| 1. |
- Faarinen, Mikko, et al.
(författare)
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Al-26 at the AMS facility in Lund
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 223-24, s. 130-134
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Tidskriftsartikel (refereegranskat)abstract
- To broaden the AMS programme in Lund by including Al studies, a new injector has been installed and tested at the 3 MV Pelletron accelerator. Detailed optical calculations have been performed to obtain maximum mass and energy resolution. The design of the injector, the improvement in the resolution compared to the old injector, as well as preliminary tests with a Al-26-beam, are presented. By using accelerator mass spectrometry (AMS) to measure the long-lived aluminium isotope Al-26 it has become possible to study the uptake, distribution and retention of aluminium in biological system under physiologically realistic conditions. Results from a pilot project on Al-26 in wheat plants are presented.
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| 2. |
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| 3. |
- Friedrich, M, et al.
(författare)
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A small and compact AMS facility for tritium depth profiling
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 223-24, s. 21-25
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Tidskriftsartikel (refereegranskat)abstract
- A dedicated AMS facility for depth profiling of tritium in carbon samples has been installed, tested and applied to routine measurements in the Forschungszentrum. Rossendorf. It is based on an SF6-insulated 100 kV tandem accelerator equipped with a thin diamond-like carbon (DLC) stripper foil of about 1 mug/cm(2). With this setup carbon samples with tritium concentrations in the range of 5 x 10(10)-10(19) atoms/cm(3) can be analysed. In first routine measurements carbon samples cut from tiles of the inner wall of the fusion experiments ASDEX-upgrade Garching/Germany, JET Culham/UK and TFTR Princeton/USA have been analysed. In addition, depth profiles of deuterium and other light elements can be measured using the Faraday cup at the entrance of the accelerator (SIMS mode of the facility) or in the case of very low concentrations after acceleration using a particle detector (AMS mode). (C) 2004 Elsevier B.V. All rights reserved.
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| 4. |
- Hellborg, Ragnar, et al.
(författare)
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Accelerator mass spectrometry
- 2003
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Ingår i: Romanian Journal of Physics. - 1221-146X. ; 48:1-4, s. 27-37
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Konferensbidrag (refereegranskat)abstract
- Accelerator mass spectrometry (AMS) is a world-wide spread technique and nearly 50 AMS laboratories exist today. The most widely spread application of AMS is for radiocarbon dating and an estimated total of nearly 100000 14C samples are measured per year. Other isotopes used are 10Be, 26Al, 36Cl, 41Ca, 129I. The number of these measured per year is estimated to be 10% of the number of 14C samples or even less
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| 5. |
- Hellborg, Ragnar, et al.
(författare)
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Accelerator mass spectrometry - an overview
- 2003
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Ingår i: Vacuum. - 0042-207X. ; 70:2-3, s. 365-372
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Tidskriftsartikel (refereegranskat)abstract
- The technique of accelerator mass spectrometry (AMS) has spread worldwide since its first demonstration 25 years ago. The equipment used today is very diverse and dedicated accelerators as well as old "nuclear physics machines" can be found in the nearly 50 AMS laboratories today. The most widely spread application of AMS is for radiocarbon dating. However, AMS with C-14 as well as with other long-lived isotopes have also found applications in many other fields in physics and beyond.
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| 6. |
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| 7. |
- Hellborg, Ragnar, et al.
(författare)
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Mechanical design of the recirculating, terminal pumping in the Lund Pelletron, and experimental experience
- 2002
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Ingår i: Pramana - Journal of Physics. - 0304-4289 .- 0973-7111. ; 59:5, s. 725-737
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Konferensbidrag (refereegranskat)abstract
- A recirculating terminal pumping system has been installed in the 3 MV Pelletron tandem accelerator in Lund. An extremly limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass Spectrometry, will be given.
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| 12. |
- Kiisk, Madis
(författare)
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Improvement of the AMS-technique and applications to 3H and 59Ni Measurements
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Accelerator mass spectrometry (AMS) is a highly sensitive technique for counting atoms. Its main advantage in comparison with radiometric methods is the smaller amount of sample required (by a factor of a thousand). The method has a high efficiency and requires only some ten mg of sample material. The radioisotope 59Ni is of great importance in nuclear waste management in the nuclear industry. This isotope is produced by the neutron activation of the stable 58Ni, close to the core of nuclear reactors. Due to its long half-life, it is necessary to determine its activity concentration in the various construction materials in connection with classification and storage considerations. In this thesis, further development of the 59Ni detection technique, using the small 3 MV tandem accelerator in Lund, is presented. Some results of measurements on 59Ni samples from nuclear power plants are presented. Improvements of the detection and chemical purification methods of the stainless steel samples, to reduce the content of the interfering isobar 59Co have been made. In order to make heavy ion AMS feasible at the Lund accelerator facility, new improvements on the AMS technique and in the detection technique have been developed. The performance and the improvements of the new gas stripper with terminal pumping are presented. Charge state distributions for various isotopes used in AMS analysis have been measured. Characteristic X-ray cross-sections have been measured for Fe, Ni and Cu ions in connection with the 59Ni project. The radioisotope 3H is the most frequently utilized isotope in biomedicine, and has numerous applications, e.g. determination of total body water, metabolism studies, dosimetry measurements, etc. The development of tritium AMS is expected to have a great impact in biomedical research for two reasons: tritium is the most widely used radioisotope in biomedicine, and secondly, used in conjunction with 14C, it allows low-level, double-labelling experiments. In this thesis, development of the chemical procedure for sample preparation and of the tritium detection technique using a 3 MV tandetron accelerator at the Rossendorf Research Centre, Germany, are presented. The first measurements of the blood samples from patients after administration of tritiated water are presented.
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| 13. |
- Kiisk, Madis, et al.
(författare)
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The charge state distribution of a carbon beam measured at the lund pelletron accelerator with the newly installed terminal pumping system in use
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 481:1-3, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Charge state distributions for (12) C and C-13 ions have been measured at the Lund Pelletron tandem accelerator for the N-2 gas stripper with a newly installed terminal pumping system in use. A comparison of the results obtained for the ion energies between 1.5 and 2.8 MeV with the foil stripper and the gas stripper without terminal pumping demonstrates the great improvement of the stripping process achieved with the new terminal pumping. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 14. |
- Kiisk, Madis, et al.
(författare)
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The charge state distribution of Be, C, Cl and Al ions at the Lund Pelletron accelerator with the recently modified terminal pumping in use
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 521:2-3, s. 299-305
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Tidskriftsartikel (refereegranskat)abstract
- Some years ago terminal pumping for the gas stripper system at the 3 MV Lund Tandem Pelletron accelerator was installed and charge state distribution measurements using the new installation were reported. Since then, new modifications of the mechanical design of the stripper system have been made. The results of pressure profile measurements as well as the results of charge state distribution measurements in a N-2 and Ar gas stripper at different, new geometrical modifications of the stripper system using C, Be, Al and Cl ion beams are reported. A comparison between pressure profiles obtained for different geometries shows a clear improvement of the vacuum conditions outside the stripper housing for the smallest conductance pipes between the stripper system and the accelerator tubes. These improvements are also well reflected in the charge state distribution measurements, as a higher mean charge state is obtained under the same vacuum conditions in the accelerator tubes for the improved stripper system in comparison with the former mechanical design. (C) 2003 Elsevier B.V. All rights reserved.
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| 18. |
- Persson, Per, et al.
(författare)
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The pressure profile in the Lund Pelletron accelerator with the newly installed terminal pumping in use
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 500:1-3, s. 55-61
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Tidskriftsartikel (refereegranskat)abstract
- Terminal pumping has recently been installed in the Lund tandem Pelletron electrostatic accelerator. The equipment allows a higher gas density in the stripper and an improved vacuum in the accelerator tubes compared to the former system. This improvement has led to an increased beam transmission and to superior measurements for our accelerator mass spectrometry programme. The pressure profile of the stripper system as well as of the accelerator tubes has been calculated using kinetic gas theory. The result will be used to identify possible technical improvements in the future. (C) 2002 Published by Elsevier Science B.V.
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| 19. |
- Stenström, Kristina, et al.
(författare)
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14C emission from Swedish nuclear power plants and its Eeffect on the 14C levels in the environment
- 2000
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The radionuclide 14C is produced in all types of nuclear reactors mainly by neutron-induced reactions in oxygen (17O), nitrogen (14N) and carbon (13C). Part of the 14C created is continuously released during normal operation as airborne effluents in various chemical forms (such as CO2, CO and hydrocarbons) to the surroundings. Because of the biological importance of carbon and the long physical half-life of 14C, it is of interest to measure the releases and their incorporation into living material. The 14C activity concentrations in annual tree rings and air around two Swedish nuclear power plants (Barsebäck and Forsmark) as well as the background 14C activity levels from two reference sites in southern Sweden during 1973-1996 are presented in this report. In order to verify the reliability of the method some investigations have been conducted at two foreign nuclear sites, Sellafield fuel reprocessing plant in England, and Pickering nuclear generating station in Canada, where the releases of 14C are known to be substantial. Furthermore, results from some measurements in the vicinity of Paldiski submarine training centre in Estonia are presented. The results of the 14C measurements of air, vegetation and annual tree rings around the two Swedish nuclear power plants show very low enhancements of 14C, if at all above the uncertainty of the measurements. Even if the accuracy of the measurements of the annual tree rings is rather good (1-2%) the contribution of 14C from the reactors to the environment is so small that it is difficult to separate it from the prevailing background levels of 14C. This is the case for all sampling procedures: in air and vegetation as well as in annual tree rings. Only on a few occasions an actual increase is observed. However, although the calculations suffer from rather large uncertainties, the calculated release rate from Barsebäck is in fair agreement with reported release data. The results of this investigation show that the effective doses to man related to the releases of 14C from the Swedish light-water reactors at Barsebäck and Forsmark are very low, especially compared to the situation at other nuclear installations, such as the fuel reprocessing plant at Sellafield, England, and the heavy-water reactors at Pickering nuclear generating station, Canada. Lund/Malmö February 2000
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