The QuarkNet DAQ card for school-network cosmic ray detectors provides a low-cost alternative to using standard particle and nuclear physics fast pulse electronics modules. The board, which can be produced at a cost of less than $500.00 (USD), produces trigger time and pulse edge time data for 2- to 4-fold coincidence levels via a universal RS232 serial port interface, usable with any PC. Individual detector stations, each consisting of four scintillation counter modules, front-end electronics, and a GPS receiver, produce a stream of data in form of ASCII text strings in identifiable set of formats for different functions. The card includes a low-cost GPS receiver module, which permits time-stamping event triggers to about 50 nanosecond accuracy in UTC between widely separated sites. The technique used for obtaining precise GPS time employs the 1PPS signal, which is not normally available to users of the commercial GPS module. We had the stock model slightly custom-modified to access this signal. The method for deriving time values was adapted from methods developed for the K2K long-baseline neutrino experiment. Performance of the low-cost GPS module used is compared to that of a more expensive unit with known quality.
Bibliographical noteFunding Information:
Manuscript received November 14, 2003; revised March 19, 2004. This work was supported in part by the U.S. Department of Energy and by QuarkNet. The authors are with the Physics Department, University of Washington, Seattle, WA 98195-1560 USA (e-mail: firstname.lastname@example.org; email@example.com; firstname.lastname@example.org; email@example.com). Digital Object Identifier 10.1109/TNS.2004.829368 Fig. 1. GPS receiver and antenna module, in a weatherproof package, and a three-meter cable providing supply power and data connection.
- Cosmic rays
- Data acquisition (DAQ)
- Global position system (GPS)
- Secondary schools
- Time synchronization