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Entry  Tue Sep 11 17:17:51 2012, Eric Q., Mike J., Configuration, Electronics, AS beam scan 
    Reply  Wed Sep 12 08:16:49 2012, Steve, Configuration, PEM, chamber must be sealed overnight! 
    Reply  Wed Sep 12 20:08:51 2012, ericq, Update, Electronics, AS beam scan 
       Reply  Thu Sep 13 19:59:43 2012, Mike J., Update, Electronics, AS beam scan 
          Reply  Fri Sep 14 01:35:55 2012, Mike J., Update, Electronics, AS beam scan PLOTS H_razor.jpegV_razor.jpeg
             Reply  Tue Sep 18 22:06:21 2012, Mike J., Update, Electronics, AS beam scan plots and chi-squared beam_width.pyH_raz.pngV_raz.png
Message ID: 7404     Entry time: Tue Sep 18 22:06:21 2012     In reply to: 7386
Author: Mike J. 
Type: Update 
Category: Electronics 
Subject: AS beam scan plots and chi-squared 

Results of the Razor Blade Beam Scan

The horizontal blade test measured the beam intensity as a razor blade passed in between it and a power meter from the left side of the beam (negative x values) until blocking it. The resulting function, found through least-squares regression of the error function, calculates a beam height of 3.6 mm +/- 16 mm. However, the function has a chi-squared value of 3.2, so that value may not be accurate.

H_raz.png

The vertical blade test measured beam intensity as a razor moved from below the beam (negative x values) until blocking it. This function, found the same way as above, calculates a beam width of 2.8mm +/- 9.6 mm, and has chi-squared value of 0.77.

 V_raz.png

Both data sets have a y-error of 0.5 micro-Watts, and an x-error of 0.127 mm. The Python code used to analyze the data and plot the results is attached.

Attachment 1: beam_width.py  5 kB  | Hide | Hide all
#############################################
#   Python code for finding Gaussian-beam   #
# 		spot size w(z) from intensity 		#
# 		 vs. blocked portion of beam  		#
#############################################
#           Coded by Mike Jenson            #
#############################################

import numpy as np
from scipy.special import erf
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