| Records |
| Author |
Villanueva-Domingo, P.; Gnedin, N.Y.; Mena, O. |
| Title |
Warm Dark Matter and Cosmic Reionization |
Type |
Journal Article |
| Year |
2018 |
Publication |
Astrophysical Journal |
Abbreviated Journal |
Astrophys. J. |
| Volume |
852 |
Issue |
2 |
Pages |
139 - 7pp |
| Keywords |
cosmology: theory; galaxies: formation; intergalactic medium; large-scale structure of universe; methods: numerical |
| Abstract |
In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3. keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn-Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in both CDM and WDM models, the full distribution of Gunn-Peterson optical depth retains the strong signature of delayed reionization in the WDM model. However, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent. |
Address  |
[Villanueva-Domingo, Pablo; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: gnedin@fnal.gov |
| 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 |
0004-637x |
ISBN |
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Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
WOS:000422865600009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3455 |
| Permanent link to this record |
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| Author |
Villanueva-Domingo, P.; Mena, O.; Miralda-Escude, J. |
| Title |
Maximum amplitude of the high-redshift 21-cm absorption feature |
Type |
Journal Article |
| Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
101 |
Issue |
8 |
Pages |
083502 - 8pp |
| Keywords |
|
| Abstract |
We examine the maximum possible strength of the global 21-cm absorption dip on the cosmic background radiation at high-redshift caused by the atomic intergalactic medium, when the Lyman-alpha coupling is maximum, assuming no exotic cooling mechanisms from interactions with dark matter. This maximum absorption is limited by three inevitable factors that need to be accounted for: (a) heating by energy transferred from the cosmic background radiation to the hydrogen atoms via 21-cm transitions, dubbed as 21-cm heating; (b) Ly alpha heating by scatterings of Ly alpha photons from the first stars; (c) the impact of the expected density fluctuations in the intergalactic gas in standard cold dark matter theory, which reduces the mean 21-cm absorption signal. Inclusion of this third novel effect reduces the maximum global 21-cm absorption by similar to 10%. Overall, the three effects studied here reduce the 21-cm global absorption by similar to 20% at z similar or equal to 17. |
| Address |
[Villanueva-Domingo, Pablo; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Paterna, Spain, Email: pablo.villanueva@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer 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 |
|
Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000523343100006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
4360 |
| Permanent link to this record |
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| Author |
Villanueva-Domingo, P.; Mena, O.; Palomares-Ruiz, S. |
| Title |
A Brief Review on Primordial Black Holes as Dark Matter |
Type |
Journal Article |
| Year |
2021 |
Publication |
Frontiers in Astronomy and Space Sciences |
Abbreviated Journal |
Front. Astron. Space Sci. |
| Volume |
8 |
Issue |
|
Pages |
681084 - 10pp |
| Keywords |
primordial black holes; dark matter; cosmology; accretion; 21 cm cosmology; gravitational waves; cosmic microwave background; microlensing |
| Abstract |
Primordial black holes (PBHs) represent a natural candidate for one of the components of the dark matter (DM) in the Universe. In this review, we shall discuss the basics of their formation, abundance and signatures. Some of their characteristic signals are examined, such as the emission of particles due to Hawking evaporation and the accretion of the surrounding matter, effects which could leave an impact in the evolution of the Universe and the formation of structures. The most relevant probes capable of constraining their masses and population are discussed. |
| Address |
[Villanueva-Domingo, Pablo; Mena, Olga; Palomares-Ruiz, Sergio] CSIC Univ Valencia, Inst Fis Corpuscular IFIC, Paterna, Spain, Email: pablo.villanueva.domingo@gmail.com |
| Corporate Author |
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Thesis |
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| Publisher |
Frontiers Media Sa |
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 |
2296-987x |
ISBN |
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Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000660081700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
4852 |
| Permanent link to this record |
| |
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| |
| Author |
Villanueva-Domingo, P.; Gariazzo, S.; Gnedin, N.Y.; Mena, O. |
| Title |
Was there an early reionization component in our universe? |
Type |
Journal Article |
| Year |
2018 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
024 - 17pp |
| Keywords |
cosmological parameters from CMBR; reionization |
| Abstract |
A deep understanding of the epoch of reionization is still missing in our knowledge of the universe. While future probes will allow us to test the precise evolution of the free electron fraction from redshifts between z similar or equal to 6 and z similar or equal to 20, at present one could ask what kind of reionization processes are allowed by present cosmic microwave background temperature and polarization measurements. An early contribution to reionization could imply a departure from the standard picture where star formation determines the reionization onset. By considering a broad class of possible reionization parameterizations, we find that current data do not require an early reionization component in our universe and that only one marginal class of models, based on a particular realization of reionization, may point to that. In addition, the frequentist Akaike information criterion (AIC) provides strong evidence against alternative reionization histories, favoring the most simple reionization scenario, which describes reionization by means of only one (constant) reionization optical depth tau. |
| Address |
[Villanueva-Domingo, Pablo; Gariazzo, Stefano; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: pablo.villanueva@ific.uv.es; |
| 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 |
|
Edition |
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| ISSN |
1475-7516 |
ISBN |
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Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
WOS:000429339200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3555 |
| Permanent link to this record |
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| Author |
Loya Villalpando, A.A.; Martin-Albo, J.; Chen, W.T.; Guenette, R.; Lego, C.; Park, J.S.; Capasso, F. |
| Title |
Improving the light collection efficiency of silicon photomultipliers through the use of metalenses |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
15 |
Issue |
11 |
Pages |
P11021 - 13pp |
| Keywords |
Optical detector readout concepts; Solid state detectors; Dark Matter detectors (WIMPS, axions, etc); Double-beta decay detectors |
| Abstract |
Metalenses are optical devices that implement nanostructures as phase shifters to focus incident light. Their compactness and simple fabrication make them a potential cost-effective solution for increasing light collection efficiency in particle detectors with limited photosensitive area coverage. Here we report on the characterization and performance of metalenses in increasing the light collection efficiency of silicon photomultipliers (SiPM) of various sizes using an LED of 630 nm, and find a six to seven-fold increase in signal for a 1.3 x 1 3 mm(2) SiPM when coupled with a 10-mm-diameter metalens manufactured using deep ultraviolet stepper lithography. Such improvements could be valuable for future generations of particle detectors, particularly those employed in rare-event searches such as dark matter and neutrinoless double beta decay. |
| Address |
[Villalpando, A. A. Loya; Martin-Albo, J.; Guenette, R.; Lego, C.] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA, Email: aloyavil@caltech.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 |
1748-0221 |
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:000595650800009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4634 |
| Permanent link to this record |
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| Author |
Villaescusa-Navarro, F. et al; Villanueva-Domingo, P. |
| Title |
The CAMELS Multifield Data Set: Learning the Universe's Fundamental Parameters with Artificial Intelligence |
Type |
Journal Article |
| Year |
2022 |
Publication |
Astrophysical Journal Supplement Series |
Abbreviated Journal |
Astrophys. J. Suppl. Ser. |
| Volume |
259 |
Issue |
2 |
Pages |
61 - 14pp |
| Keywords |
|
| Abstract |
We present the Cosmology and Astrophysics with Machine Learning Simulations (CAMELS) Multifield Data set (CMD), a collection of hundreds of thousands of 2D maps and 3D grids containing many different properties of cosmic gas, dark matter, and stars from more than 2000 distinct simulated universes at several cosmic times. The 2D maps and 3D grids represent cosmic regions that span similar to 100 million light-years and have been generated from thousands of state-of-the-art hydrodynamic and gravity-only N-body simulations from the CAMELS project. Designed to train machine-learning models, CMD is the largest data set of its kind containing more than 70 TB of data. In this paper we describe CMD in detail and outline a few of its applications. We focus our attention on one such task, parameter inference, formulating the problems we face as a challenge to the community. We release all data and provide further technical details at https://camels-multifield-dataset.readthedocs.io. |
| Address |
[Villaescusa-Navarro, Francisco; Nicola, Andrina; Spergel, David N.; Matilla, Jose Manuel Zorrilla; Shao, Helen] Princeton Univ, Dept Astrophys Sci, Peyton Hall, Princeton, NJ 08544 USA, Email: villaescusa.francisco@gmail.com |
| 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 |
|
| ISSN |
0067-0049 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
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Conference |
|
| Notes |
WOS:000780035300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5194 |
| Permanent link to this record |
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| Author |
Villaescusa-Navarro, F. et al; Villanueva-Domingo, P. |
| Title |
The CAMELS Project: Public Data Release |
Type |
Journal Article |
| Year |
2023 |
Publication |
Astrophysical Journal Supplement Series |
Abbreviated Journal |
Astrophys. J. Suppl. Ser. |
| Volume |
265 |
Issue |
2 |
Pages |
54 - 14pp |
| Keywords |
Cosmology; Hydrodynamical simulations; Astrostatistics; Galaxy formation |
| Abstract |
The Cosmology and Astrophysics with Machine Learning Simulations (CAMELS) project was developed to combine cosmology with astrophysics through thousands of cosmological hydrodynamic simulations and machine learning. CAMELS contains 4233 cosmological simulations, 2049 N-body simulations, and 2184 state-of-the-art hydrodynamic simulations that sample a vast volume in parameter space. In this paper, we present the CAMELS public data release, describing the characteristics of the CAMELS simulations and a variety of data products generated from them, including halo, subhalo, galaxy, and void catalogs, power spectra, bispectra, Lya spectra, probability distribution functions, halo radial profiles, and X-rays photon lists. We also release over 1000 catalogs that contain billions of galaxies from CAMELS-SAM: a large collection of N-body simulations that have been combined with the Santa Cruz semianalytic model. We release all the data, comprising more than 350 terabytes and containing 143,922 snapshots, millions of halos, galaxies, and summary statistics. We provide further technical details on how to access, download, read, and process the data at . |
| Address |
[Villaescusa-Navarro, Francisco; Genel, Shy; Angles-Alcazar, Daniel; Hassan, Sultan; Pisani, Alice; Wong, Kaze W. K.; Coulton, William R.; Steinwandel, Ulrich P.; Spergel, David N.; Burkhart, Blakesley; Wandelt, Benjamin; Somerville, Rachel S.; Bryan, Greg L.; Li, Yin] Flatiron Inst, Ctr Computat Astrophys, 162 5th Ave, New York, NY 10010 USA, Email: camel.simulations@gmail.com |
| 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 |
0067-0049 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000964876300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5525 |
| Permanent link to this record |
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| Author |
Vijande, J.; Tedgren, A.C.; Ballester, F.; Baltas, D.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; De Werd, L.; Perez-Calatayud, J. |
| Title |
Source strength determination in iridium-192 and cobalt-60 brachytherapy: A European survey on the level of agreement between clinical measurements and manufacturer certificates |
Type |
Journal Article |
| Year |
2021 |
Publication |
Physics and Imaging in Radiation Oncology |
Abbreviated Journal |
Phys. Imag. Radiat. Oncol. |
| Volume |
19 |
Issue |
|
Pages |
108-111 |
| Keywords |
RAKR; Calibration; HDR; PDR; Brachytherapy |
| Abstract |
Background and purpose: Brachytherapy treatment outcomes depend on the accuracy of the delivered dose distribution, which is proportional to the reference air-kerma rate (RAKR). Current societal recommendations require the medical physicist to compare the measured RAKR values to the manufacturer source calibration certificate. The purpose of this work was to report agreement observed in current clinical practice in the European Union. Materials and methods: A European survey was performed for high- and pulsed-dose-rate (HDR and PDR) highenergy sources (Ir-192 and Co-60), to quantify observed RAKR differences. Medical physicists at eighteen hospitals from eight European countries were contacted, providing 1,032 data points from 2001 to 2020. Results: Over the survey period, 77% of the Ir-192 measurements used a well chamber instead of the older Krieger phantom method. Mean differences with the manufacturer calibration certificate were 0.01% +/- 1.15% for Ir-192 and -0.1% +/- 1.3% for Co-60. Over 95% of RAKR measurements in the clinic were within 3% of the manufacturer calibration certificate. Conclusions: This study showed that the agreement level was generally better than that reflected in prior societal recommendations positing 5%. Future recommendations on high-energy HDR and PDR source calibrations in the clinic may consider tightened agreements levels. |
| Address |
[Vijande, Javier; Ballester, Facundo] Univ Valencia UV, Dept Fis Atom Mol & Nucl, Burjassot, Spain, Email: Javier.vijande@uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier |
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 |
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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:000694711800017 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4969 |
| Permanent link to this record |
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| Author |
Viegas, R.; Roser, J.; Barrientos, L.; Borja-Lloret, M.; Casaña, J.V.; Lopez, J.G.; Jimenez-Ramos, M.C.; Hueso-Gonzalez, F.; Ros, A.; Llosa, G. |
| Title |
Characterization of a Compton camera based on the TOFPET2 ASIC |
Type |
Journal Article |
| Year |
2023 |
Publication |
Radiation Physics and Chemistry |
Abbreviated Journal |
Radiat. Phys. Chem. |
| Volume |
202 |
Issue |
|
Pages |
110507 - 11pp |
| Keywords |
Compton camera; Hadron therapy; LaBr3; PETsys TOFPET2; Silicon photomultipliers |
| Abstract |
The use of Compton cameras for medical imaging and its interest as a hadron therapy treatment monitoring has increased in the last decade with the development of silicon photomultipliers. MACACOp is a Compton camera prototype designed and assembled at the IRIS group of IFIC-Valencia. This Compton camera is based on monolithic Lanthanum (III) Bromide crystals and silicon photomultipliers, and employs the novel TOFPET2 ASIC as readout electronics. This system emerged as an alternative to MACACO II prototype, with the aim of improving its limited time resolution. To test the performance of the ASIC in a Compton camera setup, the prototype was characterized, both in laboratory and in-beam. A time resolution of 1.5 ns was obtained after time corrections, which improves greatly the performance of the MACACO II. Moreover, the results obtained at high photon energies demonstrate the ability of the system to obtain 1 mm displacements of the reconstructed spots. The results reinforce the potential of the system as a monitoring device for hadron therapy. |
| Address |
[Viegas, R.; Roser, J.; Barrientos, L.; Borja-Lloret, M.; Casana, J., V; Hueso-Gonzalez, F.; Ros, A.; Llosa, G.] CSIC UV, Inst Fis Corpuscular IFIC, Valencia, Spain, Email: Rita.Viegas@ific.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Pergamon-Elsevier Science 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 |
0969-806x |
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:000870840600006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5392 |
| Permanent link to this record |
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| Author |
Vidaña, I.; Feijoo, A.; Albaladejo, M.; Nieves, J.; Oset, E. |
| Title |
Femtoscopic correlation function for the Tcc(3875)+ state |
Type |
Journal Article |
| Year |
2023 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
846 |
Issue |
|
Pages |
138201 - 9pp |
| Keywords |
Femtoscopy; Tcc |
| Abstract |
We have conducted a study of the femtoscopic correlation functions for the D0D*+ and D+D*0 channels that build the Tcc state. We develop a formalism that allows us to factorize the scattering amplitudes outside the integrals in the formulas, and the integrals involve the range of the strong interaction explicitly. For a source of size of 1 fm, we find values for the correlation functions of the D0D*+ and D+D*0 channels at the origin around 30 and 2.5, respectively, and we see these observables converging to unity already for relative momenta of the order of 200 MeV. We conduct tests to see the relevance of the different contributions to the correlation function and find that it mostly provides information on the scattering length, but should the correlation functions be measured with the precision of the latest experiments, the effective range of the D0D*+ could also be obtained. |
| Address |
[Vidana, I.] Univ Catania, Ist Nazl Fis Nucl, Dipartimento Fis Ettore Majorana, Sez Catania, Via Santa Sofia 64, I-95123 Catania, Italy, Email: isaac.vidana@ct.infn.it |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier |
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 |
0370-2693 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:001092697200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5777 |
| Permanent link to this record |
