| 1. |
- Hellborg, Ragnar, et al.
(författare)
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Accelerators for medicine
- 2005
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Ingår i: Electrostatic accelerators. Fundamentals and applications. - 3540239839 ; , s. 24-24
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Persson, Per, et al.
(författare)
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Determination of the detection limit of Ni-59 at the Lund AMS facility by using characteristic projectile X-rays
- 2000
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 160:4, s. 510-514
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Tidskriftsartikel (refereegranskat)abstract
- Accelerator mass spectrometry (AMS) is an ultra-sensitive method for counting atoms, both radionuclides and stable nuclides. When using small tandem accelerators to measure heavy isotopes, interfering isobars are often troublesome. One way to reduce this interference is to combine AMS with the detection of characteristic X-rays of the projectile. After analysis in the AMS system it is possible to identify ions of different atomic number by their characteristic X-rays, by slowing down the ions in a suitable target. In this paper, the detection limit of Ni-59 at the Land AMS facility is reported. A method for the chemical extraction of nickel from stainless steel, combined with a purification step to reduce the cobalt content in the sample by several orders of magnitude, is also described. (C) 2000 Elsevier Science B.V. All rights reserved.
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| 3. |
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| 4. |
- Alexandrescu, E, et al.
(författare)
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Os fossils humains des grottes Muierii et Cioclovina, Roumanie
- 2010
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Ingår i: L'Anthropologie. - : Elsevier BV. - 0003-5521. ; 114:3, s. 341-353
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the cultural and archaeological context of the human fossil bones from Muierii Cave, dated by us to the age of 30 150 ± 800 14C years BP (Before Present) or 34 810 ± 927 cal years BP (calibrated years Before Present), and from Cioclovina Cave, dated to the age of 29 000 ± 700 14C years BP or 33 540 ± 832 cal years BP, in the Southern Carpathians. These are among the most ancient dated human fossil remains from Central and South-Eastern Europe and are described in conjunction with other sites with Mousterian assemblages of the recent Neanderthal population, and sites with Aurignacian assemblage of early modern humans, from Romanian region, for the interval of time 34,000–26,000, the transitional period from the Middle Paleolithic to the Upper Paleolithic.
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| 5. |
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| 6. |
- Beideck, DJ, et al.
(författare)
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Lifetimes of 5d96p and 5d86s6p levels in Hg iii
- 1993
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 47:2, s. 884-889
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and theoretical studies of lifetimes and transition probabilities for doubly ionized mercury, Hg III, are reported. Such data are currently of great astrophysical interest because observations with the Goddard high resolution spectrograph on board the Hubble space telescope have shown some 5d(9)6s-5d(9)6p transitions of Hg III in the spectrum of the chemically peculiar star chi Lupi. We now report experimental lifetimes for some selected 5d(9)6p and 5d(8)6s6p levels, determined by beam-foil spectroscopy, and compare the results with theoretical transition probabilities based on relativistic multiconfiguration Dirac-Fock calculations.
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| 7. |
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| 8. |
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| 9. |
- Eriksson, Mikael, et al.
(författare)
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Accelerators for synchrotron radiation
- 2005
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Ingår i: Electrostatic Accelerators: Fundamentals and Applications. - 1611-1052. ; , s. 36-50
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- 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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| 11. |
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| 12. |
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| 13. |
- Fahlander, Claes, et al.
(författare)
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Nuclear Structure
- 2005
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Ingår i: Electrostatic Accelerators - Fundamentals and Applications. - 9783540270959 - 9783540239833 ; , s. 413-428
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Bokkapitel (refereegranskat)
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| 14. |
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| 15. |
- Gunnarsson, Mikael, et al.
(författare)
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Long-term biokinetics and radiation exposure of patients undergoing 14C-glycocholic acid and 14C-xylose breath tests.
- 2007
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Ingår i: Cancer Biotherapy & Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 22:6, s. 762-771
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Tidskriftsartikel (refereegranskat)abstract
- The (14)C-glycocholic acid and (14)C-xylose breath tests are clinically used for the diagnosis of intestinal diseases, such as bacterial overgrowth in the small intestine. The two tests have in earlier studies been thoroughly evaluated regarding their clinical value, but due to the long physical half-life of (14)C and the limited biokinetic and dosimetric data, which are available for humans, several hospitals have been restrictive in their use. The aim of this study was to investigate the long-term biokinetics and dosimetry of the two (14)C compounds in patients and volunteers, using the highly sensitive accelerator mass spectrometry (AMS) technique. Eighteen (18) subjects were included, 9 for each compound. The (14)C content in samples from exhaled air, urine, and, for some subjects, also feces were analyzed with both liquid scintillation counting (LSC) and AMS. The results from the glycocholic acid study showed that, up to 1 year after the administration, 67%+/-6% (mean+/-standard deviation) of the administered activity was recovered in exhaled air, 2.4%+/-0.4% was found in urine, and 7.6% (1 subject) in feces. In the xylose study, the major part was found in the urine (66%+/-2%). A significant part was exhaled (28%+/-5%), and the result from an initial 72-hour stool collection from 2 of the subjects showed that the excretion by feces was insignificant. The absorbed dose to various organs and tissues and the effective dose were calculated by using biokinetic models, based on a combination of experimental data from the present study and from earlier reports. In the glycocholic acid study, the highest absorbed dose was received by the colon (1.2 mGy/MBq). In the xylose study, the adipose tissue received 0.8 mGy/MBq. The effective dose was estimated to 0.5 (glycocholic acid) and 0.07 mSv/MBq (xylose). Thus, from a radiation protection point of view, we see no need for restrictions in using the two (14)C-labeled radiopharmaceuticals on adults with the activities normally administered (0.07-0.4 MBq).
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| 16. |
- 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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| 17. |
- 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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| 18. |
- Hellborg, Ragnar, et al.
(författare)
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Accelerator Mass Spectrometry
- 2008
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Ingår i: Mass Spectrometry Reviews. - : Wiley. - 0277-7037 .- 1098-2787. ; 27:5, s. 398-427
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Forskningsöversikt (refereegranskat)abstract
- In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is (14)C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 (14)C samples are measured per year. Other isotopes studied include (10)Be, (26)Al, (36)Cl, (41)Ca, (59)Ni, (129)I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of (14)C samples. (c) 2008 Wiley Periodicals, Inc., Mass Spec Rev.
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| 19. |
- 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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| 20. |
- 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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| 21. |
- Hellborg, Ragnar
(författare)
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Accelerator Mass Spectrometry – An Overview
- 2002
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Ingår i: Proc. of the 14th Int. Conf. on Electrostatic Accelerators and Beam Technologies, Obninsk Russia, 6-9 June 2001. ; , s. 10-19
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Konferensbidrag (refereegranskat)
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| 22. |
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| 23. |
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| 24. |
- Hellborg, Ragnar, et al.
(författare)
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Direct Current Accelerators for Industrial Applications
- 2011
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Ingår i: Reviews of Accelerator Science and Technology. - 1793-8058. ; 4:1, s. 183-212
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in Undetermined Direct current accelerators form the basis of many front-line industrial processes. They have many advantages that have kept them at the forefront of technology for many decades, such as a small and easily managed environmental footprint. In this article, the basic principles of the different subsystems (ion and electron sources, high voltage generation, control, etc.) are overviewed. Some well-known (ion implantation and polymer processing) and lesser-known (electron beam lithography and particle-induced X-ray aerosol mapping) applications are reviewed.
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| 25. |
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| 26. |
- Hellborg, Ragnar, et al.
(författare)
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Industrial Accelerators
- 2013
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Ingår i: Handbook of Accelerator Physics and Engineering. - 9789814415842 ; 2nd edition, s. 27-31
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Bokkapitel (refereegranskat)
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| 27. |
- Hellborg, Ragnar, et al.
(författare)
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Industrial Aspects of Ion Beam Analysis
- 2012
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Ingår i: Industrial Accelerators and their Applications. - 9789814307048 ; , s. 183-242
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Bokkapitel (refereegranskat)
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| 28. |
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| 29. |
- 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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| 30. |
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| 31. |
- Hellborg, Ragnar, et al.
(författare)
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Sources and Detectors in Accelerator Mass Spectrometry
- 2010
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Ingår i: The Encyclopedia of Mass Spectrometry: Volume 5 Elemental, Isotopic and Inorganic Analysis by Mass Spectrometry. - 9780080438047 ; 5, s. 613-620
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 32. |
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| 33. |
- Hellborg, Ragnar, et al.
(författare)
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Vacuum in an accelerator system - calculations and measurements
- 2005
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X. ; 78:2-4, s. 427-434
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Tidskriftsartikel (refereegranskat)abstract
- The importance of different sources of gases in a vacuum system is discussed and the definitions of different flow regimes are presented. The conductance is given for a few different, typical geometries in an accelerator vacuum system. The theory is applied to the vacuum system of the Lund electrostatic tandem accelerator and a pressure profile through the accelerator is calculated. The quality of this simplified method is discussed.
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| 34. |
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| 35. |
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| 36. |
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| 37. |
- 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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| 38. |
- 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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| 39. |
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| 40. |
- Laitinen, Mikko, et al.
(författare)
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Mobility determination of lead isotopes in glass for retrospective radon measurements
- 2008
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 131:3, s. 212-216
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Tidskriftsartikel (refereegranskat)abstract
- In retrospective radon measurements, the 22-y half life of Pb-210 is used as an advantage. Pb-210 is often considered to be relatively immobile in glass after alpha recoil implanted by Rn-222 progenies. The diffusion of Pb-210 could, however, lead to uncertain wrong retrospective radon exposure estimations if Pb-210 is mobile and can escape from glass, or lost as a result of cleaning-induced surface modification. This diffusion was studied by a radiotracer technique, where Pb-209 was used as a tracer in a glass matrix for which the elemental composition is known. Using the ion guide isotope separator on-line technique, the Pb-209 atoms were implanted into the glass with an energy of 39 keV. The diffusion profiles and the diffusion coefficients were determined after annealing at 470-620 degrees C and serial sectioning by ion sputtering. In addition, the effect of surface cleaning on diffusion was tested. From the Arrhenius fit, the activation enthalpy (H) was determined, which is equal to 3.2 +/- 0.2 eV, and also the pre-exponential factor D-0, in the order of 20 m(2)s(-1). This result confirms the assumption that over a time period of 50 y Pb-209 (and Pb-210) is effectively immobile in the glass. The boundary condition obtained from the measurements had the characteristic of a sink, implying loss of Pb-209 in the topmost surface at high temperatures.
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| 41. |
- Liechtenstein, VK, et al.
(författare)
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Advances in targetry with thin diamond-like carbon foils
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 480:1, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- Thin and stable diamond-like carbon (DLC) foils, which were fabricated at the Kurchatov Institute by sputter deposition, have proved recently to be advantageous for stripping and secondary electron timing of high energy heavy ions in a number of accelerator experiments. This resulted in expanding applications of these DLC foils which necessitated further development efforts directed toward the following applications of DLC targetry: (i) thin stripper foils for lower energy tandem accelerators, (ii) enlarged (up to 66 mm. in diameter) stop foils for improved time-of-flight elastic recoil detection ion beam analysis, and (iii) ultra-thin (about 0.6 mug/cm(2)) DLC foils for some fundamental and applied physics experiments. Along with the fabrication of thin DLC stripper foils for tandem accelerators, much thicker (up to 200 mug/cm(2)) foils for post-stripping of heavy-ion beams in higher energy linacs, are within reach.
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| 42. |
- Magnusson, Åsa, et al.
(författare)
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Levels of C-14 in the terrestrial environment in the vicinity of two European nuclear power plants
- 2004
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Ingår i: Radiocarbon. - 0033-8222. ; 46:2, s. 863-868
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Tidskriftsartikel (refereegranskat)abstract
- Radiocarbon is produced in all types of nuclear reactors. Most of the C-14 released into the environment is in the form of gaseous emissions. Recent data on the C-14 concentration found in terrestrial samples taken in the vicinity of nuclear power plants in Romania and Lithuania are presented. We found increased C-14 levels in the surroundings of both power plants. At the Romanian power plant Cernavoda, we found excess levels of C-14 in grass within a distance of about 1000 in, the highest C-14 specific activity being 311 Bq/kg C (approximately 28% above the contemporary C-14 background) found at a distance of 200 in from the point of release (nearest sampling location). At the Lithuanian power plant Ignalina, samples of willow, pine, and spruce showed a C-14 excess of similar magnitude, while significantly higher values were found in moss samples. The samples were analyzed at the accelerator mass spectrometry facility in Lund, Sweden.
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| 43. |
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| 44. |
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| 45. |
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| 46. |
- Olariu, A, et al.
(författare)
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Dating of some Romanian fossil bones by combined nuclear methods
- 2002
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731. ; 253:2, s. 307-311
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Tidskriftsartikel (refereegranskat)abstract
- A set of fossil bones from Romania has been analysed by accelerator mass spectrometry and by neutron activation analysis in order to estimate their age. The temporal attributing of Malu Rosu archaeological settlement has been extensively analyzed. The radiocarbon age, determined by accelerator mass spectrometry, for this site is 5510+/-200 BP. This is in agreement with the age of 6000+/-2000 BP, obtained by the dating method based on fluorine content, determined by neutron activation analysis.
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| 47. |
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| 48. |
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| 49. |
- 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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| 50. |
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