University of Nebraska A Statewide Outreach and Education Experiment in Nebraska The Cosmic Ray Observatory Project Dan Claes University of Nebraska APS-DPF2006 + JPS2006 Monday, October 30, 2006

was that the Silver Surfer could ride the shock wave of a super nova…

The Fantastic Four ® ©Marvel Comics …and that 4 astronauts that lifted off in an inadequately shielded starship…

…were blasted by Cosmic Rays and mutated into the Fantastic Four. Of course, ever since then they’ve been cool enough for me! I grew up to be a high school instructor myself, spending 7 years as a physics and mathematics teacher before returning to graduate school for my PhD.

The Fantastic Four

CROP article in Lincoln Journal Star, 7 August 2003 Here’s how we make all of that come together at the University of Nebraska. Our plan is to place on high school rooftops across the state, student-built and operated particle detectors. As this local newspaper article summarizes, CROP is mobilizing high school teams across the state of Nebraska to participate in a state-wide study of correlated high energy air showers. Our plan is to place student-built and operated particle detectors on the roofs of all 314 high schools across the state.

The Chicago Air Shower Array CROP is placing in the hands of high school teachers and students charged particle detectors inherited from the Chicago Air Shower Array, refurbished and operated by the students themselves. CROP recycles retired detectors from the Chicago Air Shower Array Located in the Utah Desert 1089 stations, 15m spacing covering 0.23 square km each houses 4 scintillators w/tubes 1 high and 1 low voltage supply

Chicago Air Shower Array (CASA) site 2000 scintillator panels, The CROP team at the Chicago Air Shower Array (CASA) site 2000 scintillator panels, 2000 PMTs, 500 low and HV power supplies now at UNL Through contacts at his former home institution at Michigan Greg brokered a deal in which we helped clean up the abandoned CASA site in exchange for whatever we could carry away. Two removal trips (September 1999, May 2001) yielded over 2000 scintillator panels, 2000 PMTs, 500 low and h.v. power supplies CASA detectors’ new home at the University of Nebraska U.S. Army Photo September 30, 1999

The Cosmic Ray Observatory Project A grid of cosmic ray research stations expanding across the state 250 miles The plan in Nebraska is to re-distribute these counters to a less geometrical but far more expansive grid, by placing them on the rooftops of Nebraska high schools, to conduct a study of correlated extensive air showers. 450 miles

co-funded by ESIE and EPP divisions • Co-PIs Greg Snow and Dan Claes • $1.34 Million NSF grant, 2000-2007 co-funded by ESIE and EPP divisions • Co-PIs Greg Snow and Dan Claes • 26 Nebraska and 5 Colorado schools enlisted trained in (2-4 week long) summer workshops about 5 new schools each year • Colorado program (SALTA) was a joint effort by CROP, WALTA, ALTA • External evaluation: CROP has accomplished most of the educational & scientific goals listed in the original proposal • CROP also serves as excellent training for student (undergrad, graduate) staff at UNL NSF

CROP Workshops In Nebraska the detectors and supporting electronics are refurbished and distributed through the 4-week Summer Workshops we run at UNL attended each year by 5-6 high school teams (of 1-2 teachers, bringing 1-4 students).

Oscilloscope training

Tearing the old CASA counters apart

Scraping, sanding and polishing

Wrapping & light-tighting

Electronics lessons

CROP data acquisition electronics card Developed by Univ. Nebraska, Fermilab (Quarknet), Univ. Washington Programmable logic device Time-to-digital converters To PC serial port GPS receiver input Four analog PMT inputs 5 Volt DC power Event counter 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 Discriminator (adjustable threshold)

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

April 2001 participant meeting at UNL results and discussing Marian High School students presenting results and discussing cosmic rays with Prof. Jim Cronin, University of Chicago A hallmark of CROP is a pair of 1-day all-day Saturday meetings held during the school year, where participating schools make presentations in a scientific conference-style setting. Jim Cronin was our guest at one Spring meeting, and when Marian high school made its report:

Statistical error bars shown Barometric Pressure (mmHg) 727 747 4-Fold Coincidences / 2 hours 3000 4200 Marian High School’s Measurement of Cosmic Ray Rate vs. Barometric Pressure Statistical error bars shown 1.3% decrease per mmHg On the variation of rates with barometric pressure he audibly gasped (he was sitting next to me and leaned over to say: “That’s exactly what WE found at CASA!”). http://marian.creighton.edu/~besser/physics/barometer.html

Mount Michael Benedictine “The Science Teacher”, November 2001 High School “The Science Teacher”, November 2001 Students at Mount Michael High School made measurements of the diurnal variation, which resulted in a publication in The Science Teacher.

Ben Plowman, Lincoln High School state finalist in the American Junior Academy of Sciences invited to present at the Washington, DC, meeting (February 2005) Rudy Resch and Kent Shirer presented a poster on their follow-up work at the Intel International Science and Engineering Fair (Phoenix, May 2005) and placed fourth in the physics category.

UNL Physics Department roof Marian High School March 8, 2002 Several schools are running detectors on their roof. UNL Physics Department roof February 2002 Westside High Omaha To give you more of an idea of the performance of these recycled counters: For over a year we have been running a set of 4 on our own rooftop. note the theater weights!

1 mile Simultaneous data-taking at 3 sites UNL Ferguson Hall Lincoln High Zoo School 1 mile DAQ card discriminator thresholds set to obtain ~ 100Hz singles rates At each school, require 3-fold coincidence of detectors Two-fold inter-school coincidences (within 2-3 microseconds) in excess of expected accidental rates have been observed! (but so far no 3-folds)

Summer 2005

Vanderbilt University Jason Keller University of Nebraska Andrea Fuscher Vanderbilt University Jason Keller University of Nebraska Andy Kubik Northwestern University Xiaoshu Xu Master’s Degree in Statistics University of Nebraska Tracie Evans Ralston Public Schools Andy Warta University of Minnesota Peter Jacobson Tulane University Katie Everett University at Buffalo

Online help and tutorials available. http://crop.unl.edu/tutorials/ Cosmic Ray Observatory Project Collecting Data with CROP DAQ Card Interface Doing an Efficiency Scan Disconnect the 4 signal cables from the DAQ card. These are the cables that connect to your 4 detectors. Open the CROP_DAQ LabVIEW Program. 3. Click on the "Efficiency" tab make sure the Efficiency Scan button is ON(lit up). 4.  Click on the "Threshold Scan" tab make sure the Threshold Scan button is OFF. 5. Click on the "Data Collection Settings" tab and set the timer ON (green button lit up). 6.  Click on the "Data Acquisition" tab and to begin run click on  (upper left corner under the Edit menu).

On-Line Oscilloscope Cheat Sheets http://unlhep2.unl.edu/~CROP/oscihomepage.html

Some Lessons Learned • Big variation among our schools in independent activities. Some real successes, some inactive sites • Hardware/software delays create frustration and idleness Close contact very important during academic year • A scheme for replacing/training new students as classes graduate is very important • High school schedules are packed (full participation in academic year Saturday meetings is difficult) • Classroom integration, affect on curriculum not automatic. Need to be tied directly to standards! • Hard to recruit for long summer workshops Our expansion phase (to ~100 schools) will be developed through shorter remote workshops hosted by the regional offices of the state’s 19 Educational Service Units.

Selected 120 mile radius (2 hr trips) arcs shown

Selected 120 mile radius (2 hr trips) arcs shown

Selected 120 mile radius (2 hr trips) arcs shown

If time allows…

SALTA: Snowmass Area Large Time-Coincidence Array Empire Aspen High School, Aspen, CO Basalt High School, Basalt, CO Roaring Fork Valley High School, Carbondale, CO Lake County High School, Leadville, CO The highest-elevation school in U.S. -- 10,152 feet above sea level Exactly 3 years ago…in July 2001 CROP and WALTA jointly sponsored a Rocky Mountain cousin involving 4 schools in the Roaring Fork Valley …recently joined by Clear Creek High school, a very interested school in not-quite-so-nearby Empire, Colorado. Clear Creek High School, Empire, CO

SALTA Workshop, July 2001, Snowmass, CO Making detectors light-tight This publicly open 1-week workshop ran in conjunction with the Snowmass meeting…where some of you may in fact have watched some of its activities. Polishing scintillator edges outside Conference Center mass phototube gluing

Henderson Mine Visit Chip deWolfe Dec 4, 2003 hosted by Chip deWolfe Hans-Gerd Berns University of Washington Dan Claes University of Nebraska Marc Whitley Aspen High School Diana Kruis Basalt High School Michelle Ernzen Lake County School Laura French Roaring Fork Valley Nancy Spletzer Clear Creek High School Claes’ began regular communication with the SALTA schools, and organized last week’s 1st meeting of them all in 2 and ½ years at a special orientation to and tour of the Henderson Mine hosted by Chip deWolfe. Scouted 3 possible locations between depths of 2800  3900 ft 110 power available

Detectors were configured into muon telescopes telescoped pair with coincidence requirement against noise sandwiching a ¼ inch lead sheet Detectors moved at 2-3 week intervals since dust posed a problem for a PC we housed a low-power serial digital data logger alongside the DAQcard 2 modules taken down into the mine A portable stand held each muon telescope. Desktop Base Station An ~identical pair of modules ran in a fixed location (surface office) to establish our baseline

SALTA’s Henderson Project was launched September 29, 2004

Clear Creek students set up the satellite modules Basalt students move the detectors to the next location

Some preliminary observations Data collected between Sept 29 – Dec 8, 2004 monitored 4 locations between depths of 2800-3900 ft Some preliminary observations Rates at Henderson surface base station (10,337 ft above sea level) = 2.5rates at Lincoln, NE (elevation: 1189 ft) Raw rates in muon telescopes seen to drop from 10 Hz (surface rate) → 1.5 Hz → 0.5 Hz → 0.3 Hz

…learning about the statistical nature of random events Successive teams of high school students have been analyzing the data identifying stable data run periods bad data channels Channel 0,1 coincidences Channel 2,3 coincidences …learning about the statistical nature of random events …and calculate accidental coincidence rates and statistical error