1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
{
"metadata": {
"name": "",
"signature": "sha256:5501457babf7cd881ef81ebc39845c677f30b7398a16e9160a7f32cf8c277a73"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"3: Thermionic Emission"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 3.1, Page number 67"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"S=2*10**-6; #tungsten filament(m**2)\n",
"T=2000; #temperature(K)\n",
"A=60.2*10**4; #value of A(amp/m**2 K) \n",
"b=52400; #value of b \n",
"e=1.6*10**-19; #electron charge(c)\n",
"\n",
"#Calculation\n",
"I=A*S*(T**2)*(math.exp(-(b/T))); #electronic emission current(amp)\n",
"J=A*(T**2)*(math.exp(-b/T)); #emission current density(A/m**2)\n",
"no=J/e; #no. of electrons emitted per unit area per sec(per m**2 sec)\n",
"\n",
"#Result\n",
"print \"maximum obtainable electronic emission current is\",round(I*10**6,3),\"micro amp\"\n",
"print \"emission current density is\",round(J,5),\"A/m**2\"\n",
"print \"no. of electrons emitted per unit area per sec is\",round(no/10**19,3),\"*10**19 per m**2 sec\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"maximum obtainable electronic emission current is 20.145 micro amp\n",
"emission current density is 10.07259 A/m**2\n",
"no. of electrons emitted per unit area per sec is 6.295 *10**19 per m**2 sec\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 3.2, Page number 67"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"Ip1=20; #plate current(mA)\n",
"Ip2=30; #changed plate current(mA) \n",
"Vp1=80; #plate voltage(V)\n",
"\n",
"#Calculation\n",
"#Ip=K*(Vp^(3/2))\n",
"Vp2=((((Vp1)**(3/2))*Ip2)/Ip1)**(2/3); #changed plate voltage(V)\n",
"\n",
"#Result\n",
"print \"plate voltage for 30mA current is\",round(Vp2,2),\"V\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"plate voltage for 30mA current is 104.83 V\n"
]
}
],
"prompt_number": 2
}
],
"metadata": {}
}
]
}
|
