6 research outputs found
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
Measuring system for in vivo multichannel neural signals recording
W pracy opisano system przeznaczony do rejestracji sygnałów neuronowych mózgu zwierzęcia znajdującego się pod narkozą. System pozwala na jednoczesny pomiar sygnałów z 64 kanałów za pośrednictwem ostrzowej matrycy elektrod. Składa się on z dedykowanego układu scalonego do wzmacniania i filtracji sygnałów, układów zasilających oraz układu kontrolnego. Do akwizycji danych wykorzystywany jest komputer typu PXI (ang. Peripheral Component Interconnect eXtensions for Instrumentation). Wstępne testy przeprowadzone przy pomocy sygnałów imitujących potencjały czynnościowe podanych za pośrednictwem elektrod i płynu fizjologicznego potwierdzają poprawne działanie systemu.This paper describes a system for recording neural signals from the brain of the animal under anesthesia. The system allows for simultaneous measurement of signals from 64 points by means of penetrating microelectrode matrix. It consists of dedicate integrated circuit for signal amplification and filtering, power supply module and control module. Dedicated data acquisition is peiformed using PXI (Peripheral Component Interconnect eXtensions for Instrumentation) computer and a custom application. Preliminary tests conducted with action potentials simulating signals provided through the electrodes and saline show that the system operates properly
A system for in vitro multichannel recording of field and action potentials using planar array of microelectrodes
Jednoczesna wielopunktowa rejestracja potencjałów czynnościowych i polowych jest kluczem do zrozumienia mechanizmów działania mózgu [1]. Postęp w technologiach mikroobróbki oraz produkcji układów scalonych o dużym stopniu integracji pozwoliły na budowę systemów umożliwiających rejestrację aktywności mózgu z kilkuset punktów. W pracy zaprezentowano system pomiarowy do rejestracji in vitro sygnałów neuronowych przy pomocy płaskiej matrycy elektrod ostrzowych o rozmiarze 16 na 16 elektrod.Simultaneous multi-point recording of activity of living neural networks is the key to understanding the mechanisms of the brain operation [1]. Advances in micromachining technology and production of integrated circuits with a high degree of integration made it possible to build systems capable of recording brain activity of electrode arrays containing up to several hundred points [2]. Neural signal recording methods can be divided into in vivo and in vitro. In vivo method consists in introducing the electrode into the brain through a hole in the skull The animal under anesthesia may be mounted in the holder (acute neural recording) or canmove freely (chronic neural recording). In the in vitro method previously extracted piece of brain tissue is arranged on a matrix of electrodes (Fig. 2) placed in a container of liquid with a suitable composition and temperature. The in vitro method allows direct injection of chemicals and is more accurate than the method for in vivo determination of the signal origin. The paper presents a system for in vitro recording of neural signals by using a planar array of 256 electrodes (16x16). The system consists of a life-support system (temperature, nutrient fluid) (Fig. 3) and a recording system. The recording system is based on a specially designed integrated circuit fabricated in CMOS 0.18 žm technology [4]. Initial tests confirmed that the system is capable of recording both field and action potentials