The ABC130 barrel module prototyping programme for the ATLAS strip tracker

For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.Comment: 82 pages, 66 figure

Strip sensor performance in prototype modules built for ATLAS ITk

TLAS experiment is preparing an upgrade of its detector for High-Luminosity LHC (HL-LHC) operation. The upgrade involves installation of the new all-silicon Inner Tracker (ITk). In the context of the ITk preparations, more than 80 strip modules were built with prototype barrel sensors. They were tested with electrical readout on a per-channel basis. In general, an excellent performance was observed, consistent with previous ASIC-level and sensor-level tests. However, the lessons learned included two phenomena important for the future phases of the project. First was the need to store and test the modules in a dry environment due to humidity sensitivity of the sensors. The second was an observation of high noise regions for 2 modules. The high noise regions were tested further in several ways, including monitoring the performance as a function of time and bias voltage. Additionally, direct sensor-level tests were performed on the affected channels. The inter-strip resistance and bias resistance tests showed low values, indicating a temporary loss of the inter-strip isolation. A subsequent recovery of the noise performance was observed. We present the test details, an analysis of how the inter-strip isolation affects the module noise, and the relationship with sensor-level quality control tests.Peer reviewe

Assembly and electrical tests of the first full-size forward module for the ATLAS ITk Strip detector

The ATLAS experiment will replace the existing Inner Detector by an all-silicon detector named the Inner Tracker (ITk) for the High Luminosity LHC upgrades. In the outer region of the ITk is the strip detector, which consists of a four layer barrel and six discs to each side of the barrel, with silicon-strip modules as basic units. Each module is composed of a sensor and one or more flex circuits that hold the read-out electronics. In the experiment, the modules are mounted on support structures with integrated power and cooling. The modules are designed with geometries that accommodate the central (barrel) and forward (end-cap) regions, with rectangular sensors in the barrels and wedge shaped sensors in the end-caps. The strips lengths and pitch sizes vary according to the occupancy of the region.Peer reviewe

Dispositivo de adquisición de datos para dispositivos detectores de diferentes tipos

1. Dispositivo de adquisición de datos para dispositivos detectores de diferentes tipos, comprende: una primera placa auxiliar (P_AUX) que incluye: - un primer dispositivo detector (1), de un primer tipo; - una pluralidad de chips de lectura (2) operativamente conectada a dicho primer dispositivo detector (1) para adquirir dichos datos proporcionando una única señal de salida de los datos adquiridos; y - una unidad de conexión (5); y - una placa principal (P_PRIN) que incluye: - una unidad de control (14) adaptada para procesar datos; y - una unidad de conexión (10), para conexión de la placa principal (P_PRIN) con un dispositivo de computación remoto para transmitir a este último los datos procesados y recibir de él diferentes comandos, caracterizado porque el dispositivo comprende, además: - al menos una segunda placa auxiliar (P_AUX) que incluye: - un segundo dispositivo detector (1), de un segundo tipo, diferente del primer tipo; - una pluralidad de chips de lectura (2) operativamente conectada a dicho segundo dispositivo detector (1) para adquirir dichos datos proporcionando una única señal de salida de los datos adquiridos, y - una unidad de conexión (5), estando conectada al menos una de las placas auxiliares (P_AUX) a una placa intermedia (P_INT), conectada a su vez a la placa principal (P_PRIN), en donde dicha placa intermedia (P_INT), que es al menos una, incluye: - una primera unidad de conexión (6) configurada para recibir la señal única de salida de los datos adquiridos, de su placa auxiliar correspondiente; - una unidad de ajuste (7) configurada para adaptarla señal única de salida recibida a un protocolo de comunicación de la placa principal (P_PRIN); y - una segunda unidad de conexión (8) configurada para transmitir la señal adaptada a la placa principal (P_PRIN) y para recibir de esta última diferentes comandos; y porque - la placa principal (P_PRIN) incluye además un dispositivo de disparo (13) configurado para detectar cuando las señales únicas de salida de los datos adquiridos están disponibles, - la unidad de control (14) de la placa principal (P_PRIN) está adaptada para procesar las señales recibidas, de la placa intermedia (P_INT) y/o de una placa auxiliar (P_AUX), proporcionándoles además una etiqueta temporal y un identificador que permita distinguirlas.Peer reviewedConsejo Superior de Investigaciones Científicas (España), Universitat de València, Alibava Systems S.L.U Solicitud de modelo de utilida

Prototyping of petalets for the Phase-II Upgrade of the silicon strip tracking detector of the ATLAS Experiment

n the high luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The ITk consists of a silicon pixel and a strip detector and exploits the concept of modularity. Prototyping and testing of various strip detector components has been carried out. This paper presents the developments and results obtained with reduced-size structures equivalent to those foreseen to be used in the forward region of the silicon strip detector. Referred to as petalets, these structures are built around a composite sandwich with embedded cooling pipes and electrical tapes for routing the signals and power. Detector modules built using electronic flex boards and silicon strip sensors are glued on both the front and back side surfaces of the carbon structure. Details are given on the assembly, testing and evaluation of several petalets. Measurement results of both mechanical and electrical quantities are shown. Moreover, an outlook is given for improved prototyping plans for large structures.Peer reviewe

Prototyping of hybrids and modules for the forward silicon strip tracking detector for the ATLAS Phase-II upgrade

For the High-Luminosity upgrade of the Large Hadron Collider an increased instantaneous luminosity of up to 7.5 ⋅ 1034cm−2s−11034cm−2s−1, leading to a total integrated luminosity of up to 3000 fb−1fb−1, is foreseen. The current silicon and transition radiation tracking detectors of the ATLAS experiment will be unable to cope with the increased track densities and radiation levels, and will need to be replaced. The new tracking detector will consist entirely of silicon pixel and strip detectors. In this paper, results on the development and tests of prototype components for the new silicon strip detector in the forward regions (end-caps) of the ATLAS detector are presented. Flex-printed readout boards with fast readout chips, referred to as hybrids, and silicon detector modules are investigated. The modules consist of a hybrid glued onto a silicon strip sensor. The channels on both are connected via wire-bonds for readout and powering. Measurements of important performance parameters and a comparison of two possible readout schemes are presented. In addition, the assembly procedure is described and recommendations for further prototyping are derived.Peer reviewe

Performance evaluation of MACACO: a multilayer Compton camera

Compton imaging devices have been proposed and studied for a wide range of applications. We have developed a Compton camera prototype which can be operated with two or three detector layers based on monolithic lanthanum bromide (${\rm LaBr}_{3}$ ) crystals coupled to silicon photomultipliers (SiPMs), to be used for proton range verification in hadron therapy. In this work, we present the results obtained with our prototype in laboratory tests with radioactive sources and in simulation studies. Images of a $^{22}$ Na and an $^{88}$ Y radioactive sources have been successfully reconstructed. The full width half maximum of the reconstructed images is below 4 mm for a $^{22}$ Na source at a distance of 5 cm

Sensors for the End-cap prototype of the Inner Tracker in the ATLAS Detector Upgrade

The new silicon microstrip sensors of the End-cap part of the HL-LHC ATLAS Inner Tracker (ITk) present a number of challenges due to their complex design features such as the multiple different sensor shapes, the varying strip pitch, or the built-in stereo angle. In order to investigate these specific problems, the “petalet” prototype was defined as a small End-cap prototype. The sensors for the petalet prototype include several new layout and technological solutions to investigate the issues, they have been tested in detail by the collaboration. The sensor description and detailed test results are presented in this paper. New software tools have been developed for the automatic layout generation of the complex designs. The sensors have been fabricated, characterized and delivered to the institutes in the collaboration for their assembly on petalet prototypes. This paper describes the lessons learnt from the design and tests of the new solutions implemented on these sensors, which are being used for the full petal sensor development. This has resulted in the ITk strip community acquiring the necessary expertise to develop the full End-cap structure, the petal.Peer reviewe

Measurement of the charge collection in irradiated miniature sensors for the upgrade of the ATLAS phase-II strip tracker

Miniature sensors with external dimensions of 10 mm x 10 mm were produced together with full-size sensors for the innermost ring (R0) of the end-cap part in the upgraded ATLAS inner tracker (ITk). AC- and DC-coupled n-type strips with three different pitches (wide, default and narrow) were processed on high-resistivity p-type FZ silicon substrates by Hamamatsu Photonics. The miniature sensors were irradiated with 70-MeV protons at CYRIC, Tohoku University (Japan) and reactor neutrons at the Jožef Stefan Institute (Slovenia) to three different 1-MeV neutron equivalent fluences: 0.5, 1 and 2 x 10 15 neq cm −2 . The upper fluence range exceeds the highest anticipated in the innermost part of the ATLAS ITk-Strips over the HL-LHC lifetime ( ∼ 1.25 × 10 15 n eq cm 2 ). The charge collection in the test sensors was evaluated systematically using a 90 Sr β -source and an Alibava analogue readout system at reverse-bias voltages up to 1000 V.Peer reviewe