Graduate Seminar Jan. 31st

Speaker: Joanna Reszczyńska

Title: Ionizing Radiation – what is the risk of cancer at low doses?

Abstract: There exists a vast number of studies of biological effects of ionizing radiation, mostly dedicated to radiation-induced cancers. Whereas the field of early effects is quite well understood, the low doses (below, say, 100 mGy) that may at best create only late or very late delatorious effects are a subject of on-going research. Estimation of a cancer risk for low doses or ionizing radiation requires universal biology-based model taking into account essential processes that take place in irradiated cells. I will try to present a relatively simple approach which can show what could be expected for the dose-effect dependence in the colony of cells as well as theoretical background of this subject.

Graduate Seminar Jan. 24th

Speaker: Slawomir Potempski, Piotr Prusiński

Title: High performance computer processing and computational fluid dynamics

Abstract: The presentation consists of two part. In the first one a general introduction to high performance computing will be given including basic information of two main programming standards: Message Passing Interface (MPI) and Open Multi-Processing (OpenMP). The second part will be devoted to solving the problems of computational fluid dynamics on CIS cluster. In particular ANSYS tools, like Fluent, available at NCBJ will be presented, basing on exemplary simulations for nuclear application reasoning the use of HPC.

Graduate Seminar Jan. 10th

Speaker: Rahul Nair

Title: Hypernuclear physics with ALICE at LHC

Abstract: Hypernucleus was first discovered in Warsaw. A historic prospective of its discovery will be presented. A short review of strangeness in particle physics will be followed by a brief discussion of the importance of the study of hypernuclei in varios fields of physics. The study of production of Hypertritium and Antihypertritium in the ALICE experiment will be presented. Its measured yield and lifetime will be compared with theoretical models and various results obtained with ALICE will be discussed.

Graduate Seminar, January 3rd

Speaker: Szymon Domański

Title: Application of the Recombination Microdosimetric Method into Mixed Radiation Dosimetry

Abstract: Recombination methods can be applied in the radiation fields of poorly known composition and practically unlimited energy range. Main dosimetric parameters, such as absorbed dose, photon component to the absorbed dose, radiation quality factor, dose equivalent, ambient dose equivalent and some other can be determined with a single instrument. During the lecture will be presented the application of such methods to experimental results.

Graduate Seminar, Dec. 20th

Speaker: Paweł Kowalski

Title: Characteristics of the J-PET detector simulated using GATE software

Abstract: Novel PET system based on plastic scintillators is developed by the J-PET collaboration. In order to determine performance characteristics of built scanner prototype, advanced computer simulations must be performed. These characteristics are, among others, spatial resolution, scatter fraction and sensitivity. Methods of obtaining these characteristics and results of simulations will be presented during the lecture.

Graduate Seminar, Dec. 6th

Speaker: Varvara Batozskaya

Title: “Measurement of phi_s with B0s->J/Psi(e+e-)Phi(K+K-) decay”

Abstract: “The determination of the CP-violating phase in B0s->J/PsiPhi decays is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model. However it can be significant enhanced by contributions from effects of new physics. The measurement of the phase phi_s, width difference DeltaGamma_s and average width Gamma_s in the electron mode of the B0s->J/PsiPhi will be present.”

Graduate Seminar, Nov. 29th

Speaker: Oleksandr Kovalenko

Title: Thermal photons as the signature of Quark Gluon Plasma and its thermometer.

Abstract: Direct photon spectrum is a probe to study the thermal properties of the QGP fireball created in ultra relativistic heavy-ion collisions.
A scheme of extracting the direct photon signal from the data will be presented. The current results on thermal photons emitted in heavy ion collisions will be reviewed.

Graduate Seminar, Nov. 22nd

Speaker: Dobromił Załoga

Title: Study of soft X-rays emission from PF-1000U discharges performed during the recent experimental campaign

Abstract: This presentation reports on measurements of soft x-rays emitted from hot plasmas produced in a modernised PF-1000U facility. The discharges were performed at the D2-filling with or without a Ne-admixture, under the initial pressure 0.9 or 1.5 torr and at the initial charging voltage 16 or 18 kV. Time-integrated x-ray images were recorded with a pinhole camera situated side-on at an angle of 75º to the z-axis. Differences in the pinch column structure were observed. Time-resolved measurements were performed with four PIN diodes located behind filtered pinholes. Two couples of PIN diodes (with Be-filters of 7 and 10 um in thickness) observed 30-mm-dia. regions which had a centre at a distance of 30 and 60 mm form the electrode outlets. From the time-resolved signals electron temperatures (Te) were estimated. For the pure D2-discharges the estimated Te values ranged from 75 to 250 eV depending on the discharge conditions. For discharges with a Ne-admixture Te values amounted to above 1 keV.