The Global Large Detector (GLD) is one of the detector concepts proposed for the future linear collider experiment. At the linear collider experiment Particle Flow Algorithm plays an important role ...in achieving excellent jet energy resolution (~30%/radicE). This method requires a finely segmented calorimeter able to separate individual particles inside jets in the calorimeter. The GLD calorimeter is a sampling calorimeter which consists of scintillator and absorber (tungsten for electromagnetic, lead or iron for hadron calorimeter) layers. It has a scintillator-strip structure; strips in successive scintillator layers are aligned in orthogonal directions to achieve effective 1 times cm 2 segmentation. To read out the signal from all the individual scintillator strips, we adopt a new photon sensor, the Multi-Pixel Photon Counter (MPPC). The MPPC consists of 100-1600 APD pixels, each of which works in the limited Geiger mode. This new photon sensor has many excellent features (compact size, low cost, high gain and photon detection efficiency and insensitivity to magnetic fields) and is suitable for use in the GLD calorimeter readout. We have tested 800 samples of 1600-pixel MPPCs and confirmed that the performance is satisfactory for calorimetric use. We have also constructed an electromagnetic calorimeter test module with 468 scintillator strips and full MPPC readout, and performed a beam test using a 1-6 GeV positron beam to evaluate its performance. The test module was measured to have good performance (energy resolution is (13.45 plusmn 0.07)% / radicE oplus (2.87 plusmn 0.08)%, deviation from linearity is less than 4%), showing that the 1600-pixel MPPC is suitable for the readout of finely segmanted calorimeters.
We investigated concentrations of mycotoxins during the growth of four cultivars of forage maize (Zea mays L.) in Nasushiobara, Tochigi prefecture, and their distribution in ears of maize grown in ...Morioka, Iwate prefecture, Japan. In experiment 1, we measured concentrations of naturally occurring fumonisin, nivalenol, deoxynivalenol and zearalenone at progressive crop growth stages. Concentrations of fumonisin in stems + leaves remained very low or not detectable, but those in ears became detectable at 40 days after heading and increased rapidly after 50 days after heading (DAH) (fumonisin B₁+ B₂<3260 μg/kg; mean value at 50–74 days after heading). Concentrations varied widely within cultivars on the same day. Concentrations of nivalenol, deoxynivalenol and zearalenone in stems + leaves and in ears were low or not detectable throughout the experiment. In experiment 2, we collected three ears of each cultivar at the late yellow-ripe stage that showed extreme symptoms of Fusarium ear rot. Concentrations of fumonisin were extremely high in the upper half of ears in all cultivars (fumonisin B₁+ B₂18,000–25,900 μg/kg) but low in the lower half and bracts. Concentrations of nivalenol, deoxynivalenol and zearalenone were extremely low or not detectable. These results show that fumonisin concentrations in ears increased rapidly after 50 DAH, they were extremely high in ears of all cultivars with symptoms of Fusarium ear rot, and fumonisin was the most common contaminant. These results will help reduce mycotoxin contamination.
This paper describes an investigation into gluing and wire bonding for assembling the Silicon Vertex Detector (SVD) for the Belle II experiment at KEK in Japan. Optimizing the gluing of the silicon ...microstrip sensors, the support frame, and the readout flex cables is important for achieving the required mechanical precision. The wire bonding between the sensors and the readout electronic chips also needs special care to maximize the physics capability of the SVD. The silicon sensors and signal fan out flex circuits (pitch adapters) are glued and connected using wire bonding. We determine that gluing quality is important for achieving good bonding efficiency. The standard deviation in the glue thickness for the best result is measured to be 3.11μm. Optimal machine parameters for wire bonding are determined to be 70mW power, 20gf force, and 20ms for the pitch adapter and 60mW power, 20gf force, and 20ms for the silicon strip sensors; these parameters provide a pull force of (10.92±0.72) gf. With these settings, 75% of the pitch adapters and 25% of the strip sensors experience the neck-broken type of break.
Inflation is the leading theory of the first instant of the universe. Inflation, which postulates that the universe underwent a period of rapid expansion an instant after its birth, provides ...convincing explanation for cosmological observations. Recent advancements in detector technology have opened opportunities to explore primordial gravitational waves generated by the inflation through “B-mode” (divergent-free) polarization pattern embedded in the cosmic microwave background anisotropies. If detected, these signals would provide strong evidence for inflation, point to the correct model for inflation, and open a window to physics at ultra-high energies. LiteBIRD is a satellite mission with a goal of detecting degree-and-larger-angular-scale B-mode polarization. LiteBIRD will observe at the second Lagrange point with a 400 mm diameter telescope and 2622 detectors. It will survey the entire sky with 15 frequency bands from 40 to 400 GHz to measure and subtract foregrounds. The US LiteBIRD team is proposing to deliver sub-Kelvin instruments that include detectors and readout electronics. A lenslet-coupled sinuous antenna array will cover low-frequency bands (40–235 GHz) with four frequency arrangements of trichroic pixels. An orthomode-transducer-coupled corrugated horn array will cover high-frequency bands (280–402 GHz) with three types of single frequency detectors. The detectors will be made with transition edge sensor (TES) bolometers cooled to a 100 milli-Kelvin base temperature by an adiabatic demagnetization refrigerator. The TES bolometers will be read out using digital frequency multiplexing with Superconducting QUantum Interference Device (SQUID) amplifiers. Up to 78 bolometers will be multiplexed with a single SQUID amplifier. We report on the sub-Kelvin instrument design and ongoing developments for the LiteBIRD mission.
We have measured performance of a lead/plastic scintillator sampling calorimeter in two separate beam tests at low (1–
4
GeV
) and high (10–
200
GeV
) energies. The calorimeter is composed of ...8-mm-thick lead plates and 2-mm-thick plastic scintillator plates for hardware compensation, where responses to electromagnetic and hadronic showers of the same energy are identical. We find the linearity to be better than 1% in the energy range between 2 and
150
GeV
for both pions and electrons. The energy resolutions are obtained to be
(46.7±0.6)%/
E
⊕(0.9±0.9)%
for pions, where the energy
E is given in GeV. The response ratio of electromagnetic showers to hadronic showers is measured to be 1.04±0.01 at low energies, and 0.99±0.01 at high energies.
The electron/hadron separation in the calorimetry can be improved if we measure the electromagnetic shower development at an early stage. The incident positions of electrons and photons can be ...precisely measured with a position sensitive detector placed near the electromagnetic shower maximum. We constructed a set of prototype preshower and shower-maximum detectors to be attached in front of a main calorimeter. Performance of the detectors was studied in combination with a lead/plastic-scintillator calorimeter module using high energy beams up to
100
GeV
at a test beam facility at Fermi National Accelerator Laboratory.
A highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 X0 depth and 180×180mm2 transverse ...dimensions was constructed, consisting of 2160 individually read out 10×45×3mm3 scintillator strips. This prototype was tested using electrons of 2–32 GeV at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined to be (12.5±0.1(stat.)±0.4(syst.))%∕EGeV⊕(1.2±0.1(stat.)−0.7+0.6(syst.))%, where the uncertainties correspond to statistical and systematic sources, respectively.
The Belle II SVD data readout system Thalmeier, R.; Adamczyk, K.; Aihara, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2017, Letnik:
845
Journal Article
Recenzirano
The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the ...standard model.
172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC).
Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network.
We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing.
The silicon vertex detector of the Belle II experiment Adamczyk, K.; Aihara, H.; Angelini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
Odprti dostop
The silicon vertex detector of the Belle II experiment, structured in a lantern shape, consists of four layers of ladders, fabricated from two to five silicon sensors. The APV25 readout ASIC chips ...are mounted on one side of the ladder to minimize the signal path for reducing the capacitive noise; signals from the sensor backside are transmitted to the chip by bent flexible fan-out circuits. The ladder is assembled using several dedicated jigs. Sensor motion on the jig is minimized by vacuum chucking. The gluing procedure provides such a rigid foundation that later leads to the desired wire bonding performance. The full ladder with electrically functional sensors is consistently completed with a fully developed assembly procedure, and its sensor offsets from the design values are found to be less than 200μm. The potential functionality of the ladder is also demonstrated by the radioactive source test.
This paper presents results obtained with the combined CALICE Scintillator Electromagnetic Calorimeter, Analogue Hadronic Calorimeter and Tail Catcher & Muon Tracker, three high granularity ...scintillator-silicon photomultiplier calorimeter prototypes. The response of the system to pions with momenta between 4 GeV/c and 32 GeV/c is analysed, including the average energy response, resolution, and longitudinal shower profiles. Two techniques are applied to reconstruct the initial particle energy from the measured energy depositions; a standard energy reconstruction which is linear in the measured depositions and a software compensation technique based on reweighting individually measured depositions according to their hit energy. The results are compared to predictions of the GEANT 4 physics lists QGSP_BERT_HP and FTFP_BERT_HP.
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