SwePub - search: L773:0018 9499

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1.	Abdel, Naseem, et al. (author) Fabrication and Characterization of Ultra-Thin PIN Silicon Detectors for Counting the Passage of MeV Ions 2013 In: IEEE Transactions on Nuclear Science. - 0018-9499. ; 60:2, s. 1182-1188 Journal article (peer-reviewed)abstract This paper describes the fabrication and initial characterization of an ultra-thin silicon PIN detector using a new technique in silicon nanotechnology. In collaboration with the Nuclear Physics Division and the Lund Nano Lab at Lund University, we have developed and manufactured ultra thin Delta E-detectors for spectroscopic applications. The fabrication process has been carried out using a double-polished silicon substrate n-type wafer and locally thinning by means of a 10:1 solution of 25% tetramethyl ammonium hydroxide (TMAH) with Isopropyl alcohol. More than 100 detectors of different thicknesses, down to 5 mu m with active areas ranging from 0.71 to 0.172 mm(2), have been fabricated. The main design considerations of our thin detectors were a very low leakage current below 12 nA and a low full depletion voltage at a reverse bias less than 1.5 V. Finally, most of our thin detectors offer an energy resolution (FWHM) as low as 31 keV for 5.487 MeV alpha particles from a Am-241 source.
2.	Akselsson, Roland, et al. (author) PIXE Analysis Research in Lund 1979 In: IEEE Transactions on Nuclear Science. - 0018-9499. ; NS-26:1, s. 1358-1362 Journal article (peer-reviewed)abstract Protons or a-particles from a 3 MV tandem Pelletron are used to induce characteristic x-rays, which are detected by a Si(Li)-detector. To optimize the quality and speed of data taking we use an absorber with a hole, pile-up rejection and on-demand beam. Forty samples may be entered simultaneously into the vacuum, and their positioning is operated by pushbuttons. The system is prepared for minicomputer steering. PIXE is combined with analysis of backscattered particles and in some cases γ-ray detection from a 19F(p,αγ) 160-reaction. At different stages of development we have a bent-chrystal spectrometer, microbeam and facilities to extract the beam from vacuum. In the introduction of PIXE to applied fields, it is important, that physicists take part in identifying, planning and performing suitable projects e.g. experiments where rapid multielemental analysis of many samples is crucial. In Lund we investigate the elemental composition of size-fractionated airborne particles from work environments and ambient air. The objectives are then to learn about sources, transport and deposition of particles and to contribute to the understanding of relations between exposure and health effects. We are also developing procedures for trace elemental analysis of water. Detection limits in the range of 0.1 ppb have been demonstrated. In other projects in progress biological and mineralogical samples are analysed.
3.	Akselsson, Roland (author) PIXE in 1980: Summary of the Second International Conference on Particle Induced X-Ray Emission and its Analytical Applications 1981 In: IEEE Transactions on Nuclear Science. - 0018-9499. ; NS-28:2, s. 1369-1373 Journal article (peer-reviewed)abstract The Second International Conference on Particle Induced X-ray Emission (PIXE) and its analytical applications was held in Lund, Sweden, June 9-12, 1980. About a hundred papers were presented, including seven invited talks (PIXE and particle scattering, microbeam analysis (2), applications to aerosols (2) and biological samples (2)). The main impression left by the conference was that both the PIXE method and its applications are in a phase of fast development. Considerable effort has successfully been devoted to optimizing the basic PIXE technique. Also the great advantage of simultaneously getting information about lighter elements and sample mass was reported to have been successfully employed in routine analyses. PIXE, which was initially considered to be a method mainly for thin samples, has also been shown to be competitive for a variety of thick samples. Consequently there were several papers dealing with problems characteristic of thick sample analysis. In this context, external beam analysis was also thoroughly discussed. Charged particle microprobes seem to be very attractive and several investigators reported progress on microprobe development and very interesting results of applied work. It is gratifying to note the increasing interest shown by non-physicists in using PIXE. These activities have greatly contributed to the fact that PIXE has now in a few areas left the phase of feasibility tests. E.g. an imposing amount of data from aerosol studies was presented. With the PIXE method, it is feasible to perform series of measurements over a long period of time, many samples in parallel and/or samples from sites of poor accessibility. However, the advantages of PIXE may be further exploited in aerosol investigations and some promising lines of sampler development were reported. Sample preparation techniques are crucial for applications to biological samples and several laboratories are engaged in such developmental work,. However, it was also evident that PIXE us already giving significant contributions to research in biology and medicine.
4.	Allison, J, et al. (author) Geant4 developments and applications 2006 In: IEEE TRANSACTIONS ON NUCLEAR SCIENCE. - 0018-9499. ; 53:1, s. 270-278 Journal article (other academic/artistic)
5.	Andreou, Charalambos M., et al. (author) Single Event Transients and Pulse Quenching Effects in Bandgap Reference Topologies for Space Applications 2016 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 63:6, s. 2950-2961 Journal article (peer-reviewed)abstract An architectural performance comparison of bandgap voltage reference variants, designed in a 0.18 mu m CMOS process, is performed with respect to single event transients. These are commonly induced in microelectronics in the space radiation environment. Heavy ion tests (Silicon, Krypton, Xenon) are used to explore the analog single-event transients and have revealed pulse quenching mechanisms in analogue circuits. The different topologies are compared, in terms of cross-section, pulse duration and pulse amplitude. The measured results, and the explanations behind the findings, reveal important guidelines for designing analog integrated circuits, which are intended for space applications. The paper includes an analysis on how pulse quenching occurs within the indispensable current mirror, which is used in every analog circuit.
6.	Anelli, A., et al. (author) Measurement and simulation of the neutron response and detection efficiency of a Pb-scintillating fiber calorimeter 2008 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 55:3, s. 1409-1412 Journal article (peer-reviewed)abstract We have measured the overall detection efficiency to neutrons of a small prototype of the KLOE Pb-scintillating fiber calorimeter in the kinetic energy range [5,175] MeV. using the neutron beam facility of The Svedberg Laboratory, TSL, Uppsala. The measurement of the neutron detection efficiency of a NE110 scintillator provided a reference calibration. At the lowest trigger threshold, the overall calorimeter efficiency ranges from 28% to 33%. This value largely exceeds the estimated similar to 8% expected if the response were proportional only to the scintillator equivalent thickness. A detailed simulation of the calorimeter and of the TSL beamline has been performed with the FLUKA Monte Carlo code. The simulated response of the detector to neutrons is presented together with first data to Monte Carlo comparison. The results show an overall neutron efficiency of about 35%. The reasons for such an efficiency enhancement, in comparison with the typical scintillator-based neutron counters, are explained, opening the road to a novel neutron detector.
7.	Argume, A., et al. (author) NOAA Image Data Acquisition to Determine Soil Moisture in Arequipa - Perú 2021 In: IEEE Transactions on Nuclear Science. - : IEEE. - 0018-9499 .- 1558-1578. ; 68:8, s. 1933-1936 Journal article (peer-reviewed)abstract In recent years, irrigations have been built on dry areas in Majes-Arequipa. Over time, the irrigations water forms moist areas in lower areas, which can have positive or negative consequences. Therefore, it is important to know in advance where the water from the new irrigation will appear. The limited availability of real-time satellite image data is still a hindrance to some applications. Data from environmental satellites NOAA (National Oceanic and Atmospheric Administration) are available fee and license free. In order to receive data, users must obtain necessary equipment. In this work we present a satellite data acquisition system with an RTL SDR receiver, two 137-138 Mhz designed antennas, Orbitron, SDRSharp, WXTolmag and MatLab software. We have designed two antennas, a Turnstile Crossed dipole antenna with Balun and a quadrifilar helicoidal antenna. The antennas parameter measurements show very good correspondence with those obtained by simulation. The RTL SDR RTL2832U receiver, combined with our antennas and software, forms the system for recording, decoding, editing and displaying Automatic Picture Transmission (APT) signals. The results show that the satellite image receptions are sufficiently clear and descriptive for further analysis.
8.	Arredondo, I., et al. (author) Adjustable ECR Ion Source Control System: Ion Source Hydrogen Positive Project 2015 In: IEEE Transactions on Nuclear Science. - 0018-9499. ; 62:3, s. 903-910 Journal article (peer-reviewed)abstract ISHP (Ion Source Hydrogen Positive) project consists of a highly versatile ECR type ion source. It has been built for several purposes, on the one hand, to serve as a workbench to test accelerator related technologies and validate in-house made developments, at the first stages. On the other hand, to design an ion source valid as the first step in an actual LINAC. Since this paper is focused on the control system of ISHP, besides the ion source, all the hardware and its control architecture is presented. Nowadays the ion source is able to generate a pulse of positive ions of Hydrogen from 2 mu s to a few range with a repetition rate ranging from 1 Hz to 50 Hz with a maximum of 45 mA of current. Furthermore, the first experiments with White Rabbit (WR) synchronization system are presented.
9.	Aykac, M., et al. (author) Timing performance of Hi-Rez detector for time-of-flight (TOF) PET 2006 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 53:3, s. 1084-1089 Journal article (peer-reviewed)abstract Positron emission tomography (PET)-based on time-of-flight (TOF) is desired to enhance the image quality by improving the noise variance in the reconstruction. This benchtop study evaluates the timing performance of the current Hi-Rez detector which is based on a 13/spl times/13 LSO array of 4 mm/spl times/4 mm/spl times/20 mm crystals and not optimized for TOF PET applications. A Hamamatsu R9779, fast, 51-mm-diameter PMT was used for some experiments in this study as a reference PMT and its time resolution was measured to be 160 ps with a plastic scintillator. The average crystal time resolution of two Hi-Rez detectors, coupled to a 2/spl times/2 array of Hamamatsu 25-mm-diameter R8619 PMTs at +1050 V, in coincidence was measured to be 733 ps. The average crystal energy resolutions for two detectors were measured 13.1% and 13.2%. The average crystal time resolution of two Hi-Rez detectors improved from 733 ps to 642 ps when the PMT voltage was increased to +1300 V. The Hi-Rez detector was originally optimized for good energy resolution to reduce scatter and high packing fraction to obtain high sensitivity and improved spatial resolution for clinical PET.
10.	Badel, Xavier, et al. (author) Metallized and oxidized silicon macropore arrays filled with a scintillator for CCD-based X-ray imaging detectors 2004 In: IEEE Transactions on Nuclear Science. - : IEEE. - 0018-9499 .- 1558-1578. ; 51:3, s. 1001-1005, s. 1006-1010 Journal article (peer-reviewed)abstract Silicon charge-coupled devices (CCDs) covered with a scintillating film are now available on the market for use in digital medical imaging. However, these devices could still be improved in terms of sensitivity and especially spatial resolution by coating the CCD with an array of scintillating waveguides. In this paper, such waveguides were fabricated by first etching pores in silicon, then performing metallization or oxidation of the pore walls and finally filling the pores with CsI(TI). The resulting structures were observed using scanning electron microscopy and tested under X-ray exposure. Theoretical efficiencies of macropore arrays filled with CsI(TI) were also calculated, indicating that the optimal pore depth for metallized macropore arrays is about 80 mum while it is around 350 mum for oxidized ones. This result, together with the roughness of the metal coating, explains why lower SNR values were measured with the metallized macropores. Indeed, the macropore arrays had depths in the range of 210-390 mum, which is favorable to oxidized structures.
11.	Badel, Xavier, et al. (author) Performance of scintillating waveguides for CCD-based X-ray detectors 2006 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 53:1, s. 3-8 Journal article (peer-reviewed)abstract Scintillating films are usually used to improve the sensitivity of CCD-based X-ray imaging detectors. For an optimal spatial resolution and detection efficiency, a tradeoff has to be made on the film thickness. However, these scintillating layers can also be structured to provide a pixellated screen. In this paper, the study of CsI(TI)-filled pore arrays is reported. The pores are first etched in silicon, then oxidized and finally filled with CsI(TI) to form scintillating waveguides. The dependence of the detector sensitivity on pore depth, varied from 40 to 400 mu m here, follows rather well theoretical predictions. Most of the detectors produced in this work have a detective quantum efficiency of the incoming X-ray photons of about 25%. However, one detector shows that higher efficiency can be achieved approaching almost the theoretical limit set by Poisson statistics of the incoming X-rays. Thus, we conclude that it is possible to fabricate scintillating waveguides with almost ideal performance. Imaging capabilities of the detectors are demonstrated.
12.	Bauer, Florian, et al. (author) Depth of interaction with a 3-dimensional checkerboard arrangement LSO-LSO block 2010 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 57:3, s. 971-975 Journal article (peer-reviewed)abstract In order to improve image quality in Positron Emission Tomography (PET) different routes are being pursued such as fast timing resolution for time-of-flight PET, higher spatial resolution by the use of smaller scintillator pixels and the use of depth-of-interaction information. The detection of the depth-of-interaction (DOI) of a gamma ray within a detector, deploying pulse shape discrimination (PSD), has been used to increase sensitivity and spatial resolution, especially at the edge of the field of view (FOV). The DOI information is used to reduce the parallax error; thus improving spatial resolution. Commonly, different scintillator materials with different decay times and light output and other differentiating factors, such as density, emission spectra, etc. are used for DOI detectors. We present a multi-layer phoswich detector comprised of LSO with different decay times in the range from 30 ns to 47 ns. The difference in decay times is achieved by co-doping LSO:Ce with Ca, resulting in short decay times of ~ 30 ns [1]. The use of a cut light guide allows the use of regular Photomultiplier tubes, giving the opportunity of a potential DOI detector replacement for current detectors. We were able to identify each pixel in the different detector layers
13.	Bauer, F., et al. (author) Dynode-Timing Method for PET Block Detectors 2008 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 55:1, s. 451-456 Journal article (peer-reviewed)abstract The focus of this paper is the investigation of a new dynode-timing technique optimized for PET block detectors. This method allows utilization of dynode signals from single but especially multiple photo-multiplier tubes (PMTs), operated with negative high-voltage. The technique will provide an event-timing trigger without deteriorating the anode signal. A printed circuit board has been developed and built for this investigation. Benchmark measurements have been performed, comparing timing of the anode signal with timing of the inverted last-dynode signal and timing of the dynode signal extracted via a newly developed LVPECL-logic based board. Timing measurements were performed with plastic as well as LSO scintillators. From single PMT measurements we find a 30 ps improvement with the dynode-timing method compared to the standard anode timing with two Photonis XP2020Q PMTs with LSO (10 mmtimes10 mmtimes10 mm). For a quad-PMT block detector, assembled of four Hamamatsu R9800 with a Hi-Rez block, the timing-resolution improves ~10%, by 43 ps compared to the standard anode timing.
14.	Bauer, F., et al. (author) Measurements and Ray-Tracing Simulations of Light Spread in LSO Crystals 2009 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 56:5, s. 2566-2573 Journal article (peer-reviewed)abstract We report on measurements of the absolute light output from LSO crystals for irradiation with 511 keV gamma rays as a function of interaction position, reflector arrangement, detector coupling geometry and optical coupling to an adjacent crystal. The light output for this series of geometrical configurations is simulated with the ZEMAX ray-tracing software. By fine-tuning the optical parameters of the bulk and at the interfaces of the crystal, a model is obtained which yields good agreement with experimental data for all configurations. The resulting parameter set is applied to calculate the light distribution in a 12$,times,$ 12 crystal block detector. A comparison of measured and calculated block position profiles shows good agreement, demonstrating the potential of the simulation model to predict block detector performance data and provide guidelines for future array designs.
15.	Bauer, F., et al. (author) Performance Study of the New Hamamatsu R9779 and Photonis XP20D0 Fast 2" Photomultipliers 2007 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 54:3, s. 422-426 Journal article (peer-reviewed)abstract The focus of this paper is the evaluation of the new fast 51 mm-diameter, 8-stage Hamamatsu R9779 photomultipliers (PMTs) with an acceleration-ring at the front-end and the Photonis XP20D0 PMTs with a screening grid in front of the anode. The following performance characteristics are presented: Timing resolution, anode-scan-uniformity and transit-time spread. The unfolded timing resolution for two R9779 was 192 ps and 210 ps using plastic scintillators. The individual timing resolutions for two XP20D0 using plastic scintillators are 181 ps and 154 ps, respectively. The variation in time resolution across the windows of the two R9779 ranged between 117 ps and 171 ps, and 79 ps and 73 ps for the two XP20D0 PMTs.
16.	Bazan, A., et al. (author) The ATLAS liquid argon calorimeter read-out system 2006 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 53:3, s. 735-740 Journal article (peer-reviewed)abstract The Liquid Argon calorimeters play a central role in the ATLAS experiment. The environment at the LHC collider imposes challenging tasks to their read-out system. To achieve measurements of particles and trigger signals at high precision, the detector signals are processed at various stages before reaching the Data Acquisition system (DAQ). Signals from the calorimeter cells are received by front-end boards, which digitize and sample the incoming pulse. Read-out Driver (ROD) boards further process the data at a trigger rate of up to 75 kHz. An optimal filtering procedure is applied to optimize the signal-to-noise ratio. The ROD boards calculate precise energy, time and quality of the detector pulse, which are then sent to the DAQ. In addition, the RODs perform a monitoring of the data. The architecture of the ATLAS Liquid Argon detector read-out is discussed, in particular the design and functionality of the ROD board. Performance results obtained with ROD prototypes as well as experience from complete test setups with final production boards are reported.
17.	Belli, Francesco, et al. (author) Conceptual Design, Development and Preliminary Tests of a Compact Neutron Spectrometer for the JET Experiment 2012 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 59:5, s. 2512-2519 Journal article (peer-reviewed)abstract A Compact Neutron Spectrometer (CNS) has been developed to measure the neutron emission spectra in Joint European Torus (JET) fusion plasma experiments. The spectrometer, based on a liquid scintillation detector (BC501A), is equipped with a Digital Pulse Shape Discrimination (DPSD) acquisition system for neutron (n) and gamma-ray(gamma) separation. The CNS enables recording the n and gamma pulse height spectra (PHS) up to total count rates of similar to 10(6) s(-1). Energy resolution, after PHS unfolding, will be <2% for 14 MeV neutrons and <4% for 2.5 MeV neutrons. The work done by ENEA-Frascati and Physikalisch-Technische Bundesanstalt (PTB) respectively in the assembly and test of DPSD and scintillation detector, along with the first results obtained by the spectrometer in JET plasma experiments are presented. The experience obtained with CNS in JET will contribute to the development of neutron spectrometers suitable for applications in the International Thermonuclear Experimental Reactor (ITER).
18.	Bertuccio, Giuseppe, et al. (author) Silicon Carbide Detectors for in vivo Dosimetry 2014 In: IEEE Transactions on Nuclear Science. - : IEEE. - 0018-9499 .- 1558-1578. ; 61:2, s. 961-966 Journal article (peer-reviewed)abstract Semiconductor detectors for in vivo dosimetry haveserved in recent years as an important part of quality assurancefor radiotherapy. Silicon carbide (SiC) can represent a bettersemiconductor with respect to the more popular silicon (Si) thanksto its physical characteristics such as wide bandgap, high electronsaturation velocity, lower effective atomic number, and high radiationresistance to X and gamma rays. In this article we present aninvestigation aimed at characterizing 4H-SiC epitaxial Schottkydiodes as in vivo dosimeters. The electrical characterization atroom temperature showed ultra low leakage current densities aslow as 0.1 pA/cm at 100 V bias with negligible dependence ontemperature. The SiC diode was tested as radiotherapy dosimeterusing 6 MV photon beams from a linear accelerator in a typicalclinical setting. Collected charge as a function of exposed radiationdose were measured and compared to three standard commerciallyavailable silicon dosimeters. A sensitivity of 23 nC/Gy withlinearity errors within 0.5% and time stability of 0.6% wereachieved. No negligible effects on the diode I-V characteristicsafter irradiation were observed.
19.	Bertuccio, Giuseppe, et al. (author) X-γ Ray Spectroscopy With Semi-Insulating 4H-Silicon Carbide 2013 In: IEEE Transactions on Nuclear Science. - : IEEE. - 0018-9499 .- 1558-1578. ; 60:2, s. 1436-1441 Journal article (peer-reviewed)abstract Radiation detectors on a semi-insulating (SI) 4H siliconcarbide (SiC) wafer have been manufactured and characterizedwith X and photons in the range 8–59 keV. The detectors were 400 μm diameter circular Ni-SiC junctions on an SI 4H-SiC wafer thinned to 70 μm. Dark current densities of 3.5 nA/cm2 at 20 °C and 0.3 μA/cm2 at 104 °C with an internal electric field of 7 kV/cm have been measured. X-γ ray spectra from 241Am have been acquired at room temperature with pulser line width of 756 eV FWHM. The charge collection efficiency (CCE) has been measured under different experimental conditions with a maximum CCE = 75 % at room temperature. Polarization effects have been observed, and the dependence of CCE on time and temperature has been measured and analyzed. The charge trapping has been described by the Hecht model with a maximum totalmean drift length of 107 μm at room temperature.
20.	Betta, Gian-Franco Dalla, et al. (author) Comments by the Senior Editor 2022 In: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 69:4, s. 647-647 Journal article (other academic/artistic)abstract The 7th edition of the International Conference on “Advancements in Nuclear Instrumentation Measurement Methods and their Applications” (ANIMMA) was held in Prague, Czech Republic, on June 21–25, 2021, in hybrid mode. The ANIMMA-2021 welcomed 320 attendees from 29 nationalities including 65 graduated students coming from academy, research institutes, and industry to discuss new scientific and technical prospects in all fields where nuclear instrumentation and measurements techniques play a major role. 30% of the attendees participated physically and 70% attended remotely.
21.	Birch, Jens, et al. (author) (B4C)-B-10 Multi-Grid as an Alternative to He-3 for Large Area Neutron Detectors 2013 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 60:2, s. 871-878 Journal article (peer-reviewed)abstract Despite its present shortage, He-3 continues to be the most common neutron converter for detectors in neutron scattering science. However, it is obvious that the development of large area neutron detectors based on alternative neutron converters is rapidly becoming a matter of urgency. In the technique presented here, grids each comprising 28 (B4C)-B-10 layers ( each 1 mu m thick) are used to convert neutrons into ionizing particles which are subsequently detected in proportional gas counters. The total active area of the prototype is 8 cm x 200 cm. To instrument this detector 4.6 m(2) of B-10-enriched boron carbide were coated onto aluminium blades using a DC magnetron sputtering machine. Characterization of the prototype showed neutron efficiency to be epsilon(n) = 46.8% for 2.5 angstrom neutrons, which is in line with expectations from MC simulation. This result demonstrates the potential of this technique as alternative to He-3-based position sensitive detectors.
22.	Bläckberg, Lisa, 1982-, et al. (author) Light spread manipulation in scintillators using laser induced optical barriers 2018 In: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 65:8, s. 2208-2215 Journal article (peer-reviewed)abstract We are using the Laser Induced Optical Barriers (LIOB) technique to fabricate scintillator detectors with combined performance characteristics of the two standard detector types, mechanically pixelated arrays and monolithic crystals. This is done by incorporation of so-called optical barriers that have a refractive index lower than that of the crystal bulk. Such barriers can redirect the scintillation light and allow for control of the light spread in the detector. Previous work has shown that the LIOB technique has the potential to achieve detectors with high transversal and depth of interaction (DOI) resolution simultaneously in a single-side readout configuration, suitable for high resolution PET imaging. However, all designs studied thus far present edge effect issues similarly as in the standard detector categories. In this work we take advantage of the inherent flexibility of the LIOB technique and investigate alternative barrier patterns with the aim to address this problem. Light transport simulations of barrier patterns in LYSO:Ce, with deeper barrier walls moving towards the detector edge show great promise in reducing the edge effect, however there is a trade-off in terms of achievable DOI information. Furthermore, fabrication and characterization of a 20 mm thick LYSO:Ce detector with optical barriers forming a pattern of 1×1×20mm3 pixel like structures show that light channeling in laser-processed detectors in agreement with optical barriers with refractive index between 1.2 and 1.4 is achievable.
23.	Bohm, Christian, et al. (author) ATLAS Level-1 Calorimeter Trigger : Subsystem Tests of a Jet/Energy-sum Processor Module 2004 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 51:5, s. 2356-2361 Journal article (peer-reviewed)abstract The ATLAS Level-1 Calorimeter Trigger consists of a Preprocessor, a Cluster Processor (CP), and a Jet/Energy-sum Processor (JEP). The CP and JEP receive digitized trigger-tower data from the Preprocessor and produce trigger multiplicities and total and missing energy for the final trigger decision. The trigger also provides region-of-interest information for the Level-2 trigger and intermediate results of the data acquisition system for monitoring and diagnostics by using Readout Driver modules. The JEP identifies and localizes jets, and sums total and missing transverse energy information from the trigger data. The Jet/Energy Module (JEM) is the main module of the JEP. The JEM prototype is designed to be functionally identical to the final production module for ATLAS and to have the full number of channels. Three JEM prototypes have been built and successfully tested. Various test vector patterns were used to test the energy summation and the jet algorithms. Data communication between adjacent JEMs and all other relevant modules of the JEP has been tested. Recent test results using the JEM prototypes are discussed.
24.	Bohm, Christian, et al. (author) Pre-Production Validation of the ATLAS Level-1 Calorimeter Trigger System 2006 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 53:3, s. 859-863 Journal article (peer-reviewed)abstract The Level-1 Calorimeter Trigger is a major part of the first stage of event selection for the ATLAS experiment at the LHC. It is a digital, pipelined system with several stages of processing, largely based on FPGAs, which perform programmable algorithms in parallel with a fixed latency to process about 300 Gbyte/s of input data. The real-time output consists of counts of different types of trigger objects and energy sums. Prototypes of all module types have been undergoing intensive testing before final production during 2005. Verification of their correct operation has been performed stand-alone and in the ATLAS test-beam at CERN. Results from these investigations will be presented, along with a description of the methodology used to perform the tests.
25.	Bohm, Christian, et al. (author) The ATLAS Level-1 Calorimeter Trigger Architecture 2004 In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 51:3, s. 356-360 Journal article (peer-reviewed)abstract The architecture of the ATLAS Level-1 Calorimeter Trigger system (L1Calo) is presented. Common approaches have been adopted for data distribution, result merging, readout, and slow control across the three different subsystems. A significant amount of common hardware is utilized, yielding substantial savings in cost, spares, and development effort. A custom, high-density backplane has been developed with data paths suitable for both the em/τ cluster processor (CP) and jet/energy-summation processor (JEP) subsystems. Common modules also provide interfaces to VME, CANbus and the LHC timing, trigger and control system (TTC). A common data merger module (CMM) uses field-programmable gate arrays (FPGAs) with multiple configurations for summing electron/photon and τ/hadron cluster multiplicities, jet multiplicities, or total and missing transverse energy. The CMM performs both crate- and system-level merging. A common, FPGA-based readout driver (ROD) is used by all of the subsystems to send input, intermediate and output data to the data acquisition (DAQ) system, and region-of-interest (RoI) data to the level-2 triggers. Extensive use of FPGAs throughout the system makes the trigger flexible and upgradable, and several architectural choices have been made to reduce the number of intercrate links and make the hardware more robust.

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