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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 16 : Superconductivity and Superconductors"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.1 page no : 431"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"# Variables\n",
"b = 0;\n",
"#m = -h\n",
"#m = x*h\n",
"# = = >> -h = x*h\n",
"\n",
"# Calculations\n",
"x = -1;\t\t\t#from above realtions\n",
"ur = x+1;\t\t\t#relative permeability\n",
"\n",
"# Results\n",
"print \"Susceptibility of superconductor = \",x\n",
"print \"Relative permeability of superconductor = \",ur\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Susceptibility of superconductor = -1\n",
"Relative permeability of superconductor = 0\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.2 pageno : 434"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"ho = 0.0803;\t\t\t#in A/m\n",
"t1 = 3.; \t\t\t#in K\n",
"t2 = 10.;\t \t\t#in k\n",
"tc = 7.17;\t\t \t#in K\n",
"\n",
"# Calculations\n",
"hc1 = ho*(1-(t1/tc)**2);\n",
"hc2 = ho*(1-(t2/tc)**2);\n",
"\n",
"# Results\n",
"print \"Critical field at 3K (in A/m) = %f A/m\"%hc1\n",
"print \"Critical field at 10K (in A/m) = %.4f A/m\"%hc2\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Critical field at 3K (in A/m) = 0.066242 A/m\n",
"Critical field at 10K (in A/m) = -0.0759 A/m\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.3 pageno : 434"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Calculations\n",
"r = 1.*10**-3;\t\t\t#in m\n",
"hc = 7.9*10**3;\t\t\t#in A/m\n",
"ic = 2.*3.14*r*hc;\t\t\t#in m\n",
"\n",
"# Results\n",
"print \"Critical current in superconducting state (in A) = %.2f A\"%ic\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Critical current in superconducting state (in A) = 49.61 A\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.4 pageno : 441"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"p = 11.4*10**3;\t\t\t#in kg/m**3\n",
"aw = 207.2;\t\t\t#in kg/kg-mol\n",
"v = 1200.;\t\t\t#in m/s\n",
"\n",
"# Calculations\n",
"na = 60.23*10**26;\t\t\t#avagadro's no\n",
"e = 1.6*10**-19;\t\t\t#charge in C\n",
"m = 9.1*10**-31;\t\t\t#mass of electron in kg\n",
"mo = 4*3.14*10**-7;\t\t\t#in H/m\n",
"ne = 2*p*na/aw;\t\t\t#in per m**3\n",
"ied = ne*e*v;\t\t\t#in A/m**2\n",
"dp = (m/(mo*(6.62*10**28)*(e**2)))**(1./2);\n",
"dp1 = round(dp*10**10,-1);\n",
"\n",
"# Results\n",
"print \"Electron density (in per m**3) = %.2e electron/m**3\"%ne\n",
"print \"Current density (in A/m**2) = %.2e A/m**2\"%ied\n",
"print \"Depth of penetration (in angstorm) = %.1f A\"%dp1\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Electron density (in per m**3) = 6.63e+29 electron/m**3\n",
"Current density (in A/m**2) = 1.27e+14 A/m**2\n",
"Depth of penetration (in angstorm) = 210.0 A\n"
]
}
],
"prompt_number": 13
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.9 page no : 446"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"ho = 65.*10**3;\t\t\t#in A/m\n",
"tc = 7.18;\t\t\t#in K\n",
"t = 4.2;\t\t\t#in K\n",
"r = 0.5*10**-3;\t\t\t#in m\n",
"\n",
"# Calculations\n",
"hc = ho*(1-(t/tc)**2);\t\t\t#in A/m\n",
"ic = 2*3.14*r*hc; \t\t\t#in A\n",
"a = 3.14*r**2;\t\t \t#area in m**2\n",
"j = ic/a;\t\t\t #in A/m**2\n",
"\n",
"# Results\n",
"print \"current density (in A/m**2) = %.2e A/m**2\"%j\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"current density (in A/m**2) = 1.71e+08 A/m**2\n"
]
}
],
"prompt_number": 14
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.10 page no : 446"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"import math \n",
"\n",
"# Variables\n",
"hc1 = 21.;\t\t\t#in A/m\n",
"hc2 = 10.;\t\t\t#in A/m\n",
"tc = 7.;\t\t\t#in K\n",
"t = 14.;\t\t\t#in K\n",
"h = hc1/hc2;\n",
"\n",
"# Calculations\n",
"#Determining critical temperature\n",
"tc1 = math.sqrt(3626./11);\t\t\t#by quadratic eqn in the example\n",
"ho = hc1/(1-(tc**2/tc1**2));\n",
"t = 4.2;\t\t\t#in k\n",
"hc = ho*(1-(t/tc1)**2);\n",
"\n",
"# Results\n",
"print \"Critical field at 0 K (in A/m) = %.2f A/m\"%ho\n",
"print \"Critical field At 4.2 k (in A/m) = %.3f A/m\"%hc\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Critical field at 0 K (in A/m) = 24.67 A/m\n",
"Critical field At 4.2 k (in A/m) = 23.347 A/m\n"
]
}
],
"prompt_number": 16
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 16.11 page no : 447"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# part (b)\n",
"# Variables\n",
"m = 39.6 # materials\n",
"Tc = 7.19 # K\n",
"\n",
"# Calculation\n",
"dp = math.sqrt(m**2 * (1 - 3**4/Tc**4))\n",
"\n",
"# Results\n",
"print \"Depth of penetration at absolute zero dp(0) = %.3f nm\"%dp"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Depth of penetration at absolute zero dp(0) = 38.995 nm\n"
]
}
],
"prompt_number": 4
}
],
"metadata": {}
}
]
}
|
