| 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. |
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| 4. |
- Gunnarsson, Mikael, et al.
(författare)
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No radiation protection reasons for restrictions on C-14 urea breath tests in children.
- 2002
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Ingår i: British Journal of Radiology. - : British Institute of Radiology. - 1748-880X .- 0007-1285. ; 75:900, s. 982-986
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Tidskriftsartikel (refereegranskat)abstract
- Traditional 14C urea breath tests are normally not used for younger children because the radiation exposure is unknown. High sensitivity accelerator mass spectrometry and an ultra-low amount (440 Bq) of 14C urea were therefore used both to diagnose Helicobacter pylori (HP) infection in seven children, aged 3–6 years, and to make radiation dose estimates. The activity used was 125 times lower than the amount normally used for older children and 250 times lower than that used for adults. Results were compared with previously reported biokinetic and dosimetric data for adults and older children aged 7–14 years. 14C activity concentrations in urine and exhaled air per unit administered activity for younger children (3–6 years) correspond well with those for older children (7–14 years). For a child aged 3–6 years who is HP negative, the urinary bladder wall receives the highest absorbed dose, 0.3 mGy MBq-1. The effective dose is 0.1 mSv MBq-1 for the 3-year-old child and 0.07 mSv MBq-1 for the 6-year-old child. For two children, the 10 min and 20 min post-14C administration samples of exhaled air showed a significantly higher amount of 14C activity than for the rest of the children, that is 6% and 19% of administered activity exhaled per hour compared with 0.3–0.9% (mean 0.5%) of administered activity exhaled per hour indicating that these two children that is were HP positive. For a 3-year-old HP positive child, absorbed dose to the urinary bladder wall was 0.3 mGy MBq-1 and effective dose per unit of administered activity was 0.4 mSv MBq-1. Using 55 kBq, which is a normal amount for older children when liquid scintillation counters are used for measurement, the effective dose will be approximately 6 µSv to a 3-year-old HP negative child and 20 µSv to a HP positive child. Thus there is no reason for restrictions on performing a normal 14C urea breath test, even on young children.
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| 5. |
- Hellborg, Ragnar, et al.
(författare)
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A high resolution AMS-injector for the Pelletron in Lund
- 2002
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Ingår i: Pramana. - 0973-7111. ; 59:6, s. 1061-1073
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Tidskriftsartikel (refereegranskat)abstract
- A high resolution injector system has recently been installed at the Lund 3 MV tandem Pelletron accelerator. The new injector, designed mainly for Al-26 ions, will increase the experimental potential of the Lund AMS facility considerably. High quality energy- and mass-resolution is obtained by using a 90degrees spherical electrostatic analyzer followed by a 90degrees magnetic analyzer. The injector is equipped with a high intensity sputtering source with a spherical ionizer. A new analytical technique for acceptance calculations as well as PC-based computational methods have been used in the design of the ion optical system of the new injector. Compared to our old injector system which has a magnetic analyzer with a bending angle of only 15degrees, the new system has a more than ten times better resolution. The beam optics of the new system is also better designed to match the accelerator acceptance. In this way the ion transmission from the ion source to the detector, for different ions of interest in our AMS programme, has been increased.
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| 6. |
- 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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| 7. |
- 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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| 8. |
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| 9. |
- 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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