Developed for Southwest High School, Piasa, Illinois

Fall, 2000

  • The general ideas of the CosRayHS project are that:

    1. to study really high energy cosmic rays, one needs an extended grid of detectors; the optimum spacing is still being studied, but 0.1-1km spacing seems reasonable;

    2. there are a few really odd events (seen in Switzerland) with correlations among 4-5 different sites spread apart by of order 50 km;

    3. in addition to studying possibly wildly interesting super-high and unexpected energies, cosmic rays are both a laboratory for high energy particle studies and probes for "cosmic" events in the formation of our galaxy and the universe, as described by James Pinfold in the April 2004 Cern Courier 4. quite a bit of information can be gathered with a comparatively simple detector... plastic scintillator material coupled to a PMT, and two or more of these in coincidence with each other, to indicate a cosmic ray sufficiently energetic to have more than one particle in the "shower" of interaction products;

    5. the above detectors are small enough and unobtrusive enough that it may be possible to put them in high schools, in order to have many detectors giving information;

    6. the general subject of cosmic rays and their unknown origin in the universe, as well as several related technical investigations, may be interesting to high school students.

  • 7. The project is too big to be done completely by any one student or scientist or any one group. Below is a list of related activities or investigations. Some are intended to help students learn more about the project, its physics and related technology. Others are steps required to make data taken by our detector reliable and interesting, either in themselves, or in conjunction with data from other stations.

    1. learn about other projects interested in the same thing. so far we know of four rather far advanced:

    a) "ALTA" , Univ. of Allberta, in Canada;

    b) "WALTA", Univ. of Washington at Seattle;

    c) "CROP", Univ. of Nebraska; and

    d)"CHICOS", a consortium of Caltech and other schools around Los Angelos (http can be found from the WALTA site).

    The Alberta site has some material developed specifically for high school students. The Washington site has a bibliography, and list of related web sites. Another web site which includes ideas about high school physics labs and investigations is Preston College has some interesting ideas for high school physics labs and investigations. The OWL website also has a good discussion of the general mystery surrounding the origin of very high energy cosmic ray primaries.

    See the 28th International Cosmic Ray Conference for a more complete description of current status and results of these and other interesting cosmic ray projects.

    2. learn about cosmic rays. what energies are specially interesting? what can they tell us about the part of the universe which created them and through which they have passed? the web sites above and associated references are good here. Scientific American articles are also good.

    3. the energies which can be studied at a single school are lower than the anomalous events described above. what can we learn from these lower energies? is study and understanding of these events necessary to understand the more complicated high energy events?

    4. work with a cloud chamber. count charged particles (generally cosmic rays) passing through the cloud chamber. compare with expectations. See the Belleville Community College web site for instructions prepared by some other students.

    5. compare the cloud chamber rates with rates seen using a Geiger counter. are they compatible?

    6. compare the cloud chamber rates with rates from other detectors available... small scintillator telescope, large scintillators,... are they compatible?

    7. compare single particle counts with double or triple coincidences... can we understand those from what is known about cosmic ray showers?

    8. compare rates at our school with rates from other schools with other detectors. are the rates compatible? do we understand the differences? (here, with counters nearly touching, we saw about 3/min. doubles; in Pittsburgh, with counters further apart, we saw about 1/2min; in Alberta (further north? does that matter?) they saw triples about 2/min (what about size and spacing of the counters?) these measurements are now being redone by some high school groups. we can get their e-mails and students could compare directly, to try to understand first what the real rates (normalized for the same time and the same area, same spacing) are, then try to understand reasons for the differences.

    9. learn about radiation and radioactivity. cosmic rays are one form of radiation, which we can't escape from. other forms are also around us in everyday materials and even within our body. radiation can even be used to sterilize food. it can be used to produce energy, but there is a fine line in a big installation between quietly producing energy and having a destructive accident. how to handle that fine line is something that is still under debate, both in our country and in the world. there are a lot of references about these questions, which need science as a component of the argument, but which cannot be decided simply on the basis of science.

    10. learn about the detectors for radiation and radioactivity. cloud chambers, geiger counters, and plastic scintillators are three types of detectors, but not the only ones. here there are also many references. one suggested at the workshop we were at is: Teacher's Guide to Nuclear Science, available from an organization called Science Kit (1-800-828-7777, or http://www.sciencekit.com).

    11. learn about how computers control, and are controlled by, external information. (one very simple example of this was the experiment we did in class where the changing of the voltage seen by the computer was able to change the word the computer read in and printed out; the same software can do much more complicated things, including, we expect, read in and manage the information from our big scintillation detectors. but we will need to learn how to tell the computer to do it.

    12. learn about how different narrow signals (narrow in time.. ours are about 10-20 nsec long) can be combined to give very well defined coincidence information. how long does it take different parts of a cosmic ray shower to get to our detector? is there any information in the times of arrival, not exactly at the same time, but a little separated, of different parts of the shower?

    13. learn about the gps system: how it works, what precision is available (Jay Farrell and Matthew Barth, "The Global Positioning System and Inertial Navigation", McGraw and Hill, 1999; also Univ. of Texas (Dallas) website.

    14. compare our position as found from national geographic survey maps (or other maps) to the position found by a gps device. this is an important piece of information when using the gps system to get good timing information, which we need to understand our events.

    15. learn how oscilloscopes work, and how they can be used to study electrical signals of different kinds. this is really in two parts: just learn how to use the oscilloscopes, or learn how the oscilloscopes really manage to carry out their functions.

    16. learn more about electricity in general.. it's the basis for a lot of this work.

    17. learn about how photomultipliers work. (photomultipliers are the light detectors which detect the light from the scintillator material in our experiment. they make an electrical signal from the light).

    18. study characteristics of "simulated" cosmic ray showers in order to better understand what our detector will see. some of our collaborators have made and will keep on making showers of different energies for us, and a lot can be learned by just looking at these showers that others have made.

    19. make a simple mathematical model (not really so simple, but a lot simpler than the complicated computer programs which made these sample events) of how the cosmic ray showers work, so that we can predict what we will see.

    20. get the complicated simulation to work at our school. (this is probably more for the future).

    21. see what connections there are from our project to other ideas. what about the weather station on the roof? can we read the information from the weather station into the computer? (either with the same software which read and printed the "word" in our classroom experiment and which we will use for control of our data acquisition, or with some commercial software?)

    22. how about putting some of our information on the school web site?

    23. in general, how is the best way to share our information with information from other installations?

    24. how often do we see coincidences with results from other installations? how often would we expect to see such coincidences.

    As you can see from the list above, there are a lot of ideas. And many other ideas will come up. Talk with your teacher about things which interest you. If you have questions you can reach us at: jth@pitt.edu (Julia Thompson) or kraus@pitt.edu (David Kraus)