Planar Pixel Sensors for the ATLAS tracker upgrade at HL-LHC

The ATLAS Planar Pixel Sensor R&D Project is a collaboration of 17 institutes and more than 80 scientists. Their goal is to explore the operation of planar pixel sensors for the tracker upgrade at the High Luminosity-Large Hadron Collider (HL-LHC). This work will give a summary of the achievements on radiation studies with n-in-n and n-in-p pixel sensors, bump-bonded to ATLAS FE-I3 and FE-I4 readout chips. The summary includes results from tests with radioactive sources and tracking efficiencies extracted from test beam measurements. Analysis results of ${2\cdot10^{16}} \text{n}_{\text{eq}}\text{cm}^{-2}$ and ${1\cdot10^{16}} \text{n}_{\text{eq}}\text{cm}^{-2}$ ($1 \text{MeV}$ neutron equivalent) irradiated n-in-n and n-in-p modules confirm the operation of planar pixel sensors for future applications

Planar n-in-n quad module prototypes for the ATLAS ITk upgrade at HL-LHC

In order to meet the requirements of the High Luminosity LHC (HL-LHC), it will be necessary to replace the current tracker of the ATLAS experiment. Therefore, a new all-silicon tracking detector is being developed, the so-called Inner Tracker (ITk). The use of quad chip modules is intended in its pixel region. These modules consist of a silicon sensor that forms a unit along with four read-out chips. The current ATLAS pixel detector consists of planar n-in-n silicon pixel sensors. Similar sensors and four FE-I4 read-out chips were assembled to first prototypes of planar n-in-n quad modules. The main focus of the investigation of these modules was the region between the read-out chips, especially the central area between all four read-out chips. There are special pixel cells placed on the sensor which cover the gap between the read-out chips. This contribution focuses on the characterization of a non-irradiated device, including important sensor characteristics, charge collection determined with radioactive sources as well as hit efficiency measurements, performed in the laboratory and at testbeams. In addition, first laboratory results of an irradiated device are presented

Novel Silicon n-in-p Pixel Sensors for the future ATLAS Upgrades

In view of the LHC upgrade phases towards HL-LHC the ATLAS experiment plans to upgrade the Inner Detector with an all silicon system. The n-in-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. We present the characterization and performance of novel n-in-p planar pixel sensors produced by CiS (Germany) connected by bump bonding to the ATLAS readout chip FE-I3. These results are obtained before and after irradiation up to a fluence of 10^16 1-MeV n_eq/cm^2, and prove the operability of this kind of sensors in the harsh radiation environment foreseen for the pixel system at HL-LHC. We also present an overview of the new pixel production, which is on-going at CiS for sensors compatible with the new ATLAS readout chip FE-I4.Comment: Preprint submitted to NIM-A Proceedings (Elba 2012

Investigation of n +-in-n planar silicon pixel detectors for application in the ATLAS experiment

One of the two large multi-purpose detectors at the LHC at CERN is the ATLAS detector. The ATLAS detector consists of several sub-detectors, each with diffe- rent tasks. The ATLAS pixel detector was enlarged with a fourth pixel layer, the Insetable B-Layer (IBL) during the first long shutdown. The IBL will increase the tracking performance under high-luminosity conditions. The IBL consists to 75% of n+-in-n slim edge planar pixel sensors. Sensors with a thickness of 200 µm and a requested fluence of 5 x 10 15 n eq cm2 were investigated in terms of leakage current per pixel, power dissipation, and average hit efficiency at bias voltages up to 1000V and a temperature of -15°C. Testbeam and laboratory measurements for the sensor decision for the IBL are presented

Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip

The ATLAS Collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing pixel detector and the vacuum pipe of the Large Hadron Collider. The extreme operating conditions at this location have necessitated the development of new radiation hard pixel sensor technologies and a new front-end readout chip, called the FE-I4. Planar pixel sensors and 3D pixel sensors have been investigated to equip this new pixel layer, and prototype modules using the FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test results are presented, including charge collection efficiency, tracking efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS

Investigation of n +-in-n planar silicon pixel detectors for application in the ATLAS experiment

One of the two large multi-purpose detectors at the LHC at CERN is the ATLAS detector. The ATLAS detector consists of several sub-detectors, each with diffe- rent tasks. The ATLAS pixel detector was enlarged with a fourth pixel layer, the Insetable B-Layer (IBL) during the first long shutdown. The IBL will increase the tracking performance under high-luminosity conditions. The IBL consists to 75% of n+-in-n slim edge planar pixel sensors. Sensors with a thickness of 200 µm and a requested fluence of 5 x 10 15 n eq cm2 were investigated in terms of leakage current per pixel, power dissipation, and average hit efficiency at bias voltages up to 1000V and a temperature of -15°C. Testbeam and laboratory measurements for the sensor decision for the IBL are presented