User:KGreguski
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About Me:
My name is Kenny Greguski and i'm 21 years old. I have lived in Lake Grove for 11 years. I currently have two jobs, Target and Abercrombie & Fitch. I guess you can say i'm a workaholic because i'm going to school full time also. But i like to stay busy.
I love watching tv but rarely have time for it. DVR is the best invention. I don't know what I would do without my computer either. I am constantly checking my email and Facebook.
After high school I attended Farmingdale State University for two years studying Architecture. After deciding that wasn't for me, I transferred to Suffolk County Community College, as a business major. Now I am at Stony Brook University continuing that degree and i'm in my junior year.
Hands on Science with Cosmic Rays:
What I Learned:
Cosmic rays are particles from our and other solar systems that fall to earth at a rate of 1/minute/cm**2. The energy they possess is determined from their source. Low energy particles com from the sun and typically have a reading of 10-100 MeV. The highest energies are above 10 EeV which are mysterious, but are linked to "Active Galactic Nuclei."
The reason we study cosmic rays is because they can be directly related to us. In fact they are thought to be the cause for evolution over past centuries.
9/3/08
Wednesday September 3rd was our first day of class. Basically it was an intro to the course with added background information about what we would be studying. The last hour of the class was spent experimenting with all the class materials and taking calculations with the computers and sensors to take readings of cosmic rays. After playing with the program in my group I understand how it works and all the steps that need to be taken in order to take the data using the computer.
Experiment 1
The main objective of the experiment is to use detectors to test if cosmic rays pass through the top and bottom detector box, as well as the middle detector box.
Observations:
Watching the screen show all the rays fall, let me see that there were times when something caused the line to pulse at the same time and for the exact distance. This can tel us that either the ray simultaneously passed throughall three detectors, or that the pulses were mere coincidences due to external noise interuptions.
Because of the coincidences we conducted our experiment with three ray detectors. We set them each to their optial voltage, and then started the computer program; setting the time intervals for 60 sec. In that 60 sec. we were looking to see how many times the top and bottom boxes counted at the exact time as well as the middle box registering a reading at the same time as the top and bottom boxes.
At the end of 9 intervals, each time increasing the main voltage by .1 volt we had enough information to create the following chart displaying our findings.
9/10/08
Experiment 2
Today we retested the experiment we conducted the first day of class. We wanted to see if their were any changes in the data we found, or if the findings were similar.
We set up the experiment the exact same way and ran multiple intervals testing the same volts.
Data:
9/17/08
Experimant Error:
"No measurement is perfect, so we need a way to discuss how close it is to the truth." That was the first thing we learned to day in class and it is true. With all the differnt calculations we take to get our data there are a million possible errors that can occur. So to estimate how much error is associated with our calculations we have this formula:
error=SQRT(N) where N= the number of counts
Experiment 3
What we did:
First we had to find the are of the ray detector. We used a sample detector box that was open to take allt he measurements for both the casing and for the plstic sheet inside the case.
Then we ran the simulation just like we did in the first two experiments. We set up the computer and the software the same way, but this time instead of playing witht the volts we set it right to 5.8 becuase that was the one we found to be most accurate in the last experiment.
We ran the simulation 4 times each for 300 seconds long. Ecah time though, we changed the position of the middle box, in reference to the top and bottom box to change how much area the rays were being detected in. Because we changed the positions we had to calculate the new area for each trial.
After all our data was taken we imported the information into Microsoft Excel. We had to calculate rate so we took the 3 fold coincidences and divided them by time, which gave us rate in Hz.
Before we could plot our findings we has to calculate the error by taking the square root of the 3 fold coincidences divided by the time.
Lastly be plotted our graph showing rate vs. area with the error added in. Because we ran our simulation for so long our error was very small and barely readable on the graph. But little error means we have very accurate findings and reliable findings. We also found the slope for the line in our graph. It was 137.56 Hz/cm^2.
9/24/08
Today in class we broke up into three different group so that we could individually perform experiments with the ray detectors. My group is experimenting rate vs. altitude, with the help of Cosmic Chris. Because we need to measure at different areas all throughout our building we needed a detector that could be easily moved, hence Cosmic Chris.
Procedure:
What we did was first take a measurement of how many rays were detected right in our classroom. Because we didn't have a computer we needed to take the data ourselves and timed the trials with a stopwatch. We conducted the first trial for 60 seconds and the second at 180 seconds. We used the same time intervals at every place we tested.
Then we moved Chris to the room next to our classroom. We wanted to see how much difference was detected due to the fact that that room was encased in 3-4 feet of concrete all around, but still at the same altitude as our classroom.
We then took measurements at the elevator on the sublevel and for every level of the physics building.
We wanted to see if there was any real difference in the number of rays detected being inside or outside, so we went outside. We took the two measurements and compared them to the data taken on the ground level. This information wasn't used in our graph but just for our curiosity. Maybe next class we will come up with a different test where we can use these corrulations.
After all our trials were taken we went back to the classroom and plotted our information.
Media:Cosmic Chris Rate 9-24.xls
There are a couple things that we can tell from plotting the graph and then adding in the error. We can see that there are two points where points on the graph don't fall within the max and min error bars. This shows that at these points something went wrong with the detectors. Either we were in a spot where there wasn't equal coverage like on the other floors, or we were getting to much interference. This just means that we have to switch up our experiment a little to try to overcome these errors. After looking at our findings in class our group decided to try taking detections in the middle of the building for a series of trials. Maybe being by the side of the building gave us some inaccuracies. Testing in the middle of the building may give us a more accurate test of rate vs. altitude.
10/1/08 & 10/8/08
NO CLASS
10/15/08
Today we started out class going over what each group was doing and the results we all found from experimenting last class. Everyone was well into their experiments, having things that went well and resulted in good data, as well as things that we wanted to re-test or try a different way. After the first 15 minutes of the class we all broke up into our groups to continue testing.
After getting feedback on our experiment we found figured out that the different spikes in our graph might not be associated with error. There are times things don't follow exact patterns and these might be one of those times. We did want to test our experiment in a different way just to see if we were able to get similar findings, or if there really were any discrepencies.
We wanted to continue with our experiment testing counts vs. altitude, the difference this time to last time was that we tested in the middle of the building. We had a hunch that even though cosmic rays fall at the same rate every second, that the number that actually reach us changes due to our surroundings. So there were two areas that we put up against eachother to see if our hypothesis was right. We conducted the same test once in the middle of the building, and once again in the bridge between the physics and math building.
Procedure:
1. First we rolled Cosmic Chris to our first location which was at the fire doors in the center of level D.
2. We turned on the Geiger counter and kept track of how many counts we got for 5 minutes.
3. We then wrote down our data and continued to the next spot, which was the same but one floor below. We used the fire doors as reference so that we were able to get the most accurate results.
4. We repeated steps 1-3 until we were on the sub-level.
Then we started the whole experiemnt over at our new location. We thought the bridge would be a great place because it wasn't surrounded by a lot of material so it would be the best way to measure how altitude changes the counts.
1. We set up Chris on level D of the bridege right outside the men's bathroom. This time the bathroom was our marker of where we would test on each floor.
2. We then took the counts on that level for the same 5 minute interval.
3. We wrote down our data then continued to the next lower floor.
4. We repeated these steps until we were once again int he sub-level.
After we were finished taking all our data we went back to the classroom to compile everything into Excel.
While plotting our data there were certain things that we thought would happen and other things we knew were going to happen. First, we thought that the number of counts would differ even on the same floor level depending on where we were in the building. Also we thought that there were also going to be weird points in the graph just like our results from last week. We knew that there was going to be a huge difference in the number of ray detected on the pl under the bridge, mainly because the only buffering between the counter and the rays was the building's 4 levels above us. There were no walls shielding from the rays, which not to our surprise gave us a reading way outside the error limits of the graph. But like I said that was to be expected.
This is what we came up with after inputting the data and plotting the graph:
Media:rate altitude revision.xls
One of the best things that we have going for our group is that we have low errors. That is partly because we run the experiment for a reletively long period of time and then get the rate. We saw this in the first experiment and we can see it again in this one. In fact the error is so low that you can't even see the error points on the graph, but if you check the formulas you can see that they are there.
There are a couple things that you can see from looking at our graph. First you can see that the lines on the graph are faily linear except for to distinct bleeps at level PL and level D. But which what we have figured out from prior experiments this is to be expected. There is an extreme count of rays detected on the PL under the bridge because we are outside with nothing sheilding the counter from the rays like in the middle of the building. And the point outside the line at level D is from the fact that you are on the top level of the building. Unlike all the other levels, D has nothing above except the ceiling. Because there isn't another floor on top of it we see a higher detection rate.
Something else you can take away from the graph is how this way of detecting rays can be used as an x-ray. We are baqsically surveying the building as we go around taking counts in different spots in the building. From looking at the data taken at level A, B, and C you can see that they increase at the same rate. The points are almost equal distances apart, and the fact that even in different locations the slope of the lines are parallel means that the areas have similarities. In this case we could confirm that each floor is exactly the same, and that there is something on top of that level. The fact that level D's counts were higher shows that something changes in the landscape of the building which we know to be the lack of another floor on top of level D.
What's Next
So we have already tested ray detection in one spot, and tested two spots against eachother to see if altitude affects detection, and we can definitely conclude that it does. We have also found out that surroundings also play a role in how many rays are detected.
10/22/08
In today's class we presented our data and talked about the different directions we could go to continue with our experiment. The main thing that i took out of it was the fact that testing the way we have been doing is really testing two things, rate vs. altitude, and rate vs. stuff at the same time. So we need to take something out of the equation so that we can get a more accurate number of counts where just altitude is being tested, or where just the amount of stuff affects our findings.
What I want to do next class is try to see how altitude directly affects ray detection. To find that out we need a way to increase our altitude without having any stuff around us. Obviously we have to go outside and the perfect place to conduct this experiment would be on the lawn outside the staller center. We could conduct a trial on each of the step-like levels of grass to see the difference in ray detection. I'm not expecting a great difference in the number of rays detected but it can give us the average rate at which the rays hit depending on the altitude.
10/29/08
So after discussion of my ideas that i had coming into class this week my group came to the conclusion not to conduct an experiment on the grass outside the Staller Center. It was a good concept to test only altitude and detection, but the results wouldn't really differ with the slight change in elevation. To try to test the same thing on a larger scale we decided to turn to the parking garage. We still will have an influence by the structure of the garage itself but it will be a lot less than being inside(we hope).
Once again we trucked Cosmic Chris half way around campus to our destination, this time being the parking garage. We tested the detection on the ground level of the garage and then for each other level in the garage. We kept the location and orientation of Chris the same in all four tests so to get a more accurate reading. Then we went back to the classroom to record and plot our data.
Side Note:The hardest thing about this experiment was the fact that we had to physically carry Chris up and down four flights of stairs, because the lack of an elevator. We are dedicated to our work.
Media:parking garage experiment.xls
11/5/08
Today it's raining outside so i think my group is going to stay indoors. It's the perfect opportunity to start testing in a new direction.
We will be testing the rate of absorbtion of the cosmic rays but this time without the help of our fourth team member Cosmic Chris. We will be using a pair of detectors in the classroom, as well as lead and steel blocks to act as barriers of absorbtion. It is my guess that the lead will interfere with the ability of the detectors to count some of the rays. It is because of this that i believe the times we test with and without the "stuff" will result in different values of rate.
Media:perpendicular detector orientation.xls
Media:parallel detector orientation.xls
After running the experiments and looking at the data we found out that the results with and without the lead really wasn't that different. We realized that the way we conducted the experiment and set up the detectors didn't produce correct results. Because we were only using two detectors even though we had them perpendicular to eachother they could still have coincidences in the places we weren't testing. Next class we are going to test the same experiment but this time using three detectors. We hope that adding the third detector this time to the top of the experiment perpendicular to that box also will in fact reduce the testing are and hopefully give us the results that we expected, which was that the lead was going to absorb some of the rays giving a much lower number.
11/12/08
Media:11-12 perp 3 fold retest 2.xls
The difference between this weeks experiment and last weeks experiment was the addition of another detector box. After looking at our data after running all of our tests we thought that the numbers we were getting were way to high especially with the addition of the lead, which we thought was going to lower our counts. What we figured out was that by only using two counters perpendicular to eachother and placing the lead in that smaller box, we were testing that area, plus the area around the lead where some rays were still hitting both detectors. So this week we added another detector to the top of the experiment to try to cut down the testing area even more.
The way our experiments from this week and last week were set up can be seen by this link: Media:11-12 perp 3 fold pics.ppt
We ran our second experiment a couple times, due to the fact that one of our plots was extremely far from our line. The difference in the trials was the time we ran the detectors for. We considerable ran the tests longer so that we could reduce our error and we can see that it worked due to the fact that in our second graphing of our data the second plot in question moved closer to the line.
Something new we learned in class was Chi^2. Chi^2 is used to test how good a given point or test is. After the computation if your number is at or close to 1 you know that it was a good test. If it far from 1 then you should retest your experiment, which was the case for us, to try to get the number closer to 1. The formula for chi^2 error is (rate - model)/ error and square the whole thing. The chi^2 error improved from 2.556 to 1.597.
11/19/08
Today was supposed to be presentations for the second time to present what we found from the previous 3 classes. Unfortunately I experienced some car trouble and missed the class, so I am going to explain everything that I was thinking about our experiment and future experiments here.
What we have been testing was a detour from our last experient using cosmic Chris but still in the same field. A common factor that we encountered in testing with Cosmic Chris was the abundance of stuff around us while we were testing. Because we were testing elevation inside a building we had to have the walls, windows, ceiling, elevator shaft, and everything else inside and around us affecting our results. We knew that tehre had to be something blocking or absorbing some of the ray shower because from the first day of testing we took a reading on the plaza level of the Physics building and we tested the exact same parameters directly outside the building a couple yards away and got drastically different numbers. The count inside the building was 1794 at 60s and 5367 at 180s. The count outside for the same times respectively were 2399 and 7120. For those numbers to be that different you couldn't deny that there was something influencing the counts.
So what we came up with was to test detection at the same altitude, but with different degrees of stuff. In this case the stuff was different layers of lead. To do this we had to ditch our friend Cosmic Chris and go back to the other way of testing using the ray detector boxes. Once again the way we set up our experiment was as follows:
There was definitely things wrong with our experiment fromt he get go but there was nothing we could do about them, so we had to adapt our experiment. What really hurt us was the lack of lead blocks. We only had enough for a 30" X 30" area so what we did was lay the detectors perpendicular to each other to try to cut down the testing area. What we didn't realize was the fact that rays could still be counted in areas not covered by lead.
After figuring that out we relized that our experiment had to change and that led to our experiment the next week using three detectors perpendicular to eachother. With the exception of the three detectors instead of two the experiment ran the exact same way. We did everything exactly the same.
This experiment worked much better at blocking some of the rays outside our testing area, but we still had instances where we had hits that we weren't supposed to be counting.
I think before we move on to another area of experimenting we should try to finish with this experiment to see if there is anything else we can take away from it. Where we are at now we can definitely see that the lead effects the ray detection. But adding the second and third layers of the lead didn't produce any real differences in detection. I wonder if this is because we are still getting to much accidental counts. To try to lower that number even more we can try the addition of a fourth detector. This time we should put it on the bottom. This will lower the area that rays can come from to be counted by all three and hopefully produce an accurate reading as to if the addition of stuff has the effect of absorbing rays.
One reason why i think we aren't getting different numbers with the addition of the second and third layers of lead is because there isn't enough of it to make a big difference. It is the same reason why we had to go up a whole level in the building to get a real difference because a foot or two wasn't enough to have a change. If the same thing applies, an addition of a couple inches of lead might not be enough to produce real change. If we had a wall of lead that might help. But we could test with the concrete walls to see if that has anything to do with absorption.
