Transcript PRINCIPALS OF VOLATILE COMPONENTS MEASUREMENTS IN …

PRINCIPALS OF VOLATILE COMPONENTS MEASUREMENTS IN THE GAP
EXPERIMENT ONBORD THE PHOBOS-GRUNT MISSION AND BEYOND.
M.V.Gerasimov and the GAP team
IKI RAS, Moscow, 11.10.2011
Origin of Phobos?
Kaidun
Trapped asteroid or in orbit formation?
How much it was differentiated?
Which type of meteorites simulates its
material?
What can we learn from investigation of
volatiles of Phobos?
Phobos
Chemical composition of some carbonaceous chondrites
Carbonaceous chondrites names
Concentration of volatiles in different petrographic types of meteorites (Wood, 1968)
petrographic types
1
2
Sulfides
-
>0.5%
Carbon
~ 2.8%
0.6 – 2.8%
Water
~20%
4 – 18%
3
4
5
<0.5%
0.2 – 1.0%
<0.2%
<2%
6
Insoluble organics in meteorites
Van Krevelen diagram of thermal
evolution of kerogen
Oxygen isotopes in the Solar System
8
6
CI
Primitive water
Earth
4
δ17O, ‰
Ordinary chondrites
Moon
SNC meteorites
(Mars)
2
CH
CR
CM
0
-2
Carbonaceous chondrites
CV
-4
-6
CO
0
5
10
δ18O, ‰
15
Hydrogen isotopes in the Solar System
Phobos Sample Return mission
(2011)
Scientific objectives of the “PhSR” mission
- to investigate the origin of Martian satellites on example of Phobos;
- to investigate properties of small planetary objects in space environment;
- to study possible differentiation of early planetary materials;
- to study volatiles inventory;
- to study organic materials;
- to study the influence of Phobos on the near Martian environment (dust
torus, gas, plasma and magnetic field perturbations);
- to investigate the detailed structure of the Martian atmosphere including
vertical profiles of temperature, aerosol, and trace atmospheric
components (water vapor, CO, CH4, etc);
- to investigate diurnal variations of surface temperature of Mars.
Three main questions to characterize volatiles:
1. Concentration of volatile elements?
Total mass of the volatile element in the sample
Concentration =
Mass of the sample
Three main questions to characterize volatiles:
1. Concentration of volatile elements?
2. Form of incorporation of volatiles in the soil?
hydrogen
water
organics
trapped hydrogen
other
carbon
carbonates
carbides
organics
other
Three main questions to characterize volatiles:
1. Concentration of volatile elements?
2. Form of incorporation of volatiles in the soil?
3. Isotopic composition of volatile elements?
Gas Analytic Package (GAP) for the “Phobos Sample Return Mission”
Scientific objectives of the GAP
1.
2.
3.
4.
5.
Investigation of chemical composition and inventory
of volatiles (water, СО2, N2, SO2, organics, noble
gases, etc.) in situ in the soil at the landing place;
Investigation of volatile-containing phases in the soil
of the Phobos;
Investigation of organic components in the soil of the
Phobos;
Measurement of isotopic composition of CHON
elements (13С/12С, D/H, 17O/16O, 18O/16O, 15N/14N)
and noble gases;
To constrain the mineralogical composition of the
Pobos soil (with emphasis on the volatile-bearing
minerals) on the basis of thermal and gas evolving
experiments with the use of data from other
experiments.
MS
GC
TDA
The structure of the GAP
Soil
preparation
and loading
system
Thermal
Differential
Analyzer
Chromatograph
Massspectrometer
Thermal Differential Analyzer (TDA)
Objectives of the TDA
1. To measure exo- and endothermal reactions in the sample of
soil to determine minerals with phase transitions at temperatures
<1000C;
2. To perform the release of volatile
components into the gas phase and
provide their transfer into GC and MS;
3. To perform pyrolysis of heavy
organics (kerogens?) for their analysis
in GC and MS;
SOil Preparation SYStem = SOPSYS
Tasks of the device
1. To take a portion of soil from the manipulator.
2. To mill large pieces of rocks and sieve the soil to extract the
necessary fraction for loading into pyrolytic cells.
3. To extract the dose of the sample for loading into the pyrolytic cell.
4. To clean itself for the next cycle.
Pyrolytic cell
PC cross-section
He + газы
He
11
10
9
8
5
3
1
6
4
7
2
Cell parameters:
Т mах - 1000С (1350С)
W max - 22 W
Mass - 20 g
Sample volume - 4 mm  5 mm
Gas Chromatograph
Tasks of the chromatograph
1. Accumulation of gases which are released from the sample during
pyrolysis.
2. Redistribution of gases of different types (permanent gases, organics,
etc.) between respective columns.
3. Separation of different gases by time of retention.
4. Measurement of abundance of separate gas component.
5. Measurement of isotopic ratios of D/H, 13C/12C, 17O/16O, 18O/16O in CO2
and H2O using TDLAS.
TDLAS scheme
Name*
Target
molecule
Sigma (cm-1)
Lambda
(nm)
C2H2
C2H2
6523.8794 cm-1
1533 nm
CO2iso
18OC16O
4898.7822 cm-1
2041 nm
18OC16O
4899.5653 cm-1
13CO
2
4899.6133 cm-1
HDO
3788.3366 cm-1
H2 17O
3788.7852 cm-1
H2 18O
3788.9125 cm-1
H2O
3727.7376 cm-1
CO2
3728.4101 cm-1
H2Oiso
H2O-CO2
HDO
HDO
H216O
H217O
lLaser = 2.64 mm
H218O
H216O
H216O
2640 nm
2682 nm
Assemblage of the GC block
Carrier gas tanks (Не)
2250 см3 40 bar.
Pressure
regulators
Pressure
sensor
TDLAS tube
Calibration gas tank
ON/OFF valves
manifolds
GC modules
Injection traps
A piece of test chromatogram
415 000
415 000
410 000
410 000
405 000
405 000
400 000
400 000
hexane
С6Н14
4,410-8 g
395 000
390 000
385 000
380 000
375 000
370 000
395 000
390 000
385 000
380 000
benzene
С6Н6
4,010-8 g
365 000
360 000
355 000
350 000
375 000
370 000
365 000
360 000
355 000
350 000
345 000
345 000
340 000
340 000
335 000
335 000
330 000
330 000
325 000
325 000
320 000
320 000
315 000
315 000
310 000
310 000
signal/noise ~ 600
305 000
305 000
300 000
300 000
295 000
295 000
290 000
290 000
6 135
6 140
6 145
6 150
6 155
6 160
6 165
6 170
6 175
6 180
6 185
6 190
6 195
6 200
The mass-spectrometer
L.P. Moskaleva (PI)
Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI)
Ryazan University (contractor)
Mass analyzer (MA)
Main parameters of the MS
Block of electronics (BE)
1. Mass
2. Power consumption
3. Dimentions:
МА
BE
4. Mass range
5. Sensitivity for Ar
6. Dynamic range
7. Mass resolution
- 3,5 кг
- 32 Вт
- 256х78х73 (mm)
- 256х110х120 (mm)
- (2÷400) amu/q
- (3÷5)х10-12 hPa
- 104
- 400(?)
A test mass-spectrum of CO2 in GC+MS mode
1200
ÑÎ
m/z=44
1000
H2Î
800
Signal (a.u.)
+
2
+
m/z=18
600
Î
400
+
m/z=16
ÑÎ
C+
200
He
+
+
m/z=28
m/z=12
+
2
Î
m/z=4
m/z=32
0
- background spectrum
0
10
20
30
40
50
60
70
Mass number (amu/q)
80
90
100
Main partners of the Phobos-Grunt
Gas Analytic Package team
IKI RAS (Russia)
GEOKHI RAS (Russia)
TDA+GC
MS
LATMOS (France)
GC
LISA University of Paris (France) GC
GSMA (France)
TDLAS
MPS (Germany)
GC
Polytechnic University of
Hong Kong (China)
SOPSYS (TDA)
Gas Analytic Package for
Lunar-Resource (2014)
and Lunar-Globe (2015)
Russian missions
Preliminary positioning
of the GAP on the
instruments panel