1. Research on cosmic rays in NCBJ Łódź 2. Gravitational waves

Speaker and affiliation: 
Drs Jacek Szabelski, Adam Zadrożny (NCBJ)
Tue, 2016-02-23 10:00
Room 2 in NCBJ Łódź building at 69, 28th Płk.Strz.Kaniowskich str., Łódź

The EUSO project, the POLAR project, and research on cosmic background neutrons conducted by Cosmic Ray Physics Team of NCBJ Astrophysics Division will be presented by Dr. Jacek Szabelski, Head of the Team.

The main objective of the Japanese Experiment Module to be launched and deployed on board of the International Space Station later this year will be to observe phenomena within the Earth atmosphere caused by cosmic rays of energies above 1019 eV. The telescope camera will be capable to register flashes of fluorescence light accompanying Large Air Showers developing within the atmosphere.

Gamma Ray Bursts (GRB) are among the most energetic events ever seen in the Universe. They are  possible sources of cosmic rays of extremely high energies. Information on polarisation of those photons may shed important light on processes responsible for emission of that radiation. POLAR is a Swiss-Polish-Chinese project to develop a detector capable to measure polarisation of GRB photons of energy within the 50-500 keV range. The detector using the double Compton scattering effect is going to be deployed on the Chinese space station in 2016 . The task assigned to the Łódź-based NCBJ Team was to develop an Engineering Model of a control circuitry and HV power supplies for 25 photomultipliers. The task assigned to some other Świerk-based NCBJ team was to develop scintillators and front end electronics. We are getting ready to analyse data measured during the experiment.

In low-background experiments (such as search for dark matter, neutrino experiments, or double beta decays) neutrons produce difficult to eliminate undesired (background) signals. Objective of the ISOTTA (ISOTope Trace Analysis) project is to create conditions favourable for producing relatively large amounts (on the order of 1 ton) of isotope-enriched materials for new-generation experiments planned to study neutrino-less double beta decays. Our participation in the project consists in simulation of processes of neutron transport/interaction with the matter and comparing the results with results of measurements done with the help of a germanium detector and a weak neutron source. The outcomes will be used to improve shields in order to reduce neutron background in Ge detectors.

In the second part of the seminar (to begin at 12.45 pm) Dr Adam Zadrożny will comment on a recent discovery of gravitational waves. The waves were registered simultaneously by two LIGO (Interferometer Gravitational-wave Observatory) detectors located in USA (Livingston, La and Hanford, Wa) on September 14, 2015.  Data acquired by interferometers owned by international collaboration have been jointly analysed by the Virgo project team and the LIGO project team since 2007. The POLGRAW group of 15 scientists from Poland has also significantly contributed to works of the Virgo project. They have laid the foundation and developed numerous methods to detect/estimate parameters of gravitational waves produced in binary black hole systems; contributed to precise modelling of such waves; have shown that binary black hole systems are the best systems from the point of view of detectability of gravitational waves by the LIGO-Virgo interferometers; studied astrophysical properties of binary systems; and looked for optical bursts possibly accompanying the collision events. Dr. Zadrożny, the speaker, was involved in the latter activity.

NCBJ bus will leave to Łódź on February 23, 2016 at 8 am from entrance gate to the Hoża 69 premises in Warsaw. The bus is expected back in Warsaw at about 4 pm.