Upgrade of the L2 electronics in the CMS Muon Drift Tubes system

The excellent performance of the DT system during the past years is expected to be pursued at the increased luminosity, so the main motivation driving the DT upgrade is focused on improving the electronic system to maintain its reliability. The fulfillment of this project envisages to turn electrical signals into optical signals for a total number of 3500 optical channels that run at up to 480 Mb/s data rate. A Bit Error Rate (BER) of the order of 10−12 with a confidence level (CL) of 95% has been measured which ensures that an appropriate components choice has been made in view of the full boards production

Epitaxial hybrid pixel with triggerless readout in 130nm Cmos technology for the Micro Vertex Detector of the Panda experiment

The Micro Vertex Detector (MVD) is the innermost one of the Panda experiment, sitting around the beam pipe. The sensors are arranged in a barrel section with two pixel and two strip layers, and 6 forward disks with mixed pixel and microstrip sensors. For the pixel detector part, a hybrid solution with thinned epitaxial sensors was chosen. The main requirements for the readout include: a pixel size of 100 · 100 μm2, an input charge measurement with 12 b that implies an amplitude resolution of 1 part out of 4096, a working frequency of 155.5MHz, and a triggerless acquisition. The readout of the pixel detector is based on a front end chip, named Topix, that is under development. The Asic will provide the time position with a resolution of 6.43 ns and a charge measurement with a Time Over Threshold (TOT) technique; it features a matrix of 116 · 110 pixel cell channels and 311 Mb/s serializers as output ports. A 130nm Cmos technology has been used to reduce the circuit size and to provide tolerance for the total dose, besides techniques against single event upset have been implemented. A Topix prototype with the full cell has been completely tested for radiation damage before and after irradiation, and a new release has been submitted to build an hybrid assembly. The stringent requirements in terms of space for the MVD lead to an architecture based on optical links. The GigaBit Transceiver (GBT) from CERN has been chosen as the baseline solution for the interface to the data acquisition. Low mass cables based on aluminium on polyimide are under development for the interconnections

The optical links for the trigger upgrade of the Drift Tube in CMS

The first phase of the upgrade of the electronics of Drift Tubes (DT) in the CMS experiment is reported. It consists of the translation of the readout and trigger data from electrical into optical and their transmission from the CMS experimental cavern to the counting room. Collecting the full information of the DT chambers in the counting room allows the development of new trigger hardware and algorithms

Front end electronics for pixel detector of the PANDA MVD

ToPix 2.0 is a prototype in a CMOS 0.13 ¹m technology of the front-end chip for the hybrid pixel sensors that will equip the Micro-Vertex Detector of the PANDA experiment at GSI. The Time over Threshold (ToT) approach has been employed to provide a high charge dynamic range (up to 100 fC) with a low power dissipation (15 ¹W/cell). In an area of 100¹m£100¹m each cell incorporates the analog and digital electronics necessary to amplify the detector signal and to digitize the time and charge information. The ASIC includes 320 pixel readout cells organized in four columns and a simplified version of the end of column readout

CMS Drift Tube Chambers Read-Out Electronics

With CMS installation nearing completion, the three levels of the final read-out system of the Drift Tube (DT) chambers are presented. First, are the Read Out Boards (ROB), responsible for time digitization of the signals generated by a charged particle track. Second, the Read Out Server (ROS) boards receive data from 25 ROB channels through a 240-Mbps copper link and perform data merging for further transmission through a 800 Mbps optical link. Finally, the Detector Dependent Units (DDU) merge data from 12 ROS to build an event fragment and send it to the global CMS DAQ through an S-LINK64 output at 320 MBps. DDUs also receive synchronization commands from the TTC system (Timing, Trigger, and Control), perform error detection on data, and send a fast feedback to the TTS (Trigger Throttling System). Functionality of these electronics has been validated in the laboratory and in several test-beams, including an exercise integrated with a fraction of the whole CMS detector and electronics that demonstrated proper operation and integration within the final CMS framework

Hybrid pixels for the PANDA Micro-Vertex Detector

PANDA is a fixed target experiment that will be carried out at the future FAIR facility. The PANDA experiment will perform precise studies of antiproton-proton and antiproton-nuclei annihilations, allowing to investigate different physics topics. The Micro-Vertex Detector (MVD), which represents the innermost part of the central tracking system, features good spatial resolution, limited material budget, radiation hardness and PID capability. To cope with this requirements the MVD is composed by pixel and strip detectors. The custom pixel detector design foresees thin epitaxial sensors and a readout electronics developed in 130nm CMOS technology able to work in a triggerless environment. The first single chip assembly prototype for the pixel detector of PANDA is composed of the ToPix3 readout chip and a dedicated epitaxial silicon sensor matching in size the 640 readout channel matrix of the ASIC prototype. The bump bonding connection was done by IZM company. To perform the first beam test, a pixel tracking station composed by 4 planes was assembled and tested with 2.7GeV/c protons at Forschungszentrum J¨ulich. The data analysis is presented

Usefulness of transesophageal echocardiography in the assessment of aortic dissection

The acute dissection of the ascending aorta requires prompt and reliable diagnosis to reduce the high risk of mortality; in addition, prognosis is influenced by longterm complications. The aim of this article is to discuss transesophageal echocardiography (TEE) and (1) its diagnostic accuracy in the presurgical evaluation of patients, (2) its role in reducing time of diagnosis and surgery, and (3) its ability to reduce hospital mortality. TEE has also been tested as a screening method in the postsurgical follow-up of these patients. The retrospective investigation concerns a sample of 80 cases of acute dissection of the aorta, submitted for surgical intervention from April 1986 to February 1999. TEE has allowed a precise estimation of aortic diameters and optimal visualization of intimal flap and tear entry with a fine distinction between true and false lumen. A direct comparison of the results of TEE and of transthoracic echocardiography has demonstrated that some elements (visualization of flap and diameters in descending aorta, sites of entry and reentry, direction of let trough intimal tears, phasic intimal flap movement, diastolic collapse of flap on the valvular plane, false lumen thrombosis, coronary involvement, intramural hematoma, and aortic fissuration) were identified only by TEE, whereas other additional diagnostic elements (cardiac tamponade, aortic valve insufficiency, left ventricular function) show a similar pattern of significance. Routine employment of this method has confirmed a reduction of hospitalization time (about 1.5 hours of waiting time), and hospital mortality has changed from 42.8% to 17.3%. In the follow-up of patients operated on for aortic dissection, fundamental information may be obtained from TEE (assessment of the progression of thrombosis in the false lumen with its complete obliteration and modifications in aortic diameter with a consequent, possible worsening of aortic valve insufficiency). In conclusion, our study demonstrated that TEE may provide fast and efficient detection of acute aortic dissection. In the postsurgical follow-up, TEE has confirmed detection of major complications that can influence long-term prognosis and may be proposed as a method with easy access-one that is repeatable and inexpensive for the screening of aortic dissection surgical patients. (C) 2000 by Excerpta Medica, Inc

Image Compression for the Silicon Drift Detectors in the ALICE Experiment

The output of each Silicon Drift Detector in the Inner Tracking System, being prepared for the future ALICE Experiment on the LHC, is a type of image composed of 256 successive digitilizations from each of 256 parallel charge measuring channels. We describe an algorithm for the zero suppression and data compression for the Silicon Drift Detectors in the ALICE Experiment, which seeks to maintain maximum precision within the limits of data transmission bandwidth, to retain two-dimensional cluster reconstructability and to statistically monitor the background.(Abstract only available, full text will follow