Publications de Andreas Pautz | EPFL Graph Search

Publications associées (121)

Design and Simulation of Gamma Spectrometry Experiments in the CROCUS Reactor

Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, Oskari Ville Pakari, Fanny Vitullo

Gamma rays in nuclear reactors, arising either from fission or decay processes, significantly contribute to the heating and dose of the reactor components. Zero power research reactors offer the possibility to measure gamma rays in a purely neutronic envir ...

E D P SCIENCES2020

Measurement of the Prompt Neutron Decay Constant in a Zero-Power Reactor Using a Novel 3D Detector System

Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, Oskari Ville Pakari, Fanny Vitullo, Michel Saliba

Analyzing neutron noise in zero-power reactors provides information about integral parameters, such as the prompt decay constant

\alpha

alpha. This information can be used to validate codes that predict said parameters, or time-dependent behavior, part ...

TAYLOR & FRANCIS INC2025

Design of Separated Element Reflector Experiments in CROCUS: PETALE

Andreas Pautz, Mathieu Hursin, Vincent Pierre Lamirand, Pavel Frajtag, Daniel Jerôme Siefman, Stefan Radman

The present article describes the preliminary design studies for an oncoming experimental programme at the CROCUS facility. CROCUS is a teaching and research zero-power reactor operated by the Laboratory for Reactor Physics and Systems Behaviour (LRS) at t ...

2017

A mm(3) Fiber-Coupled Scintillator for In-Core Thermal Neutron Detection in CROCUS

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari, Pavel Frajtag, Fanny Vitullo, Jean-Baptiste Mosset

This article presents the development, full-characterization, and in-core testing of a miniature neutron detector for the investigation of highly localized in-core neutronics effects in the zero-power reactor CROCUS, operated at the Ecole Polytechnique fed ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Characterization of High Harmonic Frequencies in Reactor Noise Experiments Within the CORTEX Project

Andreas Pautz, Vincent Pierre Lamirand

We present a novel technique of neutron noise detection and experimental data interpretation developed during the EU H2020 project CORTEX aiming to improve the capabilities for identification and localization of neutron noise sources. The experimental data ...

2022

Modeling the response of a diamond detector in the zero power reactor CROCUS

Andreas Pautz, Mathieu Hursin, Vincent Pierre Lamirand, Pavel Frajtag

The present manuscript documents the development of a practical calculation scheme to model the response of a diamond detector in the mixed (neutron and gamma) radiation field of the CROCUS experimental reactor at EPFL. The model is shown to perform reason ...

SPRINGER HEIDELBERG2021

Investigation of spatial effects on neutron noise measurements in the zero power reactor CROCUS

Andreas Pautz, Mathieu Hursin, Vincent Pierre Lamirand, Oskari Ville Pakari, Pavel Frajtag, Daniel Godat

This article presents the results of an experimental campaign in the CROCUS zero power reactor aimed at investigating the spatial effects of neutron noise measurements. Neutron noise measurements offer a non-invasive method to determine kinetic reactor par ...

American Nuclear Society2018

Measurement of the Gas Velocity in a Water-Air Mixture in CROCUS Using Neutron Noise Techniques

Andreas Pautz, Mathieu Hursin, Vincent Pierre Lamirand, Oskari Ville Pakari, Pavel Frajtag

The possibility of measuring the gas-phase velocity in a two-phase mixture through the use of neutron noise techniques is demonstrated in the zero-power reactor CROCUS of the Ecole Polytechnique Federale de Lausanne. It is the first step toward the experim ...

TAYLOR & FRANCIS INC2020

Kinetic Parameter Measurements in the CROCUS Reactor Using Current Mode Instrumentation

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari, Pavel Frajtag

This paper is an overview of developments and results regarding neutron noise measurements in current mode at the CROCUS zero power facility. Neutron noise measurements offer a noninvasive method to determine kinetic reactor parameters such as the prompt d ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2018

Hybrid halide perovskite neutron detectors

László Forró, Andreas Pautz, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Pavel Frajtag, Márton Kollár, Pavao Roko Andricevic

Interest in fast and easy detection of high-energy radiation (x-, gamma-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide pe ...

Nature Portfolio2021

Measurement of the Prompt Decay Constant in a Zero Power Reactor Using a Novel 3D Detector System

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari, Michel Saliba

Analyzing neutron noise in zero power reactors is a valuable tool for gaining insights into integral parameters, such as the prompt decay constant α. This information can be used to validate codes that predict said parameters, or time-dependent behavior, p ...

American Nuclear Society2024

Towards the Validation of Noise Experiments in the CROCUS Reactor Using the TRIPOLI-4 Monte Carlo Code in Analog Mode

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari

Intrinsic neutron noise experiments offer a non-invasive manner to measure the prompt decay constant or reactivity of fissile systems. Using the fluctuations in the density of fission chains, one can infer the kinetics parameters via correlation analysis s ...

2021

A coarse-mesh methodology for modelling of single-phase thermal-hydraulics of ESFR innovative assembly design

Andreas Pautz, Konstantin Mikityuk, Carlo Fiorina, Stefan Radman

The GeN-Foam multi-physics code enables coupled thermal-hydraulic, neutronic, and thermal-mechanical analysis of fast reactor cores with 3-D unstructured deformable meshes. Advances within the Horizon2020 ESFR-SMART project, as well as trends towards highe ...

ELSEVIER SCIENCE SA2019

Neutron-Gamma Noise Measurements in a Zero-Power Reactor Using Organic Scintillators

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari

Noise measurements in light water reactor systems aid in generating validation data for integral point kinetic parameter predictions and generating monitoring parameters for reactor safety and safeguards. The CROCUS zero-power reactor has been used to supp ...

Ieee-Inst Electrical Electronics Engineers Inc2024

High accuracy measurement of the prompt neutron decay constant in CROCUS using Gamma Noise and bootstrapped uncertainties

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari, Pavel Frajtag, Tom Mager

We experimentally demonstrate the advantages of gamma detection for noise measurements to deter-mine the prompt neutron decay constant a of a nuclear reactor using the power spectral density (PSD) method, coupled to a new uncertainty estimation scheme base ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Intra-pin Reaction Rate Measurements in the CROCUS Experimental Reactor

Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, Oskari Ville Pakari, Thomas Jean-François Ligonnet, Tom Mager

In response to the need for validating high-fidelity deterministic neutronics solvers capable of providing pin-resolved neutron flux distributions, intra-pin reaction rates measurements were performed in the CROCUS experimental reactor. A specially designe ...

2024

Stochastic vs. sensitivity-based integral parameter and nuclear data adjustments

Andreas Pautz, Mathieu Hursin, Dimitri Rochman, Daniel Jerôme Siefman

Developments in data assimilation theory allow to adjust integral parameters and cross sections with stochastic sampling. This work investigates how two stochastic methods, MOCABA and BMC, perform relative to a sensitivity-based methodology called GLLS. St ...

SPRINGER HEIDELBERG2018

Design of an Open-Loop Pile-Oscillation Program in the CROCUS Reactor

Andreas Pautz, Vincent Pierre Lamirand, Axel Guy Marie Laureau, Thomas Jean-François Ligonnet

As a follow-up to the CEA-EPFL PETALE experimental program on stainless steel nuclear data, the EPFL initiated an open-loop pile-oscillation experimental program in the CROCUS reactor: BLOOM. A reproduction of the critical experiments of PETALE, the progra ...

2024

Future experimental programmes in the CROCUS reactor

Andreas Pautz, Mathieu Hursin, Vincent Pierre Lamirand, Oskari Ville Pakari, Pavel Frajtag

CROCUS is a teaching and research zero-power reactor operated by the Laboratory for Reactor Physics and Systems Behaviour (LRS) at the Swiss Federal Institute of Technology (EPFL). Three new experimental programmes are scheduled for the forthcoming years. ...

2016

Data assimilation of post-irradiation examination data for fission yields from GEF

Andreas Pautz, Mathieu Hursin, Dimitri Rochman, Daniel Jerôme Siefman

Nuclear data, especially fission yields, create uncertainties in the predicted concentrations of fission products in spent fuel which can exceed engineering target accuracies. Herein, we present a new framework that extends data assimilation methods to bur ...

EDP SCIENCES S A2020