User:PReilly
From MariachiWiki
Pat Reilly, is currently attending his second and final year at Stony Brook University. He originally started his undergraduate career at SUNY Purchase studying Psychology but after one semester changed to History. After a year at Purchase he transfered to SUNY Suffolk Community College and after 2 years went on to transfer to SUNY Stony Brook. He is currently taking this course PHY315 because it satisfies his science DEC, but since the first class he has become extremely interested and looks forward to the hands-on approach the course offers.
He is a full-time student, but also is a Full-time employee at Apple Inc.. He is a huge fan of Apple and loves his job and serious is considering a career at Apple because of how great a company it is to work for. Aside from loving working for Apple, Pat has a huge obsession with doing research related to History and Politics and hopes to go to graduate school to become a professor of History at some point in his life as it is what he is most passionate about. Pat is currently working for the Barack Obama campaign and encourages everyone to go out and vote on Tuesday!
In his spare time Pat enjoys cooking and especially barbecuing in the summer. He spends his time off with his two young boys who are 2 and 4 respectively and his beautiful wife, Amanda and are currently living in Stony Brook, NY.
Week 2:
In the beginning of class we had a brief introduction to what we would be doing, we were given a few questions and then were able to do our first hands on experiments. We broke into small groups and I worked on the detectors with Lena and Brad. We had a bit of a slow start but soon got the rhythm pretty quickly. We were asked to figure out :
-The efficiency of the detectors- The way we were able to test this was by taking a stack of 3 detectors and turning off the one sandwiched in the middle. We would then take data in two-fold and three-fold coincidences passing through the detectors in 60 sec intervals. These numbers were then divided (3-fold/2-fold x 100) in order to determine how efficient the detectors were. when the top and bottom detectors showed concurrent hits along with a three fold coincidence, this meant the middle detector was correctly counting the hits, and not just random noise.The efficiency could be changed with voltage adjustments. We adjusted the voltage from 5.1V to 6.0V in 0.1V increments. Our Results can be found Here We found that the best voltage was around 5.7-8V for efficiency.
We also were asked to play around with the middle detector, encouraged to displace it or change its direction to and take data on the results of that. We decided to move the middle detector out by a certain percent on each trial such as 50%, 25% removed, and completely removed. These results are also on our data spreadsheet, they are at the top with no graph corresponding.
Week 3:
Coming to class this week was a trek and half, the weather was extremely nasty, being a mix of snow and freezing rain. However, i braved the storm and made it to class relatively on time. We waited around a little while for late comers and then proceeded into a discussion concerning Experimental Error. The reason we calculate error is because it shows us how close our data is to the "truth". There are 4 concepts concerning Error: Accuracy, Precision, Systematic Errors, and Random Errors.
What our group concentrated on was the amount of accidental coincidences between two detectors placed side by side. aside from placing them next to each-other spaced a foot apart, we also used an extra long wire on one of the detectors that delayed the pulse 300 nanoseconds to make sure these were definitely coincidences.
We ran this experiment around 5 or 6 times, and then Dima ran an extra long test over night. Our data can be found Image:Here.jpg
Week 5:
Since i was sick for week 4, Greg and Lena caught me up as far as what had gone on the week before. They had continued trying to figure out the reason for the systematic error with the detectors. With the help of Dima, they were able to come up with a formula for expected "accidental coincidences". However, there were "problems" with the detectors, Dima explained to me how even though they were so far apart, they were still getting a high amount of "accidental" hits due to the photomultipliers not being perfectly sealed. This was due to what Dima called "afterpulses", which could be seen when the detectors were hooked up to an oscilloscope, as seen in the pictures Lena and Greg took:
After Greg, Lena and Dima finished catching me up on what I missed the week before. Dima showed us the higher quality pair of detectors he had brought for us to use. These were of much higher quality, so the instances of there being after pulses should have been greatly reduced. Which in fact was true.
Week 6:
This week was our first round of presentations. Each of the groups presented their finding in the recent weeks and I must say that I was really amazed at the presentations given. All of them were really good in there own right. here is Our Presentation
Week 8:
This week I chose again to work in Greg's group as I thought the subject he was experimenting with seemed more up my alley than the others. The setup consisted of placing two detectors in the octagon, and placing one on the floor. Then we would change the angle as well as distance between the octagon and the floor detector. The way we collected data a little was different this time, using a digital oscilloscope and using a new program to collect the data. Unfortunately, the program to read the output of the first program was not working properly, so thankfully Dima, will be fixing the program (hopefully) our data will be fully readable. We took our data in 5 different arrangements. The overall goal is to see if we are actually recieving triple coincidences because of a shower, rather than just "accidental" coincidences and by looking at the time differences between hits we hope to be able to figure out the angle at which these showers are coming in at.
Week 9:
Continuing our experiment this week, we decided that running longer trials would be the best way to reduce our uncertainties within our original sets of data. We had one long set of data already completed, and worked on getting a second ready mainly the entire time, and discussed what we had found in regard to our theory. It looks as though we don't have a whole lot to present, considering we only had 2 full weeks of experimentation, but hopefully we will be able to continue this experiment in the coming weeks so we can present some data and come up with better results than we had in the short time period. Our presentation can be found Here.
Week 10:
After viewing the other presentations I got pretty interested in the experiment Gillian did, with Barometric Pressure effecting Cosmic Rays, I thought that was really cool, and interesting topic to look at, but I would like to further research the experiment our group was working on. Dr. Marx gave us some good feedback in regard to the methods we were using to take data, of course the first problem being we used different distances between detector 1 and 2, but also the fact that we were probably experiencing cosmic rays from multiple angles rather than "choosing" them. This contributed to the ambiguous conclusions we were getting. Being that I come into this knowing not much more than I can remember from High School Physics, Greg and Lena have helped me exponentially in understanding the mathematical side of our experiments, as well as the other groups great presentations. I reckon tomorrow we will figure out where we will move from this point, and possibly switch to new groups if our experiment proves to be to time consuming.
Week 11:
This week we continued to tinker with our experiment regarding the angle at which cosmic ray showers were coming down. Through our discussions with Michael and Dima we recieved a lot of great feedback and ideas regarding where to move to next. We decided to add a detector and place it in a configuration that should reduce the time difference between the detectors. As we stated in earlier tests the time difference was not close to what we expected it to be. The setup consisted of having the forth detector laid a foot or so directly above detector 1, by using the new set up we are hoping the time between (t1-t2) is around 1.57 nanoseconds since the detectors are much closer together. Thus we should be getting three coincidences more often if the showers are coming in at an angle, if we see more quadruple coincidences we are not quite sure what that would mean considering the spacing and different heights of the detectors.
