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1. Levosimendan in intensive care and emergency medicine: literature update and expert recommendations for optimal efficacy and safety

Author

Girardis, M., Bettex, D., Bojan, M., Demponeras, C., Fruhwald, S., Gál, J., Groesdonk, H. V., Guarracino, F., Guerrero-Orriach, J. L., Heringlake, M., Herpain, A., Heunks, L., Jin, J., Kindgen-Milles, D., Mauriat, P., Michels, G., Psallida, V., Rich, S., Ricksten, S-E, Rudiger, A., Siegemund, M., Toller, W., Treskatsch, S., Župan, Ž., and Pollesello, P.

Published
2022
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5. $\gamma$-ray linear polarization measurements and $(g_{9/2})^{-3}$ neutron alignment in $^{91}$Ru

Author

Zheng, Y., de France, G., Clément, E., Dijon, A., Cederwall, B., Wadsworth, R., Bäck, T., Moradi, F. Ghazi, Jaworski, G., Nyakó, B. M., Nyberg, J., Palacz, M., Al-Azri, H., de Angelis, G., Atac, A., Aktaş, Ö., Bhattacharyya, S., Brock, T., Davies, P. J., Di Nitto, A., Dombradi, Zs., Gadea, A., Gal, J., Joshi, P., Juhasz, K., Julin, R., Jungclaus, A., Kalinka, G., Kownacki, J., La Rana, G., Lenzi, S. M., Molnar, J., Moro, R., Napoli, D. R., Singh, B. S. Nara, Persson, A., Recchia, F., Sandzelius, M., Scheurer, J. -N., Sletten, G., Sohler, D., Söderström, P. -A., Taylor, M. J., Timar, J., Valiente-Dobon, J. J., and Vardaci, E.

Subjects
Nuclear Experiment
Abstract

Linear polarization measurements have been performed for $\gamma$-rays in $^{91}$Ru produced with the $^{58}$Ni($^{36}$Ar, $2p1n$$\gamma$)$^{91}$Ru reaction at a beam energy of 111 MeV. The EXOGAM Ge clover array has been used to measure the $\gamma$-$\gamma$ coincidences, $\gamma$-ray linear polarization and $\gamma$-ray angular distributions. The polarization sensitivity of the EXOGAM clover detectors acting as Compton polarimeters has been determined in the energy range 0.3$-$1.3 MeV. Several transitions have been observed for the first time. Measurements of linear polarization and angular distribution have led to the firm assignments of spin differences and parity of high-spin states in $^{91}$Ru. More specifically, calculations using a semi-empirical shell model were performed to understand the structures of the first and second (21/2$^{+}$) and (17/2$^{+}$) levels. The results are in good agreement with the experimental data, supporting the interpretation of the non yrast (21/2$^{+}$) and (17/2$^{+}$) states in terms of the $J_{\rm max}$ and $J_{\rm max}-2$ members of the seniority-three $\nu(g_{9/2})^{-3}$ multiplet., Comment: 19 pages, 8 figures, 2 tables

Published
2013
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6. The first candidate for chiral nuclei in the $A\sim80$ mass region: $^{80}$Br

Author

Wang, S. Y., Qi, B., Liu, L., Zhang, S. Q., Hua, H., Li, X. Q., Chen, Y. Y., Zhu, L. H., Meng, J., Wyngaardt, S. M., Papka, P., Ibrahim, T. T., Bark, R. A., Datta, P., Lawrie, E. A., Lawrie, J. J., Majola, S. N. T., Masiteng, P. L., Mullins, S. M., Gál, J., Kalinka, G., Molnár, J., Nyakó, B. M., Timár, J., Juhász, K., and Schwengner, R.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Excited states of $^{80}$Br have been investigated via the $^{76}$Ge($^{11}$B, $\alpha$3n) and $^{76}$Ge($^{7}$Li, 3n) reactions and a new $\Delta I$ = 1 band has been identified which resides $\sim$ 400 keV above the yrast band. Based on the experimental results and their comparison with the triaxial particle rotor model calculated ones, a chiral character of the two bands within the $\pi g_{9/2}\otimes \nu g_{9/2}$ configuration is proposed, which provides the first evidence for chirality in the $A\sim80$ region., Comment: 15 pages, 6 figures, accepted for publication in Physics Letters B

Published
2011
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7. Evidence for a spin-aligned neutron-proton paired phase from the level structure of $^{92}$Pd

Author

Cederwall, B., Moradi, F. Ghazi, Bäck, T., Johnson, A., Blomqvist, J., Clément, E., de France, G., Wadsworth, R., Andgren, K., Lagergren, K., Dijon, A., Jaworski, G., Liotta, R., Qi, C., Nyakó, B. M., Nyberg, J., Palacz, M., Al-Azri, H., Algora, A., de Angelis, G., Ataç, A., Bhattacharyya, S., Brock, T., Brown, J. R., Davies, P., Di Nitto, A., Dombrádi, Zs., Gadea, A., Gál, J., Hadinia, B., Johnston-Theasby, F., Joshi, P., Juhász, K., Julin, R., Jungclaus, A., Kalinka, G., Kara, S. O., Khaplanov, A., Kownacki, J., La Rana, G., Lenzi, S. M., Molnár, J., Moro, R., Napoli, D. R., Singh, B. S. Nara, Persson, A., Recchia, F., Sandzelius, M., Scheurer, J. -N., Sletten, G., Sohler, D., Söderström, P. -A., Taylor, M. J., Timár, J., Valiente-Dobón, J. J., Vardaci, E., and Williams, S.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The general phenomenon of shell structure in atomic nuclei has been understood since the pioneering work of Goeppert-Mayer, Haxel, Jensen and Suess.They realized that the experimental evidence for nuclear magic numbers could be explained by introducing a strong spin-orbit interaction in the nuclear shell model potential. However, our detailed knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers ($N = Z$), the unique nature of the atomic nucleus as an object composed of two distinct types of fermions can be expressed as enhanced correlations arising between neutrons and protons occupying orbitals with the same quantum numbers. Such correlations have been predicted to favor a new type of nuclear superfluidity; isoscalar neutron-proton pairing, in addition to normal isovector pairing (see Fig. 1). Despite many experimental efforts these predictions have not been confirmed. Here, we report on the first observation of excited states in $N = Z = 46$ nucleus $^{92}$Pd. Gamma rays emitted following the $^{58}$Ni($^{36}$Ar,2$n$)$^{92}$Pd fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution {\gamma}-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction. We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling) in the ground and low-lying excited states of the heaviest N = Z nuclei. The strong isoscalar neutron- proton correlations in these $N = Z$ nuclei are predicted to have a considerable impact on their level structures, and to influence the dynamics of the stellar rapid proton capture nucleosynthesis process., Comment: 13 pages, 3 figures

Published
2011
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8. Primer vese-adenocarcinoma és Aeromonas hydrophila okozta heveny septicaemia tatár homoki boában (Eryx tataricus).

Author

Gál, J., Hoitsy, M., Tóth, T., Marosán, M., Papp, A., Vincze, Z., and Ziszisz, Á.

Abstract

Copyright of Magyar Állatorvosok Lapja is the property of Herman Otto Intezet Nonprofit Kft. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2024
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9. Energy dependence of phi meson production in central Pb+Pb collisions at sqrt(s_nn) = 6 to 17 GeV

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Galadysz, E., Grebieszkow, K., Hegyi, S., Hoehne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kollegger, T., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Kresan, D., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puehlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Stroebele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranic, D., Wetzler, A., Walodarczyk, Z., Yoo, I. K., and Zimanyi, J.

Subjects
Nuclear Experiment
Abstract

Phi meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and to microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies., Comment: 18 pages, 12 figures, 6 tables

Published
2008
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10. Event-by-event transverse momentum fluctuations in nuclear collisions at CERN SPS

Author

Grebieszkow, K., Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Białkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csató, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gál, J., Gaździcki, M., Genchev, V., Georgopoulos, G., Gładysz, E., Hegyi, S., Höhne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Lévai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnár, J., Mrówczyński, St., Nicolic, V., Pálla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Pühlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczyński, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Siklér, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Ströbele, H., Susa, T., Szentpétery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Włodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimányi, J.

Subjects
Nuclear Experiment
Abstract

The latest NA49 results on event-by-event transverse momentum fluctuations are presented for central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV). Two different methods are applied: evaluating the $\Phi_{p_{T}}$ fluctuation measure and studying two-particle transverse momentum correlations. The obtained results are compared to predictions of the UrQMD model. The results on the energy dependence are compared to the NA49 data on the system size dependence. The NA61 (SHINE, NA49-future) strategy of searching of the QCD critical end-point is also discussed., Comment: proceedings article from CPOD07 (figure 7 - updated, reference 2 - modified)

Published
2007

13. Light charged particles as gateway to hyperdeformation

Author

Herskind, B, Hagbmann, GB, Døssing, T, Rønn Hansen, C, Schunck, N, Sletten, G, Ødegard, S, Hübel, H, Bringel, P, Bürger, A, Neusser, A, Singh, AK, Al-Khatib, A, Patel, SB, Nyakó, BM, Algora, A, Dombrádi, Z, Gál, J, Kalinka, G, Sohler, D, Molnár, J, Timár, J, Zolnai, L, Juhász, K, Bracco, A, Leon, S, Camera, F, Benzoni, G, Mason, P, Paleni, A, Million, B, Wieland, O, Bednarczyk, P, Azaiez, F, Byrski, T, Curien, D, Dakov, O, Duchene, G, Khalfallah, F, Gall, B, Piqeras, L, Robin, J, Dudek, J, Rowley, N, Redon, N, Hannachi, F, Scheurer, JN, Wilson, JN, Lopez-Martens, A, Korichi, A, Hauschild, K, Roccaz, J, Siem, S, Fallon, P, Lee, IY, Gorgen, A, Maj, A, Kmiecik, M, Brekiesz, M, Styczen, J, Zuber, K, Lisle, JC, Cederwall, B, Lagergren, K, Evans, AO, Rainovski, G, De Angelis, G, La Rana, G, Moro, R, Lieder, RM, Lieder, EO, Gast', W, Jäger, H, Pasternak, AA, Petrache, CM, and Petrache, D

Subjects
Nuclear & Particles Physics, Mathematical Sciences, Physical Sciences
Abstract

The Euroball-IV γ-detector array, equipped with the ancillary charged particle detector array DIAMANT was used to study the residues of the fusion reaction 64Ni ⇒ 128Ba at Ebeam = 255 and 261 MeV, in an attempt to reach the highest anguar momentum and verify the existence of predicted hyperdeformed rotational bands. No discrete hyperdeformed bands were identified, but nevertheless a breakthrough was obtained a systematic search for rotational ridge structure with very large moments of inertia J (2) ≥ 100 ℏ2 MeV(-1), in agreement with theoretical predictions for hyperdeformed shapes. Evidence for hyperdeformiation was obtained by charged particle + γ-ray gating, selectiong triple correlated ridge structures in the continuum of each of the nuclei, 118Te, 124Xe and 124,125Cs. In 7 additional nuclei, rotational ridges were also identified with J(2) = 71-77ℏ2Mev(-1), which most probably correspond to surperdeformed shape. The angular distributions of the emitted charged particles show an excess in forward direction over expectations from pure compound evaporation, which may indicate that in-complete fusion plays an important role in the population of very elongated shapes.

Published
2007

15. Recent Results from the NA49 Experiment

Author

Blume, C., Botje, M., van Leeuwen, M., Christakoglou, P., Georgopoulos, G., Panagiotou, A. D., Vassiliou, M., Petridis, A., Pikna, M., Cerny, V., Bracinik, J., Kreps, M., Sitar, B., Barna, D., Csato, P., Fodor, Z., Gal, J., Hegyi, S., Levai, P., Molnar, J., Palla, G., Siklér, F., Varga, D., Szentpetery, I., Veres, G. I., Zimanyi, J., Vesztergombi, G., Sziklai, J., Roland, C., Roland, G., Bartke, J., Gladysz, E., Kornas, E., Kowalski, M., Rybicki, A., Kraus, I., Foka, P., Friese, V., Markert, C., Mischke, A., Sandoval, A., Sann, H., Vranic, D., Baatar, B., Malakhov, A. I., Kolesnikov, V. I., Melkumov, G. L., Kollegger, T., Meurer, C., Betev, L., Billmeier, A., Bramm, R., Dinkelaker, P., Flierl, D., Gazdzicki, M., Mitrovski, M., Stock, R., Ströbele, H., Zaranek, J., Wetzler, A., Renfordt, R., Buncic, P., Brun, R., Fischer, H. G., Wenig, S., Mayes, B. W., Pinsky, L., Korus, R., Mrowczynski, St., Rybczynski, M., Stefanek, G., Wlodarczyk, Z., Behler, M., Höhne, C., Pühlhofer, F., Eckardt, V., Filip, P., Freund, P., Karev, A., Schmitz, N., Seyboth, P., Chvala, O., Yoo, I. K., Cramer, J. G., Reid, J. G., Trainor, T. A., Darmenov, N., Dimitrov, A., Litov, L., Makariev, M., Mateev, M., Panayotov, D., Bialkowska, H., Boimska, B., Perl, K., Retyk, W., Skrzypczak, E., Susa, T., Anticic, T., Kadija, K., Greiner, Walter, editor, Itkis, Mikhail G., editor, Reinhardt, Joachim, editor, and Güçlü, Mehmet Cem, editor

Published
2004
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17. Levosimendan in intensive care and emergency medicine: literature update and expert recommendations for optimal efficacy and safety

Author

Girardis, Massimo, Bettex, Dominique, Bojan, Mirela, Demponeras, Christos, Fruhwald, Sonja, Gál, J., Groesdonk, Heinrich Volker, Guarracino, Fabio, Guerrero-Orriach, José Luis, Heringlake, Matthias, Herpain, Antoine, Heunks, Leo, Jin, J., Kindgen-Milles, Detlef, Mauriat, Philippe, Michels, Guido, Psallida, Vasiliki, Rich, Stuart, Ricksten, Sven Erik, Rudiger, Alain, Siegemund, Martin, Toller, Wolfgang, Treskatsch, Sascha, Župan, Pollesello, Piero, Girardis, Massimo, Bettex, Dominique, Bojan, Mirela, Demponeras, Christos, Fruhwald, Sonja, Gál, J., Groesdonk, Heinrich Volker, Guarracino, Fabio, Guerrero-Orriach, José Luis, Heringlake, Matthias, Herpain, Antoine, Heunks, Leo, Jin, J., Kindgen-Milles, Detlef, Mauriat, Philippe, Michels, Guido, Psallida, Vasiliki, Rich, Stuart, Ricksten, Sven Erik, Rudiger, Alain, Siegemund, Martin, Toller, Wolfgang, Treskatsch, Sascha, Župan, and Pollesello, Piero

Abstract

The inodilator levosimendan, in clinical use for over two decades, has been the subject of extensive clinical and experimental evaluation in various clinical settings beyond its principal indication in the management of acutely decompensated chronic heart failure. Critical care and emergency medicine applications for levosimendan have included postoperative settings, septic shock, and cardiogenic shock. As the experience in these areas continues to expand, an international task force of experts from 15 countries (Austria, Belgium, China, Croatia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Spain, Sweden, Switzerland, and the USA) reviewed and appraised the latest additions to the database of levosimendan use in critical care, considering all the clinical studies, meta-analyses, and guidelines published from September 2019 to November 2021. Overall, the authors of this opinion paper give levosimendan a “should be considered” recommendation in critical care and emergency medicine settings, with different levels of evidence in postoperative settings, septic shock, weaning from mechanical ventilation, weaning from veno-arterial extracorporeal membrane oxygenation, cardiogenic shock, and Takotsubo syndrome, in all cases when an inodilator is needed to restore acute severely reduced left or right ventricular ejection fraction and overall haemodynamic balance, and also in the presence of renal dysfunction/failure., SCOPUS: re.j, info:eu-repo/semantics/published

Published
2022

23. The use of EXOGAM for in-beam spectroscopy of proton drip-line nuclei with radioactive ion beams

Author

Petri, M., Paul, E.S., Nolan, P.J., Boston, A.J., Boston, H.C., Cooper, R.J., Dimmock, M.R., Gros, S., McGuirk, B.M., Turk, G., Guinet, D., Lautesse, Ph., Meyer, M., Redon, N., Rossé, B., Schmitt, Ch., Stézowski, O., Bhattacharyya, S., De France, G., Mukherjee, G., Rejmund, F., Savajols, H., Scheurer, J.N., Gál, J., Molnár, J., Nyakó, B.M., Timár, J., Zolnai, L., Juhász, K., Astier, A., Deloncle, I., Porquet, M.G., Prévost, A., Pucknell, V.F.E., Wadsworth, R., Joshi, P., La Rana, G., Moro, R., Trotta, M., Vardaci, E., Hackman, G., and Ball, G.C.

Published
2009
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24. Prothrombotic alterations of von Willebrand factor level and ADAMTS13 activity in hospitalized COVID-19 patients

Author

Sinkovits, G, additional, Mező, B, additional, Réti, M, additional, Müller, V, additional, Iványi, Z, additional, Gál, J, additional, Gopcsa, L, additional, Reményi, P, additional, Szathmáry, B, additional, Lakatos, B, additional, Szlávik, J, additional, Bobek, I, additional, Prohászka, ZZ, additional, Förhécz, Z, additional, Csuka, D, additional, Hurler, L, additional, Kajdácsi, E, additional, Cervenak, L, additional, Kiszel, P, additional, Masszi, T, additional, and Vályi-Nagy, I, additional

Published
2021
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33. Evidence for a spin-aligned neutron–proton paired phase from the level structure of 92Pd

Author

Cederwall, B., Moradi, Ghazi F., Bäck, T., Johnson, A., Blomqvist, J., Clément, E., de France, G., Wadsworth, R., Andgren, K., Lagergren, K., Dijon, A., Jaworski, G., Liotta, R., Qi, C., Nyakó, B. M., Nyberg, J., Palacz, M., Al-Azri, H., Algora, A., de Angelis, G., Ataç, A., Bhattacharyya, S., Brock, T., Brown, J. R., Davies, P., Di Nitto, A., Dombrádi, Zs., Gadea, A., Gál, J., Hadinia, B., Johnston-Theasby, F., Joshi, P., Juhász, K., Julin, R., Jungclaus, A., Kalinka, G., Kara, S. O., Khaplanov, A., Kownacki, J., La Rana, G., Lenzi, S. M., Molnár, J., Moro, R., Napoli, D. R., Singh, Nara B. S., Persson, A., Recchia, F., Sandzelius, M., Scheurer, J.-N., Sletten, G., Sohler, D., Söderström, P.-A., Taylor, M. J., Timár, J., Valiente-Dobón, J. J., Vardaci, E., and Williams, S.

Published
2011
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37. Preliminary results on Pb+Pb collisions from the Grid-TOF data analysed in Budapest

Author

Vesztergombi, G., Alber, T., Appelshäuser, H., Bächler, J., Bartke, J., Białkowska, H., Bieser, F., Bloomer, M. A., Blyth, C. O., Bock, R., Bormann, C., Brady, F. P., Brockmann, R., Buncic, P., Caines, H. L., Cebra, D., Chan, P., Cooper, G. E., Cramer, J. G., Cramer, P. B., Csató, P., Derado, I., Dunn, J., Eckardt, V., Eckhardt, F., Euler, S., Ferguson, M. I., Fischer, H. G., Fodor, Z., Foka, P., Freund, P., Fuchs, M., Gál, J., Gaździcki, M., Gładysz, E., Grebieszkow, J., Günther, J., Harris, J. W., Heck, W., Hegyi, S., Hill, L. A., Huang, I., Howe, M. A., Igo, G., Irmscher, D., Jacobs, P., Jones, P. G., Kadija, K., Kowalski, M., Kühmichel, A., Lasiuk, B., Lévai, P., Margetis, S., Molnár, J., Mitchell, J. W., Mock, A., Nelson, J. M., Odyniec, G., Pálla, G., Panagiotou, A. D., Petridis, A., Piper, A., Poskanzer, A. M., Prindle, D. J., Pühlhofer, F., Rauch, W., Renfordt, R., Retyk, W., Ritter, H. G., Röhrich, D., Rudolph, H., Runge, K., Sandoval, A., Sann, H., Schäfer, E., Schmitz, N., Schönfelder, S., Seyboth, P., Seyerlein, J., Siklér, F., Skrzypczak, E., Stock, R., Ströbele, H., Szentpétery, I., Sziklai, J., Toy, M., Trainor, T. A., Trentalange, S., Vassiliou, M., Vesztergombi, G., Vranic, D., Wenig, S., Whitten, C., Wienold, T., Wood, L., Zimányi, J., Zhu, X. -Z., Zybert, R., and NA49 Collaboration

Published
1996
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49. Radiation Measurements without Posing the Inversion Problem

Author

John A. Maxwell, Balkay L, Raics P, Gál J, and Tibro Papp

Subjects
Propagation of uncertainty, Signal processing, Spectral power distribution, business.industry, Computer science, Electrical engineering, Dead time, Poisson distribution, symbols.namesake, Histogram, symbols, business, Algorithm, Digital signal processing, Randomness
Abstract

Purpose: Radiation measurement is an exponential analysis, which is an “illposed” problem, where the solution is not unique. Therefore, the accuracy of data points is critical. If the radiation detector is sensitive during the dead time, usually an extended dead time signal processing method is necessary and the calculation of the dead time and pile up rate invoke the inversion problem, which is difficult to solve, and only approximated. We have used two new approaches, where the inversion problem is not posed, and there is no need to assume the Poisson distribution or constant source strength. It goes beyond all previous techniques by handling the presence of discriminators. The preamplifier-signal processing chain has dead times and applies discriminators, as a consequence disturbs the randomness, and other distributions may also contribute. Although an undisturbed nuclear decay should be Poisson in nature, the measured spectrum usually does not have a Poisson distribution. The robustness of the two methods was investigated, focusing on the traceable derivation of statistical uncertainty. The two new methods were applied in gamma spectra measurements of 152Eu calibration sources, and nuclear half-life of 68Ga PET isotope, and compared with measurements using previous techniques. Methods: CSX (Cambridge Scientific) digital signal processors were used with five HPGe detectors in two operation modes in two measurement series. In quality assurance mode, the CSX processes all events, both the accepted and rejected ones, placing each event into one or more spectra based on the applied discriminators. Based on the accepted spectrum, the rejected spectra were analyzed to determine the single, double and triple events, the rate of unrelated, and noise events all to obtain the true input counts. The second and independent approach was a time interval histogram analysis for the measurement of the gamma ray intensities. In time interval histogram mode, the CSX creates an energy spectrum as well as an interval histogram of arrival times between successive events. This operation mode does not apply discriminators and has no dead time. The CSX signal processor was selected, as it offers a dead time free and less than 1% pile up rate up to about a million counts per second input rate, as well as quality assurance at the signal processing level. Results: The CSX processors employ a non-extended dead time approach and in quality assurance mode the true input rate is readily determined. As a consequence, the inversion problem was avoided. The uncertainties and uncertainty propagation are clearly justified. For the half-life measurement of 68Ga, the time interval histogram analysis gave six times smaller standard uncertainty than the square root of the counts. The inter-arrival time histogram was sensitive to non-deterministic behaviour of the detectors, and electronic disturbances, discrediting several measurement series. This additional ability is significant for quality measurements. Conclusion: Spectroscopy with HPGe detectors has lacked a method to credibly determine the uncertainties when discrimination is applied. In addition, a calibration procedure was required to establish the output rate versus input rate relations for each input rate preferably with a similar spectral distribution as the spectrum of interest. The preamplifier signal shape varied as a function of the input rate for each of the HPGe detectors studied. In such cases both the accepted and rejected event spectra are necessary for a proper evaluation. Accounting for all the events allows the determination of the uncertainties. The time interval histogram analysis is simple and straightforward, and offers an elegant way to determine the true input rate and uncertainty. The measurement can be applied over large input counting ranges, and does not require calibration.

Published
2017

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