User:JNelson

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Hi my name is Justyn Nelson.
I have been going to school at Stony Brook University for Three Years as a commuter student. My major/plan is in Physics. I am into cars a lot, and music. I like Shiny metal things with lots of moving parts that make loudh noise. In my spare time I like to work on various projects. I also watch too many cartoons, then again, there’s no such thing as too many cartoons. It’s about 6:00 am right now and I’ve been up for 3 hours; never again will eat a whole meatball sub before bed.

Not a big fan of myspace. Facebook is ok. I have worked on a few websites, no scripting. I changed the link to the Wikipedia.org page on error, If I have learned one thing from this class it is the importance of correctly accounting for experimental error.
====As a treat, there are two secret messages, one is obvious, and only requires a translation, and the second involves copying the entirety of this wikipage into microsoft word, and spell checking to find extra letters/letters that don't belong in words, then putting those extra letters in order to form the message! first person to email both messages to poorcupine@gmail.com gets a cool prize! Winner to be announced below====

Winner-no one yet! prize is still up for grabs, read message above

Experimental Error

1 Log
2 Raw Data from Experiments (by date)
3 Gallery
4 Weikis created by other people in my class

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Log

First an introduction,
We are using detectors called scintilators for experiments involving the detetion of cosmic rays. A scintilator basically consists of a photo-reactive plastic which lights up whenever it's hit by a particle (like the ones in cosmic rays), and a detector which sends an electric pulse when it sensees the light from the plastic(the scintillators we use are packed into a black case

MARIACHI scintillators have a unique design! Scintillator_Parts_List

which blocks out most all light beside that which the plastic emits). The pulse is sent by a photoamplifier as an electric signal, to a specially designed control box, which sends info to a computer which counts each reaction with the plastic.

There are inherrent problems with this method of collecting data on cosmic rays. One of them being that no notion of speed, velocity, or orientation ( or even time of impact of any one particular cosmic ray) is recorded or made possible to record without many detectors. We use a program created in LabView (a software product from National Instruments. It records individual (thleoretical) hits on a number of detectors over a time defined by the user.(I say theoretical because there are other disturbances possible that could register a 'hit' on the equipment used).

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Faction

Tuesday September 11th, 2007; May We Always Remember: The first experiment Randy and I did was An experiment to determine the highest possible efficiency with the least noise. As I stated in the previous paragragh, a beam of light is emitted when a particle hits a piece of plastic. What I did not mention is how the photo amplifier works, it basically senses the intensity of the light signal, then upgrades the strength of that signal to be sent to the counting equipment. By varying the voltage we should (in our experiment 9-11-07 below) find The optimal voltage across the amp, a point which has high efficiency and low noise. Check out Efficiency Test.

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Experiment 1

Tuesday, September 18th ,2007:Ok, so what me and Randy set out to do today was to see if a change in flux could be measured, We moved the middle scintillator (the same one from the first experiment) over so it was out of line with the top and bottom detectors by small increments, until only half of it stood in between the tpop and bottom!. Since these detectors are rectangles we can easily say the area removed from the middle is egual to the length it's pulled out (which we will call lambda), multiplied by its width (about 20 cm). ( if this is confusing please see the diagram in the excel file titled Experiment 1

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Experiment 2

Tuesday, September 25th, 2007 :Experiment 2 a.k.a solid angle; Another way to look at flux is to measure the cosmic ray distribution on a solid angle. What this means is that we used two detectors as a telescoping array pointed skyward. We are able to see rays coming from a window created by the angle between the edge of the top scint. and the opposite edge of the bottom scint. (see fig. 2.1) We measured the cosmic ray coincidence rate versus the length of separation "r".Experiment 2 excel sheet Version 1

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Experiment 3

Tuesday, October 2nd, 2007 (-Experiment 2 Cont.'d Processing data see excel file: Experiment 2 excel sheet Version 2) :Experiment 3 Location Location Location; WhatI Our 3rd Experiment is about is focusing on different locations in the sky by changing the direction of the telescope-type configuration, instead of pointing up (at $90 ^\circ$ from the horizontal line on the floor.), we are looking at different pieces of sky based on the angle the two scint.'s make with the floor (see fig 3.1). At the distance between the two scintillators now, we are actually looking at a range of angles about 20-22 degrees wide.

Tuesday October 9th, 2007 : Experiment 3 cont.'d; In the section above I mentioned that we angled our scintillators to find different patches of sky. When we first rotated them, we took data that appeared to show a high distribution vertically (at $90 ^\circ$ ) and the lowest distribution in athe horizontal (at $0 ^\circ$ ). If we keep in mind that the "telescope" a.k.a octagon, does not "magnify" in either direction, we realize that in the horizontal position, the two scintilators count rays coming from both 0 and 180 degrees w/respect to the center of the octagon, which means any rays travelling parallel to the floor. What this may mean is that in actuality we are measuring two pieces of sky, and so each piece may only contribute half, or any other fraction, of the total number of rays coming through this horizontal setup.

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Experiment 4

Tuesday October 16th,2007: Experiment 4 round' the vertical we go. Establishing a trend between rays parallel with mthe floor through rays perpindicular to the floor, we now wanted to try sweeping parallel to the floor, to find a difference in the field of rays at directions N,S, E & W, and in between. This time however, each piece of the field we detect would be wider in the direction we're looking because the scintillators are wider than they are long, and we can't really lay the octagon on it's side. We took data at N ( facing the northernmost wall), W( $90 ^\circ$ ), S( $180 ^\circ$ ), & E ( $270 ^\circ$ ). Data can be found in the excel document labeled Experiment 4, in the data section below.

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Experiment 5

Tuesday October 23rd, : After looking at the data from experiment four, It was brought up that our graph showed something important; we haven't got much conclusive data since the error bars are soi large compared to the difference in the points of data (fig 5.1).

So this time we changed the experiment, still looking for the same thing, a trend in cosmic rays based on the orientation ( are they mostly coming from north?,south?,west?, east?, somewhere in between? ), but this time our goal was to do it better with more conclusive results. With the aid of Cosmic Chris, and the discussion in class that Dima gave on "chi" we began to realize that there is a possibility of no change in any direction. $\circ$

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Experiment 6

Tuesday October 30th a.k.a "All Hallows Eve Eve" a.k.a "Fun with Cosmic Chris" In this experiment we used Cosmic Chris to try and determine if there was a kind of shielding effect due to the layers of concrete and building that lie in the path between the cosmos and the room where we have done all of the above experiments.n
First we had chris in the spot where he was with the otcagon (Pos1), then moved him near a wall which is a close-to-4-foot-thick layer of concrete (pos2) . Positions 3 and 4 are in the corner of the 4ft walls, where Pos 3 is close to the corner, and Pos 4 is in the corner,facing towards or away from the vertex of the corner.

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Experiment 7

Is it possible to get Coincidence hits on two scintillators that aren't on top of each other, or within a solid angle of each other? the answer appears to be Yes. For this experiment we used two sets of scintilators at a seperation that would make it nearly impossible for an otbject that is traveling in a straight line to coincide on all 4 detectors.

Note: Coincidence rates are per second ( you could call it Hz)

The red line shows one of many possible paths for a single particle to show a coincidence, it seems that a better eplanation for the 4-way coincidences we got is that there are two particles traveling in a relatively straight pahth, and coinciding (w/in 100ns of each other) and so most likely came from the shower of particles caused by a cosmic ray colliding with the atmosphere.

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Experiment 8

Is it possible to detect this occurrence of 2 particles using only ONE detector, or really any number less than four? Maybe, however the geometry used when we had four detectors at our disposal is unhelpful, and not valid to say the least. The purpose of this experiment was not to be clever enough to use less scint's, but raether to observe 2 particles in a smaller area with positivity.

   This would be more of a first step toward that goal.

The Idea Prof. Marx, Dima, and I settled on was to lower the efficiency of a middle detector to about 50%. The experiment is carried out in the same fashion of the faction/efficiency tests, but by lowering the Voltage on the top and bottom detectors instead of changing the voltage The Idea being that now the photomultiplier would be sending out signals at half strength, thus it is necessary (in theory) that there are two particles hitting in order to make a signal above threshhold(i don't know if that's how you spell it) and create a pulse to send to the counter. The results, at first glance look promising, as we changed the voltage, unfortunately at steps of -|.2|V, It was only possible to get 3 data points.

When you lower the power on the scint., you get a less sensitive scintilator (that is to say the light reaching the photo multiplier from the far end is weaker than the near end, and with such a sensitive instrument it is enough difference to make particles in the far end undetectable ("invisible") to the counter.

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Experiment 9

(see experiment 7) This was a continuation of Experiment 7, With the error bars as they were the first time, we realized we needed smaller x error to really see any charecteristics of these pairs of particles. We increased the distance to where the detectors would look more like points than areas, (in other words the distance between the detectors is much smaller than the length or width of the detectors). The result is, at almost 8m, an error of less than 10% in the distance between the two simultaneous particles. This experiment proves the likelyhood of the showers which are the result of cosmic rays

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Raw Data from Experiments (by date)

Weekb 1 9-11-07 we tested a scintilator by placing it in between two other scintilators. The Idea being that a coincidence between the three would mean a real count on the scintillator in question, while the rest may just be noise. And the data interpreted: 9-16-2007
Experiment 1 9-17-2007 The Data interpreted (first interpretations Please comment) : 9-19-2007 ARRRG! International Talk Like a Pirate Daya
Experiment 2 9-27-2007 With interpretations->9-29-07
Experiment 3 10-02-2007 Octagon Experiment Excel Spreadsheet Compiled Version 1.1
Experiment 3a 10-09-2007 Octagon Expseriment Excel Spreadsheet Version 2.0