Dependence of emission coefficient of secondary electrons on atomic number

Dependence of Emission Coefficient of Secondary Electrons on Atomic
Number and Accelerating Voltage of Incident Beam
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Unlike the situation for backscattered electrons, the fraction of secondary electrons (SEs) produced is relatively independent of the atomic number of the scattering atoms as shown in Figure 4803a. Table 4803 lists some examples of secondary electron (SE) coefficients of elements in periodic table, generated with incident electron irradiation at voltages from 2 keV to 100 keV.

Emission Coefficients of Backscattering Electrons (η) and Secondary Electrons (δ)

Figure 4803a. Schematic shows emission coefficients of backscattering electrons (η) and secondary electrons (δ), depending on atomic number (Z).

Table 4803. Examples of secondary electron (SE) coefficients of elements in periodic table (at 2 keV to 100 keV of incident electron irradiation).

No.		Atomic Weight	Name	Symbol	2 keV	5 keV	10 keV	20 keV	50 keV	100 keV	Electron configuration	Ionization energy (eV)
1		1.0079	Hydrogen	H							1s¹	13.5984
2		4.0026	Helium	He							1s²	24.5874
3		6.941	Lithium	Li							[He] 2s¹	5.3917
4		9.0122	Beryllium	Be							[He] 2s²	9.3227
5		10.811	Boron	B							[He] 2s² 2p¹	8.298
6		12.0107	Carbon	C							[He] 2s² 2p²	11.2603
7		14.0067	Nitrogen	N							[He] 2s² 2p³	14.5341
8		15.9994	Oxygen	O							[He] 2s² 2p⁴	13.6181
9		18.9984	Fluorine	F							[He] 2s² 2p⁵	17.4228
10		20.1797	Neon	Ne							[He] 2s² 2p⁶	21.5645
11		22.9897	Sodium	Na							[Ne] 3s¹	5.1391
12		24.305	Magnesium	Mg							[Ne] 3s²	7.6462
13		26.9815	Aluminum	Al		0.4		0.1	0.05		[Ne] 3s² 3p¹	5.9858
14		28.0855	Silicon	Si							[Ne] 3s² 3p²	8.1517
15		30.9738	Phosphorus	P							[Ne] 3s² 3p³	10.4867
16		32.065	Sulfur	S							[Ne] 3s² 3p⁴	10.36
17		35.453	Chlorine	Cl							[Ne] 3s² 3p⁵	12.9676
18		39.948	Argon	Ar							[Ne] 3s² 3p⁶	15.7596
19		39.0983	Potassium	K							[Ar] 4s¹	4.3407
20		40.078	Calcium	Ca							[Ar] 4s²	6.1132
21		44.9559	Scandium	Sc							[Ar] 3d¹ 4s²	6.5615
22		47.867	Titanium	Ti							[Ar] 3d² 4s²	6.8281
23		50.9415	Vanadium	V							[Ar] 3d³ 4s²	6.7462
24		51.9961	Chromium	Cr							[Ar] 3d⁵ 4s¹	6.7665
25		54.938	Manganese	Mn							[Ar] 3d⁵ 4s²	7.434
26		55.845	Iron	Fe							[Ar] 3d⁶ 4s²	7.9024
27		58.9332	Cobalt	Co							[Ar] 3d⁷ 4s²	7.881
28		58.6934	Nickel	Ni							[Ar] 3d⁸ 4s²	7.6398
29		63.546	Copper	Cu							[Ar] 3d¹⁰ 4s¹	7.7264
30		65.39	Zinc	Zn							[Ar] 3d¹⁰ 4s²	9.3942
31		69.723	Gallium	Ga							[Ar] 3d¹⁰ 4s² 4p¹	5.9993
32		72.64	Germanium	Ge							[Ar] 3d¹⁰ 4s² 4p²	7.8994
33		74.9216	Arsenic	As							[Ar] 3d¹⁰ 4s² 4p³	9.7886
34		78.96	Selenium	Se							[Ar] 3d¹⁰ 4s² 4p⁴	9.7524
35		79.904	Bromine	Br							[Ar] 3d¹⁰ 4s² 4p⁵	11.8138
36		83.8	Krypton	Kr							[Ar] 3d¹⁰ 4s² 4p⁶	13.9996
37		85.4678	Rubidium	Rb							[Kr] 5s¹	4.1771
38		87.62	Strontium	Sr							[Kr] 5s²	5.6949
39		88.9059	Yttrium	Y							[Kr] 4d¹ 5s²	6.2173
40		91.224	Zirconium	Zr							[Kr] 4d² 5s²	6.6339
41		92.9064	Niobium	Nb							[Kr] 4d⁴ 5s¹	6.7589
42		95.94	Molybdenum	Mo							[Kr] 4d⁵ 5s¹	7.0924
43	*	98	Technetium	Tc							[Kr] 4d⁵ 5s²	7.28
44		101.07	Ruthenium	Ru							[Kr] 4d⁷ 5s¹	7.3605
45		102.9055	Rhodium	Rh							[Kr] 4d⁸ 5s¹	7.4589
46		106.42	Palladium	Pd							[Kr] 4d¹⁰	8.3369
47		107.8682	Silver	Ag							[Kr] 4d¹⁰ 5s¹	7.5762
48		112.411	Cadmium	Cd							[Kr] 4d¹⁰ 5s²	8.9938
49		114.818	Indium	In							[Kr] 4d¹⁰ 5s² 5p¹	5.7864
50		118.71	Tin	Sn							[Kr] 4d¹⁰ 5s² 5p²	7.3439
51		121.76	Antimony	Sb							[Kr] 4d¹⁰ 5s² 5p³	8.6084
52		127.6	Tellurium	Te							[Kr] 4d¹⁰ 5s² 5p⁴	9.0096
53		126.9045	Iodine	I							[Kr] 4d¹⁰ 5s² 5p⁵	10.4513
54		131.293	Xenon	Xe							[Kr] 4d¹⁰ 5s² 5p⁶	12.1298
55		132.9055	Cesium	Cs							[Xe] 6s¹	3.8939
56		137.327	Barium	Ba							[Xe] 6s²	5.2117
57		138.9055	Lanthanum	La							[Xe] 5d¹ 6s²	5.5769
58		140.116	Cerium	Ce							[Xe] 4f¹ 5d¹ 6s²	5.5387
59		140.9077	Praseodymium	Pr							[Xe] 4f³ 6s²	5.473
60		144.24	Neodymium	Nd							[Xe] 4f⁴ 6s²	5.525
61	*	145	Promethium	Pm							[Xe] 4f⁵ 6s²	5.582
62		150.36	Samarium	Sm							[Xe] 4f⁶ 6s²	5.6437
63		151.964	Europium	Eu							[Xe] 4f⁷ 6s²	5.6704
64		157.25	Gadolinium	Gd							[Xe] 4f⁷ 5d¹ 6s²	6.1501
65		158.9253	Terbium	Tb							[Xe] 4f⁹ 6s²	5.8638
66		162.5	Dysprosium	Dy							[Xe] 4f¹⁰ 6s²	5.9389
67		164.9303	Holmium	Ho							[Xe] 4f¹¹ 6s²	6.0215
68		167.259	Erbium	Er							[Xe] 4f¹² 6s²	6.1077
69		168.9342	Thulium	Tm							[Xe] 4f¹³ 6s²	6.1843
70		173.04	Ytterbium	Yb							[Xe] 4f¹⁴ 6s²	6.2542
71		174.967	Lutetium	Lu							[Xe] 4f¹⁴ 5d¹ 6s²	5.4259
72		178.49	Hafnium	Hf							[Xe] 4f¹⁴ 5d² 6s²	6.8251
73		180.9479	Tantalum	Ta							[Xe] 4f¹⁴ 5d³ 6s²	7.5496
74		183.84	Tungsten	W							[Xe] 4f¹⁴ 5d⁴ 6s²	7.864
75		186.207	Rhenium	Re							[Xe] 4f¹⁴ 5d⁵ 6s²	7.8335
76		190.23	Osmium	Os							[Xe] 4f¹⁴ 5d⁶ 6s²	8.4382
77		192.217	Iridium	Ir							[Xe] 4f¹⁴ 5d⁷ 6s²	8.967
78		195.078	Platinum	Pt							[Xe] 4f¹⁴ 5d⁹ 6s¹	8.9587
79		196.9665	Gold	Au		0.7		0.2	0.1		[Xe] 4f¹⁴ 5d¹⁰ 6s¹	9.2255
80		200.59	Mercury	Hg							[Xe] 4f¹⁴ 5d¹⁰ 6s²	10.4375
81		204.3833	Thallium	Tl							[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹	6.1082
82		207.2	Lead	Pb							[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²	7.4167
83		208.9804	Bismuth	Bi							[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³	7.2856
84	*	209	Polonium	Po							[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴	8.417
85	*	210	Astatine	At							[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵	9.3
86	*	222	Radon	Rn							[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶	10.7485
87	*	223	Francium	Fr							[Rn] 7s¹	4.0727
88	*	226	Radium	Ra							[Rn] 7s²	5.2784
89	*	227	Actinium	Ac							[Rn] 6d¹ 7s²	5.17
90		232.0381	Thorium	Th							[Rn] 6d² 7s²	6.3067
91		231.0359	Protactinium	Pa							[Rn] 5f² 6d¹ 7s²	5.89
92		238.0289	Uranium	U							[Rn] 5f³ 6d¹ 7s²	6.1941
93	*	237	Neptunium	Np							[Rn] 5f⁴ 6d¹ 7s²	6.2657
94	*	244	Plutonium	Pu							[Rn] 5f⁶ 7s²	6.0262
95	*	243	Americium	Am							[Rn] 5f⁷ 7s²	5.9738
96	*	247	Curium	Cm								5.9915
97	*	247	Berkelium	Bk								6.1979
98	*	251	Californium	Cf								6.2817
99	*	252	Einsteinium	Es								6.42
100	*	257	Fermium	Fm								6.5
101	*	258	Mendelevium	Md								6.58
102	*	259	Nobelium	No								6.65
103	*	262	Lawrencium	Lr								4.9
104	*	261	Rutherfordium	Rf
105	*	262	Dubnium	Db
106	*	266	Seaborgium	Sg
107	*	264	Bohrium	Bh
108	*	277	Hassium	Hs
109	*	268	Meitnerium	Mt
No.		Atomic Weight	Name	Symbol	2 keV	5 keV	10 keV	20 keV	50 keV	100 keV	Electron configuration	Ionization energy (eV)

Figure 4803b shows the simulated and experimental yields of SEs for the electron incident voltages lower than 5 keV for a silicon sample.

Simulated and experimental yields of SEs for the electron incident voltages lower than 5 keV for a silicon sample

Figure 4803b. Simulated and experimental yields of SEs for the electron incident voltages lower than 5 keV for a silicon sample. [1, 2]

[1] Hendrix Demers, Nicolas Poirier-Demers, Alexandre Real Couture, Dany Joly, Marc Guilmain, Niels De Jonge And Dominique Drouin, Three-Dimensional Electron Microscopy Simulation with the CASINO Monte Carlo Software, CANNING 33, 135–146 (2011).
[2] Bronstein IM, Fraiman BS. 1969. Vtorichnaya elektronnaya emissiya. Moskva: Nauka.

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