Artículos (Física Aplicada I)

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10Be low-energy AMS with the passive absorber technique
(ScienceDirect, 2019-01) Scognamiglio, Grazia; Lachner, J.; Chamizo Calvo, Elena; López Gutiérrez, José María; Priller, A.; Universidad de Sevilla. Departamento de Física Aplicada I; Ministerio de Economía y Competitividad (MINECO). España
The passive absorber technique is one of the most common ways to suppress the 10B interference during 10Be measurements at facilities working with beam energies above 7 MeV. At lower energies, the range straggling complicates the application of absorbers, so that other suppression techniques are normally preferred. Several experiments were conducted at the SARA (hosted at Centro Nacional de Aceleradores, Seville, Spain) and VERA (Faculty of Physics, University of Vienna, Austria) AMS facilities to demonstrate the potential of the passive absorber technique also at and below 2.4 MeV. Two different absorber setups were installed and tested. For the detection of the rare isotopes both facilities used a gas ionization chamber optimized for light ions detection based on the same design. The absorber installed at the SARA facility was a combination of SiN foils and an isobutane gas volume, whereas VERA was equipped with an absorber constituted of a stack of SiN foils. In both cases, 10Be could be clearly separated from 10B and the use of a passive absorber at the entrance of the detector gave higher transmission compared to the degrader method. Depending on the absorber design, different background contributions could be identified: Rutherford scattering of 10B on the protons contained in the SiN foils and isobutane gas was responsible of a severe background at SARA, and fragments from 9Be1H molecules surviving the stripping process resulted in events partially overlapping the 10Be gate at VERA. The measured transmissions and background levels will be presented for the tested setups, as well as the advantages and disadvantages of each absorber design.
129I in sediment cores from the Celtic Sea by AMS through a microwave digestion process
(Elsevier, 2022) Lérida Toro, Victoria; Abascal Ruíz, Unai; Villa Alfageme, María; Klar, Jessica K.; Hicks, Natalie; López Gutiérrez, José María; Universidad de Sevilla. Departamento de Física Aplicada II; Universidad de Sevilla. Departamento de Física Aplicada I
Radiochemical methods before measurement are indispensable to determine Iodine-129 by Accelerator Mass Spectrometry (AMS) in environmental samples. In particular, in sediments, iodine is associated with both inorganic and organic matter, and it presents in several chemical forms. Therefore, the radiochemical procedure must be designed to extract all the different iodine species from the matrix, whilst being as robust and time effective as possible. In this work, different microwave digestion methods, together with the processing of the iodine species to be measured by AMS, were tested and their performances are presented here. Two sediment cores, one with muddy sediment (core A) and one with permeable sandy sediment (core I), collected in the Celtic Sea, were used and the results were evaluated to determine an optimized iodine extraction. The method consisted of a microwave digestion with concentrated nitric acid followed by a double liquid–liquid extraction and the final precipitation of silver iodide (AgI), required to measure iodine by AMS. Back extraction of iodine in a reducing solution during purification was carried out with hydrazine (NH2-NH2). Subsequent additional steps were added to optimize all iodine species extraction. First, hydrochloric hydroxylamine (NH2OH⋅HCl) and so dium bisulfite (Na2S2O5) were used to homogenize all iodine species before extraction through a redox process. Second, sodium hypochlorite (NaOCl) was added to remove any final organic matter after digestion. The final method incorporated sodium hydroxide (NaOH) combined with NaOCl to facilitate reduction of iodine in so lution and enhance the NaOCl effect. The different methods were validated against an internal standard and the last method was chosen, as it showed the most reproducible and accurate results. As practical application, Iodine129 concentration from both cores were compared, showing concentrations between 0.19 × 1012 at/kg and 7.16 × 1012 at/kg for core A and between 0.28 × 1012 at/kg and 2.40 × 1012 at/kg for core I. Despite the 129I diffusion detected in the deeper layers, depth profiles accurately reproduced Sellafield discharges, which is the nuclear fuel reprocessing plant closest to the cores.
210Pb distribution in riverwaters and sediments near phosphate fertilizer factories
(Elsevier, 1996) Martínez Aguirre, Aránzazu; García León, Manuel; Universidad de Sevilla. Departamento de Física Aplicada I; Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear; European Union (UE)
two fertilizer factories operate at the estuary formed by the Odiel and Tinto rivers in Southwestern Spain. In previous work the authors have shown that such operation enhances the natural radionuclide background of the sea. Thus, fairly high levels of U, Th and Ra-isotopes were found in water and sediment samples taken from the estuary. In this paper, we have extended the study to investigate the presence of 210Pb in the dissolved aqueous phase of the river and in bottom sediments. Significant enhancement of 210Pb concentrations have been detected confirming the previously reported results.
210Pb enhancement in rivers affected by the phosphate rock processing in southwestern Spain
(Elsevier, 1997) Martínez Aguirre, Aránzazu; García León, Manuel; Universidad de Sevilla. Departamento de Física Aplicada I; Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear; Dirección General de Investigación Científica y Técnica (DGICYT). España; European Union (UE)
The activity levels of 210Pb in solution and bottom sediments were measured in the estuary formed by the Odiel and Tinto rivers in southwest Spain. The levels in both water and sediment samples indicate that the discharges from two fertilizer factories in the area enhance the radioactivity of such samples.
210Pb-based dating of recent sediments with the χ-mapping version of the Constant Sediment Accumulation Rate (CSAR) model
(Elsevier, 2023) Abril Hernández, José María; Universidad de Sevilla. Departamento de Física Aplicada I
The 210Pb-based method aims at determining the absolute age of recent sediments on the centennial scale. A family of models assumes that at the sediment-water interface the flux of unsupported 210Pb ( 210Pbexc), F, relates to its initial activity concentration, Ao, and the mass sedimentation rate, w, as: F = Aow. Additional specific assumptions that allow for analytical formulations of the models are: i) constant Ao (CIC), constant F (CF), and constant F with constant w (CFCS). A model with constant w (CSAR) was suggested for completeness but never used because of the lack of a suitable analytical formulation. The TERESA model assumes random and independent variability for Ao and w, described by normal distributions. It systematically generates a large number (~105 ) of potential solutions, whose performance for fitting the empirical 210Pbexc profile is quantified through the χ-function. This work aims to adapt the above methodology to formulate the χ-mapping version of the CSAR model. The performance of the model is evaluated with a set of synthetic and real cores for which an independent chronology is available. CSAR is able to capture the mean sedimentation rate from the 210Pbexc data and provides reliable chronologies and paleorecords of Ao, useful for tracking past changes in sedimentary conditions. CSAR provides an interesting different perspective for researchers working with 210Pb-based dating of recent sediments.
210Pb-based dating of recent sediments with χ-mapping versions of the CFCS, CIC, CF and TERESA models
(Elsevier, 2023) Abril Hernández, José María; Universidad de Sevilla. Departamento de Física Aplicada I
The 210Pb-based method allows for absolute age determination in recent sediments on the centennial scale. The most common sedimentary scenarios involve ideal deposition without any further redistribution. The conventional models apply to such conditions by adding specific assumptions that allow analytical formulations: constant flux (CF), constant initial concentration (CIC), and constant flux with constant sedimentation (CFCS). The χ-mapping models are presented as a novel methodological approach. They generate a large number (105 to 106 ) of potential solvers, consisting of sets of n (the number of slices in the core) values of initial activity concentrations, A0, and sedimentation rates, w. Empirical data serve to attract the solver that minimizes a χ function after encountering the best sorting along the core of the A0 and w values. The specific assumptions of the above models are reformulated in terms of the statistical distributions of A0 and w. The performance of the χ-mapping versions is demonstrated with a set of cores from the literature with independent chronologies. The main advantages compared to known analytical formulations are: i) χ-mapping provides a more robust fitting method. ii) It overcomes the problem of age reversals often found in the CIC model. iii) The CF model successfully applies to cores with unsteady and/or incomplete inventories. iv) The TERESA model (time estimates from random entries of sediments and activities), without analytical counterpart, is the only model that can manage continuous trends of change in the fluxes of unsupported 210Pb. The work discusses the conditions for compensating model errors in the chronologies, and the use of the palaeorecords of fluxes, A0 and w. The methodology can be extended to other assumptions (models) and provides novel and insightful views on the 210Pb-based dating of recent sediments.
210Pb-dating of sediments with models assuming a constant flux: CFCS, CRS, PLUM, and the novel χ-mapping. Review, performance tests, and guidelines
(Elsevier, 2023) Abril Hernández, José María; Universidad de Sevilla. Departamento de Física Aplicada I
The 210Pb-based method has been widely used for five decades to determine absolute ages in recent sediments on the centennial scale. Decoding a chronology from the empirical data set requires a series of assumptions that define a mathematical model of the sedimentary conditions. This work aims to provide a comprehensive review of the fundamentals of the existing family of models assuming a constant flux of excess 210Pb at the sediment surface, namely the CFCS, CRS, and PLUM models, and to present the novel χ-mapping versions of the CFCS and CF models. Their performance is assessed with a selected group of five cores from literature data, with varve chronologies or independent time marks. The PLUM model did not produce reliable chronologies in any of the cores studied. The CRS model is too sensitive to an accurate estimation of the total inventory. A weighted-fit and the χ-mapping versions of the CFCS model are prone to over-represent the younger regions of the core. The CFCS model with least squares fitting and the χ-CF models performed best under the most common sedimentary conditions, which involve temporal variability in the fluxes randomly distributed in the time line. A practical strategy is suggested to identify the occurrence of such sedimentary conditions through the combined use of a set of models, providing this way further strength to the 210Pb-dating.
239Pu sorption by suspended matter from Hueznar reservoir (southern Spain): Experimental and modelling study
(E. D. P. Sciences, 2005) El Mrabet, Rachid; Barros Rojas, Haydn; Abril Hernández, José María; Manjón Collado, Guillermo; García-Tenorio García-Balmaseda, Rafael; Universidad de Sevilla. Departamento de Física Aplicada I; Universidad de Sevilla. Departamento de Física Aplicada II; ENRESA
Kinetic transfer coefficients are important parameters to understand and reliably model the behaviour of non-conservative radionuclides in aquatic environments. This report pertains to a series of radiotracer experiments on 239Pu uptake in natural unfiltered waters from the Hueznar reservoir (southern Spain). The experimental procedure ensures the preservation of environmental conditions and the dissolved Pu activity was measured by liquid scintillation technique. The data suggest that the main pathways for Pu uptake consist of two parallel and reversible reactions. We studied the effects of suspended matter concentrations and the specific surface area on the kinetic transfer coefficients.
2D compositional self-patterning in magnetron sputtered thin films
(Elsevier B.V., 2019-06-30) García Valenzuela, Aurelio; Álvarez Molina, Rafael; Rico, Víctor; Espinos, Juan P.; López Santos, Carmen; Solís, Javier; Siegel, Jan; del Campo, Adolfo; Palmero Acebedo, Alberto; González Elipe, Agustín Rodríguez; Universidad de Sevilla. Departamento de Física Aplicada I; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Ministerio de Economia, Industria y Competitividad (MINEICO). España; Universidad de Sevilla
Unlike topography patterning, widely used for numerous applications and produced by means of different technologies, there are no simple procedures to achieve surface compositional patterning at nanometric scales. In this work we have developed a simple method for 2D patterning the composition of thin films. The method relies on the magnetron sputtering deposition at oblique angles onto patterned substrates made by laser induced periodic surface structures (LIPSS). The method feasibility has been demonstrated by depositing SiOx thin films onto LIPSS structures generated in Cr layers. A heterogeneous and aligned distribution of O/Si ratios (and different Si n+ chemical states) along the LIPSS structure in length scales of some hundreds nm's has been proven by angle resolved X-ray photoelectron spectroscopy and a patterned arrangement of composition monitored by atomic force microscopy-Raman analysis. The obtained results are explained by the predictions of a Monte Carlo simulation of this deposition process and open the way for the tailored one-step fabrication of surface devices with patterned compositions.
A 210Pb-based chronological model for recent sediments with random entries of mass and activities: Model development
(Elsevier, 2016) Abril Hernández, José María; Universidad de Sevilla. Departamento de Física Aplicada I; Ministerio de Economía y Competitividad (MINECO). España; Universidad de Sevilla. RNM-138: Física Nuclear Aplicada
Unsupported 210Pb (210Pbexc) vs. mass depth profiles do not contain enough information as to extract a unique chronology when both, 210Pbexc fluxes and mass sediment accumulation rates (SAR) independently vary with time. Restrictive assumptions are needed to develop a suitable dating tool. A statistical correlation between fluxes and SAR seems to be a quite general rule. This paper builds up a new 210Pb-based dating tool by using such a statistical correlation. It operates with SAR and initial activities that closely follow normal distributions, what leads to the expected correlation between fluxes and SAR. An intelligent algorithm solves their best arrangement downcore to fit the experimental 210Pbexc vs. mass depth profile, generating then solutions for the chronological line, and for the histories of SAR and fluxes. Parametric maps of a χ-function serve to find out the solution and to support error estimates. Optionally, the model's answers can be better constrained through the use of time markers. The performance of the model is illustrated with a synthetic core, and with real cases using published data for varved sediment cores.
A 4-view imaging to reveal microstructural differences in obliquely sputter-deposited tungsten films
(Elsevier B.V., 2020-04-01) El Beainou, Raya; García Valenzuela, Aurelio; Raschetti, Marina; Cote, Jean Marc; Álvarez Molina, Rafael; Palmero Acebedo, Alberto; Potin, Valérie; Martin, Nicolas; Universidad de Sevilla. Departamento de Física Aplicada I
We report on the morphological disparity of the columnar growth in W thin films sputter-deposited by oblique angle deposition. Oriented tungsten thin films (400 ± 50 nm thick) are prepared using a tilt angle α of 80° and a sputtering pressure of 0.25 Pa. Inclined columns (β = 38 ± 2°) are produced and the microstructure is observed by scanning electron microscopy. A 4-view imaging is performed in order to show inhomogeneous growing evolutions in the columns. Morphological features vs. viewing direction are also investigated from a growth simulation of these tilted W columns. Experimental and theoretical approaches are successfully compared and allow understanding how the direction of the W particle flux leads to dense or fibrous morphologies, as the column apexes are in front of the flux or in the shadowing zone.
A 40-year retrospective European radon flux inventory including climatological variability
(PERGAMON-ELSEVIER SCIENCE LTD, 2013) López Coto, I.; Más Balbuena, José Luis; Bolivar, J. P.; Universidad de Sevilla. Departamento de Física Aplicada I
In this work, a 40-year retrospective European radon flux inventory has been calculated. Average values of the radon exhalation rate, probability distributions and seasonal fluctuations have been obtained. To achieve this, a numerical model of radon transport through finite, heterogeneous and porous media has been implemented, enabling us to calculate the radon exhalation rate of European soils with a horizontal resolution of 0.5' (~1km). Geological, geochemical and climatological parameters derived from European and international databases (FOREGS, HWSD, ERA-40) have been coupled to the model.The theoretical model is based on the fundamental equation of radon transport in porous media, taking into account the dependency of the transport coefficient on temperature and humidity. It also includes a simple model that evaluates the effect of snow cover. In general, the results show wide variations depending on location and season of the year, with a spatial standard deviation close to the annual average value (30Bqm-2h-1) In turn, the seasonal deviation is about 25% of the annual average value.The inventory can be easily integrated into atmospheric transport models acting as baseline that could be used for policy decisions regarding the identification of areas with a high risk of exposure to radon. The gridded data are available for the scientific community upon request. The limitations and sources of errors and uncertainties of the model are also discussed in detail.
A comparison between active and passive techniques for measurements of radon emanation factors
(PERGAMON-ELSEVIER SCIENCE LTD, 2009) López Coto, I.; Más Balbuena, José Luis; San Miguel, E. G.; Bolivar, J. P.; Sengupta, D.; Universidad de Sevilla. Departamento de Física Aplicada I
Some radon related parameters have been determined through two different techniques (passive and active) in soil and phosphogypsum samples. Emanation factors determined through these techniques show a good agreement for soil samples while for phosphogympsum samples appear large discrepancies. In this paper, these discrepancies are analyzed and explained if non-controlled radon leakages in the passive technique are taken into account.
A comparison of 210Pbxs, 137Cs, and Pu isotopes as proxies of soil redistribution in South Spain under severe erosion conditions
(Springer, 2023-06-01) Peñuela Fernández, Andrés; Hurtado Bermúdez, Santiago José; García Gamero, Vanesa; Más Balbuena, José Luis; Ketterer, M. E.; Vanwalleghem, Tom; Gómez Calero, José Alfonso; Universidad de Sevilla. Departamento de Física Aplicada II; Universidad de Sevilla. Departamento de Física Aplicada I; Ding, Shiming; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; Universidad de Sevilla; Universidad de Sevilla. RNM138: Física Nuclear Aplicada
Purpose The use of fallout radionuclides as proxies for the study of soil redistribution processes in semiarid environments of Southern Spain has been restricted to 137Cs. The potential and limitations of alternative proxies such as 239+240Pu and 210Pbxs should be explored given the expected constrains imposed by the features of the study area. Materials and methods Four soil and one sediment cores were collected in a highly eroded area to test the feasibility of these proxies under demanding conditions. The use of gamma spectrometry and ICP-MS did allow exploring the potential of 210Pbxs and Pu isotopes against the well-established tracer, 137Cs. The activity ratios 239+240Pu/137Cs were explored to evaluate the previous evolution of the sampling sites. Soil redistribution rates were estimated using the model MODERN. Results and discussion Despite all the profles showed intense perturbation, Pu isotopes showed the highest potential thanks to higher sensitivity and sample throughput. The deviations of 239+240Pu/137Cs inventory ratios (0.012–0.158) from the global fallout average (0.026±0.003) suggest that the sediment core was a deposition site involving alternate episodes of topsoil removal and incorporation from diferent sources. The calculated erosion rates ranged 34–43 t ha−1 year−1, being in good agreement for 137Cs and 239+240Pu. 210Pbxs was not used due to low-quality data. Conclusions The use of Pu as a tracer of soil redistribution processes in semiarid areas seems to be promising even under severe erosion conditions. The use of 210Pbxs is not recommended in this area due to its low concentration.
A comparison of marine radionuclide dispersion models for the Baltic Sea in the frame of IAEA MODARIA program
(Elsevier, 2015) Periáñez Rodríguez, Raúl; Bezhenar, R.; Iosjpe, Mikhail; Maderich, V.; Nies, Hartmut; Osvath, Iolanda; Outola, I.; With, G. de; Universidad de Sevilla. Departamento de Física Aplicada I; European Union (UE); Universidad de Sevilla. RNM138: Física Nuclear Aplicada
Four radionuclide dispersion models have been applied to simulate the transport and distribution of 137Cs fallout from Chernobyl accident in the Baltic Sea. Models correspond to two categories: box models and hydrodynamic models which solve water circulation and then an advection/diffusion equation. In all cases, interactions of dissolved radionuclides with suspended matter and bed sediments are included. Model results have been compared with extensive field data obtained from HELCOM database. Inventories in the water column and seabed, as well as 137Cs concentrations along 5 years in water and sediments of several sub-basins of the Baltic, have been used for model comparisons. Values predicted by the models for the target magnitudes are very similar and close to experimental values. Results suggest that some processes are not very relevant for radionuclide transport within the Baltic Sea, for instance the roles of the ice cover and, surprisingly, water stratification. Also, results confirm previous findings concerning multi-model applications.
A comparison of radionuclide dispersion model performances for the Baltic Sea and Fukushima releases in the Pacific Ocean
(EDP Sciences, 2016) Periáñez Rodríguez, Raúl; Bezhenar, R.; Brovchenko, I.; Cuffa, D.; Iosjpe, M.; Jung, K. T.; Kobayashi, T.; Lamego, F.; Maderich, V.; Min, B. I.; Nies, H.; Osvath, Iolanda; Outola, I.; Psaltaki, M.; Suh, K. S.; With, G. de; Universidad de Sevilla. Departamento de Física Aplicada I; Universidad de Sevilla. RNM-138: Física Nuclear Aplicada
State-of-the art dispersion models were applied to simulate 137Cs dispersion from Chernobyl nuclear power plant disaster fallout in the Baltic Sea and from Fukushima Daiichi nuclear plant releases in the Pacific Ocean after the 2011 Tsunami. Models were of different nature, from box to full three-dimensional models, and included water/ sediment interactions. Agreement between models was very good in the Baltic. In the case of Fukushima, results from models could be considered to be in acceptable agreement only after a model harmonization process consisting of using exactly the same forcing (water circulation and parameters) in all models
A Deep Learning Approach for Molecular Classification Based on AFM Images
(MDPI, 2021-06) Carracedo-Cosme, Jaime; Romero-Muñiz, Carlos; Pérez Pérez, Rubén; Universidad de Sevilla. Departamento de Física Aplicada I; Comunidad de Madrid Industrial Doctorate Programme 2017 under reference number IND2017/IND-7793; Spanish MINECO Nd AEI/FEDER, UE project MAT2017-83273-R; Spanish Ministry of Science and Innovation, through the “María de Maeztu” Programme for Units of Excellence in R&D CEX2018-000805-M
In spite of the unprecedented resolution provided by non-contact atomic force microscopy (AFM) with CO-functionalized and advances in the interpretation of the observed contrast, the unambiguous identification of molecular systems solely based on AFM images, without any prior information, remains an open problem. This work presents a first step towards the automatic classification of AFM experimental images by a deep learning model trained essentially with a theoretically generated dataset. We analyze the limitations of two standard models for pattern recognition when applied to AFM image classification and develop a model with the optimal depth to provide accurate results and to retain the ability to generalize. We show that a variational autoencoder (VAE) provides a very efficient way to incorporate, from very few experimental images, characteristic features into the training set that assure a high accuracy in the classification of both theoretical and experimental images.
A description of bubble growth and gas release during thermal annealing of helium implanted copper
(ScienceDirect, 2004-04) Evans, J.H.; Escobar-Galindo, Ramón; Veen, A. van; Universidad de Sevilla. Departamento de Física Aplicada I
This paper describes an investigation into the migration and coalescence of equilibrium bubbles in helium implanted copper. Using computer simulation methods, the results indicate that when the swelling averaged over the implant depth approached 12%, the subsequent migration and coalescence leads to the unexpected formation of relatively massive bubbles with radii of the order of the helium range (∼130 nm), some 10 times the average bubble radius. Such behaviour would appear to provide an explanation for the surface pores and the large helium loss during annealing observed in the experimental results of Escobar Galindo et al. [Nucl. Instr. and Meth. B, in press].
A Holistic Solution to Icing by Acoustic Waves: De-Icing, Active Anti-Icing, Sensing with Piezoelectric Crystals, and Synergy with Thin Film Passive Anti-Icing Solutions
(Wiley-Blackwell, 2023) del Moral, Jaime; Montes, Laura; Rico Gavira, Victor Joaquin; López Santos, Carmen; Jacob, Stefan; Oliva Ramirez, Manuel; Gil Rostra, Jorge; Fakhfouri, Armaghan; Pandey, Shilpi; Gonzalez del Val, Miguel; González Elipe, Agustín Rodríguez; Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear; Universidad de Sevilla. Departamento de Física Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España; European Union (UE). H2020
Icing has become a hot topic both in academia and in the industry given its implications in transport, wind turbines, photovoltaics, and telecommunications. Recently proposed de-icing solutions involving the propagation of acoustic waves (AWs) at suitable substrates may open the path for a sustainable alternative to standard de-icing or anti-icing procedures. Herein, the fundamental interactions are unraveled that contribute to the de-icing and/or hinder the icing on AW-activated substrates. The response toward icing of a reliable model system consisting of a piezoelectric plate activated by extended electrodes is characterized at a laboratory scale and in an icing wind tunnel under realistic conditions. Experiments show that surface modification with anti-icing functionalities provides a synergistic response when activated with AWs. A thoughtful analysis of the resonance frequency dependence on experimental variables such as temperature, ice formation, or wind velocity demonstrates the application of AW devices for real-time monitoring of icing processes.
A Korteweg-de Vries description of dark solitons in polariton superﬂuids
(Elsevier, 2017) Carretero-González, Ricardo; Cuevas-Maraver, Jesús; Frantzeskakis, Dimitri J.; Horikis, T. P.; Kevrekidis, Panayotis G.; Rodrigues, Augusto S.; Universidad de Sevilla. Departamento de Física Aplicada I; Universidad de Sevilla. FQM280: Física no Lineal
We study the dynamics of dark solitons in an incoherently pumped exciton-polariton condensate by means of a system composed by a generalized open-dissipative Gross-Pitaevskii equation for the polaritons’ wavefunction and a rate equation for the exciton reservoir density. Considering a perturbative regime of suﬃciently small reservoir excitations, we use the reductive perturbation method, to reduce the system to a Korteweg-de Vries (KdV) equation with linear loss. This model is used to describe the analytical form and the dynamics of dark solitons. We show that the polariton ﬁeld supports decaying dark soliton solutions with a decay rate determined analytically in the weak pumping regime. We also ﬁnd that the dark soliton evolution is accompanied by a shelf, whose dynamics follows qualitatively the eﬀective KdV picture.

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