Month: March 2019

Graduate Seminar, 1st April

Speaker: Jakub Sierchuła

Title: Determination of the liquid eutectic metal fuel Dual Fluid Reactor (DFRm) design – steady state calculations

Abstract: The Dual Fluid Reactor (DFR) is a novel concept of a very high-temperature (fast) reactor which falls-off the classification of Generation IV International Forum (GIF). DFR makes best of the two previous designs: Molten Salt Reactor (MSR) and Lead-cooled Fast Reactor (LFR). During the presentation a novel reactor design (DFRm) with the liquid eutectic U-Cr metal fuel composition and the lead coolant will be present. By performing the first steady state neutronic calculations for such a reactor it will be shown that this 250 MWth reactor is critical, and that it can operate almost 20 years without refuelling. The geometry (reflector thickness, fuel tubes pin pitch) was optimise with respect to the multiplication factor. The optimisation together with some other opportunities for the liquid metal fuel design (e.g the use of electromagnetic pumps to circulate the medium) allows DFRm to be of a small size. This rises economy of the construction as expressed nicely in terms of the Energy Return on Invested (EROI) factor which is even higher than for the molten salt fuel design (DFRs). Last but not least, DFRm has all the (fuel, coolant, reflector) temperature coefficients negative, which is an important factor of the passive safety.

Graduate Seminar, 25th March

Speaker: Szymon Nakoneczny

Title: Catalog of quasars from the Kilo-Degree Survey Data Release 3

Abstract: Broad spectroscopic lines, large redshift range and variety of properties make quasar detection in photometric surveys a particularly difficult task. I will present a quasar detection method based on photometric ugri data in Kilo-Degree Survey (KIDS) – an imaging deep and wide field survey covering 447 sq. deg. on the sky. The KiDS third data release contains 49 millions of sources among which, however, a vast majority does not have any spectroscopically confirmed identification. We successfully trained a Random Forest classifier based on the KIDS data and a set of known quasars identified by the SDSS spectroscopic survey. The presented catalog consists of 190,000 quasar candidates, and its training purity equals 91%. Additional validation of the catalog was made by the means of comparison with GAIA second data release, other already existing quasar catalogs and WISE photometric data.

Graduate Seminar, 11th March

Speaker: Paritosh Verma

Title: Gravitational waves in the Jordan-Brans-Dicke theory

Abstract: I shall talk about gravitational waves in Jordan Brans Dicke (JBD) theory. There are two tensor polarization states in the General theory of relativity but there can also be vector and scalar polarization states in alternative theories of gravity. The JBD theory is one of the attempts to modify general theory of relativity by varying gravitational constant G and it has three polarization states. The first two states are the same as in GR and the third one is the scalar polarization.

Venue: Pasteura 7, Room 404.