{ "metadata": { "name": "", "signature": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "chapter 09 : Interaction of charged Particle and Neutron With Matters" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex9.1 : Pg:201 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Maximum energy transferred by alpha particles\n", "E_alpha = 3e+06 # Incident energy of alpha particles, eV\n", "m = 9.1e-031 # Mass of an electron, kg\n", "M = 4*1.67e-027 # Mass of an alpha particle, kg\n", "# As E_alpha = 1/2*M*v**2 so E_electron = 1/2*m*(2*v)**2\n", "# From the two equations\n", "E_electron = 4*E_alpha*m/M # Maximum energy of electron, eV\n", "print \"The maximum energy transferred by alpha particles to the electron = %5.3f keV\"%(E_electron/1e+03) " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum energy transferred by alpha particles to the electron = 1.635 keV\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex9.2 : Pg:201 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Rate of energy loss and range of deuteron and alpha particle\n", "E_loss_P = 59 # Specific rate of energy loss per unit mass per unit area of proton, keV per mg cm square\n", "R_prime_P = 50 # Range of proton, mg per cm\n", "Z_D = 1 # Atomic number of deuteron\n", "m_D = 2 # Mass of deuteron, units\n", "E_loss_D = Z_D**2*E_loss_P # Specific rate of energy loss per unit mass per unit area of deuteron, keV per mg cm square\n", "R_prime_D = R_prime_P*m_D/Z_D**2 # Range of deuteron, mg per cm square\n", "Z_alpha = 2 # Atomic number of alpha particle\n", "m_alpha = 4 # Mass of alpha particle, units\n", "E_loss_alpha = Z_alpha**2*E_loss_P # Specific rate of energy loss per unit mass per unit area of alpha particle, keV per mg cm square\n", "R_prime_alpha = R_prime_P*m_alpha/Z_alpha**2 # Range of alpha particle, mg per cm square\n", "print \"The specific rate of energy loss per unit mass per unit area of deuteron = %2d keV per mg cm square\"% (E_loss_D) \n", "print \"The range of deuteron = %3d mg per cm square\"% (R_prime_D) \n", "print \"The specific rate of energy loss per unit mass per unit area of alpha particle = %2d keV per mg cm square\"% (E_loss_alpha) \n", "print \"The range of alpha particle = %2d mg per cm square\"% (R_prime_alpha) " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The specific rate of energy loss per unit mass per unit area of deuteron = 59 keV per mg cm square\n", "The range of deuteron = 100 mg per cm square\n", "The specific rate of energy loss per unit mass per unit area of alpha particle = 236 keV per mg cm square\n", "The range of alpha particle = 50 mg per cm square\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex9.3 : Pg:202 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log\n", "#Thickness of concrete collimator\n", "rho = 2200e-03 # Density of concrete, g per cm\n", "mu_m = 0.064 # Mass attenuation coefficient of concrete, cm square per g\n", "mu = rho*mu_m # Linear attenuation coefficient o concrete, per cm\n", "# As attenuation exponential is exp(-mu*x) = 1e+06, solving for x\n", "x = -log(1e-06)/mu \n", "print \"The required thickness of concrete to attenuate a collimated beam = %2d cm\"% x " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The required thickness of concrete to attenuate a collimated beam = 98 cm\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex9.4 : Pg:202 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log\n", "#Average number of collsions for thermalization of neutrons\n", "A = 9.0 # Mass number of beryllium\n", "xi = 2.0/A - 4.0/(3*A**2) # Logarithmic energy decrement of energy distribution of neutron\n", "E0 = 2.0 # Initial energy of neutrons, MeV\n", "En_prime = 0.025e-06 # Thermal energy of the neutrons, MeV\n", "n = 1.0/xi*log(E0/En_prime) # Average number of collisions needed for neutrons to thermalize\n", "En_half = 1.0/2*E0 # Half of the initial energy of neutrons, MeV\n", "n_half = 1.0/xi*log(E0/En_half) # Number of collsions for half the initial energy of neutrons\n", "print \"The average number of collsions for thermalization of neutrons = %2d\"% n \n", "print \"The number of collsions for half the initial energy of neutrons = %3.1f\"% n_half " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The average number of collsions for thermalization of neutrons = 88\n", "The number of collsions for half the initial energy of neutrons = 3.4\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex9.5 : Pg:202 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Change in voltage across a G.M. tube\n", "e= 1.6e-019 # Charge on an electron, coulomb\n", "W = 25 # Ionization potential of gas (Ar/N2), eV\n", "E = 5e+06 # Energy of incident alpha particles, eV\n", "C = 1e-010 # Capacity of the system, farad\n", "N = E/W # Number of ions produced\n", "delta_V = N*e/C # Change in voltage across the G.M. tube, volt\n", "print \"The change in voltage across the G.M. tube = %3.1e volt\"% delta_V" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The change in voltage across the G.M. tube = 3.2e-04 volt\n" ] } ], "prompt_number": 13 } ], "metadata": {} } ] }