| 51. |
- Braumann, Ilka, et al.
(författare)
-
Semi-dwarf barley (Hordeum vulgare L.) brh2 and ari-l mutants are deficient in a U-box E3 ubiquitin ligase
- 2018
-
Ingår i: Plant Growth Regulation. - : Springer Science and Business Media LLC. - 0167-6903 .- 1573-5087. ; 86:2, s. 223-234
-
Tidskriftsartikel (refereegranskat)abstract
- Lodging is the process where crop plants fall over and lie on the ground due to strong winds and heavy precipitation. This problem reduces yield and increases the risk of fungal infections and pre-harvest germination. In order to avoid lodging, plant breeders utilize short-culm mutants, which often have a robust culm that can support the weight of a heavy spike. In barley (Hordeum vulgare L.), thousands of short-culm mutants have been isolated in breeding programs around the world. Our long-term goal is to reveal the genetic network underlying culm length, with the objective to provide an enlarged repertoire of genes and alleles suitable for future breeding of lodging resistant barley. In the present work we studied a group of allelic brh2 and ari-l mutants, which have a relatively strong semi-dwarf phenotype and are phenotypically similar to previously identified mutants deficient in brassinosteroid signalling or metabolism. The Brh2 gene is located in the centromeric region of chromosome 4H and we applied a candidate gene approach to identify the gene. Brh2 is orthologous to TUD1 in rice (Orysa sativa L.), which encodes a U-box E3 ubiquitin ligase. We identified one missense mutation, one nonsense mutation and four deletions of the complete Brh2 gene. The mutants could respond to exogenously applied brassinolide, which suggests that the apparent brassinosteroid deficient phenotype of barley brh2 and ari-l mutants is related to brassinosteroid metabolism rather than signalling.
|
|
| 52. |
- Breunlin, Jonas, et al.
(författare)
-
Methods for measuring sub-pm rad vertical emittance at the Swiss Light Source
- 2015
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 803, s. 55-64
-
Tidskriftsartikel (refereegranskat)abstract
- We report on methods capable of measuring a rms vertical electron beam size of 3 pm with a runs error of less than 10% at a diagnostic beamline at the Swiss Light Source (SLS). This corresponds to a vertical emittance 01 06 pm rad with a 20% rms error. We showed this capability by presenting the theoretical basis for, and the data from, a series of measurements on a stable beam at 1.6 pm rad vertical emittance at the SLS. The methods presented utilized either pi- or sigma-polarized synchrotron radiation (SR) in the visible to ultra violet (vis-UV) spectral range. In addition to the established g-polarization method, we introduced a diffraction method with a potentially high resolution capability. Also an intensity imbalanced diffraction scheme was introduced, but was found to be prone to SR induced carbon contamination on optical elements. (C) 2015 Elsevier B.V. All rights reserved.
|
|
| 53. |
- Bruzzi, M, et al.
(författare)
-
Radiation-hard semiconductor detectors for SuperLHC
- 2005
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 541:1-2, s. 189-201
-
Tidskriftsartikel (refereegranskat)abstract
- An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 1035 cm-2 s-1 has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 1016cm-2. The CERN-RD50 project "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" has been established in 2002 to explore detector materials and technologies that will allow to operate devices up to, or beyond, this limit. The strategies followed by RD50 to enhance the radiation tolerance include the development of new or defect engineered detector materials (SiC, GaN, Czochralski and epitaxial silicon, oxygen enriched Float Zone silicon), the improvement of present detector designs and the understanding of the microscopic defects causing the degradation of the irradiated detectors. The latest advancements within the RD50 collaboration on radiation hard semiconductor detectors will be reviewed and discussed in this work.
|
|
| 54. |
- Carlén, Lars, et al.
(författare)
-
CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. III. readout system
- 2004
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 516:2-3, s. 327-347
-
Tidskriftsartikel (refereegranskat)abstract
- (CHICSi) Celsius Heavy Ion Collaboration Si detector system is a high granularity, modular detector telescope array for operation around the cluster-jet target/circulating beam intersection of the CELSIUS storage ring at the The. Svedberg Laboratory in Uppsala, Sweden. It is able to provide identity and momentum vector of up to 100 charged particles and fragments from proton-nucleus and nucleus-nucleus collisions at intermediate energies, 50-1000A MeV. All detector telescopes as well as the major part of electronic readout system are placed inside the target chamber in ultra-high vacuum (UHV, 10(-9)-10(-7) Pa). This requires Very Large Scale Integrated (VLSI) microchip for the spectroscopic signal processing and the generation and transport of digital control signals. Eighteen telescopes, read out with chip-on-board technique by ceramics Mother Boards (MB) and corresponding 18 microchips are mounted on a 450 x 45 mm(2) Grand Mother Board (GMB), processed on FR4 glass-fibre material. Each of these 28 GMB units contains a daisy-chain organisation of the VLSI chips and associated protection circuits. Analogue-to-digital conversion of the spectroscopic signals is performed on a board outside the chamber which is connected on one side to a power distribution board, directly attached to a UHV mounting flange, and on the other side to the VME-based data acquisition system (CHICSiDAQ). This in its turn is connected via a fibre-optic link to the general TSL acquisition system (SVEDAQ), and in this way data from auxiliary detector systems, read out in CAMAC mode, can be stored in coincidence with CHICSi data.
|
|
| 55. |
- Carlsson, Lars-Eric, et al.
(författare)
-
PIXE Analysis of Samples of Intermediate Thickness
- 1981
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 179-183
-
Tidskriftsartikel (refereegranskat)abstract
- A procedure for making accurate matrix corrections in PIXE analyses of samples of intermediate thickness has been developed. The transmission of a collimated X-ray beam through different parts of the sample is measured with a Si(Li) detector to determine the thickness and shape of the sample. Experiments have been performed using uniform polymer foils doped with known concentrations of different elements and with thicknesses ranging from 1.5 to 11 mg/cm2. The results from these samples indicate that the accuracy of the correction procedure is better than 5%. The correction procedure has been applied to, e.g., samples obtained in single orifice cascade impactors.
|
|
| 56. |
- Carlsson, Lars-Eric, et al.
(författare)
-
Rapid Determination of Major and Trace Elements in Geological Material with Proton-Induced X-Ray and Gamma-Ray Emission
- 1981
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 531-537
-
Tidskriftsartikel (refereegranskat)abstract
- The simultaneous detection of proton-induced X-rays and gamma-rays enables rapid determination of both major and trace elements in thick homogeneous samples. Using protons of energy 2.55 MeV, the atomic numbers of the elements detectable with this technique were Z=3, 5, 9, 11–13 from gamma-ray analysis and Z=13–92 from X-ray analysis. Thick target concentrations were determined from a thoroughly made thin target calibration and from matrix-dependent conversion factors calculated from fundamental parameters. The major compositions of samples needed in these calculations are derived in an iterative procedure using the spectra recorded. The method proposed has been tested on six USGS rock standards. Detection limits for one of the standards are presented. Approximately 20 elements were detected in each sample 5 min irradiations. For elements well above their detection limits, the results are typically accurate to within 5%. The precision of repeated day-to-day analysis is about 2% (one standard deviation).
|
|
| 57. |
- Christiansen, Peter, et al.
(författare)
-
The influence of detector effects on TPC performance
- 2009
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 609:2-3, s. 149-155
-
Tidskriftsartikel (refereegranskat)abstract
- TPC stand alone simulations based on different energy loss models are compared to previously reported measurements with an ALICE TPC prototype. The performance obtained from simulations is shown to depend significantly on all the included detector effects stressing that energy loss model calculations alone are inadequate for describing the performance. When all effects are included, a good quantitative description of both the specific energy loss and the space point resolution can be obtained from all models. This shows that the TPC description in the official ALICE TPC simulation is in agreement with the measured test beam data. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 58. |
- Cutic, Nino, et al.
(författare)
-
Characterization of the arrival time jitter at the MAX-lab test-FEL using electro-optical spectral decoding
- 2011
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 626, s. 16-19
-
Tidskriftsartikel (refereegranskat)abstract
- Electro-optical spectral decoding is used as an online diagnostic tool at the MAX-lab test-FEL to characterize the arrival time of electrons relative to the seed-laser pulse, measure the jitter between them and to measure the relative width of the electron bunch in order to optimize compression. Frequency characteristics of the jitter are presented. The measurements are used to get information on possible causes of the jitter and accompanying drifts. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 59. |
- Da Via, C, et al.
(författare)
-
Lightwave Analogue Links For LHC Detector Front-ends
- 1994
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 344:1, s. 199-211
-
Tidskriftsartikel (refereegranskat)abstract
- The requirements on optical links for transferring analog and digital signals from the detector front-ends to the readout electronics at future high-luminosity colliders are reviewed. The advantages of external modulation techniques are discussed. An outline is given of the the R&D programme recently started at CERN by a collaboration involving high-energy physics institutes, optoelectronics research laboratories and industry, in order to develop electro-optic intensity modulator arrays, particularly for analogue applications, and to investigate the feasibility of volume production. The design of multichannel demonstrators in lithium niobate and III-V semiconductor technology is described. Preliminary results of the performance measurements are presented.
|
|
| 60. |
- Desaedeleer, Georges G, et al.
(författare)
-
Monitoring Aerosol Elemental Composition in Particle Size Fractions for Predicting Human Respiratory Uptake
- 1977
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 142:1-2, s. 97-99
-
Tidskriftsartikel (refereegranskat)abstract
- Proton induced X-ray emission analysis is useful in measuring changes in particle size distribution of trace elements on exposure of aerosol to the human lung environment and deposition in the air-ways. PIXE analysis is also useful in detecting variations in particle size distributions of elements as they occur in the atmosphere. For the case of lead aerosol along a highway, it is shown that the extent and site of respiratory deposition of particles depend on their size, and the size distribution may vary under urban atmospheric conditions sufficiently to affect respiratory deposition efficiency.
|
|
