D. Beznosko

The T2K ND280 Off-Axis Pi-Zero Detector

Abstract The pi–zero detector (POD) is one of the subdetectors that makes up the off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino experiment. The primary goal for the POD is to measure the relevant cross-sections for neutrino interactions that generate π 0 s, especially the cross-section for neutral current π 0 interactions, which are one of the dominant sources of background to the ν μ → ν e appearance signal in T2K. The POD is composed of layers of plastic scintillator alternating with water bags and brass sheets or lead sheets and is one of the first detectors to use Multi-Pixel Photon Counters (MPPCs) on a large scale.

Small scintillating cells as the active elements in a digital hadron calorimeter for the e + e − linear collider detector

The ability to distinguish between hadronic W and Z decays is one of the most challenging requirements for the future linear collider detector. Such sensitivity requires unprecedented jet energy resolution, which may be possible with energy-flow algorithms. A calorimeter that is optimized for energy-flow must have fine lateral and longitudinal segmentation. Small scintillating cells with wavelength shifting fibre readout represent an attractive basis for a digital hadron calorimeter that trades dynamic range for superior granularity, at an affordable price. We present the expected jet resolution for such a device, based on Monte Carlo simulations. Then we describe the initial prototyping studies. In particular, detailed studies are presented on cell performance under different combinations of manufacture and assembly.

FNAL-NICADD extruded scintillator

The possibility to produce a scintillator that satisfies the demands of physicists from different science areas has emerged with the installation of an extrusion line at FNAL (Fermi National Accelerator Laboratory). The extruder is the product of the fruitful collaboration between FNAL and NICADD NIU (Northern Illinois Center for Accelerator and Detector Development at Northern Illinois University). The results from light output, light attenuation length and mechanical tolerance indicate that FNAL-NICADD scintillator is of high quality. Improvements in the extrusion die will yield better scintillator profiles and decrease the time needed for initial tuning. This paper will present the characteristics of the FNAL-NICADD scintillator based on the measurements performed. They include the response to MIPs from cosmic rays for individual extruded strips and irradiation studies where extruded samples were irradiated up to 1 Mrad. We will also discuss the results achieved with a new die design. The attractive perspective of using the extruded scintillator with MRS (metal resistive semiconductor) photodetector readout will also be shown.

Characterization and Modeling of a Water-based Liquid Scintillator

We have characterised Water-based Liquid Scintillator (WbLS) using low energy protons, UV-VIS absorbance, and fluorescence spectroscopy. We have also developed and validated a simulation model that describes the behaviour of WbLS in our detector configurations for proton beam energies of 210 MeV, 475 MeV, and 2 GeV and for two WbLS compositions. Our results have enabled us to estimate the light yield and ionisation quenching of WbLS, as well as to understand the influence of the wavelength shifting of Cherenkov light on our measurements. These results are relevant to the suitability of WbLS materials for next generation intensity frontier experiments.

Quality Control Studies of Wavelength Shifting Fibers for a Scintillator-Based Tail Catcher Muon Tracker for Linear Collider Prototype Detector

Detailed measurements of the wavelength shifting fiber response to a stable and reliable light source are presented. Particulars about materials, a double reference method, and measurement technique are included. The fibers studied were several hundred Kuraray, Y-11, multiclad, 1.2-mm outer diameter wavelength shifting fibers, each cut from a reel to about one meter length. The fibers were polished, mirrored, and the mirrors were UV epoxy protected. Each fiber passed quality control requirements before installation. About 94% of the fibers tested have a response within 1% of the overall mean

Random Number Hardware Generator Using Geiger-Mode Avalanche Photo Detector

This paper presents the physical concept and test results of sample data of the high-speed hardware true random number generator design based on typically used for High Energy Physics hardware. Main features of this concept are the high speed of the true random numbers generation (tens of Mbt/s), miniature size and estimated lower production cost. This allows the use of such a device not only in large companies and government offices but for the end-user data cryptography, in classrooms, in scientific Monte-Carlo simulations, computer games and any other place where large number of true random numbers is required. The physics of the operations principle of using a Geiger-mode avalanche photo detector is discussed and the high quality of the data collected is demonstrated.

Extruded scintillator for the Calorimetry applications

An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co‐extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R&D work with extruded and co‐extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co‐extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co‐extruded plastic scintillator will be presented here as well as results with non‐traditional photo read‐out.

Measuring response of extruded scintillator to UV LED in magnetic field

The experimental results on the performance of the extruded scintillator and WLS fiber, and various LEDs in the magnetic fields of 1.8T and 2.3T respectively, are reported. The methodic used is being described.

MRS photodiode in strong magnetic field

The experimental results on the performance of the MRS (Metal/Resistor/Semiconductor) photodiode in the strong magnetic field of 4.4T, and the possible impact of the quench of the magnet at 4.5T on sensors operation are reported.

Optimization of the Liquid Scintillator Composition

Nowadays, many particle detectors use liquid scintillator (LS) as a detection medium. In particular, Water-based Liquid Scintillator (WbLS) that is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cherenkov and scintillation light, as well as the total cost reduction compared to pure liquid scintillator. An important part of either the pure LS or WbLS production is to choose the right fluor and shifter and their concentrations. The choice affects the spectral distribution of the light output and the detection efficiency as each photodetector has its own spectral sensitivity region. This work presents the results of the study on the pseudocumen (PC) based LS with the 2,5-diphenyloxazole (PPO) and 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP)/1,4-Bis(2-mehylstyryl)benzene (MSB) as a fluor and shifters of choice. Both the total light yield and the spectral differences in the outputs with different amounts of components are shown. This study can be applied to plastic scintillators as well. Typically, each experimental group does the process of scintillator composition optimization per their needs. It is done to minimize the amount of scintillator components used. This research is done in order to assist future experiments in the optimization process.