The Cosmic Ray Observatory Project: Results of a Summer High-School Student, Teacher, University Scientist Partnership Using a Capstone Research Experience

Abstract

This paper reports results from evaluation of the Cosmic Ray Observatory Project (CROP), a student, teacher, scientist partnership to engage high-school students and teachers in school based cosmic ray research. Specifically, this study examined whether an intensive summer workshop experience could effectively prepare teacher—student teams to engage in cutting edge high-energy physics research. Results showed that teachers and students could acquire enough knowledge about cosmic ray physics and self-efficacy for conducting cosmic ray research during a summer workshop to be full participants in an SSP conducting research in their schools, and a capstone anchoring approach using an authentic research activity was effective for motivating student engagement in didactic classroom learning. CROP demonstrated “proof of concept” that setting up cosmic ray detector arrays in schools run by teachers and students was feasible, but found that set-up and operation in a high-school was technically difficult.

Appendices

Appendix A

See Table 11.

Table 11 CROP workshop classroom topics

Appendix B

Typical CROP workshop week.

Appendix C

CROP Year 4 pre- and post-knowledge test

• 1. What are cosmic rays?

• 2. What is meant by “primary” and “secondary” cosmic ray particles?

• 3. The energy distribution of primary cosmic rays bombarding the earth has been measured by a number of experiments. In the space below, sketch a graph of the number of observed primary cosmic rays vs. cosmic ray energy, and describe the distribution in a sentence or two.

• 4. Where do we believe most primary cosmic rays come from? What questions remain about the origin of the highest energy primary cosmic rays?

• 5. Describe three different detector devices which might be used to detect the presence of cosmic rays at the earth’s surface.

• 6. Explain how a scintillation counter works, i.e., write down the sequence of events from the passage of a charged particle through a scintillator to the generation of an electric signal in a photomultiplier tube.

• 7. Describe how an energetic cosmic ray creates a giant air shower in the earth’s atmosphere.

• 8. Describe the structure of an atom down to its smallest pieces.

• 9. What two pieces of information will be needed from a GPS receiver in CROP, and how will this information be used in measurements of cosmic-ray air showers?

• 10. Many detectors capable of tracking the path taken by a charged particle are designed to operate within a surrounding magnetic field. What properties of the incoming particle can be determined by such an arrangement and how?

• 11a. Why did the physicist Pauli suggest and Fermi develop a controversial idea like the existence of a new neutral (perhaps massless, or at least nearly so) particle (the neutrino)? What observations were they attempting to explain?

• 11b. What is meant by the recently observed phenomenon called “neutrino oscillations”? [eliminated in Year 5 test]

• 12. Describe some characteristic differences between electromagnetic showers and hadronic showers created when particles impinge on a block of matter or a cosmic ray enters the atmosphere. Hint: think in terms of the type of particle which initiates the shower, the type of secondary particles in the shower, the shape of the shower, depth penetration of the shower particles, etc.

• 13. What do the terms “real” and “accidental” coincidences mean in an experiment employing two scintillation detectors and an electronic coincidence circuit?

• 14. Describe two types of measurements or observations you could make to determine whether a CROP scintillation counter has a “light leak”.

• 15. What is meant by the “efficiency” of a scintillation counter? Describe the set-up you might use to measure this quantity.

• 16. The singles rates (counts per minute) of one of your scintillation counters, which you have observed to be stable for a few days, suddenly changes (increase or decreases) by a factor of 4. What do you suspect may be the cause of such a change? How would you verify that your suspected cause (or causes) is correct?

• 17. The oscilloscope.

• a. What is the amplitude (in millivolts, mV) of the square pulse traced by the oscilloscope above?

• b. What is the pulse’s width (in nanoseconds, ns)?

• c. The oscilloscope settings are now adjusted to a new sensitivity of 500 mV/division and trace speed of 5 ns/division. Sketch below how you expect the pulse to appear now.

• 18a. The Poisson distribution

$$ P(n) = {\frac{{\mu^{n} e^{ - n} }}{n!}} $$

describes the probability of counting n randomly occurring events during some fixed period of time.

• What mean (average) number of counts does it predict?

• What (in principle) is the maximum and minimum count it allows?

• 18b. What is the best estimate of “error” in counting the events described by the above expression?