LABORATORY SPECTROSCOPY
OF RELEVANCE TO CASSINI
UVIS AND ISS
JOSEPH AJELLO
ALEX AGUILAR
RAO MANGINA
PAUL JOHNSON
CHARLES MALONE
DAREK DZICZEK
JPL
H. ABGRALL
MEUDON
MICHAEL STEVENS
NRL
XIANMING LIU
SET
Ian Stewart
Kris Larsen
LASP
ELECTRON IMPACT INDUCED UV & NEAR IR
FLUORESCENCE LAB STUDIES (80-1200 nm)

N2 (UVIS TITAN)
MATCH LAB & UVIS AND ID UVIS TITAN EUV SPECTRA
TRANSITION MOMENT STUDIES OF Liu et al., 2007 FOR TITAN UVIS
MODELS

H2 (UVIS, ISS SATURN, JUPITER)
MEASURE VOIR SPECTRA (400-1000 nm) AND CROSS SECTIONS 100
eV of EF,GK,HH 1Sg+,I 1Pg ,J 1Dg
 B,B’ 1Su+, C 1Pg FOR ISS
PROVIDE UV CASCADE CROSS SECTION TO LYMAN & WERNER BANDS
FOR UVIS
20 eV SPECTRA GIVE 3p 3Pu, 4p 3Pu – a 3Sg+, FULCHER-a , BETA
BAND CROSS SECTION
COMPARE TO MEUDON MODEL

SO2 (ISS IO)
MEASURE VOIR SPECTRA AND CROSS SECTIONS 25 AND 100 eV
APPLY RESULTS TO ISS IO FILTER IMAGE INTENSITIES
UVIS EUV IMAGE ON 13 DEC2004 BRIGHT
LIMB ALTITUDE DEPENDENCE AT 03h 43’



TARGET DISTANCE:
160k&16 deg phase
Data(60,26,555)
& records of 240”
PEAK EMISSION
1100-1200 KM
(hvert~1015-16 cm-2)
VS PEAK
PRODUCTION AT
900KM (hvert ~1018
cm-2)
LOW RESOLUTION-OPTICALLY THICK 20 eV LAB
SPECTRUM WITH ID COMPARED TO UVIS TITAN
13DEC04
VOYAGER BASED* MODEL INTENSITIES AND
IDENTIFICATIONS OF EUV UVIS AIRGLOW FEATURES
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#
wavelength(A) UVIS disk rayleighs
1
804
0.437595
2
820
0.316011
3
833
1.03374
4
855
1.41705
5
887
1.22913
6
905
0.982033
7
916
0.969838
8
928
0.825229


9
945
2.13978
10
964
1.13641
11
983
3.26767
12
1004
2.14150
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

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
13
14
15
16
17
18
19
20
21
Theory (AURIC component Rayleighs-IDs)*
0.7
identity+
c5(0,0),c6(0,0)
c'(6,0),NI,c(0,0)
c'(4,0),c'(6,2),b'(11,0),NI
c'(3,0),c'(4,1),b'(16,2),b'(12,1)
b'(11,1),NII
0.2(c'64),0.2(b'91)
0.2b'(16-3),0.1(c'31)
c'(3,1),c'(6,4),b'(9,1),b'(8,1)
4.8
2.6(NI953),0.8(c'4,3),0.6(c'3,2)
0.1(b'9,2)0.1(b'16-4),0.5(c'65)
c'(4,3),c'(3,2),NI,b'(16,4),b'(9,2),c'(6,5)
4.1
2.8(NI964),0.4c'(4,4),0.2(c'66)
0.1(b'93),0.3(c'del v=0)
NI,c' delta v=0)
9.8
7.6(c'0,1),0.6(c'4,5),0.5c'(34),
0.3c'(6,7),0.3(b'94),0.1(b'16-6)
c'(0,1),c'(4,5),b(1,0),c'(6,7),
2.4
1.0(c'0,2),0.6(b1,1),0.3(b'16-7)
0.1(b'95),0.3(c'del v=2),0.1(c'46)
c'(delta v=2),b'(9,5),b(1,1)
H L(beta),c'(6,9),b(1,2)
c'(delta v=4),NI,b(1,3),b'(3,5)
NI,b'(11,8),c'(delta v=5)
15.0
NII
NI,b'(1,6),b'(9,9),b'(6,8),b'(3,7)
b'(2,7),b'(1,7)
NI
NI,b'(1,8)
NI,b'(0,8),b'(1,8)
total(36.8R)
1026
2.64403
1057
0.733667
1067-77
0.651997
1085.
2.94249
1100-1110 1.02141
1110-1120 0.502661
1135.
1.74414
1148.
1.55175
1158.
1.48184
total(29.2R)
+Ajello et al.,1989;James et al., 1990
*Stevens(2001) F10.7=256(VI,II SOLAR MAX) VS F10.7=90 DEC13, 2004
HIGH RESOLUTION LAB WITH ID SPECTRUM
COMPARED TO UVIS TITAN 13 DEC2004
Lab Study of Pressure Effects of the N2 EUV
Spectrum by Electron Impact at 20 eV
 Geissler
et al., 2004
VOIR APPARATUS
Vis-Optical-near IR (200-1200 nm)
CASSINI ANALYSIS WITH SO2 LABORATORY
SPECTRUM
CASSINI ISS FILTERS
Filter Center FWHM
UV1
255 40

UV2
300 60

UV3
340 70

BL1
445 105

BL2
440 30

GRN
562 145
nm

IR1
IR4

ISS OBSERVATIONS
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Filter
UV1
UV2
UV3
BL1
GRN
752 180
1002 200
8 eV
0.0
0.33
1.00
0.27
0.29
18 eV 98 eV
0.34
0.3
0.42
0.41
1.00 1.00
0.39
0.79
0.20 0.97
ISS
< 1.0
0.30
1.00
0.93
0.96
CASSINI ISS LAB STUDIES
DIRECT MEASUREMENT OF H2 GERADE STATE
CASCADE CROSS SECTION TO UV RYDBERG STATES
VOIR EF-B CASCADE SPECTRUM
IN CROSS SECTION UNITS
DISCREPANCY BETWEEN MODEL AND DATA
FOR HIGHER LYING GERADE STATES
COMPARISON OF CROSS SECTIONS TO UNIVERSITY
OF ARKANSAS GROUP
MAJOR 100 eV CROSS SECTION
RESULTS IN THE VOIR
TABLE 1


e + H2 VOIR process
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(10-19 cm2)
total VOIR cross section (singlets +triplets+ H-lines)…………63
total triplet cross section …………………….…………………… ……..1.2
total ungerade singlet cascade cross section…………………..51
total H lines .................................................................
EF-state...................................................................... 20-30
GK+HH+IJ+................................................................ ?
e+H2 UV Process
total UV direct +cascade ungerade states


CROSS SECTION
EXP
MODEL
PREVIOUS
(10-19cm2)
37
?
Too large
(10-19cm2)
50*
11***
(B+C+B'+D+...)……………………………… 460**
*Dziczek et al; 2000 (UV Technique)
**Jonin et al; 2000
*** Karolis and Harting;1978 and Vroom and de Heer;1969
CONCLUSIONS
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EARTH AND TITAN PRESENT SIMILAR EUV SPECTRA
OVER 100 N AND N2 FEATURES CONTRIBUTE TO TITAN EUV
CHANNEL UVIS SPECTRA
EXCEPT FOR N2(c’[0,0]) BAND UVIS SPECTRUM IS WELLMATCHED BY 20-30 eV OPTICALLY THICK LAB SPECTRA OF
e + N2
e + H2 VOIR EF-B SPECTRA GERADE-UNGERADE ARE
MODELED 7500-10000 A AND DISCREPANCIES 4000-7500
A
HIGH LYING GERADE STATE MODELS ARE TOO STRONG(JB,C)
H2 VOIR TRIPLET STATES ARE STRONG AT 20 eV
GROUND-BASED AND HUBBLE IO SO2 EMISSIONS ARE
SUGGESTED AT 777,845 NM FOR OI AND 922 NM FOR SI.
OPTICALLY THICK LAB SPECTRUM AT 0.6 AND 0.2 A
FWHM COMPARED TO CASSINI 4A FWHM
GEOMETRY OF 13 DEC2004 TWO LIMB AND
DISK OBSERVATIONS
TARGET DISTANCE: 160k and 125k km
Data(60,26,555) AND Data(60,32,555)
records of 240” each
Solar incidence angle=78 deg and 90 deg
Target phase angle=16 deg
Solar emission angle=90 deg limb
Peak emission 1200 km
Temp=150k , H(N2)=70 km, Nhvert (N2)=7x1015 cm-2
Number density N2=109 cm-3
CHAPMAN FACTOR=22 SLANT/VERTICAL
Low Res. EUV slit =2mR (0.1deg) x 59 mR (3.6 deg)
STUDY OF FULCHER-a BANDS (d 3Pu -a 3Sg+) OF H2
TITAN EUV AIRGLOW DISK SPECTRUM