Pxiel to wavelength
  • Used equation,
 \begin{equation} \lambda= \sum_{n=1}^{n}C_n(p-\alpha m)^n \end{equation}

  • Cut off point= -0.05, $x(i+\Delta x) - x(i-\Delta x), \Delta x=1$, minimum x range to be considered a peak=2.
  • $C_n$ coefficient, equal to the gradient of the plot for pixel and wavelength values. $p$ is the pixel values. $\alpha$ is another scaling coefficient as moving 1mm does not move pixel by 1pixel. m is the micrometer setting. n is the order of polynomial

  • Plot for Helium spectrum:
    wavelength.png
Behaviour

  • Helium line at 4.20mm:
    He_0420_raw.png
  • Sigma value of 3 pixels

  • Helium spectrum at 0.50mm:
    He_spectrum_0050.png
  • Sigma value of 6 pixels

  • Helium spectrum at 7.80mm:
    He_spectrum_0780.png
  • Sigma value of 7 pixels
-- JamesAngthopo - 09 Dec 2016
Topic attachments
I Attachment Action Size Date Who Comment
PNGpng He_0420_raw.png manage 26.9 K 09 Dec 2016 - 13:50 WillBurrows Helium line at 4.20mm
PNGpng He_spectrum_0050.png manage 41.2 K 09 Dec 2016 - 13:54 WillBurrows Helium spectrum at 0.50mm
PNGpng He_spectrum_0780.png manage 41.7 K 09 Dec 2016 - 13:55 WillBurrows Helium spectrum at 7.80mm
PNGpng wavelength.png manage 86.0 K 09 Dec 2016 - 13:58 JamesAngthopo Plot for Helium spectrum

Physics WebpagesRHUL WebpagesCampus Connect • Royal Holloway, University of London, Egham, Surrey TW20 0EX; Tel/Fax +44 (0)1784 434455/437520

Topic revision: r4 - 19 Jan 2017 - JamesAngthopo

 
This site is powered by the TWiki collaboration platformCopyright © 2008-2018 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding RHUL Physics Department TWiki? Send feedback