The Cosmic Ray Observatory Project in Nebraska

Conference on Teacher Research ExperiencesUniversity of Rhode Island

25-27 April 2005

An education and research experiment for Nebraska high schools

PresentersProfs. Daniel Claes and Gregory Snow / University of Nebraska, Lincoln

Fr. Michael Liebl / Mt. Michael Benedictine High School, Elkhorn, NE

Overview• CROP is in its 5th year of operation

• Funded by a $1.34 Million grant, U.S. National Science Foundation

• Managed by a small team at the University 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• 6060 cm2 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

A small number of inter-school coincidences have been observed

Air shower cartoon, school set-up, participating schools

700 km

November 2004 One-day Participant Meeting

Teachers and students from about half of CROP’s schools, all yearsTypical school team: 1-2 physics teachers, 3-4 students

• 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

CROP’s Cosmic Ray Detectors

Summer 2004 Workshop ActivitiesDetector assembly and testing

Summer 2004 Workshop ActivitiesOscilloscope and DAQ card lessons

Summer 2004 Workshop ActivitiesPractice experiments to be performed at school

Summer 2004 Workshop ActivitiesDetectors return to school

5 VoltDC power

To PCserial port

Four analogPMT inputs

Discriminatorthreshold

adjust

GPS receiverinput

Eventcounter

Programmablelogic device

Time-to-digitalconverters

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 psec resolution

User-friendly, LabView-based control and monitoring GUI

Two detectorsfiring at thesame time

Data streamfor eachevent

Eventcounter

Elapsedrun

time

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 is 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