From f873023db6ddb02bba555fb650a4b4c90340f56a Mon Sep 17 00:00:00 2001 From: nice Date: Wed, 27 Aug 2014 16:12:51 +0530 Subject: adding book --- Modern_Physics/Chapter7.ipynb | 230 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 230 insertions(+) create mode 100755 Modern_Physics/Chapter7.ipynb (limited to 'Modern_Physics/Chapter7.ipynb') diff --git a/Modern_Physics/Chapter7.ipynb b/Modern_Physics/Chapter7.ipynb new file mode 100755 index 00000000..5f1ccec9 --- /dev/null +++ b/Modern_Physics/Chapter7.ipynb @@ -0,0 +1,230 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:75c249ea2e8c0a6e5f6f1e7aa12f02f35c3e7e62df28f6611e18b53d1b7e6dcd" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 7: Tunneling Phenomena" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.1, page no. 235" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "h = 1.973 * 10**3 #planck's constant (eV.A'/c)\n", + "me = 511 * 10**3 #mass of electron (eV/c^2)\n", + "U = 10.0\n", + "E = 7.0\n", + "L = 50.00 #thickness of layer (A')\n", + "\n", + "#Calculation\n", + "\n", + "a = math.sqrt(2*me*(U-E))/h\n", + "T=(1.0+(1.0/4.0)*(U**2/(E*(U-E)))*(math.sinh(a*L))**2)**-1\n", + "\n", + "#Result\n", + "\n", + "print \"The transmission coefficient for L=\",L,\"A' is\",round(T/10**-38,3),\"X 10^-38\"\n", + "\n", + "#(b)if the layer thickness is 1.00nm.\n", + "\n", + "#Variable Declaration\n", + "\n", + "L = 10 #thickness of layer (A')\n", + "\n", + "#Calculation\n", + "\n", + "T=(1.0+(1.0/4.0)*(U**2/(E*(U-E)))*(math.sinh(a*L))**2)**-1\n", + "\n", + "#Result\n", + "\n", + "print \"The transmission coefficient for L=\",L,\"A' is\",round(T/10**-7,3),\"X 10^-7\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The transmission coefficient for L= 50.0 A' is 0.963 X 10^-38\n", + "The transmission coefficient for L= 10 A' is 0.657 X 10^-7\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.2, page no. 236" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "#Variable declaration\n", + "\n", + "e = 1.6 * 10 ** -19 #charge of electron (C)\n", + "I = 1.00 * 10 ** -3 #electron current(A)\n", + "T = 0.657 *10**-7 #Transmission coefficient\n", + "\n", + "#Calculation\n", + "\n", + "Ne = I / e\n", + "Nadj = Ne * T\n", + "Iadj = Nadj * e\n", + "\n", + "#Result\n", + "\n", + "print \"The number of electrons per second continuing on the adjacent wire is\",round(Nadj/10**8,2),\"X 10^8 and the transmitted current is\",round(Iadj/10**-12,1),\"pA.\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The number of electrons per second continuing on the adjacent wire is 4.11 X 10^8 and the transmitted current is 65.7 pA.\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.5, page no. 241" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "\n", + "import math\n", + "\n", + "#Variable Declaration\n", + "\n", + "e = 1.6 * 10 **-19 #charge of electron(C)\n", + "f = 1.0*10**30 #collision frequency (s^-1.cm^-2)\n", + "Ec = 5.5 * 10 ** 10 \n", + "V = 10 * 10 ** 3 #potential difference(V)\n", + "d = 0.010 * 10**-3 #plate separation(m)\n", + "\n", + "#Calculation\n", + "\n", + "E = V /d\n", + "Te = math.exp(-Ec/E)\n", + "rate = f * Te\n", + "I = e * rate\n", + "\n", + "#result\n", + "\n", + "print \"The tunneling current is\",round(I/10**-12,2),\"pA.\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The tunneling current is 0.21 pA.\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.6, page no. 244" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + " \n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "\n", + "Zth = 90 #atomic number of thorium\n", + "Zdth = 88 #atomic number of thorium's daughter nucleus\n", + "E = 4.05 #energy of ejected alphas(MeV)\n", + "Zpo = 84 #atomic number of polonium\n", + "Zdpo = 82 #atomic number of polonium's daughter nucleus\n", + "Epo = 8.95 #energy of ejected alphas(MeV)\n", + "R = 9.00 #nucleus size(fm)\n", + "r0 = 7.25 #Bohr radius of alpha(fm)\n", + "E0 = 0.0993 #(MeV)\n", + "f = 10 ** 21 #collision frequency(Hz)\n", + "\n", + "\n", + "#Calculation\n", + "\n", + "Te = math.exp(-4*math.pi*Zdth*math.sqrt((E0/E))+ 8 * math.sqrt(Zdth*R/r0))\n", + "rate = f * Te\n", + "t = math.log(2)/rate\n", + "Tep = math.exp(-4*math.pi*Zdpo*math.sqrt((E0/Epo))+ 8 * math.sqrt(Zdpo*R/r0))\n", + "ratep = f * Tep\n", + "tp = math.log(2)/ratep\n", + "\n", + "\n", + "#Result\n", + "\n", + "print \"The half life of thorium is\",round(t/10**17,1),\"X 10^17 s and that of polonium is\",round(tp/10**-10,1),\"X 10^-10 s.\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The half life of thorium is 5.4 X 10^17 s and that of polonium is 8.4 X 10^-10 s.\n" + ] + } + ], + "prompt_number": 14 + } + ], + "metadata": {} + } + ] +} \ No newline at end of file -- cgit