The Cosmic Ray Observatory Project

Introduction

According to several 2006 science and engineering indicators [1], while U.S. students (grade school through high school) have shown improved performance in mathematics, they have not done soin science. Exacerbating the problem arethe manyteachers who teach in a field outside their training, often without full certification.

For the past 7 years the University of Nebraska has been engaging teams of high school teachers and students in a genuine long-term cross-disciplinary research experience: studying correlations of extended cosmic ray air showers across the state of Nebraska.

High Energy physicists Snow and Claes developed CROP (the Cosmic Ray Observatory Project) [2] with seed grants from various UNL sources. A National Science Foundation (NSF) grant (expiring this year) launched the pilot phase of the project in July 2000, providing primarily participant funds (student and teacher stipends, housing, and travel). Through a series of summer workshops and academic year meetings, CROP has now trained 36 science instructors and over 150 students, representing 29 school teams, in the hands-on maintenance and use of their own student-built cosmic ray particle detectors.

In addition to clusters of schools in both Lincoln and Omaha, CROP now extends as far west as Scottsbluff and as far north as Springview.

While seven of these schools are from the Lincoln-Omaha metropolitan areas, three serve communities of 5000, and ten are from the consolidated rural school districts of communities under 1000, including Loup County High School, identified by the U.S. Department of Commerce’s Bureau of Economic Analysis as the poorest county in the entire nation [3]. To date the teachers include 2 biology, 2 earth science, 1 chemistry, 2 calculus, and 6 physics teachers. The remaining teachers rotate their teaching responsibilities through the school's full range of science courses (typical of the remote rural school districts). Over 80% of Nebraska’s science teachers have their primary teaching in biology.

CROP provides an ideal means of merging the three primary missions of a land grant institution: research, teaching, and outreach. During the NSF’s February 2000 Committee of Visitors review, the Division of Physics repeatedly cited CROP as an exemplary initiative helping to meet its education and research charge. CROP's unique collaboration between researchers and high schools in a long-term, viable experimental program was recognized as having great potential to increase the impact of experimental research on the nation.

The Scientific Potential of CROP

Particles from extended showers will be sampled by arrays of student-built and maintained scintillation counters placed on high school rooftops, while a PC-based data acquisition system located inside the school building records events. A GPS receiver provides a time stamp so that coincidences with other sites, signaling the presence of extended cosmic ray showers, can be detected. Student participants will compare data with other sites via the Internet and share experiences through regional workshops organized around the state's 19 Educational Service Units.

Although the main thrust of CROP has been to expose its participants to the science of cosmic rays, data acquisition and analysis, the CROP experiment will address topics to complement the major ground-based arrays. Primary cosmic ray energies and direction-of-origin distributions will be collected for building-sized showers (E = 1015 eV, plenty of rate) using the detector array at each school and city-sized showers (E=1019 eV, lower rate) using time-coincidences among schools in populated areas like Omaha and Lincoln for comparison with the above experiments. In addition, CROP will make a unique scientific contribution by having detector sites that eventually cover the 75,000 mi2 area of the state, many times the coverage of the above arrays. The sparsely-spaced sites in western Nebraska will allow CROP participants to investigate very long-distance correlations which would indicate extensive cosmic-ray bursts. In simple terms, when an Omaha school detects an energetic shower do schools in Lincoln, Kearney, Ogalalla, or Scottsbluff detect any activity at the same time? The scientific impact of CROP will be strengthened in proportion to the number of sites collecting data simultaneously, making expansion across the state the primary goal following its pilot stage.

Progress since last ICRC

A special one-week workshop July 18-22, 2005 brought students and teachers from 15 of the schools in addition to a small gourp of international observers (2 visitors from the HiSparc project in the Netherlands, and one from Turkey). Most of the students were new to CROP, since many of the original students had graduated. Participants brought their own equipment for refresher training and the installation of new firmware and data acquisition software. The last night of the workshop, all detectors were set up on the lawn outside Ferguson Hall and air shower data were accumulated. The workshop received local press coverage in the Lincoln Journal Star and on Nebraska Public Radio and local television news broadcasts.

Progress continues on several fronts, largely guided by the CROP staff of undergraduate and graduate students: many improvements were made to the LabView-based data acquisition software that runs on a school’s PC, and several CROP staff members visited participating schools around Nebraska to help with their detector installation and data-taking procedures. Students from a number of high schools were guided by CROP staff in performing stand-alone measurements with CROP detectors that served as entries to science fairs.

LincolnHigh School physics teacher Jim Rynearson, who joined CROP with several students in 2001, said “I use CROP to introduce students to real research. The really nice thing about CROP is that it deals with modern physics topics which most students don’t see in high school.” One of Rynearson’s students, Ben Plowman, received a Top 5 ranking at the state Academy of Science fair based on cosmic ray measurements he made with the Lincoln High detectors, which took him to Washington, D.C. in 2005 to compete at the national level.(Several of Jim’s students, even through 2007 have placed in state-wide science fairs).

Three Lincoln High School (LHS) students, Ben Plowman, Rudy Resch, and Kent Shirer, prepared entries to national science fairs based on measurements they performed using equipment supplied by CROP. Triggering on cosmic ray muons passing through scintillator panels with different geometries, the team studied the light collection efficiency as a function of distance from the photomultiplier tube. Plowman, accompanied by LHS CROP teacher Jim Rynearson, presented a poster 'The Efficiency of Photmultiplier Tube Cosmic Ray Detectors' at the American Junior Academy of Sciences meeting in Washington, DC, in February 2005. Resch and Shirer prsented a poster with the same title at the Intel International Science and Engineering Fair in Phoenix in May 2005 and placed fourth in the team physics category.

Eyob Meles and Phone Tran from LincolnHigh School performed a study of the variation of cosmic ray muon rates with barometric pressure. Eyob presented the results at the Greater Nebraska Science and Engineering Fair held in Nebraska City on April 22, 2006, and received a 3rd place special award. Phong presented the results at the regional Nebraska Junior Academy of Sciences Fair held in Concordia, Nebraska, on April 22, 2006, and received the 3rd place overall award. He went on to the state JuniorAcademy competition held at WestlandUniversity, Lincoln, and was ranked among the top 5 entries. This allows Phong to travel to the national JuniorAcademy competition to be held in San Fransisco in February 2007.

Jingyao Yu studied the detectors sensitivity to solar flares over a six month period

Another enthusiastic teacher is Fr. Michael Liebl from Mt.MichaelBenedictineHigh School in Elkhorn, whose team joined CROP in 2000. “One of the things students learn is that real science is messy,” he said. “I don’t always know the answers when the students come to me.” Since Mt.Michael is a boarding school, resident students have been able to compare daytime measurements of cosmic rays to nighttime when the earth blocks particles coming from the sun. The Mt.Michael team published their study in a 2001 issue of The ScienceTeacher, the monthly publication of the National Science Teachers Association, which almost solely publishes articles written by university professors, high school teachers, and education specialists.

Our next goal is to have over 20 of our pilot schools will begin taking data simultaneously with production versions of the data-acqusition electronics card developed by our group and engineers at Fermilab and University of Washington [ ]. A GPS receiver read in by the card provides an accurate time stamp for cosmic ray events at each school, allowing schools separated by up to several miles to detect city-sized

Funding history

The main CROP detector components - polystyrene scintillator tiles, photomultiplier tubes, and power supplies - are being recycled from the completed Chicago Air Shower Array (CASA) [4]. Operated between 1990-1998 by the Universities of Chicago, Utah and Michigan, CASA employed 1089 separate detector stations arranged in a 0.25 square kilometer grid within the Dugway Proving Grounds (operated by the U.S. Army) in western Utah. Each station housed four 60 cm x 60 cm scintillators and a low and high voltage power supply. Spare CASA counters formed the basis for prototype detector development at UNL, led by UNL undergraduate assistants; the retired CASA equipment has been donated to CROP free of charge. UNL’s Vice Chancellor of Academic Affairs helped sponsor two major equipment recovery trips to the CASA site. As CMS collaborators (at CERN), Claes and Snow also received support from its Education/Outreach task. CROP has drawn on the volunteered expertise of Fermilab electrical engineers and other colleagues in developing an inexpensive electronics card designed to handle the triggering, signal processing, GPS timing, and data acquisition for the CROP detectors at each school.

The $1.3 million 4-year NSF award (ESIE-911855, funded jointly by the Division of Elementary, Secondary, and Informal Education and the Division of Physics) that launched the pilot phase of this project has provided participant funds (student and teacher stipends, housing, and travel allowances as well as some undergraduate and technical support salaries) but explicitly precluded hardware purchases and curriculum development. The UNL High Energy Physics group secured a Nebraska Foundation major equipment grant, part of which was earmarked to cover the first 30 (PC-interfaced) data acquisition cards and GPS antenna-receivers

Evaluation

CROP is guided by an 8-member Advisory Panel with varied expertise in cosmic-ray physics, secondary science education, interactive science museums, and other national-scope science outreach programs. One full panel meeting per year overlaps with the spring participant workshop, and selected panel representatives observe the summer and spring workshops.

With NSF support, CROP employs an external evaluator. The Advisory Panel and UNL's Center for Instructional Innovation also contribute to project assessment. While critiquing CROP's success at establishing a statewide network of detector sites, the evaluation's primary focus is the educational value that CROP experiences provide participating teachers and students, using established assessment tools. The formative stages of evaluation have focused on teachers' self-efficacy for conducting CROP research and classroom activities and changes in students' interest and attitudes about science.

Pre- and post-testing at the summer workshops demonstrate participants gain sufficient expertise in operating their detectors to perform assigned mini-experiments during the following academic years. Participant exit interviews continue to identify the most useful content presentations and a number of ways to enhance the laboratory activities. There is also evidence that CROP participation leads some students to major in science in college.

Each year the workshop organization and the nature of its presentations have been fine-tuned as a result of evaluations. A paid Teacher Advisory Panel has been formed to tie CROP activities to the science education standards and assist in running the workshops. It is in direct response to the annual evaluation reports that the threshold for joining CROP will be reduced by streamlining training into much shorter workshops.

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One very useful recommendation has been to hold refresher courses for all teachers (and possibly short courses for new students) at the annual NATS October meeting. Also identified is a need for remote training to include interactive webpages and streamed video.

CROP is advised in general to identify activities for classroom use that can be developed and tested during the workshop, and specifically to further fulfill its interdisciplinary role by recognizing the biological training of most of the state’s science teachers, and provide curriculum materials relevant to them.

CROP, Phase II: Statewide Expansion

Now at the end of its pilot program, CROP hasestablished school sites in 16 of the state's 19 Educational Service Units (ESUs). At this stage the focus will be redirected toward building upon these remote sites, expanding to reach all the high schools in Nebraska. The format of 4-week summer workshops conducted on campus will be replaced by decentralized 5-day workshops held on a rotating basis at the respective ESU centers.

Two-three such remote summer workshops will be held annually, rotating among the ESUs, selected to provide maximum coverage of the state each year. Run by UNL staff and assisted by the regional CROP teachers (at least 2, getting help from adjacent ESUs when necessary) the workshops will introduce the equipment to be used and offer practice in installing it and all supporting software. Participating schools will carry with them fully functional detectors to take back to their home institution at the workshop's conclusion.

Workshop activities include hands-on labwork with detector assembly, diagnostic testing, maintenance and operation, as well as mini-courses exploring relevant topics in astronomy, charged particle detection, Monte Carlo applications, triggering, and data acquisition.

Reliance on remote Web-based training and instruction, some currently under development, will need to be expanded considerably: video-streamed training films and presentations, regularly moderated chatlines, a quick turn-around hotline (phone and email) manned throughout most of the day by undergrad and graduate student help. A response plan for failing equipment must include the building and routine testing of refurbished spares. This will become an activity for later generations of students at active sites. A network of pooled spares will be developed and made available as needed by neighboring districts. All of this will be complemented with free distribution of CDs carrying teaching materials and lesson plans.

In parallel it will be necessary to develop a fully functional local grid in the Lincoln area. This local effort will serve as the model for a strategy of expansion in Nebraska ESUs facilitated by the hub school districts already participating. The expansion plan depends heavily on the experience and expertise of the teachers at the regional centers that have been under development since early in the program. Working in collaboration with UNL Computer Science & Engineering graduate workers and the students and instructors from Lincoln Public Schools' IT FocusSchool, within one year we expect to have the PC-interfaced daq card (complete with GPS timestamp) running at each local school, and a scheme in place for the internet sharing of data. This local effort will serve as the model for a strategy of expansion in Nebraska ESUs facilitated by the hub school districts already participating in CROP. The expansion plan depends heavily on the experience and expertise of the teachers at the regional centers that have been under development since early in the program.

100 mile circles centered on selected ESU office locations show how 3 annual training workshops can reach almost any school accessible (within a day trip) l in the state. Workshop locations will be rotated among the 19 ESUs.

REFERENCES

[1]National Science Board. 2006. Science and Engineering Indicators 2006. Two volumes. Arlington, VA: National Science Foundation (volume 1, NSB 06-01; volume 2, NSB 06-01A).

[2] “The Cosmic Ray Observatory Project – a statewide education and outreach experiment in Nebraska, USA” D.R.Claes, V.Mariupolskaya, G.Snow,Proceedings of ICRC 2001;

“High School Students Will Soon Join in the Hunt for High-Energy Cosmic Rays”, Physics Today, October 1998;

“Cosmic Rays Through the Heartland” Daniel ClaesandGregory Snow, The American Physical Society's Forum on Education, Spring, 2001, available at

[3] “7 counties rank high in poverty”, Lincoln Journal Star, Sunday, June 8, 2003. See also

[4] CASA

[5] “Low-cost Data Acquisition Card for School-network Cosmic Ray Detectors”, S. Hansen, T. Jordan, T.Kiper, D. Claes, G. Snow, H. Berns, T.H. Burnett, R. Gran, R. J. Wilkes, Proceedings of the 2003 IEEE Trans. Nucl. Sci. 51: 926-930 (2004).