ABSTRACT
Hydrogen chloride (HCl) is a polar, electron-attaching molecule with 18 electronsIt has electronic polarizability of 293 × 10−40 F m2, dipole moment of 1109 D, and ionization potential of 12749 eVThe energy for the fundamental vibrational mode is 3708 meV
Table 201 shows the selected references for data on HCl
Table 202 and Figure 201 present total scattering cross sections (Hamada and Sueoka, 1994)
The rotational constant for HCl molecule is very low, 131 meV, and the energy for the first rotational excitation (Δj = 1) is 262 eV Knoth et al(1989) have measured the differential scattering cross sections for the first vibrational level, simultaneous with strong rotational levels for HCl as shown in Table 203 Vibrational excitation is the dominant
201 Selected References for Data 135 202 Total Scattering Cross Sections 135 203 Ro-Vibrational Excitation Cross Sections 135 204 Elastic Scattering Cross Sections 136 205 Attachment Processes 137 206 Attachment Cross Sections 137 207 Attachment Rate Constants 137 208 Drift Velocity of Electrons 138 209 Consolidated Cross Sections 138 References 138
TABLE 20.1 Selected References for Data
Parameter Range: eV, (Td), [K] Reference
ka <004 Speck et al. (2001) QT 08-400 Hamada and Sueoka (1994) QT 10-5000 Jain and Baluja (1992) Qv 0-2 Schafer and Allen (1991) Qv 0-10 Knoth et al. (1989) Qv 0-10 Knoth et al. (1989) Qel 0-10 Rädle et al. (1989) Qa 05-20 Petrovic´ et al. (1988) ka [300, 515] Adams et al. (1986) Qa 50-120 Orient and Srivastava (1985) ka, W (20-200) Penetrante and Bardsley (1983) ka 0149-0213 Miller and Gould (1978) Qv 0-6 Rohr and Linder (1976) ka 004 Davis et al. (1973) Qa 0-20 Christophorou et al. (1968) Qex 0-14 Compton et al. (1968) Qa 0-2 Frost and McDowell (1958) η (0-30) Bradbury (1934)
Note:ka = Attachment rate; Qa = attachment cross section; Qel = elastic scattering cross section; QT = total scattering; Qv = vibrational excitation cross section; η = attachment coefficientBold font indicates experimental study
30 to 120 T
Rädle et al (1989) have measured the integral elastic scattering cross sections as shown in Table 204 and Figure 202 which also include the theoretical calculations of Padial and Norcross (1984)The minimum at 15 eV is identified as Ramsauer-Townsend minimum (Rädle et al, 1989)
TABLE 20.2 Total Scattering Cross Sections
Energy (eV)
QT (10−20 m2)
Energy (eV)
QT (10−20 m2)
Energy (eV)
QT (10−20 m2)
08 3539 65 2415 22 2026
10 3255 70 2484 25 1920
12 2853 75 2534 30 1695
14 2623 80 2744 35 1567
16 2427 85 2780 40 1471
18 2375 90 2807 50 1280
20 2297 95 2766 60 1194
22 2203 100 2831 70 1090
25 2172 110 2812 90 990
28 2255 120 2763 100 943
31 2326 130 2692 120 849
34 2339 140 2691 150 765
37 2354 150 2572 200 668
40 2343 160 2482 250 588
45 2404 170 2381 300 527
50 2310 180 2262 350 489
55 2418 190 2201 400 443
60 2344 200 2167
Source:Adapted from Hamada, Aand OSueoka, J. Phys. B: At. Mol. Opt. Phys., 27, 5055, 1994
10-1 100 101 102 103 104 Energy (eV)
1.0
0.1
Q (1
m 2 )
A
C
B
HCl
A-Total scattering B-Elastic C-Inelastic
Cross Sections for the First Vibrational Level for HCl
Energy (eV) Differential Cross Section (10−20 m2/sr)
Angle (°) 0.5 1.5
15 034 013
30 057 018
45 064 017
60 089 015
75 093 016
90 091 018
105 085 020
120 087 020
135 090 021
Source:Adapted from Knoth, Get al, J. Phys. B: At. Mol. Opt. Phys., 22, 299, 1989
TABLE 20.4 Integral Elastic Scattering Cross Sections for HCl
Energy (eV) Qel (10−20 m2) Energy (eV) Qel (10−20 m2)
05 1988 45 1293
10 943 50 1352
15 635 60 1780
20 633 70 1962
25 630 80 2143
30 815 90 2443
35 1026 100 2746
40 1187
Source:Adapted from Rädle, Met al, J. Phys. B: At. Mol. Opt. Phys, 22, 1455, 1989
0.1 1 10 Energy (eV)
Q e l(
10 –2
0 m 2 )
Elastic scattering (HCl)
(Rädle,1989) E (Padial,1984) T
processes (Petrovic´ et al, 1988):
HCl + e → H + Cl− (201)
HCl + e → H− + Cl (202)
Appearance potentials and peak cross sections measured for the process (Reaction 201) are shown in Table 205
The attachment cross sections tabulated by Itikawa (2003) on the basis of measurements of Petrovic´ et al(1988) for Cl− ion and Orient and Srivastava (1985) for H− ion are shown in Table 206 and Figure 203
Table 207 provides the attachment rate constants for HCl The attachment rate constants as a function of E/N are shown in Figure 204
TABLE 20.6 Attachment Cross Sections for HCl
Cl− Ion H− Ion
Energy (eV) Qa (10−20 m2) Energy (eV) Qa (10−20 m2)
063 00024 50 45 × 10−5
0678 0004 55 27 × 10−3
070 0008 60 844 × 10−3
0715 00141 65 168 × 10−2
0747 00396 70 205 × 10−2
0772 00496 708 2067 × 10−2
080 00707 75 169 × 10−2
08212 00892 80 116× 10−2
0854 0113 85 96 × 10−3
0877 0124 90 9 × 10−3
0891 0127 95 7 × 10−3
090 0127 100 462 × 10−3
0914 0125 105 276 × 10−3
09263 0119 110 124 × 10−3
09463 01128 115 4 × 10−4
09679 0103 120 7 × 10−5
10 0097
1042 00848
10672 0074
TABLE 20.5 Attachment Process
Process
Appearance Potential
(eV)
Peak Energy (eV)
Peak Cross Section
(10−22 m2) Reference
Reaction 201 085 2659 Orient and Srivastava (1985)
064 081 198 Christophorou et al (1968)
062 077 Frost and McDowell (1958)
Reaction 202 ~50 71 207 Orient and Srivastava (1985)
905 093
Cross Sections for HCl
Cl− Ion H− Ion
Energy (eV) Qa (10−20 m2) Energy (eV) Qa (10−20 m2)
01403 00672
12 0056
1244 0045
13 0033
135 0028
14 0023
15 0018
17 00116
19 00048
Source: Adapted from Itikawa, Y, in Interactions of Photons and Electrons with Molecules, Springer-Verlag, New York, NY, 2003, Chapter 5-2, pp 5-87
0.1
0.01
0.001 4 8 12
Energy (eV)
Q a (1
m 2 )
Attachment (HCl) Cl-
H-
TABLE 20.7 Attachment Rate Constants
Temperature (K)
Rate Constant (10−18 m3/s) Method Reference
170 <10 P/LP Speck et al (2001) 300 <10 FA/LP Adams et al (1986) 515 <10
~100 e-Beam Kliger et al (1981)
2475 11 Flame/MWC Miller and Gould (1978)
2200 06
1950 034
1730 003
Note: Temperature is thermal unless otherwise mentionedMWC = microwave cavity; P/LP = plasma/Langmuir probe; FA= flowing afterglow
obtained from simulation studies (Penetrante and Bardsley, 1983)
A set of cross sections used for Monte Carlo simulation is available in Penetrante and Bardsley (1983)See Figure 205
20 100 E/N (Td)
10-16
104 10-18
10-17
At ta
ch m
en tr
at e( k a
,m 3 /
s)
Dr ift
ve lo
cit y(
W ,m
/s )
HCl
W
ka
10-1 100 101 102
10-1
10-2
Cr os
ss ec
tio n
(1 0-
2 )
Qel
QM
Qi
QM (0-2)
Qel (B + C)Qel (A)
Qa
QM(0-1)
QM (N2)
QT R (3-4)
Electron energy (eV)
