The silicon pixel vertex detector is a key element of the BTeV spectrometer. Sensors bump-bonded to prototype front-end devices were tested in a high energy pion beam at Fermilab. The spatial resolution and occupancies as a function of the pion incident angle were measured for various sensor-readout combinations. The data are compared with predictions from our Monte Carlo simulation and very good agreement is found.
The silicon pixel vertex detector is one of the key elements of the BTeV spectrometer. Detector prototypes were tested in a beam at Fermilab. We report here on the measured spatial resolution as a function of the incident angles for different sensor-readout electronics combinations. We compare the results with predictions from our Monte Carlo simulation.
We report on measurements performed on silicon pixel sensor prototypes exposed to a 200 MeV proton beam at the Indiana University Cyclotron Facility. The sensors are of n+/n/p+ type with multi-guard ring structures on the p+-side and p-stop electrode isolation on the n+-side. Electrical characterization of the devices was performed before and after irradiation up to a proton fluence of 4E14 p/cm2. We tested pixel sensors fabricated from normal and oxygen-enriched silicon wafers and with two different p-stop isolation layouts: common p-stop and individual p-stop.
The energy dependence of the energy and position resolutions of the electromagnetic calorimeter prototype made of lead tungstate crystals produced in Bogoroditsk (Russia) and Shanghai (China) is presented. These measurementswere carried out at the Protvino accelerator using a 1 to 45 GeV electron beam. The crystals were coupled to photomultiplier tubes. The dependence of energy and position resolutions on different factors as well as the measured electromagnetic shower lateral profile are presented.
We report on the performance of a prototype CMS Hadron Barrel Calorimeter (HCAL) module in a test beam. The prototype sampling calorimeter used copper absorber plates and scintillator tiles with wavelength shifting fibers for readout. Placing a lead tungstate crystal electromagnetic calorimeter in front of HCAL affects the linearity and energy resolution of the combined system to hadrons. The data are used to optimize the choice of total absorber depth, sampling frequency, and longitudinal readout segmentation.
The Belle II experiment at the Super B factory SuperKEKB, an asymmetric $e^+e^-$ collider located in Tsukuba, Japan, is tailored to perform precision B physics measurements. The centre of mass energy of the collisions is equal to the rest mass of the $Upsilon(4S)$ resonance of $m_{Upsilon(4S)} = 10.58,rm GeV$. A high vertex resolution is essential for measuring the decay vertices of B mesons. Typical momenta of the decay products are ranging from a few tens of MeV to a few GeV and multiple scattering has a significant impact on the vertex resolution. The VerteX Detector (VXD) for Belle II is therefore designed to have as little material as possible inside the acceptance region. Especially the innermost two layers, populated by the PiXel Detector (PXD), have to be ultra-thin. The PXD is based on DEpleted P-channel Field Effect Transistors (DEPFETs) with a thickness of only $75,rmmu m$. Spatial resolution and hit efficiency of production detector modules were studied in beam tests performed at the DESY test beam facility. The spatial resolution was investigated as a function of the incidence angle and improvements due to charge sharing are demonstrated. The measured module performance is compatible with the requirements for Belle II.