ABSTRACT
Argon (Ar) atom has 18 electrons with an electronic polarizability of 1826 × 10−40 F m2 and a first ionization potential of 1576 eV
See Table 11
11 Selected References for Data 3 12 Total Scattering Cross Section 4 13 Elastic Scattering Cross Section 4 14 Momentum Transfer Cross Section 6 15 Scattering Length 6 16 Ramsauer-Townsend Minimum 6 17 Excitation Cross Section 6 18 Ionization Cross Sections 7 19 Drift Velocity of Electrons 8 110 Diffusion Coefficient 8 111 Mean Energy 8 112 Reduced First Ionization Coefficient 11 113 Gas Constants 11 114 Penning Ionization Cross Section 11 115 Positive Ion Mobility 12 References 13
TABLE 1.1 Selected References
Quantity Range: eV (Td) Reference
Drift velocity (1-3000) Lisovskiy et al. (2006) All cross sections 0-1000 Raju (2005)
Inelastic cross sections 10-1000 Yanguas-Gil et al (2005)
All cross sections 0-1000 Raju (2004)
Qi 16-1000 Kobayashi et al. (2002) Qi 17-1000 Rejoub et al. (2002) Qi 140-4000 Sorokin et al. (2000) QT 05-10,000 Zecca et al (2000)
Qi, (α/N) 16-1000, (25-2000) Phelps and Petrovic´ (1999) Qel, Qex, Qi 45-1000 Brusa et al (1996)
Qdiff, Qel, QM 1-10 Gibson et al. (1996) continued
The highlights of total cross section as a function of electron energy are
1 Increasing cross section as the energy is reduced toward zero, reaching a plateau of 75 × 10−20 m2
2 Ramsauer-Townsend minimum at ~025 eV
3 A broad resonance at ~20 eVThis feature, attributed to onset of inelastic collisions including ionization, is common to many gases
4 A monotonic decrease for energy >20 eV This feature is also common to many gases (see Table 12)
See Table 13
Quantity Range: eV (Td) Reference
QT 05-220 Szmytkowski and Maciag (1996) Qi 17-1000 Straub et al. (1995) Qi 18-5300 McCallion et al. (1992) Qi 18-660 Syage (1992) QM 00001-100 Pack et al. (1992) Qi 20-500 Ma et al. (1991) QT 3-20 Furst et al. (1989) Qi 20-1000 Krishnakumar and Srivastava (1988) Transport coefficients (025-50) Nakamura and Kurachi (1988) Qi 20-1000 Lennon et al (1988)
Diffusion coefficient 565-5650 Al-Amin and Lucas (1987) QT 07-100 Subramanian and Kumar (1987) Qdiff, Qel, QM 40-1000 Iga et al. (1987) Qel 3-300 Nahar and Wadhera (1987)
Qi 16-200 Wetzel et al (1987)
QT 100-3000 Zecca et al. (1987) QT 012-200 Buckman and Lohmann (1986) QT 008-200 Ferch et al. (1985) QT 4-300 Nickel et al. (1985) QT 20-100 Wagenaar and de Heer (1985) QT 005-60 Jost et al. (1983) Qi 500, 700, 1000 Nagy et al. (1980) Qi 20-180 Stephan et al. (1980) QT 15-800 Kaupilla et al. (1981) Transport coefficients (28-566) Kücükarpaci and Lucas (1981) Qdiff, QM 3-100 Srivastava et al. (1981) QT, Qdiff, Qel, QM 15-3000 de Heer et al (1979)
Qi 16-500 Fletcher and Cowling (1973) Qi 16-1000 Rapp and Englander-Golden (1965)
α/N 20-2000 Kruithoff (1940)
Note:Qdiff = differential scattering; QT = total scattering; Qel = elastic scattering; QM = momentum transfer; α/N = reduced first ionization coefficient; Qi = ionization; Qex = excitation Bold font indicates experimental study
Recommended Total SCross S
Energy (eV)
QT (10−20 m2)
Energy (eV)
QT (10−20 m2)
Energy (eV)
QT (10−20 m2)
008 150 09 105 30 1452 009 136 095 114 40 1209 01 119 1 122 50 1069 011 110 11 140 60 989 012 100 12 157 70 932 013 0910 13 179 80 882 014 0820 14 198 90 839 015 0750 15 213 100 800 016 0687 16 233 125 726 017 0625 17 252 150 665 02 0491 19 288 200 583 025 0383 2 297 250 523 03 0327 3 484 300 480 0345 0311 4 645 350 451 04 0328 5 864 400 418 045 0367 6 1010 450 390 05 0416 7 1210 500 366 055 0478 8 1400 550 346 06 0548 10 1890 600 328 065 0624 12 2310 650 312 07 0700 14 2400 700 297 075 0780 16 2350 800 289 08 0870 20 2020 900 270 085 0960 25 1621 1000 251
Note:See Figure 11 for graphical presentation
Cross Section for Ar Energy (eV)
Qel (10−20 m2)
Energy (eV)
Qel (10−20 m2)
Energy (eV)
Qel (10−20 m2)
008 1500 08 0756 75 582 009 1360 09 0934 80 549 01 1190 10 107 90 500 011 1100 15 219 100 486 012 1037 20 312 125 433 013 0844 30 496 150 379 014 0778 40 682 200 320 015 0680 50 881 250 283 016 0646 60 1113 300 247 017 0581 80 1566 350 229 018 0553 10 2006 400 212 019 0526 12 2125 450 200 020 0500 14 2256 500 189 025 0334 15 2322 550 181 030 0313 16 2230 600 173 034 0318 18 1952 650 165 036 0318 20 1860 700 157 040 0309 25 1627 750 149 045 0328 30 1394 800 145 050 0374 40 951 850 141 055 0437 50 774 900 136 060 0487 60 680 950 132 065 0555 70 615 1000 127 070 0629
Source:Adapted from Raju, GG Gaseous Electronics: Theory and Practice, Taylor & Francis, New York, NY, 2005
Note:See Figure 12 for graphical presentation
Energy (eV)
Q e l(
10 –2
0 m 2 )
1 1
10 100 1000
Elastic scattering (Ar)
Qel
QT
See Table 14
Ramsauer-Townsend minimum is observed in elastic scattering, momentum transfer, and total cross sections as shown in Table 16
Only electronic excitation cross sections are considered Threshold energies for selected excitation are shown in Table 17 See Figure 14 for graphical presentation of cross sections for individual levels Table 18 and Figure 15 show selected excitation cross sections available in the literature
TABLE 1.5 Scattering Length (A0) for Ar
Length (10−11 m) Reference
−772 Petrovic´ et al (1995) −892 Pack et al (1992) −763 Buckman and Lohmann (1986) −868 Weyhreter et al (1988) −767 Ferch et al (1985) −797 McEachran and Stauffer (1983) −787 Haddad and O’Malley (1982)
Note:4πA02 is the cross section at zero electron energy Scattering length is assigned a negative value in gases that exhibit the Ramsauer-Townsend effect
TABLE 1.6 Ramsauer-Townsend Minimum in Ar
Authors Method Energy (eV)
Cross Section (10−20 m2)
Pack et al (1992) Momentum transfer 025 0091
Buckman and Lohmann (1986)
Total 030 031
Ferch et al (1985) Total 034 031
Milloy et al (1977) Momentum transfer 025 0095
Golden and Bandel (1966) Total 028 015
0.001 0.01
0.1 0.1 1 10 100 1000
Energy (eV)
Cr os
ss ec
tio n
(1 0-
2 ) Momentum transfer (Ar)
TABLE 1.4 Recommended Momentum Transfer Cross Section
Energy (eV)
QM (10−20 m2)
Energy (eV)
QM (10−20 m2)
Energy (eV)
QM (10−20 m2)
0000 75 035 0235 60 81
0001 75 040 033 70 96
0002 71 050 051 80 117
0003 67 070 086 10 150
0005 61 10 138 12 152
0007 54 12 166 15 141
0009 505 13 182 17 131
0010 46 15 21 20 95
0015 375 17 23 25 74
0020 325 19 25 30 60
0030 25 21 28 50 35
0040 205 22 29 75 23
0050 173 25 33 100 17
0070 113 28 38 150 11
010 059 30 41 200 085
012 04 33 45 300 045
015 023 36 49 400 028
017 016 40 54 500 020
020 0103 45 61 700 015
025 0091 50 67 1000 012
030 0153
Note: See Figure 13 for graphical presentation
Seventeen sets of data are available as shown in Figure 16 Recommended values are shown in Table 19 and Figure 17
Energy (eV)
TABLE 1.8 Excitation Cross Section
Energy (eV) Qex (10−20 m2) Energy (eV) Qex (10−20 m2)
1162 0001 700 0689
120 0003 800 0670
140 0035 900 0649
160 0097 100 0627
180 0175 200 0454
200 0256 300 0357
250 0428 400 0296
300 0542 500 0254
350 0615 600 0223
400 0658 700 0200
450 0683 900 0166
500 0696 1000 0154
600 0700
Sources:Adapted from Pitchford, LC, JPBouef, and JPMorgan, www siglo-kinemacom 1996Also see Fiala, A, LCPitchford, and J P Boeuf, Phys. Rev. E, 49, 5607, 1994
Selected Excitation TEnergy for A 11-15eV Energy Range
Level Number Threshold
Energy (eV) Notation
1 1155 4 2 0 3
2s P[3/2] 2 1172 4 0
3 1291 4p[1/2]1 4 1327 4p[1/2]0
1328 4p′[3/2]1 5 1348 4p′[1/2]0 6 1385 3 1 2 0
0d[ / ]
7 1415 3 3 2 1 0d[ / ]
8 1421 3 3 2 2 0d′[ / ]
9 1430 3 3 2 1 0d′[ / ]
10 1446 5 1 2 1 0p[ / ]
11 1458 5p[1/2]0 12 1468 5p′[3/2]1 13 1469 4 1 2 0
0d[ / ]
14 1474 5p′[1/2]0 15 1486 4 3 2 1
0d[ / ]
16 1490 4f[3/2]2 17 1491 4f[7/2]3 18 1495 4 3 2 1
0d′[ / ]
19 1500 4 3 2 1 0d′[ / ]
Source:Adapted from GGRaju, IEEE Trans. Diel. Elec. Insul, 11, 649, 2004
See Table 110
Radial diffusion coefficients expressed as a ratio to mobility (Dr/µ), also termed as characteristic energy, at 293 K are shown in Table 111 and Figure 110 (Raju, 2005)
See Table 112
10 100 1000 Energy (eV)
0.1
Ionization cross section (Ar)
×0.1
Cr os
ss ec
tio n
(1 0-
2 )
Ionization Cross SAr
Rejoub et al. (2002) Kobayashi et al. (2002) Rapp and Englander-
Golden (1965)
Energy (eV)
Qi (10−20 m2)
Energy (eV)
Qi (10−20 m2)
Energy (eV)
Qi (10−20 m2)
17 0159 17 0128 17 0134
185 0419 18 0281 185 0377
20 0604 19 0440 20 0627
21 0769 20 0600 21 0787
225 1000 22 0893 225 0994
25 1250 25 1246 25 1302
275 1580 26 1348 28 1601
30 1750 30 1727 30 1803
325 2070 32 1878 32 1962
35 2210 36 2148 36 2243
40 2410 40 2291 40 2393
45 2491 45 2380 45 2489
50 2554 50 2428 50 2533
55 2608 55 2489 55 2595
60 2671 60 2544 60 2656
65 2738 65 2614 65 2727
70 2794 70 2648 70 2771
75 2804 75 2697 75 2815
80 2860 80 2722 80 2841
90 2898 90 2737 90 2859
100 2873 100 2726 100 2850
110 2848 110 2708 110 2832
120 2785 120 2690 120 2806
140 2680 140 2612 140 2727
160 2582 160 2524 160 2621
180 2488 180 2413 180 2516
200 2382 200 2334 200 2393
225 2277 225 2219
250 2167 250 2111 250 2173
275 2033
300 1955 300 1917 300 1979
350 1783 350 1855 350 1812
400 1659 400 1797 400 1680
500 1427 500 1643 500 1460
600 1269 600 1592 600 1302
700 1139 700 1527 700 1161
800 1030 800 1450 800 1064
900 0957 900 1410 900 0985
1000 0881 1000 1364 1000 0915
Note:See Figures 17 and 18 for graphical presentation Sources:Adapted from Rejoub, R, BGLindsay, and RFStebbings,
Phys. Rev. A, 65, 042713, 2002; Courtesy of DrKobayashi for tabulated data in columns 3 and 4
10 100 1000 Energy (eV)
Cr os
ss ec
tio n
(1 0-
Ionization cross section (Ar)
TABLE 1.10 Recommended Drift Velocity of Electrons
E/N (Td)
W (103 m/s)
E/N (Td)
W (103 m/s) E/N (Td)
W (103 m/s)
1 × 10−2 0935 04 239 40 344 12 0972 05 252 50 412
14 1005 060 263 60 491
17 1047 070 273 70 584
20 1084 080 281 80 680
25 1144 10 295 100 855
30 1205 20 344 200 149
35 1252 30 381 300 217
40 1294 40 412 400 282
50 1368 50 475 500 351
60 1437 60 564 600 424
70 1500 70 654 700 497
80 1556 80 761 800 568
01 1654 10 956 1000 704
012 1741 12 117 2000 1190
014 1820 14 134 3000 1600
017 1918 17 163 4000 1770
020 200 20 188 5000 1860
025 213 25 224 6000 2060
030 223 30 271
035 231 35 311
Source:Adapted from Raju, GG, Gaseous Electronics: Theory and Practice, Taylor & Francis, New York, NY, 2005
Note:See Figure 19 for graphical presentation
Energy for Ar; 0.01≤ E/N ≤ 50a, 56.5≤ E/N ≤ 5650b
E/N (Td) Dr/µ (V) E/N (Td) Dr/µ (V) E/N (Td) Dr/µ (V) 001 045 10 770 254 738 002 08 12 742 424 745 004 105 14 737 565 805 007 145 20 736 678 855 010 185 25 750 848 886 035 28 30 761 1130 112 10 478 35 760 1413 118 20 635 40 746 1695 130 30 736 50 691 1978 146 40 804 565 640 2260 151 50 824 848 766 2825 164 60 829 113 735 3390 152 70 854 141 779 4238 140 80 818 198 711 5650 128
Sources:a Adapted from Raju, G G Gaseous Electronics: Theory and Practice, Taylor & Francis, New York, NY, 2005
b Adapted from Al-Amin, S A J and J Lucas, J. Phys. D: Appl. Phys., 20, 1590, 1987
10-4
10-3 10-2 10-1 100 101 102 103 104 E/N (Td)
Drift velocity (Ar)
10 100 1000 Energy (eV)
Cr os
ss ec
tio n
(1 0-
2 )
0.01
0.1
0.001
Ar
Ar2+
Ar3+
See Table 113
Gas constants evaluated according to expression (see inset of Figure 112)
α N
F E
=
exp
GN
(11)
are F = 728 × 10−21 m2 and G = 1798 Td for the range 25 ≤ E/N ≤ 350 Td
Penning effect occurs according to
Ar* + B → Ar + B+ + e (12)
Ionization Coefficient for Ar
E/N (Td) Phelps et al. (1999)
α/N (10−20 m2) Kruithoff (1940) α/N (10−20 m2)
Recommended α/N (10−20 m2)
20 300E-04 300E-04
25 928E-04 900E-04 914E-04
30 00021 00022 00022
35 00040 00042 00041
40 00069 00071 00070
50 00157 00151 00154
60 00277 00257 00267
70 00421 00389 00405
80 00581 00550 00566
90 00751 00734 00743
100 00930 00923 00927
125 0141 0151 0146
150 0195 0213 0204
175 0255 0277 0266
200 0320 0342 0331
225 0390 0406 0398
250 0463 0472 0468
300 0614 0606 0610
350 0764 0735 0750
400 0910 0860 0885
450 105 0981 102
500 118 110 114
550 130 122 126
600 141 133 137
650 151 144 148
700 161 154 158
750 170 163 167
800 178 172 175
850 186 181 184
900 193 190 192
950 199 197 198
1000 206 205 206
1500 250 265 258
1750 264 288 276
2000 276 307 292
2500 291 336 314
4000 310 376 343
4500 311 386 349
Note:See Figure 112 for graphical presentation
0.01 0.1 1 10 100 1000 10,000
0.1
0.01
E/N (Td)
En er
gy (e
V)
Mean energy (Ar)
Mean Energy of ElAr
E/N (Td) ε (eV) E/N (Td) ε (eV) E/N (Td) ε (eV) 1 590 90 774 700 1247 2 600 100 791 800 1312 5 647 150 846 900 1361 10 638 200 875 1000 1394 20 714 250 938 1500 1528 30 747 300 1009 2000 1809 40 744 350 1059 3000 2362 50 740 400 1089 4000 3142 60 740 450 1109 5000 3707 70 747 500 1127 80 758 600 1180
Note:See Figure 111 for graphical presentation
Table 114)
TABLE 1.14 Penning Ionization Cross Section (in Units of 10−20 m2) for Ar with Other Gases
Excitation Level (Ar*) Ar* Energy (eV)
B
Kr O2 3P2 1155 1 12 1P1 1183 18 3P0 1172 18 3P1 11623 16
Source: Adapted from Eletskii, A V in I S Grigoriev and Z Meilikhov (Eds), Handbook of Physical Quantities, CRC Press, Boca Raton, FL, 1999, Chapter 20
TABLE 1.15 Reduced Ion Mobility and Drift Velocity for Ar+
E/N (Td)
µ0 (10−4 m2/V s)
W+ (102 m/s)
E/N (Td)
µ0 (10−4 m2/V s)
W+ (102 m/s)
800 153 0329 150 116 468
100 153 0411 200 106 570
120 153 0493 250 099 665
150 152 0613 300 095 766
200 151 0811 400 085 914
250 149 100 500 078 105
300 147 118 600 072 116
400 144 155 800 063 135
500 141 189 1000 056 150
600 138 222 1200 051 164
800 132 284 1500 046 185
100 127 341 2000 040 215
120 122 393
Source:Adapted from Akridge, GRet al, J. Chem. Phys., 62, 4578, 1975 Note:See Figure 113 for graphical presentation
104103102101100 101
E/N (Td)
Dr ift
ve lo
cit y(
m /s
)
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