This paper describes the ATLAS experiment as installed in i ts experimental cavern at point 1 at CERN. It also presents a brief overview of the expec ted performance of the detector.

http://absimage.aps.org/image/SES08/MWS_SES08-2008-020010.pdf

The ATLAS Experiment at the CERN Large Hadron Collider

Nuclear Instruments and Methods in Physics Research. Section B; Microstructural Characterization of Semi-Interpenetrating Polymer Networks by Positron Lifetime Spectroscopy

During the shutdown of the CERN Large Hadron Collider in 2013-2014, an additional pixel layer was installed between the existing Pixel detector of the ATLAS experiment and a new, smaller radius beam pipe. The motivation for this new pixel layer, the Insertable B-Layer (IBL), was to maintain or improve the robustness and performance of the ATLAS tracking system, given the higher instantaneous and integrated luminosities realised following the shutdown. Because of the extreme radiation and collision rate environment, several new radiation-tolerant sensor and electronic technologies were utilised for this layer. This paper reports on the IBL construction and integration prior to its operation in the ATLAS detector.

Production and integration of the ATLAS Insertable B-Layer

We present a comprehensive review of the properties of the epitaxial 4H silicon carbide polytype (4H–SiC). Particular emphasis is placed on those aspects of this material related to room, high-temperature and harsh environment ionizing radiation detector operation. A review of the characterization methods and electrical contacting issues and how these are related to detector performance is presented. The most recent data on charge transport parameters across the Schottky barrier and how these are related to radiation spectrometer performance are presented. Experimental results on pixel detectors having equivalent noise energies of 144 eV FWHM (7.8 electrons rms) and 196 eV FWHM at +27 °C and +100 °C, respectively, are reported. Results of studying the radiation resistance of 4H–SiC are analysed. The data on the ionization energies, capture cross section, deep-level centre concentrations and their plausible structures formed in SiC as a result of irradiation with various particles are reviewed. The emphasis is placed on the study of the 1 MeV neutron irradiation, since these thermal particles seem to play the main role in the detector degradation. An accurate electrical characterization of the induced deep-level centres by means of PICTS technique has allowed one to identify which play the main role in the detector degradation.

https://iopscience.iop.org/article/10.1088/0957-0233/19/10/102001/pdf

Silicon carbide and its use as a radiation detector material

A review of radiation-induced displacement damage effects in semiconductor devices is presented, with emphasis placed on silicon technology. The history of displacement damage studies is summarized, and damage production mechanisms are discussed. Properties of defect clusters and isolated defects are addressed. Displacement damage effects in materials and devices are considered, including effects produced in silicon particle detectors, visible imaging arrays, and solar cells. Additional topics examined include NIEL scaling, carrier concentration changes, random telegraph signals, radiation hardness assurance, and simulation methods for displacement damage. Areas needing further study are noted.

Displacement Damage Effects in Irradiated Semiconductor Devices

A junction termination structure for silicon radiation detectors is investigated, featuring all-p-type multiguard and scribe-line implants, with metal field-plates providing complete coverage of the oxide upper surface above nonimplanted regions. The sensitive interface between oxide and n-type substrate is thus electrostatically screened from the external environment, resulting in improved long-term stability of the device and excellent insensitivity to ambient conditions both before and after X-ray and neutron irradiations. Careful design of the multiguard layout enables high-voltage operation to be achieved. With respect to a previously proposed structure, the adoption of alternate outward and inward field plates between adjacent rings allows a significant improvement in the voltage handling capability.

An improved termination structure for silicon radiation detectors with all-P-type multiguard and cut-line implants

3D Silicon sensors fabricated at FBK-irst with the Double-side Double Type Column (DDTC) approach and columnar electrodes only partially etched through p-type substrates were tested in laboratory and in a 1.35 Tesla magnetic field with a 180 GeV pion beam at CERN SPS. The substrate thickness of the sensors is about 200 {mu}m, and different column depths are available, with overlaps between junction columns (etched from the front side) and ohmic columns (etched from the back side) in the range from 110 {mu}m to 150 {mu}m. The devices under test were bump bonded to the ATLAS Pixel readout chip (FEI3) at SELEX SI (Rome, Italy). We report leakage current and noise measurements, results of functional tests with Am{sup 241} {gamma}-ray sources, charge collection tests with Sr90 {beta}-source and an overview of preliminary results from the CERN beam test.

Preliminary results of 3D-DDTC pixel detectors for the ATLAS upgrade

3D sensors are a promising option for the innermost pixel layers at the High Luminosity LHC. However, the required very high hit-rate capabilities, increased pixel granularity, extreme radiation hardness, and reduced material budget call for a device downscale as compared to existing 3D sensors, involving smaller pitch (e.g., 50×50 or 25×100 μm2), shorter inter-electrode spacing (~30 μm), narrower electrodes (~5 μm), and reduced active thickness (~100 μm). The development of a new generation of 3D pixel sensors with these challenging features is under way by many research groups, in collaboration with processing facilities like FBK, CNM, and SINTEF. This paper talk will review the lessons learned from existing 3D detectors, and will address the main design and technological issues for small pitch 3D devices. Preliminary results from the electrical and functional characterization of the first prototypes will be reported and compared to TCAD simulations.

/pdf/small-pitch-3d-devices-hrbyb7z27q.pdf

Small pitch 3D devices

In the past two years 3D silicon radiation detectors have been developed at ITC-irst (Trento, Italy). As a first step toward full 3D devices, simplified structures featuring columnar electrodes of one doping type only were fabricated. This paper reports the electro-optical characterization of 3D test diodes made with this approach. Experimental results and TCAD simulations provide good insight into the charge collection mechanism and response speed limitation of these structures.

Sabina Ronchin

Papers

An improved termination structure for silicon radiation detectors with all-P-type multiguard and cut-line implants

Preliminary results of 3D-DDTC pixel detectors for the ATLAS upgrade

Small pitch 3D devices

Electro-optical measurements of 3D-stc detectors fabricated at ITC-irst

Silicon carbide for future intense luminosity nuclear physics investigations