From vertex detectors to inner trackers with CMOS pixel sensors

The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order of magnitude improvement on readout speed and improved radiation tolerance. This triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz 180 nm, for the design of a CPS well adapted for the new ALICE-ITS running conditions. This paper reports the R&D results for the conception of a CPS well adapted for the ALICE-ITS.Comment: 4 pages, 4 figures, VCI 2016 conference proceeding

Atomistic mechanisms for the ordered growth of Co nano-dots on Au(788): comparison of VT-STM experiments and multi-scaled calculations

Hetero-epitaxial growth on a strain-relief vicinal patterned substrate has revealed unprecedented 2D long range ordered growth of uniform cobalt nanostructures. The morphology of a Co sub-monolayer deposit on a Au(111) reconstructed vicinal surface is analyzed by Variable Temperature Scanning Tunneling Microscopy (VT-STM) experiments. A rectangular array of nano-dots (3.8 nm x 7.2 nm) is found for a particularly large deposit temperature range lying from 60 K to 300 K. Although the nanodot lattice is stable at room temperature, this paper focus on the early stage of ordered nucleation and growth at temperatures between 35 K and 480 K. The atomistic mechanisms leading to the nanodots array are elucidated by comparing statistical analysis of VT-STM images with multi-scaled numerical calculations combining both Molecular Dynamics for the quantitative determination of the activation energies for the atomic motion and the Kinetic Monte Carlo method for the simulations of the mesoscopic time and scale evolution of the Co submonolayer

States on pseudo effect algebras and integrals

We show that every state on an interval pseudo effect algebra $E$ satisfying some kind of the Riesz Decomposition Properties (RDP) is an integral through a regular Borel probability measure defined on the Borel $\sigma$-algebra of a Choquet simplex $K$. In particular, if $E$ satisfies the strongest type of (RDP), the representing Borel probability measure can be uniquely chosen to have its support in the set of the extreme points of $K.

Development of ultra-light pixelated ladders for an ILC vertex detector

The development of ultra-light pixelated ladders is motivated by the requirements of the ILD vertex detector at ILC. This paper summarizes three projects related to system integration. The PLUME project tackles the issue of assembling double-sided ladders. The SERWIETE project deals with a more innovative concept and consists in making single-sided unsupported ladders embedded in an extra thin plastic enveloppe. AIDA, the last project, aims at building a framework reproducing the experimental running conditions where sets of ladders could be tested

A high purity measurement of RbR_b at SLD

Precision measurement of Rb can provide important information about the Standard Model and beyond. SLD has developed a new method for measuring Rb with very high purity. This measurement has the lowest systematic error reported to date and future measurements using this method will likely have the lowest total uncertainty. This paper will be divided into the five sections: introduction, hardware, topological vertexing tag method, results and conclusions. The introduction will discuss the importance of Rb and the problems with other measurement techniques. The hardware section will give a brief description of the SLC/SLD system concentrating on its advantages over LEP. An outlook towards the future of SLD Rb measurements will be included in the conclusions

The STAR Silicon Strip Detector (SSD)

The STAR Silicon Strip Detector (SSD) completes the three layers of the Silicon Vertex Tracker (SVT) to make an inner tracking system located inside the Time Projection Chamber (TPC). This additional fourth layer provides two dimensional hit position and energy loss measurements for charged particles, improving the extrapolation of TPC tracks through SVT hits. To match the high multiplicity of central Au+Au collisions at RHIC the double sided silicon strip technology was chosen which makes the SSD a half million channels detector. Dedicated electronics have been designed for both readout and control. Also a novel technique of bonding, the Tape Automated Bonding (TAB), was used to fullfill the large number of bounds to be done. All aspects of the SSD are shortly described here and test performances of produced detection modules as well as simulated results on hit reconstruction are given.Comment: 11 pages, 8 figures, 1 tabl

Autophagy suppresses the formation of hepatocyte-derived cancer-initiating ductular progenitor cells in the liver

Hepatocellular carcinoma (HCC) is driven by repeated rounds of inflammation, leading to fibrosis, cirrhosis, and, ultimately, cancer. A critical step in HCC formation is the transition from fibrosis to cirrhosis, which is associated with a change in the liver parenchyma called ductular reaction. Here, we report a genetically engineered mouse model of HCC driven by loss of macroautophagy and hemizygosity of phosphatase and tensin homolog, which develops HCC involving ductular reaction. We show through lineage tracing that, following loss of autophagy, mature hepatocytes dedifferentiate into biliary-like liver progenitor cells (ductular reaction), giving rise to HCC. Furthermore, this change is associated with deregulation of yes-associated protein and transcriptional coactivator with PDZ-binding motif transcription factors, and the combined, but not individual, deletion of these factors completely reverses the dedifferentiation capacity and tumorigenesis. These findings therefore increase our understanding of the cell of origin of HCC development and highlight new potential points for therapeutic intervention

Proton Interaction Vertex Imaging With Silicon-Pixel CMOS Telescope For Carbon Therapy Quality control

International audienceMonitoring of the dose deposition during carbon ion therapy is a crucial issue for the quality control of such treatments. Recent studies have demonstrated that an ion-range control with millimeter resolution is feasible on a pencil-beam basis in homogeneous targets with prompt gamma detection for proton beams [1] and with Proton Interaction Vertex Imaging (PIVI) for carbon beams [2]. The present communication aims at describing our experimental and Monte Carlo simulation results. [1] J. Smeets et al., Phys. Med. Biol. 57 (2012) 3371-3405 [2] P. Henriquet et al., Phys. Med. Biol. 57 (2012) 4655-466

Detector and Front-end electronics for ALICE and STAR silicon strip layers

Detector modules consisting of Silicon Strip Detector (SSD) and Front End Electronics (FEE) assembly have been designed in order to provide the two outer layers of the ALICE Inner Tracker System (ITS) [1] as well as the outer layer of the STAR Silicon Vertex Tracker (SVT) [2]. Several prototypes have beenproduced and tested in the SPS and PS beam at CERN to validate the final design. Double-sided, AC-coupled SSD detectors provided by two different manufacturers and also a pair of single-sided SSD have been asssociated to new low-power CMOS ALICE128C ASIC chips in a new detector module assembly. The same detectors have also been associated to current Viking electronics for reference purpose. These prototype detector modules are described and some first results are presented

CMOS pixel sensor development: a fast read-out architecture with integrated zero suppression

International audienceCMOS Monolithic Active Pixel Sensors (MAPS) have demonstrated their strong potential for tracking devices, particularly for flavour tagging. They are foreseen to equip several vertex detectors and beam telescopes. Most applications require high read-out speed, which imposes sensors to feature digital output with integrated zero suppression. The most recent development of MAPS at IPHC and IRFU addressing this issue will be reviewed. The design architecture, combining pixel array, column-level discriminators and zero suppression circuits, will be presented. Each pixel features a preamplifier and a correlated double sampling (CDS) micro-circuit reducing the temporal and fixed pattern noises. The sensor is fully programmable and can be monitored. It will equip experimental apparatus starting data taking in 2009/2010