Recent content by sportfreak801

  1. S

    Rutherford Backscattering Spectroscopy Question

    Thanks for the tip! That may be a possibility; however, we were provided what I had presumed to be two different samples. The first being the reference sample made up of known layers: a Silicon layer of 115\times10^{15} atoms/cm^{2} then a Bismuth layer of 5.65\times10^{15} atoms/cm^{2} and...
  2. S

    Rutherford Backscattering Spectroscopy Question

    I took the Q's to be approximately equal to each other since the same dose was used in both the reference experiment and the example experiment.
  3. S

    Rutherford Backscattering Spectroscopy Question

    I'll be more careful next time... It seems that the Nt for Beryllium is quite large compared to the Nt for Bismuth. There is a factor of 10^{3} difference, are such densities plausible?
  4. S

    Rutherford Backscattering Spectroscopy Question

    I tried calculating the mass of the target particle of the first peak in my energy spectra M_{2} and then the number of particles per cm^2 Nt. However, the numbers that I found do not seem to be correct: K = \frac{E_{1}}{E_{0}}=\left ( \frac{M_{1}cos\theta + \sqrt{M_{2}^{2}-M_{1}^{2}\left (...
  5. S

    Rutherford Backscattering Spectroscopy Question

    To calculate Z I would use the equation: \left ( \frac{d\sigma}{d\Omega} \right )=\left [ \frac{Z_{1}Z_{2}e^{2}}{4E} \right ]^{2}\frac{4\left \{ \left [ 1-\left ( \left ( M_{1}/M_{2} \right )sin^{2}\theta \right ) \right ]^{1/2} + cos\theta \right \}^{2}}{sin^{4}\theta \left [ 1-\left (...
  6. S

    Rutherford Backscattering Spectroscopy Question

    Thank you for your response! I do, however, have some questions that I would like clarified. Does this mean that multiple peaks in the spectra correspond to the same element? For example, if in my spectra I have three distinct peaks that occur at different energy levels and have different...
  7. S

    Rutherford Backscattering Spectroscopy Question

    In class we learned about the fundamentals behind RBS using a linear accelerator that accelerates He+ ions to 2MeV. We were then provided an example where those ions collided with a sample with layers of Silicon-Bismuth-Silicon, each of known thickness; and, we were then shown the corresponding...
  8. S

    Polarization of Coaxial Cable with Compound Dielectric

    \oint D\cdot nda = Q_e D\oint da = Q_e D(2\pi rl) = Q_e D = \frac{\lambda}{2r\pi} E_1 = \frac{D}{\epsilon_1} = \frac{\lambda}{2r\pi \epsilon_1} The potential from a to b over the first dielectric \Delta\varphi_1 = E_1 (b - a) \Delta\varphi_1 = \frac{\lambda...
  9. S

    Polarization of Coaxial Cable with Compound Dielectric

    Homework Statement A coaxial cable of circular cross section has a compound dielectric. The inner conductor has an outside radius a , which is surrounded by a dielectric sheath of dielectric constant K_1 and of outer radius b . Next comes another dielectric sheath of dielectric constant...
  10. S

    Electric Potential by Integrating Poisson's Equation

    Now, I am supposed to derive the same answer using \varphi(r) = \frac{1}{4\pi\epsilon_0}\int\frac{dq}{|r - r'|} I know that q = \rho V and dq = \rho dV And that V = \frac{4}{3}\pi r^3 However, I know that dV = 4\pi r^2 dr is not true because if it were then I would get \varphi(r)...
  11. S

    Electric Potential by Integrating Poisson's Equation

    My mistake, I forgot to substitute r = R... So it should read \frac{\rho}{\epsilon_0}\frac{R}{3} = -\frac{\alpha}{R^2} -\frac{\rho R^3}{3\epsilon_0} = \alpha -\frac{\rho R^2}{6\epsilon_0} + D = -\frac{\alpha}{R} -\frac{\rho R^2}{6\epsilon_0} + D = \frac{\rho R^2}{3\epsilon_0}...
  12. S

    Electric Potential by Integrating Poisson's Equation

    -\mathbf{\nabla}((-\frac{\rho}{\epsilon_0}\frac{r^2}{6}) + D)= -\mathbf{\nabla}(-\frac{\alpha}{r}) -\frac{d}{dr}((-\frac{\rho}{\epsilon_0}\frac{r^2}{6}) + D)= -\frac{d}{dr}(-\frac{\alpha}{r}) \frac{\rho}{\epsilon_0}\frac{r}{3} = -\frac{\alpha}{r^2} -\frac{\rho r^3}{3\epsilon_0} = \alpha...
  13. S

    Electric Potential by Integrating Poisson's Equation

    C = 0 So if the gradient of the potential must be continuous everywhere then -\mathbf{\nabla}((-\frac{\rho}{\epsilon_0}\frac{R^2}{6}) + D)= -\mathbf{\nabla}(-\frac{\alpha}{R})
  14. S

    Electric Potential by Integrating Poisson's Equation

    So then the Electric Field is continuous everywhere. Also, the electric potential is finite everywhere. \textbf{E}=-\mathbf{\nabla}\varphi So I take the -\mathbf{\nabla}\varphi in spherical coordinates knowing that the Electric field is independent of \theta and \phi .
  15. S

    Electric Potential by Integrating Poisson's Equation

    The Electric field \textbf{E}=-\mathbf{\nabla}\varphi is discontinuous when the electric field passes through the charged surface of the sphere.
Back
Top