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We report a study of the original image reconstruction algorithm based on the time-of-flight maximum likelihood expectation maximisation (TOF MLEM), developed for the total-body (TB) Jagiellonian PET (J-PET) scanners. The method is applicable to generic cylindrical or modular multi-layer layouts and is extendable to multi-photon imaging. The system response matrix (SRM) is represented as a set of analytical functions, uniquely defined for each pair of plastic scintillator strips used for the detection. A realistic resolution model (RM) in detector space is derived from fitting the Monte Carlo simulated emissions and detections of annihilation photons on oblique transverse planes. Additional kernels embedded in SRM account for TOF, parallax effect and axial smearing. The algorithm was tested on datasets, simulated in GATE for the NEMA IEC and static XCAT phantoms inside a 24-module 2-layer TB J-PET. Compared to the reference TOF MLEM with none or a shift-invariant RM, an improvement was observed, as evaluated by the analysis of image quality, difference images and ground truth metrics. We also reconstructed the data with additive contributions, pre-filtered geometrically and with non-TOF scatter correction applied. Despite some deterioration, the obtained results still capitalise on the realistic RM with better edge preservation and superior ground truth metrics. The envisioned prospects of the TOF MLEM with analytical SRM include its application in multi-photon imaging and further upgrade to account for the non-collinearity, positron range and other factors.

Genetic algorithms (GAs) are an alternative to local optimization procedures in structure refinement. As a nondeterministic method, they may possibly yield better results. Some general principles of the Rietveld refinement procedure have been adapted to use with GAs, including quantities which enable the algorithm to determine how well a model diffraction pattern fits the experimental curve, named fit factors or R-factors. The search for the structure of the crystalline regions of the PANI/CSA conducting polymer system is specific in that the crystalline component used for structure determination is very different from typical diffraction patterns. It belongs to a class of diffraction curves exhibiting a small number of very broad peaks. As this introduces ambiguity not present in the formulation of the problem for the original Rietveld method, it should be investigated whether typical R-factors may still be used. It is determined that a simple sum of squares based factor and one of the original Rietveld factors R f may still be useful, but using R wp may lead to qualitatively poor results. Some new, custom R-factors are introduced and investigated for performance, along with the original ones. Advanced formulas combining different aspects of curve fitting appear to be the best choices for fit factors while still remaining computationally efficient.

The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification also via pulse shape analysis. The achievement of top performances imposes specific electronics which has been developed by FAZIA and features high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program centered on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams., 8 pages, 2 figures, Contribution to conference proceedings of the 25th International Nuclear Physics Conference (INPC 2013) Journal-ref: 25th International Nuclear Physics Conference (INPC 2013), Firenze : Italy (2013)

The response of silicon–silicon–CsI(Tl) telescopes, developed within the FAZIA collaboration, to fragments produced in nuclear reactions 84Kr+120-124Sn at 35 A MeV, has been used to study ion identification methods. Two techniques are considered for the identification of the nuclear products in the silicon stages. The standard ΔE−E one requires signals induced in two detection layers by ions punching through the first one. Conversely, the digital Pulse Shape Analysis (PSA) allows the identification of ions stopped in the first silicon layer. The capabilities of these two identification methods have been compared for different mountings of the silicons, i.e. rear (particles entering through the low electric field side) or front (particles entering through the high electric field side) side injection. The ΔE−E identification method gives exactly the same results in both configurations. At variance, the pulse shape discrimination is very sensitive to the detector mounting. In case of rear side injection, the identification with the “energy vs. charge rise time” PSA method presents energy thresholds which are significantly lower than in the case of front side injection.

The response of silicon–silicon–CsI(Tl) telescopes,developed within the FAZIA collaboration, to fragments produced in nuclear reactions 84Kr+120-124Sn at 35 AMeV, has been used to study ion identification methods. Two techniques are considered for thei dentification of thenuclear products in the silicon stages. The standard ΔE-E one requires signals induced in two detection layers by ions punching through the first one. Conversely, the digital Pulse Shape Analysis (PSA) allows the identification of ions stopped in the first silicon layer. The capabilities of these two identification methods have been compared for different mountings of thesilicons, i.e.rear (particles entering through the low electric field side) or front (particles entering through the high electric field side) side injection.The ΔE-E identification method gives exactly the same results in both configurations. At variance, the puls eshape discrimination is very sensitive to the detector mounting. In case of rear side injection, the identification with the‘‘energyvs.charge risetime’’ PSA method presents energy thresholds which are significantly lower than in the case of front side injection.

Particle production of charged kaons in central Au+Au collisions at has been studied as a function of rapidity by the BRAHMS collaboration at RHIC. The kaon spectral shapes are described well by an exponential in transverse mass for the rapidity range of 0 ≤ yK ≤ 3.3 with smoothly decreasing inverse slopes as the rapidity increases. For the charged kaon to pion ratios, while there is no significant rapidity dependence for the K+/π+ ratio, the K−/π− ratio shows a significant decrease from y ≈ 1 towards higher rapidities. The systematics of K−/K+ and ratios in the measured rapidity range demonstrates a strongly correlated behaviour which can be described by thermal–statistical models.

In this article we present a novel method of hit time and hit position reconstruction in long scintillator detectors. We take advantage of the fact that for this kind of detectors amplitude and shape of registered signals depends strongly on the position where particle hit the detector. The reconstruction is based on determination of the degree of similarity between measured and averaged signals stored in a library for a set of well-defined positions along the scintillator. Preliminary results of validation of the introduced method with experimental data obtained by means of the double strip prototype of the J-PET detector are presented.

Results from the BRAHMS Collaboration for the inaugural physics run with the relativistic heavy ion collider (RHIC), Au + Au collisions at √sNN = 130 GeV in the late summer of 2000, and some results of the very first data from the summer of 2001 at √sNN = 200 GeV are presented. Here the main focus is on the determination of the pseudorapidity distribution of charged particles as a function of collision centrality and on the measurement of the antiproton to proton and the K− to K+ ratios as a function of rapidity. The pseudorapidity density at midrapidity reaches dN(ch)/dη = 553 ± 36 for the most central collisions (0–5%) at √sNN = 130 GeV; the corresponding number for a higher energy is dN(ch)/dη = 632 ± 36, demonstrating an increase in multiplicity of about 14%. The measured antiproton/proton ratios peak at midrapidity around N()/N(p) = 0.64 ± 0.06 and drop to 0.41 ± 0.04 at y ≈ 2 for √sNN = 130 GeV reactions; the K− to K+ ratios are 0.90 ± 0.06 (y ≈ 0) and 0.83 ± 0.1 (y ≈ 2.5).

We present charged particle densities as a function of pseudorapidity and collision centrality for the 197Au+197Au reaction at sqrt{s_{NN}}=130 GeV. An integral charged particle multiplicity of 3860+/-300 is found for the 5% most central events within the pseudorapidity range -4.7

Transverse momentum spectra and rapidity densities, dN/dy, of protons, antiprotons, and net protons (p-p) from central (0%-5%) Au+Au collisions at square root of S(NN)=200 GeV were measured with the BRAHMS experiment within the rapidity range 0

We have measured rapidity densities dN/dy of pi+/- and K+/- over a broad rapidity range (-0.1y3.5) for central Au + Au collisions at square root(sNN) = 200 GeV. These data have significant implications for the chemistry and dynamics of the dense system that is initially created in the collisions. The full phase-space yields are 1660 +/- 15 +/- 133 (pi+), 1683 +/- 16 +/- 135 (pi-), 286 +/- 5 +/- 23 (K+), and 242 +/- 4 +/- 19 (K-). The systematics of the strange to nonstrange meson ratios are found to track the variation of the baryochemical potential with rapidity and energy. Landau-Carruthers hydrodynamics is found to describe the bulk transport of the pions in the longitudinal direction.

We report on a study of the transverse momentum dependence of nuclear modification factors R(dAu) for charged hadrons produced in deuteron + gold collisions at sqrt[s(NN)]=200 GeV, as a function of collision centrality and of the pseudorapidity (eta=0, 1, 2.2, 3.2) of the produced hadrons. We find a significant and systematic decrease of R(dAu) with increasing rapidity. The midrapidity enhancement and the forward rapidity suppression are more pronounced in central collisions relative to peripheral collisions. These results are relevant to the study of the possible onset of gluon saturation at energies reached at BNL RHIC.

Charged-particle pseudorapidity densities are presented for the d + Au reaction at sqrt[s(NN)] = 200 GeV with -4.2or = etaor = 4.2. The results, from the BRAHMS experiment at BNL Relativistic Heavy-Ion Collider, are shown for minimum-bias events and 0%-30%, 30%-60%, and 60%-80% centrality classes. Models incorporating both soft physics and hard, perturbative QCD-based scattering physics agree well with the experimental results. The data do not support predictions based on strong-coupling, semiclassical QCD. In the deuteron-fragmentation region the central 200 GeV data show behavior similar to full-overlap d+Au results at sqrt[s(NN)] = 19.4 GeV.

Transverse momentum spectra and rapidity densities, dN/dy, of protons, antiprotons, and net protons (p-p) from central (0%-5%) Au+Au collisions at square root of S(NN)=200 GeV were measured with the BRAHMS experiment within the rapidity range 0/=y/=3. The proton and antiproton dN/dy decrease from midrapidity to y=3. The net-proton yield is roughly constant for y1 at dN/dy approximately 7, and increases to dN/dy approximately 12 at y approximately 3. The data show that collisions at this energy exhibit a high degree of transparency and that the linear scaling of rapidity loss with rapidity observed at lower energies is broken. The energy loss per participant nucleon is estimated to be 73+/-6 GeV.

We present spectra of charged hadrons from Au+Au and d+Au collisions at sqrt[s(NN)]=200 GeV measured with the BRAHMS experiment at RHIC. The spectra for different collision centralities are compared to spectra from p+(-)p collisions at the same energy scaled by the number of binary collisions. The resulting ratios (nuclear modification factors) for central Au+Au collisions at eta=0 and eta=2.2 evidence a strong suppression in the high p(T) region (2 GeV/c). In contrast, the d+Au nuclear modification factor (at eta=0) exhibits an enhancement of the high p(T) yields. These measurements indicate a high energy loss of the high p(T) particles in the medium created in the central Au+Au collisions. The lack of suppression in d+Au collisions makes it unlikely that initial state effects can explain the suppression in the central Au+Au collisions.

We present ratios of the numbers of charged antihadrons to hadrons (pions, kaons, and protons) in Au+Au collisions at sqrt[s(NN)]=200 GeV as a function of rapidity in the range y=0-3. While the ratios at midrapidity are approaching unity, the K(-)/K(+) and p;/p ratios decrease significantly at forward rapidities. An interpretation of the results within the statistical model indicates a reduction of the baryon chemical potential from mu(B) approximately 130 MeV at y=3 to mu(B) approximately 25 MeV at y=0.

We present charged-particle multiplicities as a function of pseudorapidity and collision centrality for the ${}^{197}\mathrm{Au}{+}^{197}\mathrm{Au}$ reaction at $\sqrt{{s}_{\mathrm{NN}}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}200\mathrm{GeV}$. For the $5%$ most central events we obtain ${\mathrm{dN}}_{\mathrm{ch}}/d\ensuremath{\eta}{|}_{\ensuremath{\eta}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}625\ifmmode\pm\else\textpm\fi{}55$ and ${N}_{\mathrm{ch}}{|}_{\ensuremath{-}4.7\ensuremath{\le}\ensuremath{\eta}\ensuremath{\le}4.7}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4630\ifmmode\pm\else\textpm\fi{}370$, i.e., $14%$ and $21%$ increases, respectively, relative to $\sqrt{{s}_{\mathrm{NN}}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}130\mathrm{GeV}$ collisions. Charged-particle production per pair of participant nucleons is found to increase from peripheral to central collisions around midrapidity. These results constrain current models of particle production at the highest RHIC energy.

We present charged-particle multiplicities as a function of pseudorapidity and collision centrality for the 197Au+197Au reaction at square root[s(NN)] = 200 GeV. For the 5% most central events we obtain dN(ch)/deta/(eta = 0) = 625+/-55 and N(ch)/(-4.7or =etaor =4.7) = 4630 +/- 370, i.e., 14% and 21% increases, respectively, relative to square root[s(NN)] = 130 GeV collisions. Charged-particle production per pair of participant nucleons is found to increase from peripheral to central collisions around midrapidity. These results constrain current models of particle production at the highest RHIC energy.

Measurements, with the BRAHMS detector, of the antiproton-to-proton ratio at midrapidities and forward rapidities, are presented for Au+Au reactions at square root of [s(NN)] = 130 GeV, and for three different collision centralities. For collisions in the 0%-40% centrality range, we find N(pmacr;)/N(p) = 0.64+/-0.04((stat))+/-0.06((syst)) at y approximately 0, 0.66+/-0.03+/-0.06 at y approximately 0.7, and 0.41+/-0.04+/-0.06 at y approximately 2. The ratios are found to be nearly independent of collision centrality and transverse momentum. The antiproton and proton rapidity densities vary differently with rapidity, and indicate a significant degree of collision transparency, although a net-baryon free midrapidity plateau (Bjorken limit) is not yet reached.

In the paper assessment of a prevalence of hepatitis B and C viruses infections as well as HIV infections in potential blood donors and patients from internal disease ward in Debica was performed. In none of tested individuals from the group of blood donors and patients from the internal disease ward a presence of HIV was found. AntiHCV serum antibodies were identified in 2% of patients being hospitalized in the internal disease ward. Positive HBs antigen was found in serum of one potential blood donor and 3 hospitalized patients that makes 0,94% and 3%, respectively, whereas positive antiHBc serum antibodies were identified in 12 (12%O patients from internal disease ward.

The effect of a single oral dose of Nitrendipine (20 mg) on mean pulmonary arterial pressure was studied in 14 patients with COPD and chronic cor pulmonale and 12 patients with COPD and without coexistent cor pulmonale. Parameters were assessed with Doppler echocardiography calculating average acceleration time of blood from the pulmonary artery. Simultaneously arterial pressure and heart rate were determined. The authors found that a single oral dose (20 mg) of Nitrendipine significantly lowered elevated pressure in the pulmonary artery during at least 6 hours without effecting heart rate.

Recent observations of particle emission in coincidence with heavy residues and with the fragments of binary decay processes provide information on both the statistical and the dynamical aspects of the decay of highly excited ‘‘Hot’’ nuclei. Evidence has been obtained for significant decreases in the nuclear level density with increasing excitation energy, for limiting temperatures which may signal a cluster phase in nuclear matter and for mass asymmetry dependent dynamic delays which invalidate simple statistical decay assumptions at intermediate excitation energies. A brief review of some such experiments is presented.

In 14 patients with chronic obstructive pulmonary disease and symptoms of cor pulmonale a single dose of nifedypine was administered and Doppler echocardiography measurements were performed to evaluate a degree of pulmonary hypertension. An acceleration time (AcT) and mean pulmonary artery pressure (MPAP) before and after 20 mg dose of nifedypine were determined, parallel with evaluation of systolic and diastolic blood pressure. In performed examinations it was documented that 20 mg dose of nifedypine induced a decrease of MPAP in observed patients.

Elastic scattering of /sup 24/Mg(/sup 20/Ne,/sup 20/Ne)/sup 24/Mg at /b E //sub lab/=50, 60, 80, 90, and 100 MeV was measured in an angular range of 10 degrees < thetas /sub c.m/

Intermediate mass fragment cross-sectionsσ(E, θ, 4≤Z≤11) have been measured in the reaction6Li+46Ti at 156 MeV incident energy. A simple sequential binary decay model describes most of theZ>8 data as evaporation from the compound nucleus. The complete fusion cross-section is also well reproduced. An intermediate velocity source model (β=2β CN, T=7 MeV) has been used in order to explain the small angle and Z≤8 data which indicate aZ −4.1 dependence.

A gas ionization chamber is described for on-line identification of products from nuclear reactions. The chamber can work with two different anodes: the resistor type or the split type. Response of the device, proved experimentally, enables fast identification of Z values subtending some defined region. Possible modifications of the detector are discussed. The concept of extending the Z value flexibility of the system is proposed.

A telescope for the identification of heavy ions over an extended energy range is described. The energy loss Δ E is measured with an ionisation chamber supplied with the range-sensitive charge collection system. The particle residual energy E can be measured with a solid state detector. Two modes of operation are available: a standard ΔEt − E identification, or a charge integration along the track with a continuous resistivity anode. By a proper formation of this resistivity, one can obtain an identification signal proportional to the Z value in a large range of incident energies.

The cross sections for nonelastic break-up modes have been studied for the 6Li + 40Ca reaction at ELi = 156 MeV. Gamma-ray spectra from target-like residual nuclei were measured in coinci- dence with beam-velocity projectile fragments and a value for the nonelastic break-up cross section σb.unon = 582 ± 110 mb has been found. Together with results of inclusive charged-particle measure- ments we infer for the total break-up cross section σb.utot = 930 ± 115 mb comprising about 50% of the total reaction cross section. The nonelastic contribution of the break-up reaction appears to be less than predicted by the DWBA break-up theory. This result is directly evident from the differential cross sections by comparing inclusive and exclusive results.

Inclusive ..gamma.. spectra from the /sup 20/Ne+ /sup 24/Mg interaction have been measured using from 45 up to 105 MeV /sup 20/Ne beams. Experimental mass and charge spectra are compared with statistical model calculations. Total reaction and fusion cross sections are extracted. The optical, Glas and Mosel, and Bass model calculations are presented and compared with the data. The limitation of the fusion cross section by the statistical yrast line is also discussed.

Inclusive gamma spectra from the /sup 20/Ne+/sup 24/Mg interaction have been measured using 55- and 85-MeV /sup 20/Ne ions. The identification of gamma lines allows the determination of mass spectra in the region 12

It is shown that volume integrals of all the equivalent real potentials are equal to the tail region. This implies the crossing of all these potentials around the sensitive radius.