| 1. |
- Allison, J, et al.
(författare)
-
Geant4 developments and applications
- 2006
-
Ingår i: IEEE TRANSACTIONS ON NUCLEAR SCIENCE. - 0018-9499. ; 53:1, s. 270-278
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 2. |
|
|
| 3. |
- Arce, P., et al.
(författare)
-
Report on G4-Med, a Geant4 benchmarking system for medical physics applications developed by the Geant4 Medical Simulation Benchmarking Group
- 2021
-
Ingår i: Medical Physics. - : Wiley. - 0094-2405 .- 2473-4209. ; 48:1, s. 19-56
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing. Aims: To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics. Materials and Methods: G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes. Results: This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data. Discussion: Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics. Conclusion: The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application.
|
|
| 4. |
- Farnocchia, Davide, et al.
(författare)
-
The Second International Asteroid Warning Network Timing Campaign: 2005 LW3
- 2023
-
Ingår i: The Planetary Science Journal. - : Institute of Physics (IOP). - 2632-3338. ; 4:11
-
Tidskriftsartikel (refereegranskat)abstract
- The Earth close approach of near-Earth asteroid 2005 LW3 on 2022 November 23 represented a good opportunity for a second observing campaign to test the timing accuracy of astrometric observation. With 82 participating stations, the International Asteroid Warning Network collected 1046 observations of 2005 LW3 around the time of the close approach. Compared to the previous timing campaign targeting 2019 XS, some individual observers were able to significantly improve the accuracy of their reported observation times. In particular, U.S. surveys achieved good timing performance. However, no broad, systematic improvement was achieved compared to the previous campaign, with an overall negative bias persisting among the different observers. The calibration of observing times and the mitigation of timing errors should be important future considerations for observers and orbit computers, respectively.
|
|
| 5. |
|
|
| 6. |
- Kpeglo, D. O., et al.
(författare)
-
Assessment of natural radioactivity levels and associated radiological hazard in scale and sludge from Jubilee oilfield of Ghana
- 2019
-
Ingår i: International Journal of Low Radiation. - 1477-6545. ; 11:2, s. 143-157
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of accurate radio-isotopic signatures and chemical constituents is essential in assessing potential radiological hazards to the public and workers from exposure to NORM waste. For that reason, scale and sludge samples from Ghanaian oilfields were assessed using alpha spectrometry, gamma spectrometry, radon monitoring and scanning electron microscope techniques. Activity concentration of 238U, 232Th-series and 40K radionuclides for NORM residues have been evaluated. Fourteen trace elements were also identified and semi-qualitatively quantified. The obtained results clearly reflect that scale and sludge may present radiological risk for workers, public and environment. Copyright © 2019 Inderscience Enterprises Ltd.
|
|
| 7. |
- Milena-Pérez, A., et al.
(författare)
-
Determination and Dose Contribution of Uranium Isotopes and 2010Po Activity Concentrations of Natural Spring Waters in the Province of Granada, Spain
- 2018
-
Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 181:4, s. 350-359
-
Tidskriftsartikel (refereegranskat)abstract
- The activity concentrations of alpha-emitters comprising isotopes of uranium (238, 234, 235U) and polonium (210Po) were measured using alpha-particle spectrometry in natural spring waters in the province of Granada, Spain. These water are consumed by the population of the zone who live in villages. This is almost half of the population of the whole region. Mean values of activity concentrations found are 42.61 ± 2.66; 49.55 ± 3.03; 1.64 ± 0.28 and 1.74 ± 0.15 mBq L-1 for 238U, 234U, 235U and 210Po, respectively. Finally, the radiological impact of the analysed waters has been determined, in terms of the estimation of the committed annual effective dose due to the ingestion of the water. The assessment has been carried out for five age groups with the aim to cover all the population. The calculated annual effective doses are observed to be below the prescribed dose limit of 100 μSv y-1 recommended by WHO.
|
|
| 8. |
- Kpeglo, D. O., et al.
(författare)
-
Radiochemical characterization of produced water from two production offshore oilfields in Ghana
- 2016
-
Ingår i: Journal of Environmental Radioactivity. - : Elsevier BV. - 0265-931X. ; 152, s. 35-45
-
Tidskriftsartikel (refereegranskat)abstract
- Produced water from two Ghanaian offshore production oilfields has been characterized using alpha spectrometry after radiochemical separation, non-destructive gamma spectrometry and ICP-MS and other complimentary analytical tools. The measured concentrations of main NORM components were in the range of 6.2-22.3 Bq.L-1, 6.4-35.5 Bq.L-1, and 0.7-7.0 Bq.L-4 (f)or Ra-226, Ra-228 and Ra-224 respectively. A good correlation between several physico-chemical parameters and radium isotopes was observed in each production oilfield. The radium concentrations obtained in this study for produced water from the two oilfields of Ghana are of radiological importance and hence there may be the need to put in place measures for future contamination concerns due to their bioavailability in the media and bioaccumulation characteristics. The results will assist in critical decision making for future set up of appropriate national guidelines for the management of NORM waste from the emerging oil and gas industry in Ghana. (C) 2015 Elsevier Ltd. All rights reserved.
|
|
| 9. |
|
|
| 10. |
|
|
