1. The Cosmic Ray Observatory Project (CROP) Gregory R. Snow University of Nebraska / USA CRSP Meeting NIKHEF, Amsterdam March 7, 2005 Overview Staff and school participants Classroom and lab training sessions Hardware, software, analysis status NATLA, consortium of US efforts Some lessons learned

2. First, where is Nebraska? State of Nebraska Pierre Auger northern hemisphere site in Utah or Colorado Fermilab Batavia, Illinois University of Nebraska, Lincoln

3. One-slide overview CROP is in its 5 th year of operation Funded by a $1.34 Million grant, U.S. National Science Foundation Managed by a small team at the Univ. of Nebraska 26 participating schools, about 5 new schools added per year 4-week summer training workshops and 2 academic year meetings Hardware and software 60  60 cm 2 scintillators, PMTs, high voltage supplies from the now-complete Chicago Air Shower Array Data acquisition electronics card developed jointly with Fermilab and QuarkNet LabView control and monitoring program runs on PC at school Inter-school data analysis starting, development underway

4. CROP Personnel at Univ. of Nebraska CROP staff at University of Nebraska Faculty: Dan Claes and Greg Snow Educational evaluator: Dr. Duane Shell Physics graduate student: Xiaoshu Xu Undergraduate research assistants: L. Burk, M. Everett, J. Keller, L. Neukirch, Y. Qin Administrative Secretary: Marilyn McDowell Lab manager: High school teacher, John Rogers CROP has employed a steady stream of graduate and undergraduate students from Physics, Computer Science, and Science Education, including high school participants who have come to the University to major in Physics or Engineering. Undergraduate Physics majors have entered graduate school in Experimental Physics based on the experiences in CROP. Summer 2004

5. CROP article in Lincoln Journal Star, 7 August 2003

6. Colored squares are participating schools 700 km

7. The Science of CROP Each school records building-sized showers -- plenty of rate. 2500 ft 2 shower (10 14 eV ) Neighboring schools in same city (Lincoln, Omaha) see coincidences from highest-energy showers -- low rate. 10 sq.mi shower ~10 19 eV 50 sq.mi shower ~10 20 eV Nebraska is 450 x 250 square miles -- schools separated by very large distances explore whether showers come in large, correlated bursts That is, does the whole state of Nebraska ever “light up”?

8. November 2004 One-day Participant Meeting Teachers and students from about half of CROP’s schools, all years Typical school team: 1-2 physics teachers, 3-4 students

9. The Chicago Air Shower Array CROP uses retired detectors from the Chicago Air Shower Array 1089 boxes each with: 4 scintillators and photomultiplier tubes (PMT) 1 high voltage and 1 low voltage power supply Two removal trips (September 1999, May 2001) yielded over 2000 scintillator panels, 2000 PMTs, 500 low and power supplies Sufficient hardware for all Nebraska high schools

10. U.S. Army Photo September 30, 1999 The CROP team at Chicago Air Shower Array (CASA) site

11. Equipment recovery trip to Dugway, Utah, May 2001

12. Lab Curriculum Polishing, cleaning scintillator Gluing PMT and wrapping scintillator Assembling high-voltage supply Oscilloscope lesson Turning on counters, source tests, finding/fixing light leaks Measure counter efficiency, high voltage plateau Class Curriculum History of cosmic rays Interaction of charged particles with matter Scintillators and photomultiplier tubes Cosmic ray energy spectrum Julian calendar, UTM, galactic coordinates Global positioning system Ionizing particle detectors Calorimeters and showering Particle zoo and the Standard Model Tour of high-energy particle accelerators Random events, probability Monte Carlo simulations Lightning protection Curriculum Topics Available What we accomplish in 4 weeks Preparing detectors to take to the schools, experimental techniques Learning the physics of cosmic rays and particle detectors

13. Photomultiplier Tubes Schematic drawing of a photomultiplier tube Photons eject electrons via photoelectric effect Photocathode Each incident electron ejects about 4 new electrons at each dynode stage Vacuum inside tube “Multiplied” signal comes out here An applied voltage difference between dynodes makes electrons accelerate from stage to stage Incident light from scintillator

14. Summer 2004 Workshop Activities Detector assembly and testing

15. Summer Workshop Activities Attaching phototubes

16. Summer 2004 Workshop Activities Oscilloscope and DAQ card lessons

17. Summer 2004 Workshop Activities Practice experiments to be performed at school

18. Summer 2004 Workshop Activities Detectors return to school

19. Detectors in a vertical telescope Mini-experiments Coincidence rate vs. barometric pressure Day-night variation of cosmic ray rate Coincidence rate vs. angle of incidence Coincidence rate vs. vertical separation

20. Electronics Configuration for Telescope

21. Detector set-ups at schools Telescope set-ups for indoor experiments

22. April 2001 participant meeting at UNL Marian High School students presenting results and discussing cosmic rays with Prof. Jim Cronin, University of Chicago

23. Barometric Pressure (mmHg) 727 747 4-Fold Coincidences / 2 hours 3000 4200 Statistical error bars shown 1.3% decrease per mmHg Marian High School’s Measurement of Cosmic Ray Rate vs. Barometric Pressure

24. Mount Michael High School “The Science Teacher”, November 2001

25. 5 Volt DC power To PC serial port Four analog PMT inputs Discriminator threshold adjust GPS receiver input Event counter Programmable logic device Time-to-digital converters CROP data acquisition electronics card Developed by Univ. Nebraska, Fermilab (Quarknet), Univ. Washington 43 Mhz (24 nsec) clock interpolates between 1 pps GPS ticks for trigger time TDC’s give relative times of 4 inputs with 75 picosecond resolution

26. User-friendly, LabView-based control and monitoring GUI Two detectors firing at the same time Data stream for each event Event counter Elapsed run time

27. Labview software Tabs for different experimental procedures

28. Simultaneous data-taking at 3 sites in Lincoln UNL Ferguson Hall Lincoln High Zoo School Concerted effort to collect data continuously since mid-August 2004 Each school writes data file, collected twice per week. Analysis file-by-file at UNL Searching for events occurring at the same time (within a microsecond)

29. Installation at Lincoln High School, August 2003 GPS receiver

30. Weigh down cable bundles at various points Nice, neat cable bundles fanned out

31. GPS receiver must be in a weather-tight enclosure which is NOT metallic We used Tupperware container half-filled with sand GPS receiver on top of sand Connection to long extension cable INSIDE Tupperware Make sure it’s weather-tight

32. GPS mount at the Spalding Academy What’s wrong with this picture?

33. GRID computing being applied to data analysis needs Web site explains data analysis framework See: http://quarknet.fnal.gov/grid/

34. Web site explains data analysis framework See: http://quarknet.fnal.gov/grid/

35. Schools can upload raw data files to server.

36. Some simple analysis tools in place. Example: search for time coincidences among chosen schools’ data files.

37. Univ. of Nebraska Research Computing Facility Nebraska named Tier 2 computing center for CMS/LHC Future host of CROP analysis David Swanson Dept. of Computer Science and Engineering

38. CROPSCRODSALTA CHICOS WALTA ALTA NALTA The North American Large-Scale Time-Coincidence Array http://csr.phys.ualberta.ca/nalta/ Includes links to individual project Web pages TECOS

39. Institutions LA area schools California Institute of Technology California State University, Northridge University of California, Irvine Funding Caltech NSF Nuclear Physics Los Angeles Area Schools (Animation by L.A. school teacher)

40. 164 detector stations recovered 2 detectors per school foreseen About 10 schools in process of being outfitted

41. Aiming toward a worldwide network of cosmic ray detectors

42. Some lessons learned Big variation among schools in independent activity/investigations during school year. Some real successes, some inactive sites Close contact very important during academic year Scheme for replacing/training new students as classes graduate important Classroom integration, affect on curriculum is not automatic. Scheme to guide this needed. Hardware and software delays create frustration and idleness Hard to recruit for long summer workshops High school schedules are packed, hard to get full participation in academic year Saturday meetings of all participants