Autor: Consolati, G. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Quasi-Positronium in Polyethylene Terephthalate - Temperature and Magnetic Quenching Effects
Autorzy:: Consolati, G.
Quasso, F.
Tematy:: 71.60.+z
78.70.Bj; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1928970.pdf Link otwiera się w nowym oknie
Opis:: The features of the positron-electron bound system (quasi-positronium, qPs) in the semicrystalline polymer polyethylene terephthalate (mylar) are obtained while studying the dependence of the ortho-qPs lifetime on temperature in the range of 25-105°C, in the presence as well as in the absence of magnetic fields. In particular, the "anomalous" effect, previously discovered by Bisi et al. at room temperature, is maintained at higher temperature.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Discrete and Continuous Analysis of Positron Lifetime Spectra: a Comparison
Autorzy:: Consolati, G.
Quasso, F.
Tematy:: 36.10.Dr
71.60.+z
78.70.Bj; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2007998.pdf Link otwiera się w nowym oknie
Opis:: Positron lifetime spectra in poly[1-(trimethylsilyl)]propine membranes were collected at different temperatures and various number of accumulated counts, in order to compare the results from analyses obtained by different decay models: discrete (that is, purely exponential) or continuous (with at least one distribution of lifetimes). Analysis into four discrete components is inadequate, unless a low number of counts (1 to 2 millions) is accumulated. Conversely, deconvolutions which allow the ortho-positronium lifetime to be distributed give satisfactory fits, even at the highest statistics (60 millions). An equivalent good fit in terms of χ$\text{}^{2}$ test is obtained with a five discrete components analysis, from which it is possible to extract information on the first moments (centroid and standard deviation) of ortho -positronium lifetime distribution.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Water Sorption and Dessiccation in a Portland Cement Paste: Positron Annihilation Results
Autorzy:: Consolati, G.
Dotelli, G.
Quasso, F.
Tematy:: 78.70.Bj
71.60.+z
81.05.Rm; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2024222.pdf Link otwiera się w nowym oknie
Opis:: Positron annihilation experiments were carried out on a Portland cement paste one year aged, which was subjected to cycles of dessiccation and subsequent water resaturation, in order to study possible changes of the porosity. Analysis of the annihilation time spectra suggests that drying and rewetting treatments do not induce irreversible modifications in the configuration of the finest gel pores.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Numerical Solution of a Two-Particle Model of Positronium Confined in Small Cavities
Autorzy:: Tanzi Marlotti, G.
Castelli, F.
Consolati, G.
Tematy:: 36.10.Dr
34.80.Lx
78.70.Bj; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1033255.pdf Link otwiera się w nowym oknie
Opis:: The positronium atom (Ps) is widely used as a probe to characterize nanoporous and mesoporous materials. Existing theoretical models for describing Ps annihilation rates by pick-off processes generally treat Ps as a point particle confined in a potential well. Hence these models do not justify any change in the internal structure of Ps, which is experimentally accessible by means of the contact density parameter. Recently we formulated a two-particle model in which only the electron is confined in the cavity, while the positron is moving freely and feels the medium via a positive work function. We present here a numerical treatment of the problem of calculating contact densities and pick-off annihilation rates, by using a variational method. Results are in agreement with experimental data for a large class of materials, and suggest a way to connect these data with pore sizes and positron work functions.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Outdoor Ageing of an Ethylene-Propylene Copolymer: A Positron Annihilation Study
Autorzy:: Consolati, G.
Quasso, F.
Gallo, R.
Severini, F.
Tematy:: 61.41.+e
78.70.Bj
81.05.Lg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2043322.pdf Link otwiera się w nowym oknie
Opis:: An investigation on the environmental degradation of an ethylene-propylene copolymer was carried out through positron annihilation lifetime spectroscopy, density and differential scanning calorimetry measurements. Polymer sheets were exposed to sunlight up to 11000 hours. Density and melting enthalpy increase with ageing, while ortho-positronium intensity decreases; ortho-positronium lifetime does not show significant variations up to 4400 hours. At higher exposures it starts to decrease. Outdoor ageing produces an increased crystallinity of the copolymer; also a degradation occurs with formation of carbonyl groups. The corresponding Ps inhibition is the main reason for the decrease in ortho-positronium intensity, the other one being the reduced amount of the amorphous phase available. The lifetime decrease observed at the highest exposures can be interpreted in terms of a shrinking of the nanoholes trapping positronium.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Production of Cold Positronium Atoms
Autorzy:: Brusa, R.
Mariazzi, S.
Consolati, G.
Dupasquier, A.
Quasso, F.
Giammarchi, M.
Tematy:: 78.70.Bj
36.10.Dr
36.10.Gv; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1812479.pdf Link otwiera się w nowym oknie
Opis:: Positronium will play a primary role in the next generation of antimatter experiments through the following antihydrogen production reaction: p̅ + Ps* → p̅e⁺ + e¯. In order to study antimatter physical properties (CPT (charge, parity, time) invariance and principle of equivalence test) it is necessary to keep this system at the lowest possible (sub-kelvin) temperatures. This requires the generation of a suitable flux of cold Ps atoms in a vacuum, a non-trivial requirement at the light of the present experimental results. In this paper we discuss the state of the actual knowledge on positronium formation and consequent emission from metallic surfaces and insulators and we show the opportunity to use suitable porous materials to cool positronium through collisions with the inner walls of the pores. We get a rough indication on the geometrical parameters of the pore and we propose a simple experiment to obtain the kinetic energy - and therefore the equivalent temperature - of emitted positronium without using a positron beam.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: AEgIS experiment at CERN : design and commissioning of SARA (Scintillator Assemblies to Reveal Annihilations)
Autorzy:: Consolati, G.
Lappo, L.
Moskal, Paweł
Berghold, M.
Sharma, Sushil
Conte, P.
Caravita, R.
Ferguson, R.
Penasa, L.
Grosbart, M.
Münster, M.
Khatri, G.
Guatieri, F.
Prata, M.
Haider, S.
Opis:: SARA is the system of plastic scintillators coupled with silicon photomultipliers that will take part in the AEgIS experiment at CERN, measuring the time-of-flight of antihydrogen as it falls through a moiré deflectometer. Its development focused on simplicity, versatility and economy of the design and was supported by both physical tests and numerical simulations. The instrument structure pairs the utilization of the scintillators as structural components with custom made 3D printed corner elements and the electronics allows selection between coincidence discrimination made on each scintillator and made between different scintillators.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 8.

Tytuł:: Positronium for antihydrogen production in the AEGIS experiment
Autorzy:: Consolati, G.
Aghion, S.
Amsler, C.
Bonomi, G.
Brusa, R.
Caccia, M.
Caravita, R.
Castelli, F.
Cerchiari, G.
Comparat, D.
Demetrio, A.
Di Noto, L.
Doser, M.
Evans, C.
Fanì, M.
Ferragut, R.
Fesel, J.
Fontana, A.
Gerber, S.
Giammarchi, M.
Gligorova, A.
Guatieri, F.
Haider, S.
Hinterberger, A.
Holmestad, H.
Kellerbauer, A.
Khalidova, O.
Krasnicky, D.
Lagomarsino, V.
Lansonneur, P.
Lebrun, P.
Malbrunot, C.
Mariazzi, S.
Marton, J.
Matveev, V.
Mazzotta, Z.
Müller, S.
Nebbia, G.
Nedelec, P.
Oberthaler, M.
Pacifico, N.
Pagano, D.
Penasa, L.
Petracek, V.
Prelz, F.
Prevedelli, M.
Ravelli, L.
Rienaecker, B.
Robert, J.
Røhne, O.
Rotondi, A.
Sandaker, H.
Santoro, R.
Smestad, L.
Sorrentino, F.
Testera, G.
Tietje, I.
Widmann, E.
Yzombard, P.
Zimmer, C.
Zmeskal, J.
Zurlo, N.
Tematy:: 04.80.Cc
07.77.-n
36.10.Dr
78.70.Bj; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1057954.pdf Link otwiera się w nowym oknie
Opis:: The primary goal of the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEGIS) collaboration is to measure for the first time precisely the gravitational acceleration of antihydrogen, H̅, a fundamental issue of contemporary physics, using a beam of antiatoms. Indeed, although indirect arguments have been raised against a different acceleration of antimatter with respect to matter, nevertheless some attempts to formulate quantum theories of gravity, or to unify gravity with the other forces, consider the possibility of a non-identical gravitational interaction between matter and antimatter. We plan to generate H̅ through a charge-exchange reaction between excited Ps and antiprotons coming from the Antiproton Decelerator facility at CERN. It offers the advantage to produce sufficiently cold antihydrogen to make feasible a measurement of gravitational acceleration with reasonable uncertainty (of the order of a few percent). Since the cross-section of the above reaction increases with n⁴, n being the principal quantum number of Ps, it is essential to generate Ps in a highly excited (Rydberg) state. This will occur by means of two laser excitations of Ps emitted from a nanoporous silica target: a first UV laser (at 205 nm) will bring Ps from the ground to the n=3 state; a second laser pulse (tunable in the range 1650-1700 nm) will further excite Ps to the Rydberg state.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Positron-positronium converters in reflection and transmission geometry for gravitational experiments with antihydrogen using Moiré deflectometry
Autorzy:: Consolati, G.
Prelz, F.
Povolo, L.
Khatri, G.
Pecak, D.
Rienäcker, B.
Glöggler, L. T.
Gustafsson, F.
Zielinski, J.
Volponi, M.
Ferguson, R. C.
Hugenschmidt, C.
Kasprowicz, G.
Pospisil, S.
Germann, M.
Camper, A.
Gusakova, N.
Piwiński, M.
Bergmann, B.
Kempny, K.
Linek, A.
Huck, S.
Rodin, V.
Brusa, R. S.
Smolyanskiy, P.
Krumins, V.
Auzins, M.
Pandey, Piyush
Røhne, O. M.
Janik, M. A.
Alfaro Campos, S.
Münster, M.
Zurlo, N.
Rawat, B. S.
Caravita, R.
Lappo, L.
Doser, M.
Berghold, M.
Ciuryło, R.
Eliaszuk, K.
Giszczak, A.
Welsch, C. P.
Chehaimi, A.
Tefelski, D.
Rangwala, S. A.
Kornakov, G.
Rauschendorfer, T.
Penasa, L.
Petracek, V.
Grosbart, M.
Mariazzi, S.
Sandaker, H.
Guatieri, F.
Burian, P.
Vafeiadis, T.
Haider, S.
Zawada, M.
Kłosowski, Ł.
Sharma, Sushil
Castelli, F.
Cerchiari, G.
Moskal, Paweł
Graczykowski, Ł.
Sowiński, T.
Januszek, T.
Opis:: In the context of the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) located at CERN, positron-positronium converters with a high positron-positronium conversion efficiency have been designed in both reflection and transmission geometries. The converters utilize nanochanneled silicon target technology with positron conversion efficiencies up to around 50% and around 16%, at room temperature and in the absence of magnetic fields, for reflection and transmission respectively. The positron-positronium converters allow for the pulsed production of antihydrogen ($\overline{H}$) within the AEgIS experiment. This paper discusses the use of a pulsed $\overline{H}$ beam in a moiré deflectometer to perform a precise gravitational measurement on $\overline{H}$ at AEgIS. This work describes the principles and technical details of the current design of a moiré deflectometer using the pulsed $\overline{H}$ beam. The main goal of this work is to summarize the ongoing project of adding the described moiré deflectometer to the AEgIS experiment to further their efforts toward probing the material dependence of gravity and testing the weak equivalence principle (WEP).
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 10.

Tytuł:: Laser cooling positronium with broadband laser pulses
Autorzy:: Consolati, G.
Prelz, F.
Povolo, L.
Khatri, G.
Pecak, D.
Rienäcker, B.
Glöggler, L. T.
Gustafsson, F.
Zielinski, J.
Volponi, M.
Hugenschmidt, C.
Kasprowicz, G.
Pospisil, S.
Germann, M.
Camper, A.
Gusakova, N.
Piwiński, M.
Bergmann, B.
Kempny, K.
Linek, A.
Huck, S.
Rodin, V.
Brusa, R. S.
Smolyanskiy, P.
Krumins, V.
Auzins, M.
Pandey, Piyush
Røhne, O. M.
Janik, M. A.
Alfaro Campos, S.
Münster, M.
Zurlo, N.
Ferguson, R.
Caravita, R.
Lappo, L.
Rawat, B. S.
Doser, M.
Berghold, M.
Ciuryło, R.
Eliaszuk, K.
Giszczak, A.
Welsch, C. P.
Chehaimi, A.
Tefelski, D.
Rangwala, S. A.
Kornakov, G.
Rauschendorfer, T.
Penasa, L.
Petracek, V.
Grosbart, M.
Mariazzi, S.
Sandaker, H.
Guatieri, F.
Burian, P.
Vafeiadis, T.
Haider, S.
Zawada, M.
Kłosowski, Ł.
Sharma, Sushil
Castelli, F.
Cerchiari, G.
Moskal, Paweł
Graczykowski, Ł.
Sowiński, T.
Januszek, T.
Opis:: The first successful demonstration of broadband laser cooling of positronium (Ps) atoms, obtained within the AEgIS experiment at CERN, is presented here. By employing a custom-designed pulsed alexandrite laser system at 243 nm featuring long-duration pulses of 70 ns and an energy able to saturate the 13S–23P transition over the broad spectrum range of 360 GHz, the temperature of a room-temperature Ps cloud was reduced from 380 K to 170 K in 70 ns. This advancement opens new avenues for precision spectroscopy, antihydrogen production, and fundamental tests with antimatter.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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