientific objectives
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.
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
4
Update and functional test
results for SWIM
Test setup

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
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
5
Update and functional test
results for SWIM
Test setup
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
6
Update and functional test
results for SWIM
Functional test outcome

Several issues regarding the HVPS was
identified



Deflector high
voltage plates
Ripple on the high voltage outputs
Non-zero minimum on high voltages
i+
Mechanical manufacturing error

Analyzer channel walls not aligned to the
same origo
i+
0.104 mm
Analyzer high
voltage plate
0.133 mm
TOF
START CCEM
STOP CCEM
START
plate
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
e-
STOP plate
7
Update and functional test
results for SWIM
Functional test outcome

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.
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
8
Update and functional test
results for SWIM
Functional test outcome

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.
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
9
Update and functional test
results for SWIM
Functional test outcome

TOF spectra for H2O+ using
different post-acceleration settings.

One can clearly see the influence
on the TOF-spectra.
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
10
Update and functional test
results for SWIM
Functional test summary

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.
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
11
Title
Update and functional test results
for SWIM
David McCann
Solar system physics and space technology
IRF, Kiruna
Supervisor: Professor Stas Barabash
David McCann, IRF ([email protected]) Workshop, Estec 14-15/9
12