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- Rodriguez, D., et al.
(författare)
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MATS and LaSpec : High-precision experiments using ion traps and lasers at FAIR
- 2010
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Ingår i: The European physical journal. Special topics. - : Springer Science and Business Media LLC. - 1951-6355 .- 1951-6401. ; 183, s. 1-123
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Forskningsöversikt (refereegranskat)abstract
- Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique ""fingerprint"". Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10(-5) to below 10(-8) for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10(-9) can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. This accuracy limit is important for fundamental interaction tests, but also allows for the study of the fine structure of the nuclear mass surface with unprecedented accuracy, whenever required. The use of the FT-ICR technique provides true single ion sensitivity. This is essential to access isotopes that are produced with minimum rates which are very often the most interesting ones. Instead of pushing for highest accuracy, the high charge state of the ions can also be used to reduce the storage time of the ions, hence making measurements on even shorter-lived isotopes possible. Decay studies in ion traps will become possible with MATS. Novel spectroscopic tools for in-trap high-resolution conversion-electron and charged-particle spectroscopy from carrier-free sources will be developed, aiming e. g. at the measurements of quadrupole moments and E0 strengths. With the possibility of both high-accuracy mass measurements of the shortest-lived isotopes and decay studies, the high sensitivity and accuracy potential of MATS is ideally suited for the study of very exotic nuclides that will only be produced at the FAIR facility. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The dependencies of the hyperfine splitting and isotope shift on the nuclear moments and mean square nuclear charge radii are well known and the theoretical framework for the extraction of nuclear parameters is well established. These extracted parameters provide fundamental information on the structure of nuclei at the limits of stability. Vital information on both bulk and valence nuclear properties are derived and an exceptional sensitivity to changes in nuclear deformation is achieved. Laser spectroscopy provides the only mechanism for such studies in exotic systems and uniquely facilitates these studies in a model-independent manner. The accuracy of laser-spectroscopic-determined nuclear properties is very high. Requirements concerning production rates are moderate; collinear spectroscopy has been performed with production rates as few as 100 ions per second and laser-desorption resonance ionization mass spectroscopy (combined with beta-delayed neutron detection) has been achieved with rates of only a few atoms per second. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy, which will provide a complete system with respect to the physics and isotopes that can be studied. Since MATS and LaSpec require high-quality low-energy beams, the two collaborations have a common beamline to stop the radioactive beam of in-flight produced isotopes and prepare them in a suitable way for transfer to the MATS and LaSpec setups, respectively.
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| 12. |
- Waschitz, Y., et al.
(författare)
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Independent isotopic fission yields of Cf-252 spontaneous fission via mass measurements at the FRS Ion Catcher
- 2023
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Ingår i: 15th International Conference on Nuclear Data for Science and Technology, ND2022. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- We present first preliminary results of a novel method for measuring independent isotopic fission yields (IIFYs) of spontaneous fission (SF) via direct mass measurements, at the FRS Ion Catcher (FRS -IC) at GSI. Fission products were generated from a Cf-252 source installed in a cryogenic stopping cell, and were identified and counted with the multiple-reflection time-of-flight mass spectrometer (MR-TOR-MS) of the FRS-IC, utilizing well-established measurement and data analysis methods. The MR-TOR-MS resolves isobars unambiguously, even with limited statistics, and its non-scanning nature ensures minimal relative systematic uncertainties amongst fission products. The analysis for extracting IIFYs includes isotope-dependent efficiency corrections for all components of the FRS -IC. In particular, we applied a self-consistent technique that takes into account the element-dependent survival efficiencies in the CSC, due to chemical reactions with the buffer gas. Our IIFY results, which cover several tens of fission products in the less -accessible high-mass peak (Z = 56 to 63) down to fission yields at the level of 10(-5), are generally similar to those of the nuclear database ENDF/B-VII.O. Nevertheless, they reveal some structures that are not observed in the database smooth trends. These are the first results of a planned campaign to investigate IIFY distributions of spontaneous fission at the FRS-IC. Upcoming experiments will extend our results to wider Z and N ranges, lower fission yields, and other spontaneously-fissioning actinides.
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- Andreasson, M., et al.
(författare)
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Altered CSF levels of monoamines in hereditary spastic paraparesis 10 A case series
- 2019
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- Objective To perform a comprehensive clinical characterization and biochemical CSF profile analyses in 2 Swedish families with hereditary spastic paraparesis (HSP) 10 (SPG10) caused by 2 different mutations in the neuronal kinesin heavy chain gene (KIF5A). Methods Structured clinical assessment, genetic studies, and neuroradiologic and electrophysiological evaluations were performed in 4 patients from 2 families with SPG10. Additional CSF analysis was conducted in 3 patients with regard to levels of neurodegenerative markers and monoamine metabolism. Results All patients exhibited a complex form of HSP with a mild to moderate concurrent axonal polyneuropathy. The heterozygous missense mutations c.767A>G and c.967C>T in KIF5A were found. Wide intrafamilial phenotype variability was evident in both families. CSF analysis demonstrated a mild elevation of neurofilament light (NFL) chain in the patient with longest disease duration. Unexpectedly, all patients exhibited increased levels of the dopamine metabolite, homovanillic acid, whereas decreased levels of the noradrenergic metabolite, 3-methoxy-4-hydroxyphenylglycol, were found in 2 of 3 patients. Conclusions We report on CSF abnormalities in SPG10, demonstrating that NFL elevation is not a mandatory finding but may appear after long-standing disease. Impaired transportation of synaptic proteins may be a possible explanation for the increased dopaminergic turnover and noradrenergic deficiency identified. The reasons for these selective abnormalities, unrelated to obvious clinical features, remain to be explained. Our findings need further confirmation in larger cohorts of patients harboring KIF5A mutations.
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- Andreasson, M., et al.
(författare)
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Parkinson's disease with restless legs syndrome-an in vivo corneal confocal microscopy study
- 2021
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Ingår i: npj Parkinson's Disease. - : Springer Science and Business Media LLC. - 2373-8057. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Small fiber neuropathy (SFN) has been suggested as a trigger of restless legs syndrome (RLS). An increased prevalence of peripheral neuropathy has been demonstrated in Parkinson's disease (PD). We aimed to investigate, in a cross-sectional manner, whether SFN is overrepresented in PD patients with concurrent RLS relative to PD patients without RLS, using in vivo corneal confocal microscopy (IVCCM) and quantitative sensory testing (QST) as part of small fiber assessment. Study participants comprised of age- and sex-matched PD patients with (n = 21) and without RLS (n = 21), and controls (n = 13). Diagnosis of RLS was consolidated with the sensory suggested immobilization test. Assessments included nerve conduction studies (NCS), Utah Early Neuropathy Scale (UENS), QST, and IVCCM, with automated determination of corneal nerve fiber length (CNFL) and branch density (CNBD) from wide-area mosaics of the subbasal nerve plexus. Plasma neurofilament light (p-NfL) was determined as a measure of axonal degeneration. No significant differences were found between groups when comparing CNFL (p = 0.81), CNBD (p = 0.92), NCS (p = 0.82), and QST (minimum p = 0.54). UENS scores, however, differed significantly (p = 0.001), with post-hoc pairwise testing revealing higher scores in both PD groups relative to controls (p = 0.018 and p = 0.001). Analysis of all PD patients (n = 42) revealed a correlation between the duration of l-dopa therapy and CNBD (rho = -0.36, p = 0.022), and p-NfL correlated with UENS (rho = 0.35, p = 0.026) and NCS (rho = -0.51, p = 0.001). Small and large fiber neuropathy do not appear to be associated with RLS in PD. Whether peripheral small and/or large fiber pathology associates with central neurodegeneration in PD merits further longitudinal studies.
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- Andreasson, M, et al.
(författare)
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Polyneuropathy in Gaucher disease type 1 and 3 - a descriptive case series
- 2019
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 15358-
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Tidskriftsartikel (refereegranskat)abstract
- Polyneuropathy (PNP) has been reported to be a possible phenotypic feature in Gaucher disease type 1 (GD1), while less is known about PNP in type 3 (GD3). We performed a cross-sectional study, exploring PNP in a Swedish GD cohort. Clinical assessment and blood biochemistry were carried out in 8 patients with GD1 and 11 patients with GD3. In patients with symptoms or clinical findings indicative of PNP, nerve conduction studies and quantitative sensory testing were performed. Assessments were compared to historic controls. A subclinical small fiber neuropathy (SFN) was demonstrated in 2 of 8 patients in the significantly (p = 0,021) older GD1 cohort. A large fiber PNP was evident in an additional 3 GD1 patients but could not be ascribed as disease manifestation. No GD3 patients exhibited neurophysiological evidence of small or large fiber PNP attributed to GD3. Compared to historic controls, no significant group differences were evident with regard to neuropathy rating scores. In summary, our study does not support large fiber PNP as a prevalent manifestation of GD. SFN is a possible feature in GD1, although small sample size limits definite conclusions. Our study provides novel data, arguing against clinically significant small or large fiber PNP in GD3.
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- Kolhinen, V. S., et al.
(författare)
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Recommissioning of JYFLTRAP at the new IGISOL-4 facility
- 2013
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 317:Part B, s. 506-509
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Tidskriftsartikel (refereegranskat)abstract
- The JYFLTRAP double Penning-trap system was moved to a new location along with the Ion Guide Isotope Separator On-line (IGISOL) facility at the Accelerator Laboratory of the University of Jyväskylä. The move made it possible to upgrade various parts of the facility. For example, separate beam lines for JYFLTRAP and the collinear laser spectroscopy station were constructed after the radio-frequency quadrupole cooler and buncher. In this contribution we give an overview of the new JYFLTRAP facility and results from the first stable ion-beam tests.
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| 22. |
- Minde, Jan, et al.
(författare)
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A novel NGFB point mutation : a phenotype study of heterozygous patients
- 2009
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Ingår i: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ Publishing Group Ltd. - 0022-3050 .- 1468-330X. ; 80:2, s. 188-195
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: A family with neurological findings similar to hereditary sensory and autonomic neuropathy type V having a point mutation in the nerve growth factor beta (NGFB) gene was recently described. The homozygous genotype gives disabling symptoms. The purpose of the present study was to evaluate the symptoms in heterozygous patients. METHODS: 26 patients heterozygous for the NGFB mutation (12 men, mean age 50 (13-90) years) were examined clinically and answered a health status questionnaire, including the Michigan Neuropathy Screening Instrument (MNSI). 28 relatives (15 men, mean age 44 (15-86) years) without the mutation served as controls in the clinical examination part. 23 of the heterozygotes were examined neurophysiologically and six heterozygous patients underwent a sural nerve biopsy. RESULTS: The heterozygous phenotype ranged from eight patients with Charcot arthropathy starting in adult age and associated with variable symptoms of neuropathy but without complete insensitivity to pain, anhidrosis or mental retardation, to 10 symptom free patients. There was no difference in MNSI between the young heterozygous cases (<55 years old) and the controls. Six of 23 heterozygous patients had impaired cutaneous thermal perception and 11 of 23 had signs of carpal tunnel syndrome. Sural nerve biopsies showed a moderate reduction of both small myelinated (Adelta) and unmyelinated (C) fibres. No apparent correlation of small fibre reduction to symptoms was found. CONCLUSIONS: The NGFB mutation in its heterozygous form results in a milder disease than in homozygotes, with a variable clinical picture, ranging from asymptomatic cases to those with Charcot arthropathy appearing in adult age. Particularly age, but perhaps lifestyle factors also, may influence the development of clinical polyneuropathy.
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