Institute of Computer Science, Pedagogical University of Krakow, 30-084 Krakow, Poland
Nikolay Budnev
Faculty of Physics, Irkutsk State University, 664003 Irkutsk, Russia
David E. Alvarez-Castillo
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland
Niraj Dhital
Central Department of Physics, Tribhuvan University, Kirtipur 44613, Nepal
Alan R. Duffy
Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne 3122, Australia
Michał Frontczak
Institute of Computer Science, Pedagogical University of Krakow, 30-084 Krakow, Poland
Dariusz Góra
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland
Alok C. Gupta
Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263001, India
Bartosz Łozowski
Faculty of Natural Sciences, University of Silesia in Katowice, Bankowa 9, 40-007 Katowice, Poland
Mikhail V. Medvedev
Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA
Justyna Mędrala
Department of Biocybernetics and Biomedical Engineering, AGH University of Science and Technology, 30-059 Krakow, Poland
Justyna Miszczyk
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland
Michał Niedźwiecki
Department of Computer Science, Faculty of Computer Science and Telecommunications, Cracow University of Technology, 31-155 Krakow, Poland
Marcin Piekarczyk
Institute of Computer Science, Pedagogical University of Krakow, 30-084 Krakow, Poland
Krzysztof Rzecki
Department of Biocybernetics and Biomedical Engineering, AGH University of Science and Technology, 30-059 Krakow, Poland
Jilberto Zamora-Saa
Departamento de Ciencias Fisicas, Universidad Andres Bello, Piso 7, Sazie, Santiago 2212, Chile
Katarzyna Smelcerz
Department of Computer Science, Faculty of Computer Science and Telecommunications, Cracow University of Technology, 31-155 Krakow, Poland
Karel Smolek
Institute of Experimental and Applied Physics, Czech Technical University in Prague, Husova 240/5, 110 00 Prague, Czech Republic
Tomasz Sośnicki
Department of Biocybernetics and Biomedical Engineering, AGH University of Science and Technology, 30-059 Krakow, Poland
Jaroslaw Stasielak
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland
Sławomir Stuglik
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland
Oleksandr Sushchov
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland
Arman Tursunov
Research Centre for Theoretical Physics and Astrophysics, Institute of Physics, Silesian University in Opava, Bezručovo nám. 13, CZ-74601 Opava, Czech Republic
Tadeusz Wibig
Theoretical Physics Department, University of Lodz, Pomorska Street 149/153, 90-236 Lodz, Poland
The Cosmic Ray Extremely Distributed Observatory (CREDO) pursues a global research strategy dedicated to the search for correlated cosmic rays, so-called Cosmic Ray Ensembles (CRE). Its general approach to CRE detection does not involve any a priori considerations, and its search strategy encompasses both spatial and temporal correlations, on different scales. Here we search for time clustering of the cosmic ray events collected with a small sea-level extensive air shower array at the University of Adelaide. The array consists of seven one-square-metre scintillators enclosing an area of 10 m × 19 m. It has a threshold energy ~0.1 PeV, and records cosmic ray showers at a rate of ~6 mHz. We have examined event arrival times over a period of over 2.5 years in two equipment configurations (without and with GPS timing), recording ~300 k events and ~100 k events. We determined the event time spacing distributions between individual events and the distributions of time periods which contained specific numbers of multiple events. We find that the overall time distributions are as expected for random events. The distribution which was chosen a priori for particular study was for time periods covering five events (four spacings). Overall, these distributions fit closely with expectation, but there are two outliers of short burst periods in data for each configuration. One of these outliers contains eight events within 48 s. The physical characteristics of the array will be discussed together with the analysis procedure, including a comparison between the observed time distributions and expectation based on randomly arriving events.