Kaon and Phi Production in Pion-Nucleus Reactions at 1.7 GeV/c

EPJ Web of Conferences ◽

10.1051/epjconf/201817113002 ◽

2018 ◽

Vol 171 ◽

pp. 13002 ◽

Cited By ~ 1

Author(s):

Joana Wirth

Keyword(s):

Nuclear Matter ◽

Nuclear Reactions ◽

Beam Momentum ◽

Double Ratio ◽

Exchange Processes

The production and properties of K+, K− and ϕ in nuclear reactions π− + A (A = C,W) at a beam momentum of 1:7 GeV/c has been studied with the HADES setup at SIS18/GSI. Of particular interest is the K− absorption in nuclear matter which should be driven by strangeness exchange processes on one (K−N → Yπ) or more nucleons (K−NN → YNπ). In this context, also the ϕ has to be taken into account, since ϕ decays into K+K− pairs may substantially affect the measured K− abundance. A solid reference is needed to evaluate the K− absorption with in the nucleus and in this work we discuss the determination of this reference. A double ratio of K−=K+(W)=K−=K+(C) is measured within the acceptance and compared to the reference.

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Statistical Description of Isotope Exchange Processes: A Multisite Model for the 18O Exchange

Zeitschrift für Naturforschung C ◽

10.1515/znc-1982-11-1219 ◽

1982 ◽

Vol 37 (11-12) ◽

pp. 1161-1169 ◽

Cited By ~ 1

Author(s):

Paul Rösch

Keyword(s):

Active Site ◽

Isotope Exchange ◽

Analytical Procedure ◽

Matrix Formalism ◽

Model Calculations ◽

Exchange Processes ◽

Reaction Solution ◽

Different Types ◽

Refinement Procedure

Abstract An analytical procedure has been developed for the determination of isotope exchange processes as exemplified by the 18O exchange catalysed by enzyme-nucleotide complexes. The model is able to handle more than one type of active site per reaction solution and is also able to distinguish between different types of inequivalence of the oxygens of enzyme bound Pi. Use of transition matrix formalism and basic statistical considerations lead directly to the simple model. A data refinement procedure is introduced and model calculations are shown.

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A NUCLEAR MANY-BODY THEORY AT FINITE TEMPERATURE APPLIED TO A PROTONEUTRON STAR

International Journal of Modern Physics E ◽

10.1142/s0218301302000727 ◽

2002 ◽

Vol 11 (02) ◽

pp. 83-104 ◽

Cited By ~ 16

Author(s):

GUILHERME F. MARRANGHELLO ◽

CESAR A. Z. VASCONCELLOS ◽

MANFRED DILLIG ◽

J. A. DE FREITAS PACHECO

Keyword(s):

Phase Transition ◽

Nuclear Matter ◽

Finite Temperature ◽

Degrees Of Freedom ◽

Many Body ◽

Many Body Theory ◽

The Masses ◽

Protoneutron Stars ◽

Protoneutron Star

Thermodynamical properties of nuclear matter are studied in the framework of an effective many-body field theory at finite temperature, considering the Sommerfeld approximation. We perform the calculations by using the nonlinear Boguta and Bodmer model, extended by the inclusion of the fundamental baryon octet and leptonic degrees of freedom. Trapped neutrinos are also included in order to describe protoneutron star properties through the integration of the Tolman–Oppenheimer–Volkoff equations, from which we obtain, beyond the standard relations for the masses and radii of protoneutron stars as functions of the central density, new results of these quantities as functions of temperature. Our predictions include: the determination of an absolute value for the limiting mass of protoneutron stars; new structural aspects on the nuclear matter phase transition via the behavior of the specific heat and, through the inclusion of quark degrees of freedom, the properties of a hadron-quark phase transition and hybrid protoneutron stars

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ЗМІНА ЕЛЕКТРИЧНИХ ВЛАСТИВОСТЕЙ НАСІННЯ ПІД ВПЛИВОМ ВИСОКОЧАСТОТНОГО ЕЛЕКТРОМАГНІТНОГО ОПРОМІНЕННЯ

Вісник Полтавської державної аграрної академії ◽

10.31210/visnyk2014.02.31 ◽

2014 ◽

pp. 151-155

Author(s):

О. М. Петровський

Keyword(s):

Electromagnetic Field ◽

High Frequency ◽

Electric Properties ◽

Electric Resistance ◽

Active Resistance ◽

Exchange Processes ◽

High Frequency Electromagnetic Field ◽

Stimulation Of

Розглянуті питання передпосівної стимуляції на-сіння високочастотним електромагнітним полем.Запропоновано спосіб опромінення насіння і визна-чення його електричних характеристик. На основібудови клітин визначені електричні властивості біо-логічної тканини, з якої складається насіння. Пока-зана зміна складових активного опору в залежностівід частоти струму. Експериментально доведено,що еквівалентну електричну схему неможливо звес-ти до простих випадків з’єднання опорів і ємностей,а саме насіння не можна вважати нейтральнимдіелектриком. Розроблена методика оцінки інтенси-вності обмінних процесів залежно від електричногоопору насіння. The questions of stimulation of seed before sowing are considered by the high-frequency electromagnetic field considered. The method of irradiation of seed and determination of him is offered electric descriptions. On the basis of structure of cages electric properties of biological fabric which seed consist of are certain. The change of constituents of active resistance is shown depending on frequency of current. It is experimentally proved that it is impossible to erect an equivalent electric chart to the simple cases of connection of resistances and capacities, namely seed can not be considered a neutral dielectric. The method of estimation of intensity of exchange processes is developed depending on electric resistance of seed.

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Study of the 232Th(n,f) Cross section at NCSR ‘Demokritos’ using Micromegas Detectors

HNPS Proceedings ◽

10.12681/hnps.2994 ◽

2020 ◽

Vol 27 ◽

pp. 106

Author(s):

Sotirios Chasapoglou ◽

A. Tsantiri ◽

A. Kalamara ◽

M. Kokkoris ◽

V. Michalopoulou ◽

...

Keyword(s):

Cross Section ◽

Cross Sections ◽

Nuclear Reactions ◽

Detection Efficiency ◽

High Energy ◽

Tandem Accelerator ◽

Line Detector ◽

Accelerator Driven Systems ◽

The Masses

The accurate knowledge of neutron-induced fission cross sections in actinides, is of great importance when it comes to the design of fast nuclear reactors, as well as accelerator driven systems. Specifically for the 232Th(n,f) case, the existing experimental datasets are quite discrepant in both the low and high energy MeV regions, thus leading to poor evaluations, a fact that in turn implies the need for more accurate measurements.In the present work, the total cross section of the 232Th(n,f) reaction has been measured relative to the 235U(n,f) and 238U(n,f) ones, at incident energies of 7.2, 8.4, 9.9 MeV and 14.8, 16.5, 17.8 MeV utilizing the 2H(d,n) and 3H(d,n) reactions respectively, which generally yield quasi-monoenergetic neutron beams. The experiments were performed at the 5.5 MV Tandem accelerator laboratory of N.C.S.R. “Demokritos”, using a Micromegas detector assembly and an ultra thin ThO2 target, especially prepared for fission measurements at n_ToF, CERN during its first phase of operations, using the painting technique. The masses of all actinide samples were determined via α-spectroscopy. The produced fission yields along with the results obtained from activation foils were studied in parallel, using both the NeusDesc [1] and MCNP5 [2] codes, taking into consideration competing nuclear reactions (e.g. deuteron break up), along with neutron elastic and inelastic scattering with the beam line, detector housing and experimental hall materials. Since the 232Th(n,f) reaction has a relatively low energy threshold and can thus be affected by parasitic neutrons originating from a variety of sources, the thorough characterization of the neutron flux impinging on the targets is a prerequisite for accurate cross-section measurements, especially in the absence of time-of-flight capabilities. Additional Monte-Carlo simulations were also performed coupling both GEF [3] and FLUKA [4] codes for the determination of the detection efficiency.

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