8682177
First Beam Test Characterisation of a 3D-stc Silicon Short Strip Detector
The planned upgrade to the CERN Large Hadron Collider (LHC), the Super-LHC (sLHC) will increase its luminosity by a factor of ten. This necessitates the development of silicon tracking detectors that are significantly more radiation resistant than the ones employed at the LHC. Currently, new detector technologies are being developed to cope with the increased levels of radiation damage at the sLHC. A possible radiation hard option for silicon short strip devices (SSD) in the inner layers of sLHC trackers are 3-D detectors with rows of columnar electrodes processed into the bulk material. These are joined together to form strips. While the excellent radiation hardness of this design has been proven before in lab experiments, a 3-D SSD prototype has now been investigated for the first time in a beam test with pions of a nominal energy of 180 GeV. The use of analog LHC-speed electronics, a beam telescope and time-resolved measurements allowed for detailed studies of the signal behavior on the hit strip and its neighboring strips. Charge collection and efficiency were as well measured with respect to time and point of incidence of the beam particles on the detector. The results of these measurements are presented in this paper.
109063356
Laser characterisation of a 3D single-type column p-type prototype module read out with ATLAS SCT electronics
In this paper measurements of a 3D single-type column (3D-stc) microstrip silicon device are shown. The 3D-stc sensor has n-type columns in p-type substrate. It has been connected to an ATLAS SCT ABCD3T chip and is readout with ATLAS SCT electronics at 40 MHz. Spatial measurements were done with a laser setup to investigate the expected low field region in 3D devices. An influence of the p-stops on the collected charge has been observed.
109469281
3D silicon strip detectors
Abstract While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2–3 cm length are foreseen to cover the region from 28 to 60 cm distance to the beam. These SSD will be exposed to radiation levels up to 10 15 N eq / cm 2 , which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of 10 15 N eq / cm 2 . The tests were performed with three systems: a highly focused IR-laser with 5 μ m spot size to make position-resolved scans of the charge collection efficiency, an Sr 90 β -source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180 GeV pions at CERN. This article gives a brief overview of the results obtained with 3D-STC-modules.
26356337
Investigation of 3D silicon microstrip detectors for the sLHC
An increase of the luminosity of the Large Hadron Collider (LHC) at CERN is foreseen around 2017 by about an order of magnitude. This will translate into a largely increased radiation dose, with which the present trackers can not cope. The development of radiation-hard silicon detectors is required for the innermost tracking layers. One option for radiation-hard silicon sensors is the 3D technology, where columnar electrodes are etched, perpendicular to the surface, into the silicon bulk. In this paper we investigated 3D single type columns (3D-STC) detectors which were irradiated with 26 MeV protons to fluences up to 2.5×10 15 1-MeV equivalent neutrons(Neq)/cm 2 which corresponds to fluences expected at the inner tracking layers of the sLHC. Before and after irradiations the sensors were tested with a beta-source setup to measure and quantify the radiation induced damage.
120247908
3D stc sensors with different strip isolation schemes and substrate materials
Abstract For the innermost layers of the foreseen upgrade to the ATLAS tracker, charge trapping will be the main limitation in terms of the sensor lifetime. A possible solution to the degradation of the charge collection efficiency (CCE) could be the use of 3D detectors. In 3D detectors the electrodes are processed not just at the surface of the sensor, but they extend partly or completely through the silicon bulk. The distance between the columnar electrodes of 3D detectors can be adjusted to the expected fluence range. We designed and constructed prototype modules comprising ATLAS SCT front-end electronics and 3D single-type column (stc) p-type strip detectors with different strip isolation techniques and different substrate materials. With a strip length of 18.4 mm these sensors could be a radiation hard option for the innermost short strip region of the inner detector in the upgraded ATLAS experiment. We characterised these 3D stc p-type sensors in terms of their noise behaviour and hence their effective capacitance as a function of applied bias voltage at a read-out speed of 40 MHz which is also anticipated for sLHC. Employing an IR laser and automated x – y stages with micrometer resolution we characterised the sensors regarding the CCE in dependence of the bias voltage and the IR laser position relative to the sensors before irradiation.
121972934
Signal and charge collection efficiency of a p-type STC 3D-detector irradiated to sLHC-fluences, read out with 40 MHz
Abstract Using ATLAS SCT front-end electronics, we have built a 3D prototype detector module which was then irradiated to a fluence of 1 × 10 15 n eq / cm 2 . After irradiation, the module was tested with an IR-laser yielding relative CCE measurements with high spatial resolution. Position-sensitive measurements are required, as from simulation the STC 3D-detector geometry is expected to have low-field regions with lower CCE. We report on the performance of the irradiated 3D-module read out at 40 MHz, compare it to the unirradiated behaviour and draw conclusions about the feasibility of using such detectors for tracking at the sLHC.
117820337
Neutron Structure — New Results with CLAS at Jefferson Lab
New measurements using the 6 GeV continuous electron beam and the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab have collected information on the form factors and the unpolarized structure functions of the neutron, with minimal uncertainty from nuclear binding effects. One experiment has also tried to measure these binding effects more directly, using the method of “spectator tagging”. These experiments are forerunners for an extensive program with the energy‐upgraded 12 GeV accelerator at Jefferson Lab.
53121220
Nucleon Structure Functions : Experiments and Models
In these lectures, I describe measurements of the polarized and unpolarized structure functions of the proton and the neutron. The main emphasis is on a clear, straightforward description of what is being measured and how it can be interpreted in a simple quark model of the nucleon. The intended audience are graduate students who are beginning their work in Nuclear or Particle Physics. More advanced students are referred to the extensive literature.
121886810
Experimental Results in DIS, SIDIS and DES from Jefferson Lab
Jefferson Lab’s electron accelerator in its present incarnation, with a maximum beam energy slightly above 6 GeV, has already enabled a large number of experiments expanding our knowledge of nucleon and nuclear structure (especially in Deep Inelastic Scattering—DIS—at moderately high x, and in the resonance region). Several pioneering experiments have yielded first results on Deeply Virtual Compton Scattering (DVCS) and other Deep Exclusive Processes (DES), and the exploration of the rich landscape of transverse momentum‐dependent (TMD) structure functions using Semi‐Inclusive electron scattering (SIDIS) has begun. With the upgrade of CEBAF to 12 GeV now underway, a significantly larger kinematic space will become available. The 12 GeV program taking shape will complete a detailed mapping of inclusive, TMD and generalized distribution functions for quarks, antiquarks and gluons in the valence region and beyond.