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

ATLAS pixel detector electronics and sensors

The silicon pixel tracking system for the ATLAS experiment at the Large Hadron Collider is described and the performance requirements are summarized. Detailed descriptions of the pixel detector electronics and the silicon sensors are given. The design, fabrication, assembly and performance of the pixel detector modules are presented. Data obtained from test beams as well as studies using cosmic rays are also discussed

Results on 0.7% X0 thick pixel modules for the ATLAS detector

Modules are the basic building blocks of the ATLAS pixel detector system, they are made of a silicon sensor tile containing ~46000 pixel cells of 50 mu m*400 mu m, 16 front-end chips connected to the sensor through bump bonding, a kapton flex circuit and the module controller chip. The pixel detector is the first to encounter particles emerging from LHC interactions, minimization of radiation length of pixel modules is therefore very important. We report here on the construction techniques and on the operation of the first ATLAS pixel modules of 0.7% radiation length thickness. We have operated these modules with threshold of 3700*10+or-300*10, mean noise value of 225*10 and 0.3% dead channels. (3 refs)

MCC: the Module Controller Chip for the ATLAS Pixel Detector.

In this article we describe the architecture of the Module Controller Chip for the ATLAS Pixel Detector. The project started in 1997 with the definition of the system specifications. A first fully-working rad-soft prototype was designed in 1998, while a radiation hard version was submitted in 2000. The 1998 version was used to build pixel detector modules. Results from those modules and from the simulated performance in ATLAS are reported. In the article we also describe the hardware/software tools developed to test the MCC performance at the LHC event rate

Outcomes for family carers of a nurse-delivered hospital discharge intervention for older people (the Further Enabling Care at Home Program): Single blind randomised controlled trial

Background: Hospital discharge of older people receiving care at home offers a salient opportunity to identify and address their family caregivers’ self-identified support needs. Objectives: This study tested the hypothesis that the extent to which family caregivers of older people discharged home from hospital felt prepared to provide care at home would be positively influenced by their inclusion in the new Further Enabling Care at Home program. Design: This single-blind randomised controlled trial compared outcomes from usual care alone with those from usual care plus the new program. The program, delivered by a specially trained nurse over the telephone, included: support to facilitate understanding of the patient's discharge letter; caregiver support needs assessment; caregiver prioritisation of urgent needs; and collaborative guidance, from the nurse, regarding accessing supports. Setting and participants: Dyads were recruited from the medical assessment unit of a Western Australian metropolitan public hospital. Each dyad comprised a patient aged 70 years or older plus an English speaking family caregiver. Methods: The primary outcome was the caregiver's self-reported preparedness to provide care for the patient. Data collection time points were designated as: Time 1, within four days of discharge; Time 2, 15–21 days after discharge; Time 3, six weeks after discharge. Other measures included caregivers’ ratings of: their health, patients’ symptoms and independence, caregiver strain, family well-being, caregiver stress, and positive appraisals of caregiving. Data were collected by telephone.Results: Complete data sets were obtained from 62 intervention group caregivers and 79 controls. Groups were equivalent at baseline. Needs prioritised most often by caregivers were: to know whom to contact and what to expect in the future and to access practical help at home. Support guidance included how to: access help, information, and resources; develop crisis plans; obtain referrals and services; and organise legal requirements. Compared to controls, preparedness to care improved in the intervention group from Time 1 to Time 2 (effect size = 0.52; p = 0.006) and from Time 1 to Time 3 (effect size = 0.43; p = 0.019). These improvements corresponded to a change of approximately 2 points on the Preparedness for Caregiving instrument. Small but significant positive impacts were also observed in other outcomes, including caregiver strain. Conclusions: These unequivocal findings provide a basis for considering the Furthering Enabling Care at Home program's implementation in this and other similar settings. Further testing is required to determine the generalisability of results

Test beam results of 3D silicon pixel sensors for the ATLAS upgrade

Results on beam tests of 3D silicon pixel sensors aimed at the ATLAS Insertable B-Layer and High Luminosity LHC (HL-LHC) upgrades are presented. Measurements include charge collection, tracking efficiency and charge sharing between pixel cells, as a function of track incident angle, and were performed with and without a 1.6 T magnetic field oriented as the ATLAS inner detector solenoid field. Sensors were bump-bonded to the front-end chip currently used in the ATLAS pixel detector. Full 3D sensors, with electrodes penetrating through the entire wafer thickness and active edge, and double-sided 3D sensors with partially overlapping bias and read-out electrodes were tested and showed comparable performance

The evaporative cooling system for the ATLAS inner detector

This paper describes the evaporative system used to cool the silicon detector structures of the inner detector sub-detectors of the ATLAS experiment at the CERN Large Hadron Collider. The motivation for an evaporative system, its design and construction are discussed. In detail the particular requirements of the ATLAS inner detector, technical choices and the qualification and manufacture of final components are addressed. Finally results of initial operational tests are reported. Although the entire system described, the paper focuses on the on-detector aspects. Details of the evaporative cooling plant will be discussed elsewhere. © 2008 IOP Publishing Ltd and SISSA