Dominik Dworak - Academia.edu (original) (raw)

Papers by Dominik Dworak

Research paper thumbnail of The Energy Deposition for No-air-gap Design of the TESLA Beam Dump

Research paper thumbnail of Direct Energy Deposition in the Lateral Concrete Shielding of the TESLA Water Dump and the Rise of Shielding Temperature

A water beam dump for the TESLA electron-positron collider is being designed. Energy deposition a... more A water beam dump for the TESLA electron-positron collider is being designed. Energy deposition and related power release in concrete shielding which is surrounding the dump are calculated using Monte-Carlo simulations. High values of the released power has been found which could result in a shield temperature increase of a few hundred centigrade and finally in a shield damage. Additional shielding by different materials (Fe, Al, C, and water) have been proposed for further shield designs. For all0 designed case energy deposited in the outer concrete shield is reduced about two orders of magnitude and kept near the limit needed. Also is calculated the radiation field and its composition, fluences and energy spectra of the particles produced inside the dump and shielding.

Research paper thumbnail of Detection of explosives and other illicit materials by a single nanosecond neutron pulses — Monte Carlo simulation of the detection process

Journal of Instrumentation, 2012

Research paper thumbnail of Monte Carlo Simulations of Powerful Neutron Interaction with Matter for the Goals of Disclosure of Hidden Explosives and Fissile Materials and for Treatment of Cancer Diseases versus their Experimental Verifications

Applications of Monte Carlo Methods in Biology, Medicine and Other Fields of Science, 2011

Research paper thumbnail of A single-shot nanosecond neutron pulsed technique for the detection of fissile materials

Journal of Instrumentation, 2012

A novel technique with the potential of detecting hidden fissile materials is presented utilizing... more A novel technique with the potential of detecting hidden fissile materials is presented utilizing the interaction of a single powerful and nanosecond wide neutron pulse with matter. The experimental system is based on a Dense Plasma Focus (DPF) device as a neutron source generating pulses of almost mono-energetic 2.45 MeV and/or 14.0 MeV neutrons, a few nanoseconds in width. Fissile materials, consisting of heavy nuclei, are detected utilizing two signatures: firstly by measuring those secondary fission neutrons which are faster than the elastically scattered 2.45 MeV neutrons of the D-D reaction in the DPF; secondly by measuring the pulses of the slower secondary fission neutrons following the pulse of the fast 14 MeV neutrons from the D-T reaction. In both cases it is important to compare the measured spectrum of the fission neutrons induced by the 2.45 MeV or 14 MeV neutron pulse of the DPF with theoretical spectra obtained by mathematical simulation. Therefore, results of numerical modelling of the proposed system, using the MCNP5 and the FLUKA codes are presented and compared with experimental data.

Research paper thumbnail of The filter/moderator arrangement-optimisation for the boron-neutron capture therapy (BNCT)

Radiation Protection Dosimetry, 2004

The paper presents results of the numerical modelling of the fission-converter-based epithermal n... more The paper presents results of the numerical modelling of the fission-converter-based epithermal neutron source designed for the boron neutron capture therapy (BNCT) facility to be located at the Polish research nuclear reactor MARIA at Swierk. The unique design of the fission converter has been proposed due to a specific geometrical surrounding of the reactor. The filter/moderator arrangement has been optimised to moderate fission neutrons to epithermal energies and to remove both fast neutrons and photons from the therapeutic beam. The selected filter/moderator set-up ensures both high epithermal neutron flux and suitably low level of beam contamination. Photons originating from the reactor core are almost eliminated what is the exceptional advantage of the proposed design. It yields one order of magnitude lower gamma radiation dose than the maximum allowed dose in such a type of therapeutic facility. The MCNP code has been used for the computations.

Research paper thumbnail of Studies on the neutron field behind the shielding of proton accelerators Part II: Iron shielding

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1996

Energy-and angular distributions of neutrons behind concrete side shielding of proton accelerator... more Energy-and angular distributions of neutrons behind concrete side shielding of proton accelerators were calculated. Simple arguments are given to understand the characteristic shape of the neutron spectrum. Calculations were repeated to receive data for simple shielding estimations. The dose equivalent attenuation coefficient of concrete for monoenergetic neutrons with energies between 1 and 400 MeV were determined and compared with the coefficient for neutrons leaving an accelerator shield at angles around 90". Data for shielding gaps in accelerator shielding walls are given as an application. The calculations were performed by using the Monte Carlo codes FLUKA92 and MORSE.

Research paper thumbnail of The field of scattered radiation in the tunnel of the proton storage ring HERA: measurements and calculations

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1999

The field of scattered radiation produced by a stored 820 GeV proton beam in the HERA tunnel is s... more The field of scattered radiation produced by a stored 820 GeV proton beam in the HERA tunnel is studied. Neutron spectra and doses as well as fluences of charged particles were measured by means of conventional detectors. Secondary particles emitted at both small and large angles with respect to the beam are investigated. They were produced by interactions of the

Research paper thumbnail of Conceptual design of an intense neutron source for time-of-flight measurements

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007

Among the accelerator-based neutron sources, the ones that are driven by electron Linacs still ap... more Among the accelerator-based neutron sources, the ones that are driven by electron Linacs still appear quite attractive, notably in the case of cross-section measurements with the time-of-flight method. This is due to their better beam quality and economy aspects, which make them complementary, rather than inferior to the hadron (protons, deuterons)-driven spallation facilities.A conceptual design study of a powerful neutron

Research paper thumbnail of Doses due to neutrons and charged particles in the angular range 10° to 170° behind concrete shield of high-energy proton accelerators

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1997

Spectra and dose equivalents of neutrons, protons, and pions behind ordinary concrete shields or ... more Spectra and dose equivalents of neutrons, protons, and pions behind ordinary concrete shields or iron-loaded concrete shields are calculated. The results are parametrized by means of a simple formula.

Research paper thumbnail of Calculation of hadron yields around thick targets and doses behind concrete shielding of high-energy electron accelerators

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2000

The "eld of neutrons, protons, and pions produced by high-energy electrons hitting thick targets ... more The "eld of neutrons, protons, and pions produced by high-energy electrons hitting thick targets is studied by means of the FLUKA Monte Carlo code. Particle spectra and dependences of #uences on primary energy (1}250 GeV), on angle (20}1503) and on target mass number are given, together with the total number of low-energy neutrons and of high-energy neutrons per electron. The attenuation of the total hadron dose equivalent in concrete and dose ratios of the main components are calculated. All results are parametrized and expressed by simple formulae. In addition, the hadron "eld behind copper and lead absorbers (beam shutters) in beam direction, its composition and its dependence on primary energy (1}50 GeV), on distance, and on absorber type are studied. Again the total hadron dose equivalent can be expressed by a simple equation. The dose attenuation by an additional concrete shield behind an absorber is examined.

Research paper thumbnail of Calculations of the photon dose behind concrete shielding of high energy proton accelerators

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1992

Research paper thumbnail of Neutronic analyses and tools development efforts in the European DEMO programme

Fusion Engineering and Design, 2014

The European Fusion Development Agreement (EFDA) recently launched a programme on Power Plant Phy... more The European Fusion Development Agreement (EFDA) recently launched a programme on Power Plant Physics and Technology (PPPT) with the aim to develop a conceptual design of a fusion demonstration reactor (DEMO) addressing key technology and physics issues. A dedicated part of the PPPT programme is devoted to the neutronics which, among others, has to define and verify requirements and boundary conditions for the DEMO systems. The quality of the provided data depends on the capabilities and the reliability of the computational tools. Accordingly, the PPPT activities in the area of neutronics include both DEMO nuclear analyses and development efforts on neutronic tools including their verification and validation. This paper reports on first neutronics studies performed for DEMO, and on the evaluation and further development of neutronic tools.

Research paper thumbnail of Attenuation of the neutron dose equivalent in labyrinths through an accelerator shield

… and Methods in Physics Research Section …, 1993

The attenuation of the neutron dose equivalent in labyrinths is calculated. Long straight access ... more The attenuation of the neutron dose equivalent in labyrinths is calculated. Long straight access ways and rectangular three-sectional labyrinths are considered. The Monte Carlo calculations are checked against earlier measurements. Simple formulas for the ...

Research paper thumbnail of Numerical modeling of the gamma-gamma density tool responses in horizontal wells with an axial asymmetry

Research paper thumbnail of Asymptotic solutions of neutron transport equation and the limits of correct use of diffusion approximation for rocks

Applied Radiation and Isotopes, 2001

The diffusion approximation solution for neutron transport has been used in well-logging geophysi... more The diffusion approximation solution for neutron transport has been used in well-logging geophysics for calculating tool responses in boreholes, sometimes with success. The problem of the dimension of different materials to which it can be applied with success is important for the borehole environment. The results obtained show that the diffusion approximation can be used for distances greater than a few millimetre in some rock types. For iron, barium, and other highly absorbing media the use of the diffusion approximation is inappropriate even for large distances.

Research paper thumbnail of The Energy Deposition for No-air-gap Design of the TESLA Beam Dump

Research paper thumbnail of Direct Energy Deposition in the Lateral Concrete Shielding of the TESLA Water Dump and the Rise of Shielding Temperature

A water beam dump for the TESLA electron-positron collider is being designed. Energy deposition a... more A water beam dump for the TESLA electron-positron collider is being designed. Energy deposition and related power release in concrete shielding which is surrounding the dump are calculated using Monte-Carlo simulations. High values of the released power has been found which could result in a shield temperature increase of a few hundred centigrade and finally in a shield damage. Additional shielding by different materials (Fe, Al, C, and water) have been proposed for further shield designs. For all0 designed case energy deposited in the outer concrete shield is reduced about two orders of magnitude and kept near the limit needed. Also is calculated the radiation field and its composition, fluences and energy spectra of the particles produced inside the dump and shielding.

Research paper thumbnail of Detection of explosives and other illicit materials by a single nanosecond neutron pulses — Monte Carlo simulation of the detection process

Journal of Instrumentation, 2012

Research paper thumbnail of Monte Carlo Simulations of Powerful Neutron Interaction with Matter for the Goals of Disclosure of Hidden Explosives and Fissile Materials and for Treatment of Cancer Diseases versus their Experimental Verifications

Applications of Monte Carlo Methods in Biology, Medicine and Other Fields of Science, 2011

Research paper thumbnail of A single-shot nanosecond neutron pulsed technique for the detection of fissile materials

Journal of Instrumentation, 2012

A novel technique with the potential of detecting hidden fissile materials is presented utilizing... more A novel technique with the potential of detecting hidden fissile materials is presented utilizing the interaction of a single powerful and nanosecond wide neutron pulse with matter. The experimental system is based on a Dense Plasma Focus (DPF) device as a neutron source generating pulses of almost mono-energetic 2.45 MeV and/or 14.0 MeV neutrons, a few nanoseconds in width. Fissile materials, consisting of heavy nuclei, are detected utilizing two signatures: firstly by measuring those secondary fission neutrons which are faster than the elastically scattered 2.45 MeV neutrons of the D-D reaction in the DPF; secondly by measuring the pulses of the slower secondary fission neutrons following the pulse of the fast 14 MeV neutrons from the D-T reaction. In both cases it is important to compare the measured spectrum of the fission neutrons induced by the 2.45 MeV or 14 MeV neutron pulse of the DPF with theoretical spectra obtained by mathematical simulation. Therefore, results of numerical modelling of the proposed system, using the MCNP5 and the FLUKA codes are presented and compared with experimental data.

Research paper thumbnail of The filter/moderator arrangement-optimisation for the boron-neutron capture therapy (BNCT)

Radiation Protection Dosimetry, 2004

The paper presents results of the numerical modelling of the fission-converter-based epithermal n... more The paper presents results of the numerical modelling of the fission-converter-based epithermal neutron source designed for the boron neutron capture therapy (BNCT) facility to be located at the Polish research nuclear reactor MARIA at Swierk. The unique design of the fission converter has been proposed due to a specific geometrical surrounding of the reactor. The filter/moderator arrangement has been optimised to moderate fission neutrons to epithermal energies and to remove both fast neutrons and photons from the therapeutic beam. The selected filter/moderator set-up ensures both high epithermal neutron flux and suitably low level of beam contamination. Photons originating from the reactor core are almost eliminated what is the exceptional advantage of the proposed design. It yields one order of magnitude lower gamma radiation dose than the maximum allowed dose in such a type of therapeutic facility. The MCNP code has been used for the computations.

Research paper thumbnail of Studies on the neutron field behind the shielding of proton accelerators Part II: Iron shielding

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1996

Energy-and angular distributions of neutrons behind concrete side shielding of proton accelerator... more Energy-and angular distributions of neutrons behind concrete side shielding of proton accelerators were calculated. Simple arguments are given to understand the characteristic shape of the neutron spectrum. Calculations were repeated to receive data for simple shielding estimations. The dose equivalent attenuation coefficient of concrete for monoenergetic neutrons with energies between 1 and 400 MeV were determined and compared with the coefficient for neutrons leaving an accelerator shield at angles around 90". Data for shielding gaps in accelerator shielding walls are given as an application. The calculations were performed by using the Monte Carlo codes FLUKA92 and MORSE.

Research paper thumbnail of The field of scattered radiation in the tunnel of the proton storage ring HERA: measurements and calculations

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1999

The field of scattered radiation produced by a stored 820 GeV proton beam in the HERA tunnel is s... more The field of scattered radiation produced by a stored 820 GeV proton beam in the HERA tunnel is studied. Neutron spectra and doses as well as fluences of charged particles were measured by means of conventional detectors. Secondary particles emitted at both small and large angles with respect to the beam are investigated. They were produced by interactions of the

Research paper thumbnail of Conceptual design of an intense neutron source for time-of-flight measurements

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007

Among the accelerator-based neutron sources, the ones that are driven by electron Linacs still ap... more Among the accelerator-based neutron sources, the ones that are driven by electron Linacs still appear quite attractive, notably in the case of cross-section measurements with the time-of-flight method. This is due to their better beam quality and economy aspects, which make them complementary, rather than inferior to the hadron (protons, deuterons)-driven spallation facilities.A conceptual design study of a powerful neutron

Research paper thumbnail of Doses due to neutrons and charged particles in the angular range 10° to 170° behind concrete shield of high-energy proton accelerators

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1997

Spectra and dose equivalents of neutrons, protons, and pions behind ordinary concrete shields or ... more Spectra and dose equivalents of neutrons, protons, and pions behind ordinary concrete shields or iron-loaded concrete shields are calculated. The results are parametrized by means of a simple formula.

Research paper thumbnail of Calculation of hadron yields around thick targets and doses behind concrete shielding of high-energy electron accelerators

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2000

The "eld of neutrons, protons, and pions produced by high-energy electrons hitting thick targets ... more The "eld of neutrons, protons, and pions produced by high-energy electrons hitting thick targets is studied by means of the FLUKA Monte Carlo code. Particle spectra and dependences of #uences on primary energy (1}250 GeV), on angle (20}1503) and on target mass number are given, together with the total number of low-energy neutrons and of high-energy neutrons per electron. The attenuation of the total hadron dose equivalent in concrete and dose ratios of the main components are calculated. All results are parametrized and expressed by simple formulae. In addition, the hadron "eld behind copper and lead absorbers (beam shutters) in beam direction, its composition and its dependence on primary energy (1}50 GeV), on distance, and on absorber type are studied. Again the total hadron dose equivalent can be expressed by a simple equation. The dose attenuation by an additional concrete shield behind an absorber is examined.

Research paper thumbnail of Calculations of the photon dose behind concrete shielding of high energy proton accelerators

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1992

Research paper thumbnail of Neutronic analyses and tools development efforts in the European DEMO programme

Fusion Engineering and Design, 2014

The European Fusion Development Agreement (EFDA) recently launched a programme on Power Plant Phy... more The European Fusion Development Agreement (EFDA) recently launched a programme on Power Plant Physics and Technology (PPPT) with the aim to develop a conceptual design of a fusion demonstration reactor (DEMO) addressing key technology and physics issues. A dedicated part of the PPPT programme is devoted to the neutronics which, among others, has to define and verify requirements and boundary conditions for the DEMO systems. The quality of the provided data depends on the capabilities and the reliability of the computational tools. Accordingly, the PPPT activities in the area of neutronics include both DEMO nuclear analyses and development efforts on neutronic tools including their verification and validation. This paper reports on first neutronics studies performed for DEMO, and on the evaluation and further development of neutronic tools.

Research paper thumbnail of Attenuation of the neutron dose equivalent in labyrinths through an accelerator shield

… and Methods in Physics Research Section …, 1993

The attenuation of the neutron dose equivalent in labyrinths is calculated. Long straight access ... more The attenuation of the neutron dose equivalent in labyrinths is calculated. Long straight access ways and rectangular three-sectional labyrinths are considered. The Monte Carlo calculations are checked against earlier measurements. Simple formulas for the ...

Research paper thumbnail of Numerical modeling of the gamma-gamma density tool responses in horizontal wells with an axial asymmetry

Research paper thumbnail of Asymptotic solutions of neutron transport equation and the limits of correct use of diffusion approximation for rocks

Applied Radiation and Isotopes, 2001

The diffusion approximation solution for neutron transport has been used in well-logging geophysi... more The diffusion approximation solution for neutron transport has been used in well-logging geophysics for calculating tool responses in boreholes, sometimes with success. The problem of the dimension of different materials to which it can be applied with success is important for the borehole environment. The results obtained show that the diffusion approximation can be used for distances greater than a few millimetre in some rock types. For iron, barium, and other highly absorbing media the use of the diffusion approximation is inappropriate even for large distances.