User:VTreadwell
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THiS iS MEE!
Hi Everyone!! I am Veronica Treadwell, a freshman at Stony Brook University. I was born and raised on Long Island, and have a huge family, so im used to responsibility. I can baby sit with the best of them. In my house we are big hockey fans and I will admit I am a huge New York Islanders fan!! My Hobbies include: watching TV, hanging out with my family & my very best friends, shopping, I love food, I love to sing and dance, just doing anything to make people smile. I am a very hard-working and determined individual, and my school work is top priority. I am a Physics major, and I plan to one day be a high school physics teacher. During high school I took physics, and instantly fell in love, and with some help from some amazing teachers I have ended up with the career goals I have now. With wonderful recommendations, I was placed in the W.I.S.E. program here at Stony Brook, where I met friends to last a lifetime:Gabrielle (User:GNLEWIS89), Sanche, & Ashley. With support from my friends and family, ANYTHING is possible.
Day 1 April 8th, 2008
Today we learned how some of the equipment works in the lab. We use the detector to detect rays floating through air. In order to gain some knowledge of the properties of cosmic rays, we count the number of rays that go through the detector in any given amount of time. Our first experiment was to find the voltage that produces the detector to work most efficiently. In order to do this we elminate "noise" thats picked up by the detector, the computer does this by counting how many rays go through three stacked detectors. Because the possibility that "noise" would occur in all three detectors is about 1 in 10,000, we can assume that the counter is accurate. We used the counters and the DAQ computer program to calculate efficiency. These were our readings:
Using the coincidences between detector 1 (top) and detector 2 (bottom), and the coincidences between all three scintillators we calculate the voltage at which the detectors work most efficiently. We also use the number of detections through the middle scintillator and the total time the program was running to calculate the noise level.
From this graph we can determine that as the voltage increases to 5V the the efficiency rate levels off, in whats referred to as a plateau. We also notice that the noise level increases as we increas the voltage, thus we conclude that if we raise the voltage too high we increase the chance that there will be "noise" in all three of the detectors at the same instance, we also risk damaging the equipment.
Day 2 April 10th,2008
Today we brainstormed project ideas. In order to do this we thought about the how the detectors work and the factors that would affect detection.
To see my experiment ideas see (Results wise08cr ).
Day 3 April 15th,2008
Today Joanna and I raised very similiar questions: does the angle of the detectors, relative to the ground, affect the rate of detection? and does the direction of the detectors, relative to a compass(N,S,E,W) affect the rate of detection? My initial experiment had a few flaws. In order to get a more accurate reading, we discussed that there must be two detectors, to elminate the noise, and we must seperate the detectors to elminate the "extreme" detections. Seperating the detectors provides a cone-like space of detection, the more narrow the cone the more accurate our results. Once we determine the distance we can then roatate the two detectors and prepare to take our results.
The Beginning- Rate vs Angle
The first thing that Joanna and I did, was check the connections on the detectors to the counter. We then ran a test run, to make sure that all connections were correct and working. We then ran three angles: 180, 45, and 90, this was to give us a general idea of where other angles would fall. We then decided that in order to produce an accurate graph, we had to do one of two things: Run the counter for a longer amount of time, or take a small time increments but mulitple times and average out the coincidences. This is the graph of our first findings (based on 60sec intervals):
Day 4 April 17th, 2008
Today we learned about experimental and statistical erors. When doing this we keep four things in mind: 1) Accuracy- how close to the truth; 2) Precision- how repeatable; 3) Systematic Error- in measurement technique; 4) Random Error- improvement with repeated measurement. To calculate statistical error we take the square-root of the measurement, divided by the measurment( i.e. n=9 sqrt(9)/9 => 3/9 => 1/3 => 33% error) Based on logic we conclude that the bigger n is the more accurate your results will be. After learning how to do this, Joanna and I continued with our experiment of the rate of coincidence in realtion to the angle. We began observing less obvious angles using geometry. This time we used 120sec intervals, but we used the rate in our graph to account for the time. Our data is as follows:
And so our graph looks like this:
Day 5 April 22nd, 2008
Today we decided that we had gotten enough data for out Rate vs. Angle experiment, so we started our Rate Vs Compass experiment. In this expermiment we hope to determine whether particles are detected more frequently at N, S, E, W, or anywhere in between. Our initial data:
And plotting our data we see the following graph:
We conclude from this graph that there is no "pattern", except thet the trendline appears to be a horizontal line. From this we deterimine that the coincidence rate is not affected by the direction.
Day 6 April 24th, 2008
After we discussed with each other and the instructors the results from our previous experiment, Joanna and I decided that to reduce the error in our expermient we would move the detectors, around the compass at a 45 degree angle with respect to the floor. In doing this we elminate coincidences that may from the opposite side were actually measuring. This is our data for today:
And grpahing our data :
The one data point that falls below the rest of them is because of the mass of the building was to the West. The particles have more to travel through resulted in the lower coincidence rate.
Conclusions
To view my final report please see MARIACHI-LAB FINAL REPORT- VERONICA TREADWELL
