| Records |
| Author |
Balaudo, A.; Calore, F.; De Romeri, V.; Donato, F. |
Title  |
NAJADS: a self-contained framework for the direct determination of astrophysical J-factors |
Type |
Journal Article |
| Year |
2024 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
001 - 33pp |
| Keywords |
dark matter simulations; dark matter theory; dark matter detectors |
| Abstract |
Cosmological simulations play a pivotal role in understanding the properties of the dark matter (DM) distribution in both galactic and galaxy -cluster environments. The characterization of DM structures is crucial for informing indirect DM searches, aiming at the detection of the annihilation (or decay) products of DM particles. A fundamental quantity in these analyses is the astrophysical J -factor. In the DM phenomenology community, J -factors are typically computed through the semi -analytical modelling of the DM mass distribution, which is affected by large uncertainties. With the scope of addressing and possibly reducing these uncertainties, we present NAJADS, a self-contained framework to derive the DM J -factor directly from the raw simulations data. We show how this framework can be used to compute all -sky maps of the J -factor, automatically accounting for the complex 3D structure of the simulated halos and for the boosting of the signal due to the density fluctuations along the line of sight. After validating our code, we present a proof -of -concept application of NAJADS to a realistic halo from the IllustrisTNG suite, and exploit it to make a thorough comparison between our numerical approach and traditional semi -analytical methods. JCAP02(2024)001 |
| Address |
[Balaudo, Anna] Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands, Email: balaudo@strw.leidenuniv.nl; |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1475-7516 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:001182021200006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6018 |
| Permanent link to this record |
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| Author |
Wagner, C.; Verde, L.; Boubekeur, L. |
| Title |
N-body simulations with generic non-Gaussian initial conditions I: power spectrum and halo mass function |
Type |
Journal Article |
| Year |
2010 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
10 |
Issue |
10 |
Pages |
022 - 24pp |
| Keywords |
power spectrum; cosmological simulations; initial conditions and eternal universe; galaxy clusters |
| Abstract |
We address the issue of setting up generic non-Gaussian initial conditions for N-body simulations. We consider inflationary-motivated primordial non-Gaussianity where the perturbations in the Bardeen potential are given by a dominant Gaussian part plus a non-Gaussian part specified by its bispectrum. The approach we explore here is suitable for any bispectrum, i.e. it does not have to be of the so-called separable or factorizable form. The procedure of generating a non-Gaussian field with a given bispectrum (and a given power spectrum for the Gaussian component) is not univocal, and care must be taken so that higher-order corrections do not leave a too large signature on the power spectrum. This is so far a limiting factor of our approach. We then run N-body simulations for the most popular inflationary-motivated non-Gaussian shapes. The halo mass function and the non-linear power spectrum agree with theoretical analytical approximations proposed in the literature, even if they were so far developed and tested only for a particular shape (the local one). We plan to make the simulations outputs available to the community via the non-Gaussian simulations comparison project web site http://icc.ub.edu/similar to liciaverde/NGSCP.html. |
| Address |
[Wagner, Christian; Verde, Licia] Univ Barcelona, ICCUB IEEC, E-08028 Barcelona, Spain, Email: cwagner@icc.ub.edu |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1475-7516 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
ISI:000283577600013 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
339 |
| Permanent link to this record |
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| Author |
Zhang, X.; Xiao, Y.T.; Gimeno, B. |
| Title |
Multipactor Suppression by a Resonant Static Magnetic Field on a Dielectric Surface |
Type |
Journal Article |
| Year |
2020 |
Publication |
IEEE Transactions on Electron Devices |
Abbreviated Journal |
IEEE Trans. Electron Devices |
| Volume |
67 |
Issue |
12 |
Pages |
5723-5728 |
| Keywords |
Radio frequency; Dielectrics; Magnetic resonance; Discharges (electric); Surface discharges; Surface waves; Electrostatics; Monte Carlo simulation; multipactor discharge; orthogonal waves; resonant static magnetic field; secondary electron yield |
| Abstract |
In this article, we study the suppression of the multipactor phenomenon on a dielectric surface by a resonant static magnetic field. A homemade Monte Carlo algorithm is developed for multipactor simulations on a dielectric surface driven by two orthogonal radio frequency (RF) electric field components. When the static magnetic field is perpendicular to the tangential and normal RF electric fields, it is shown that if the normal electric field lags the tangential electric field by pi/2, the superposition of the normal and tangential electric fields will trigger a gyro-acceleration of the electron cloud and restrain the multipactor discharge effectively. By contrast, when the normal electric field is in advance of the tangential electric field by pi/2, the difference between the normal and tangential electric fields drives gyro-motion of the electron cloud. Consequently, two enhanced discharge zones are inevitable. The suppression effects of the resonant static magnetic field that is parallel to the tangential RF electric field or to the normal RF electric field are also presented. |
| Address |
[Zhang, Xue; Xiao, Yuting] Xiangtan Univ, Sch Automat & Elect Informat, Xiangtan 411105, Hunan, Peoples R China, Email: zhangxue.iecas@yahoo.com; |
| Corporate Author |
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Thesis |
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| Publisher |
Ieee-Inst Electrical Electronics Engineers Inc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0018-9383 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000594337700064 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4627 |
| Permanent link to this record |
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| Author |
Hornillos, M.B.G.; Gorlychev, V.; Caballero, R.; Cortes, G.; Poch, A.; Pretel, C.; Calvino, F.; Tain, J.L.; Algora, A.; Agramunt, J.; Cano-Ott, D.; Martinez, T.; Mendoza, E.; Rissanen, J.; Aysto, J.; Jokinen, A.; Eronen, T.; Moore, I.; Penttila, H. |
| Title |
Monte Carlo Simulations for the Study of a Moderated Neutron Detector |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of the Korean Physical Society |
Abbreviated Journal |
J. Korean Phys. Soc. |
| Volume |
59 |
Issue |
2 |
Pages |
1573-1576 |
| Keywords |
Monte Carlo simulations; GEANT4; MCNPX; Beta delayed neutron emission; Neutron detector |
| Abstract |
This work presents the Monte Carlo simulations performed with the MCNPX and GEANT4 codes for the design of a BEta deLayEd Neutron detector, BELEN-20. This detector will be used for the study of beta delayed neutron emission and consists of a block of polyethylene with dimensions 90 x 90 x 80 cm(3) and 20 cylindrical (3)He gas counters. The results of these simulations have been validated experimentally with a (252)Cf source in the laboratory at UPC, Barcelona. Also the first experiment with this detector has been carried out in November 2009 in JYFL, Finland. In this experiment the neutron emission probability after beta decay of the fission products (88)Br, (94,95)Rb, and (138)I has been measured; this data is still under analysis. Simulations with MCNPX and GEANT4 have been performed in order to obtain the efficiency of the BELEN-20 detector for each of the above nuclei using the neutron energy distribution corresponding to each nucleus. |
| Address |
[Hornillos, MBG; Gorlychev, V; Caballero, R; Cortes, G; Poch, A; Pretel, C; Calvino, F] Univ Politecn Cataluna, Seccio Engn Nucl, E-08028 Barcelona, Spain, Email: belen.gomez@upc.edu |
| Corporate Author |
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Thesis |
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| Publisher |
Korean Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0374-4884 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000294080700028 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
733 |
| Permanent link to this record |
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| Author |
Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Tain, J.L.; Algora, A.; Berthoumieux, E.; Colonna, N.; Domingo-Pardo, C.; Gonzalez-Romero, E.; Heil, M.; Jordan, D.; Kappeler, F.; Lampoudis, C.; Martinez, T.; Massimi, C.; Plag, R. |
| Title |
Monte Carlo simulation of the n_TOF Total Absorption Calorimeter |
Type |
Journal Article |
| Year |
2012 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
671 |
Issue |
|
Pages |
108-117 |
| Keywords |
Monte Carlo simulation; Geant4; Neutron cross-sections; Time-of-flight; Neutron capture |
| Abstract |
The n_TOF Total Absorption Calorimeter (TAC) is a 4 pi BaF2 segmented detector used at CERN for measuring neutron capture cross-sections of importance for the design of advanced nuclear reactors. This work presents the simulation code that has been developed in GEANT4 for the accurate determination of the detection efficiency of the TAC for neutron capture events. The code allows to calculate the efficiency of the TAC for every neutron capture state, as a function of energy, crystal multiplicity, and counting rate. The code includes all instrumental effects such as the single crystal detection threshold and energy resolution, finite size of the coincidence time window, and signal pile-up. The results from the simulation have been validated with experimental data for a large set of electromagnetic de-excitation patterns: beta-decay of well known calibration sources, neutron capture reactions in light nuclei with well known level schemes like Ti-nat, reference samples used in (n,gamma) measurements like Au-197 and experimental data from an actinide sample like Pu-240. The systematic uncertainty in the determination of the detection efficiency has been estimated for all the cases. As a representative example, the accuracy reached for the case of Au-197(n,gamma) ranges between 0.5% and 2%, depending on the experimental and analysis conditions. Such a value matches the high accuracy required for the nuclear cross-section data needed in advanced reactor design. |
| Address |
[Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Gonzalez-Romero, E.; Martinez, T.] CIEMAT, Ctr Invest Energet Medioambientales & Tecnol, E-28040 Madrid, Spain, Email: carlos.guerrero@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0168-9002 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000301474600013 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
973 |
| Permanent link to this record |
