E. Passoth - Academia.edu (original) (raw)

Papers by E. Passoth

Research paper thumbnail of HNPS 2016 Sponsors

Accelerator-based atomic physics is a mature field that started in the ‘60s by experimental nucle... more Accelerator-based atomic physics is a mature field that started in the ‘60s by experimental nuclear physicists looking for new research directions in both basic and applied acceleratorbased physics. Presently, it is particularly strong in the EU with important contributions to fusion, hot plasmas, astrophysics, accelerator technology and basic atomic physics of ion-atom collision dynamics, structure and technology. After presenting some of the basic parameters of interest in this field I shall try to give a flavor of how things work by discussing in more detail the ongoing APAPES1 project at the Demokritos Tandem, while at the same time bringing out similarities and differences with acceleratorbased nuclear physics. In the APAPES project, a new beam line dedicated to atomic physics was setup at L45 from ground zero in 2013 and is now fully operational. It uses state-of-the-art high resolution Auger electron spectroscopy of projectile ions to explore atomic collisions mechanisms acti...

Research paper thumbnail of Displacement damage effects in InGaAs photodiodes produced by electrons, protons and neutrons irradiations

IEEE Transactions on Nuclear Science, 2020

Research paper thumbnail of 197Au(n,xn) reactions at The Svedberg Laboratory high-energy neutron facility in Uppsal

HNPS Proceedings, 2019

Cross section measurements for the197Au(n,xn) reactions have been performed at The Svedberg Labor... more Cross section measurements for the197Au(n,xn) reactions have been performed at The Svedberg Laboratory (TSL) high-energy neutron facility in Uppsala,Sweden. The 45.6 and 58.3 MeVquasi-monoenergetic neutron beams were produced by means of the 7Li(p,n) reaction and were monitored with thin-film breakdown counters (TFBCs). After the end of the irradiations, the activity induced by the neutron beams in the targets and in reference foils, has been measured by a HPGe detector. In order to determine the cross sections of the (n,xn) reactions, the spectral neutron flux distribution is needed, thus the characterization of the beam is of major importance. Therefore, simulations that take into account the whole experimental setup of the irradiation have been performed with the use of MCNP5 code and the results are presented in this work. Currently, further analysis of the data is in progress.

Research paper thumbnail of Characterization of a Be(p,xn) Neutron Source for Fission Yields Measurements

Nuclear Data Sheets, 2014

We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neu... more We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neutron converter for independent fission yield studies at the IGISOL-JYFLTRAP facility (Jyväskylä, Finland). A 30 MeV proton beam impinged on a 5 mm water-cooled Beryllium target. Two independent experimental techniques have been used to measure the neutron spectrum: a Time of Flight (TOF) system used to estimate the high-energy contribution, and a Bonner Sphere Spectrometer able to provide precise results from thermal energies up to 20 MeV. An overlap between the energy regions covered by the two systems will permit a cross-check of the results from the different techniques. In this paper, the measurement and analysis techniques will be presented together with some preliminary results.

Research paper thumbnail of Measurement of the energy spectrum from the neutron source p lanned for IGISOL

We report on the characterisation measurements of the energy spectra from a Be(p,xn) neutron sour... more We report on the characterisation measurements of the energy spectra from a Be(p,xn) neutron source to be installed at the IGISOL-JYFLTRAP facility for studies of neutron-induced independent fission yields. The measurements were performed at The Svedberg Laboratory (Uppsala, Sweden), during 50 hours of beam-time in June, 2012. A 30 MeV proton beam impinged on a mock-up of the proton-neutron converter; this was a 5 mm-thick beryllium disc inserted in an aluminium holder, with a 1-cm thick layer of cooling water on the backside. The geometry of the mock-up has been chosen to reproduce the one that will be used as the IGISOL-JYFLTRAP source. During the experiment, two configurations for the neutron source have been used: a fast neutron field, produced using the bare target; and a moderated field, obtained adding a 10 cm-thick Polyethylene block after the target assembly. The neutron fields have been measured using an Extended Range Bonner Sphere Spectrometer (ERBSS), able to simultaneously determine all energy components of the spectrum from thermal energies up to tens of MeV. In addition to that, a Time of Flight (TOF) system was used to study more in detail the high-energy component of the neutron fields (E 5 MeV).

Research paper thumbnail of A neutron source for IGISOL-JYFLTRAP: Design and characterisation

The European Physical Journal A, 2017

A white neutron source based on the Be(p, nx) reaction for fission studies at the IGISOL-JYFLTRAP... more A white neutron source based on the Be(p, nx) reaction for fission studies at the IGISOL-JYFLTRAP facility has been designed and tested. 30 MeV protons impinge on a 5 mm thick water-cooled beryllium disc. The source was designed to produce at least 10 12 fast neutrons/s on a secondary fission target, in order to reach competitive production rates of fission products far from the valley of stability. The Monte Carlo codes MCNPX and FLUKA were used in the design phase to simulate the neutron energy spectra. Two experiments to characterise the neutron field were performed: the first was carried out at The Svedberg Laboratory in Uppsala (SE), using an Extended-Range Bonner Sphere Spectrometer and a liquid scintillator which used the time-of-flight (TOF) method to determine the energy of the neutrons; the second employed Thin-Film Breakdown Counters for the measurement of the TOF, and activation foils, at the IGISOL facility in Jyväskylä (FI). Design considerations and the results of the two characterisation measurements are presented, providing benchmarks for the simulations.

Research paper thumbnail of Detailed Geant4 Simulations of the ANITA and ANITA-CUP Neutron Facilities

2015 15th European Conference on Radiation and Its Effects on Components and Systems (RADECS), 2015

Research paper thumbnail of Target thickness dependence of the Be(p,xn) neutron energy spectrum

EPJ Web of Conferences, 2014

Research paper thumbnail of The ANITA Neutron Facility for SER Testing at TSL: Status and New Developments

Research paper thumbnail of CUP–A New High-Flux Irradiation Position at the ANITA Neutron Facility at TSL

IEEE Transactions on Nuclear Science, 2014

ABSTRACT A new irradiation position has been constructed, characterized, and put into operation a... more ABSTRACT A new irradiation position has been constructed, characterized, and put into operation at the ANITA facility in The Svedberg Laboratory (TSL) for accelerated testing of components and systems for single event effects. Results of beam characterization measurements are reported. The energy-integrated neutron flux above 10 MeV, amounting to more than 10(7) cm(-2).s(-1), is the highest among the facilities with atmospheric-like spectra. The employed characterization and simulation techniques are applicable for a broad class of neutron facilities.

Research paper thumbnail of Compact Thermal Neutron Sensors for Moderator-Based Neutron Spectrometers

Radiation Protection Dosimetry, 2013

In the framework of the NESCOFI@BTF project of the Italian Institute of Nuclear Physics, differen... more In the framework of the NESCOFI@BTF project of the Italian Institute of Nuclear Physics, different types of active thermal neutron sensors were studied by coupling semiconductor devices with a suitable radiator. The objective was to develop a detector of small dimensions with a proper sensitivity to use at different positions in a novel moderating assembly for neutron spectrometry. This work discusses the experimental activity carried out in the framework of the ERINDA program (PAC 3/9 2012) to characterise the performance of a thermal neutron pulse detector based on (6)Li.

Research paper thumbnail of An experimental study of plasma density determination by a cylindrical Langmuir probe at different pressures and magnetic fields in a cylindrical magnetron discharge in heavy rare gases

Journal of Physics D: Applied Physics, 1997

... density determination by a cylindrical Langmuir probe at different pressures and magnetic fie... more ... density determination by a cylindrical Langmuir probe at different pressures and magnetic fields in a cylindrical magnetron discharge in heavy rare gases E Passoth†, P Kudrna‡, C Csambal§, JF Behnke†, M Tichý‡¶ and V Helbig§+ ... 1763 Page 3. E Passoth et al 1. Introduction ...

Research paper thumbnail of Radial behaviour of the electron energy distribution function in the cylindrical magnetron discharge in argon

Journal of Physics D: Applied Physics, 1999

... Radial behaviour of the electron energy distribution function in the cylindrical magnetron di... more ... Radial behaviour of the electron energy distribution function in the cylindrical magnetron discharge in argon E Passoth†, JF Behnke†, C Csambal†, M Tichý‡, P Kudrna‡, Yu B Golubovskii§ and IA Porokhova§ ... 2655 Page 3. E Passoth et al temperature Te is given by [4] ...

Research paper thumbnail of Langmuir Probe Diagnostics of a Low Temperature Non-Isothermal Plasma in a Weak Magnetic Field

Contributions to Plasma Physics, 1997

This article presents measurements by a cylindrical Langmuir probe in the plasma of a DC cylindri... more This article presents measurements by a cylindrical Langmuir probe in the plasma of a DC cylindrical magnetron discharge at the pressure 1.5 Pa that aim at the experimental assessment of the influence of a weak magnetic field to the estimation of the electron density when using conventional methods of probe data interpretation. The probe data wiis obtained under the presence of a weak magnetic field in the range 1.10-'-5. lo-' T. The influence of the magnetic field on the electron probe current is experimentally assessed for two cylindrical'probes with different radii, 50 pm and 21 pm. This assessment is based on comparison of the values of the electron density estimated from the electron current part with the values of the positive ion density estimated from the positive ion current part of the probe characteristic respectively by assuming that at the magnetic field strengths used in the present study the probe positive ion currents are possible to be assumed as uninfluenced by the magnetic field. For interpretation of the probe positive ion current two theories are used and compared to each other: the radial motion model by Allen, Boyd and Reynolds [lo] and Chen Ill] and the model that accounts for the collisions of positive ions with neutrals in the probe space charge sheath that we call Chen-Talbot model . At lower magnetic field 3. lo-' T the positive ion density values interpreted by using the Chen-Talbot model [8] are in better agreement with the values of electron density compared to those obtained by using the theory [10,11]; therefore the model [8] is used for calculation of the positive ion density from the probe data at higher magnetic fields. The comparison of the positive ion and electron density values calculated from the same probe data at higher magnetic fields shows that up to the magnetic field strength 4 . lo-' T with the probe 100 pm and up to 5.

Research paper thumbnail of A study of the electron energy distribution function in the cylindrical magnetron discharge in argon and xenon

… journal of physics, 1999

We studied the behaviour of the cylindrical magnetron discharge in argon and xenon. We concentrat... more We studied the behaviour of the cylindrical magnetron discharge in argon and xenon. We concentrated ourselves mainly on description of the transport of charge carriers in the region from the negative glow to the anode. We attempted to describe this transport using Monte-Carlo simulations as well as by standard transport parameters, mobility and diffusion coefficients. We also experimentally determined the radial shape of the electron energy distribution function (EEDF) including its detectable anisotropy caused by the presence of magnetic field. For the EEDF determination we used the planar probe whose collecting surface was adjustable at different angles to the direction of the magnetic field as well as movable in radial direction. The results of modelling and experiment are discussed. *) Dedicated to Prof. Jan Jan~a on the occasion of his 60th birthday.

Research paper thumbnail of Characterization of a Be(p,xn) Neutron Source for Fission Yields Measurements

Nuclear Data Sheets, 2014

We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neu... more We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neutron converter for independent fission yield studies at the IGISOL-JYFLTRAP facility (Jyväskylä, Finland). A 30 MeV proton beam impinged on a 5 mm water-cooled Beryllium target. Two independent experimental techniques have been used to measure the neutron spectrum: a Time of Flight (TOF) system used to estimate the high-energy contribution, and a Bonner Sphere Spectrometer able to provide precise results from thermal energies up to 20 MeV. An overlap between the energy regions covered by the two systems will permit a cross-check of the results from the different techniques. In this paper, the measurement and analysis techniques will be presented together with some preliminary results.

Research paper thumbnail of HNPS 2016 Sponsors

Accelerator-based atomic physics is a mature field that started in the ‘60s by experimental nucle... more Accelerator-based atomic physics is a mature field that started in the ‘60s by experimental nuclear physicists looking for new research directions in both basic and applied acceleratorbased physics. Presently, it is particularly strong in the EU with important contributions to fusion, hot plasmas, astrophysics, accelerator technology and basic atomic physics of ion-atom collision dynamics, structure and technology. After presenting some of the basic parameters of interest in this field I shall try to give a flavor of how things work by discussing in more detail the ongoing APAPES1 project at the Demokritos Tandem, while at the same time bringing out similarities and differences with acceleratorbased nuclear physics. In the APAPES project, a new beam line dedicated to atomic physics was setup at L45 from ground zero in 2013 and is now fully operational. It uses state-of-the-art high resolution Auger electron spectroscopy of projectile ions to explore atomic collisions mechanisms acti...

Research paper thumbnail of Displacement damage effects in InGaAs photodiodes produced by electrons, protons and neutrons irradiations

IEEE Transactions on Nuclear Science, 2020

Research paper thumbnail of 197Au(n,xn) reactions at The Svedberg Laboratory high-energy neutron facility in Uppsal

HNPS Proceedings, 2019

Cross section measurements for the197Au(n,xn) reactions have been performed at The Svedberg Labor... more Cross section measurements for the197Au(n,xn) reactions have been performed at The Svedberg Laboratory (TSL) high-energy neutron facility in Uppsala,Sweden. The 45.6 and 58.3 MeVquasi-monoenergetic neutron beams were produced by means of the 7Li(p,n) reaction and were monitored with thin-film breakdown counters (TFBCs). After the end of the irradiations, the activity induced by the neutron beams in the targets and in reference foils, has been measured by a HPGe detector. In order to determine the cross sections of the (n,xn) reactions, the spectral neutron flux distribution is needed, thus the characterization of the beam is of major importance. Therefore, simulations that take into account the whole experimental setup of the irradiation have been performed with the use of MCNP5 code and the results are presented in this work. Currently, further analysis of the data is in progress.

Research paper thumbnail of Characterization of a Be(p,xn) Neutron Source for Fission Yields Measurements

Nuclear Data Sheets, 2014

We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neu... more We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neutron converter for independent fission yield studies at the IGISOL-JYFLTRAP facility (Jyväskylä, Finland). A 30 MeV proton beam impinged on a 5 mm water-cooled Beryllium target. Two independent experimental techniques have been used to measure the neutron spectrum: a Time of Flight (TOF) system used to estimate the high-energy contribution, and a Bonner Sphere Spectrometer able to provide precise results from thermal energies up to 20 MeV. An overlap between the energy regions covered by the two systems will permit a cross-check of the results from the different techniques. In this paper, the measurement and analysis techniques will be presented together with some preliminary results.

Research paper thumbnail of Measurement of the energy spectrum from the neutron source p lanned for IGISOL

We report on the characterisation measurements of the energy spectra from a Be(p,xn) neutron sour... more We report on the characterisation measurements of the energy spectra from a Be(p,xn) neutron source to be installed at the IGISOL-JYFLTRAP facility for studies of neutron-induced independent fission yields. The measurements were performed at The Svedberg Laboratory (Uppsala, Sweden), during 50 hours of beam-time in June, 2012. A 30 MeV proton beam impinged on a mock-up of the proton-neutron converter; this was a 5 mm-thick beryllium disc inserted in an aluminium holder, with a 1-cm thick layer of cooling water on the backside. The geometry of the mock-up has been chosen to reproduce the one that will be used as the IGISOL-JYFLTRAP source. During the experiment, two configurations for the neutron source have been used: a fast neutron field, produced using the bare target; and a moderated field, obtained adding a 10 cm-thick Polyethylene block after the target assembly. The neutron fields have been measured using an Extended Range Bonner Sphere Spectrometer (ERBSS), able to simultaneously determine all energy components of the spectrum from thermal energies up to tens of MeV. In addition to that, a Time of Flight (TOF) system was used to study more in detail the high-energy component of the neutron fields (E 5 MeV).

Research paper thumbnail of A neutron source for IGISOL-JYFLTRAP: Design and characterisation

The European Physical Journal A, 2017

A white neutron source based on the Be(p, nx) reaction for fission studies at the IGISOL-JYFLTRAP... more A white neutron source based on the Be(p, nx) reaction for fission studies at the IGISOL-JYFLTRAP facility has been designed and tested. 30 MeV protons impinge on a 5 mm thick water-cooled beryllium disc. The source was designed to produce at least 10 12 fast neutrons/s on a secondary fission target, in order to reach competitive production rates of fission products far from the valley of stability. The Monte Carlo codes MCNPX and FLUKA were used in the design phase to simulate the neutron energy spectra. Two experiments to characterise the neutron field were performed: the first was carried out at The Svedberg Laboratory in Uppsala (SE), using an Extended-Range Bonner Sphere Spectrometer and a liquid scintillator which used the time-of-flight (TOF) method to determine the energy of the neutrons; the second employed Thin-Film Breakdown Counters for the measurement of the TOF, and activation foils, at the IGISOL facility in Jyväskylä (FI). Design considerations and the results of the two characterisation measurements are presented, providing benchmarks for the simulations.

Research paper thumbnail of Detailed Geant4 Simulations of the ANITA and ANITA-CUP Neutron Facilities

2015 15th European Conference on Radiation and Its Effects on Components and Systems (RADECS), 2015

Research paper thumbnail of Target thickness dependence of the Be(p,xn) neutron energy spectrum

EPJ Web of Conferences, 2014

Research paper thumbnail of The ANITA Neutron Facility for SER Testing at TSL: Status and New Developments

Research paper thumbnail of CUP–A New High-Flux Irradiation Position at the ANITA Neutron Facility at TSL

IEEE Transactions on Nuclear Science, 2014

ABSTRACT A new irradiation position has been constructed, characterized, and put into operation a... more ABSTRACT A new irradiation position has been constructed, characterized, and put into operation at the ANITA facility in The Svedberg Laboratory (TSL) for accelerated testing of components and systems for single event effects. Results of beam characterization measurements are reported. The energy-integrated neutron flux above 10 MeV, amounting to more than 10(7) cm(-2).s(-1), is the highest among the facilities with atmospheric-like spectra. The employed characterization and simulation techniques are applicable for a broad class of neutron facilities.

Research paper thumbnail of Compact Thermal Neutron Sensors for Moderator-Based Neutron Spectrometers

Radiation Protection Dosimetry, 2013

In the framework of the NESCOFI@BTF project of the Italian Institute of Nuclear Physics, differen... more In the framework of the NESCOFI@BTF project of the Italian Institute of Nuclear Physics, different types of active thermal neutron sensors were studied by coupling semiconductor devices with a suitable radiator. The objective was to develop a detector of small dimensions with a proper sensitivity to use at different positions in a novel moderating assembly for neutron spectrometry. This work discusses the experimental activity carried out in the framework of the ERINDA program (PAC 3/9 2012) to characterise the performance of a thermal neutron pulse detector based on (6)Li.

Research paper thumbnail of An experimental study of plasma density determination by a cylindrical Langmuir probe at different pressures and magnetic fields in a cylindrical magnetron discharge in heavy rare gases

Journal of Physics D: Applied Physics, 1997

... density determination by a cylindrical Langmuir probe at different pressures and magnetic fie... more ... density determination by a cylindrical Langmuir probe at different pressures and magnetic fields in a cylindrical magnetron discharge in heavy rare gases E Passoth†, P Kudrna‡, C Csambal§, JF Behnke†, M Tichý‡¶ and V Helbig§+ ... 1763 Page 3. E Passoth et al 1. Introduction ...

Research paper thumbnail of Radial behaviour of the electron energy distribution function in the cylindrical magnetron discharge in argon

Journal of Physics D: Applied Physics, 1999

... Radial behaviour of the electron energy distribution function in the cylindrical magnetron di... more ... Radial behaviour of the electron energy distribution function in the cylindrical magnetron discharge in argon E Passoth†, JF Behnke†, C Csambal†, M Tichý‡, P Kudrna‡, Yu B Golubovskii§ and IA Porokhova§ ... 2655 Page 3. E Passoth et al temperature Te is given by [4] ...

Research paper thumbnail of Langmuir Probe Diagnostics of a Low Temperature Non-Isothermal Plasma in a Weak Magnetic Field

Contributions to Plasma Physics, 1997

This article presents measurements by a cylindrical Langmuir probe in the plasma of a DC cylindri... more This article presents measurements by a cylindrical Langmuir probe in the plasma of a DC cylindrical magnetron discharge at the pressure 1.5 Pa that aim at the experimental assessment of the influence of a weak magnetic field to the estimation of the electron density when using conventional methods of probe data interpretation. The probe data wiis obtained under the presence of a weak magnetic field in the range 1.10-'-5. lo-' T. The influence of the magnetic field on the electron probe current is experimentally assessed for two cylindrical'probes with different radii, 50 pm and 21 pm. This assessment is based on comparison of the values of the electron density estimated from the electron current part with the values of the positive ion density estimated from the positive ion current part of the probe characteristic respectively by assuming that at the magnetic field strengths used in the present study the probe positive ion currents are possible to be assumed as uninfluenced by the magnetic field. For interpretation of the probe positive ion current two theories are used and compared to each other: the radial motion model by Allen, Boyd and Reynolds [lo] and Chen Ill] and the model that accounts for the collisions of positive ions with neutrals in the probe space charge sheath that we call Chen-Talbot model . At lower magnetic field 3. lo-' T the positive ion density values interpreted by using the Chen-Talbot model [8] are in better agreement with the values of electron density compared to those obtained by using the theory [10,11]; therefore the model [8] is used for calculation of the positive ion density from the probe data at higher magnetic fields. The comparison of the positive ion and electron density values calculated from the same probe data at higher magnetic fields shows that up to the magnetic field strength 4 . lo-' T with the probe 100 pm and up to 5.

Research paper thumbnail of A study of the electron energy distribution function in the cylindrical magnetron discharge in argon and xenon

… journal of physics, 1999

We studied the behaviour of the cylindrical magnetron discharge in argon and xenon. We concentrat... more We studied the behaviour of the cylindrical magnetron discharge in argon and xenon. We concentrated ourselves mainly on description of the transport of charge carriers in the region from the negative glow to the anode. We attempted to describe this transport using Monte-Carlo simulations as well as by standard transport parameters, mobility and diffusion coefficients. We also experimentally determined the radial shape of the electron energy distribution function (EEDF) including its detectable anisotropy caused by the presence of magnetic field. For the EEDF determination we used the planar probe whose collecting surface was adjustable at different angles to the direction of the magnetic field as well as movable in radial direction. The results of modelling and experiment are discussed. *) Dedicated to Prof. Jan Jan~a on the occasion of his 60th birthday.

Research paper thumbnail of Characterization of a Be(p,xn) Neutron Source for Fission Yields Measurements

Nuclear Data Sheets, 2014

We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neu... more We report on measurements performed at The Svedberg Laboratory (TSL) to characterize a proton-neutron converter for independent fission yield studies at the IGISOL-JYFLTRAP facility (Jyväskylä, Finland). A 30 MeV proton beam impinged on a 5 mm water-cooled Beryllium target. Two independent experimental techniques have been used to measure the neutron spectrum: a Time of Flight (TOF) system used to estimate the high-energy contribution, and a Bonner Sphere Spectrometer able to provide precise results from thermal energies up to 20 MeV. An overlap between the energy regions covered by the two systems will permit a cross-check of the results from the different techniques. In this paper, the measurement and analysis techniques will be presented together with some preliminary results.