Physics307L:People/Mondragon
This is my page for Junior Lab, Fall 2007. Links to my notebook and my main OWW page, where you can find contact info, below
My 307L lab notebook
[http://www-hep.phys.unm.edu/~gold/phys307L/manual.pdf Quick link to lab manual here]
My main OWW user page
Oscilloscope Lab Summary
Main notebook entry here.
see comment
To get practice in using an oscilloscope, I adjusted the volts/div, time/div, and trigger settings on the oscilloscope to get the oscilloscope to display a ~200Hz sine wave, triangle wave, and square wave. Adjusting the time and voltage settings improved how well the wave form were displayed on screen, and adjusting the trigger appropriately made the waveform displayed on the screen steady.
To gain experience taking measurements with an oscilloscope, I measured the amplitudes of these waveforms using the grid on the scope's display, the scope's horizontal cursors, and the scope's peak-to-peak measurement function. I then used the scope's vertical cursors to measure the scope's characteristic AC coupling fall time. The voltage the oscilloscope measured under AC coupling after a DC voltage step up declined to 10% after about 32ms meaning the characteristic fall time was about 14ms
e/m ratio summary
This experiment worked better than I initially expected. I haven't done any proper number crunching yet, but the e/m ratio that Lorenzo and I measured seems to float around [math]\displaystyle{ 2.9\pm0.2\times 10^{11} \tfrac{\mbox{coulombs}}{\mbox{kilogram}} }[/math]
Further investigation can be done in how electrons lose energy to the helium in the bulb and how this effects radius.
Poisson Statistics summary
notebook entries Physics307L:People/Mondragon/Notebook/070926 and Physics307L:People/Mondragon/Notebook/071003
Poisson distributions model count data of an experiment that count events that happen during a dwell time at random but do so at a definite average rate. (Nuclear decay, photon detection, etc.) Lorenzo Trujillo and I set up some gamma ray detection equipment inside of a lead shielded cavity and counted the events the equipment detected in 256 10ms, 20ms, 40ms, 80ms, 100ms, 200ms, 400ms, 800ms, 1s, and 10s time intervals. The data we collected fit Poisson distributions very well, and the average count numbers fit on a line on a average count number versus dwell time very well just like anything following a Poisson distribution should. We were counting, on average, 7.39 events per second. There was an interesting instance were we counted 27 events in a 200ms period, though. I wonder what caused that.
