Lech Wiktor Piotrowski

Preliminary analysis of EUSO - TA data

The EUSO-TA detector is a pathfinder for the JEM-EUSO project and is currently installed in Black Rock Mesa (Utah) on the site of the Telescope Array fluorescence detectors. Aim of this experiment is to validate the observation principle of JEM-EUSO on air showers measured from ground. The experiment gets data in coincidence with the TA triggers to increase the likelihood of cosmic ray detection. In this framework the collaboration is also testing the detector response with respect to several test events from lasers and LED flashers. Moreover, another aim of the project is the validation of the stability of the data acquisition chain in real sky condition and the optimization of the trigger scheme for the rejection of background. Data analysis is ongoing to identify cosmic ray events in coincidence with the TA detector. In this contribution we will show the response of the EUSO-TA detector to all the different typologies of events and we will show some preliminary results on the trigger optimization performed on such data.

The simulation of the LANFOS-H food radiation contamination detector using Geant4 package

Abstract Recent incident in the Fukushima power plant caused a growing concern about the radiation contamination and resulted in lowering the Japanese limits for the permitted amount of 137 Cs in food to 100 Bq/kg. To increase safety and ease the concern we are developing LANFOS (Large Food Non-destructive Area Sampler)—a compact, easy to use detector for assessment of radiation in food. Described in this paper LANFOS-H has a 4 π coverage to assess the amount of 137 Cs present, separating it from the possible 40 K food contamination. Therefore, food samples do not have to be pre-processed prior to a test and can be consumed after measurements. It is designed for use by non-professionals in homes and small institutions such as schools, showing safety of the samples, but can be also utilized by specialists providing radiation spectrum. Proper assessment of radiation in food in the apparatus requires estimation of the γ conversion factor of the detectors—how many γ photons will produce a signal. In this paper we show results of the Monte Carlo estimation of this factor for various approximated shapes of fish, vegetables and amounts of rice, performed with Geant4 package. We find that the conversion factor combined from all the detectors is similar for all food types and is around 37%, varying maximally by 5% with sample length, much less than for individual detectors. The different inclinations and positions of samples in the detector introduce uncertainty of 1.4%. This small uncertainty validates the concept of a 4 π non-destructive apparatus.

Mini-EUSO flight software and operations on ISS

The Mini-EUSO instrument is designed by the JEM-EUSO collaboration to pave the way for space-based observations of Extreme Energy Cosmic Rays (EECRs). To be placed inside the International Space St ...

Study of Fast Moving Nuclearites and Meteoroids using High Sensitivity CMOS Camera with EUSO-TA

Nuclearites are hypothetical super-heavy exotic particles and may be important components of the dark matter in our Universe. They are expected to have typical geocentric velocities of ~220 km/s, if they exist. Interstellar meteoroids are other interesting bodies, which can be distinguished from solar system meteoroids based on geocentric velocities larger than the limit of 72 km/s, corresponding to the sum of escape velocity from the solar system and the velocity of the Earth around the Sun. We have been studying the feasibility to search for such fast moving particles by using very high sensitivity CMOS cameras. We also propose co-observations with EUSO-TA to check the slow trigger application and to help the analysis of the observational data of EUSO-TA. nWe observed many meteor events by a single and a stereo camera system. We can estimate the observable mass range of the nuclearites and the interstellar meteoroids from the sensitivity of the camera system for these fast moving events using the observed meteor events. Observable flux limits are estimated for these mass ranges.

Mini-EUSO data processing and quasi-real time analysis

Mini-EUSO is a telescope that will observe ultra-violet night-time light emission of Earth. It will watch the atmosphere through a UV transparent window of the International Space Station. The main data stream is composed of regularly sampled exposures integrated on three different time scales: microseconds, milliseconds and seconds. This, accompanied by visible and near infra red images will be sent to Earth on hard drives for analysis. We present here the general data-processing scheme for the mission, including the data format and the tools for quick view and first analysis of the collected data.