120457455
The DELPHI Microvertex detector
The DELPHI Microvertex detector, which has been in operation since the start of the 1990 LEP run, consists of three layers of silicon microstrip detectors at average radii of 6.3, 9.0 and 11.0 cm. The 73728 readout strips, oriented along the beam, have a total active area of 0.42 m2. The strip pitch is 25 μm and every other strip is read out by low power charge amplifiers, giving a signal to noise ratio of 15:1 for minimum ionizing particles. On-line zero suppression results in an average data size of 4 kbyte for Z0 events. After a mechanical survey and an alignment with tracks, the impact parameter uncertainty as determined from hadronic Z0 decays is well described by (69pt)2 + 242 μm, with pt in GeV/c. For the 45 GeV/c tracks from Z0 → μ− decays we find an uncertainty of 21 μm for the impact parameter, which corresponds to a precision of 8 μm per point. The stability during the run is monitored using light spots and capacitive probes. An analysis of tracks through sector overlaps provides an additional check of the stability. The same analysis also results in a value of 6 μm for the intrinsic precision of the detector.
122563794
A new photomultiplier tube utilising channel plate electron multipliers as the gain producing elements
Abstract A survey of the properties of a new type of photomultiplier tube is presented. The device is a planar structure in which two cascaded channel plate electron multipliers (CPEM) produce charge gain factors of greater than 10 7 with a transit time of 1 ns. The single electron pulse rise time and transit time spread figures are 1 ns and 2.5 ns fwhm. The tube has shown its ability to operate satisfactorily in magnetic fields of 1 T without magnetic screening. Saturation of the tube occurs at a peak pulse current of 40 mA with plastic scintillator pulses. However the high plate impedances cause serious rate limitations with high output pulses.
118220175
Development of a new X-ray image intensifier for X-ray diffraction studies
109583813
Application of advanced thermal management technologies to the ATLAS SCT barrel module baseboards
Abstract The paper describes the application of advanced thermal management technologies to the design and production of the barrel module baseboard of the SemiConductor Tracker (SCT) of the ATLAS experiment at the Large Hadron Collider (LHC). The barrel modules contain silicon microstrip sensors and readout ASICs for tracking charged particles, and the baseboard forms the central element of the module, providing both its necessary thermal management and its mechanical structure. The baseboard requirements and specifications are given, and design and fabrication details are described. The properties of the 3000 baseboards successfully produced for the SCT are summarised.
24058982
The Omega Spectrometer Ring Imaging Cerenkov Detector Recent Detector Modifications and Event Analysis
A Ring Imaging Cerenkov (RICH) detector has now been successfully operated throughout a high-energy (70-200 GeV/c) photoproduction experiment at the CERN Omega Spectrometer. Recently complementary data using a hadron beam was taken with the same equipment. In each case about 20 million interactions were recorded. We discuss here features of the RICH device not yet described in previous publications and indicate by means of examples the way in which the RICH information is being used in the context of the overall experimental data analysis.
18645695
The recent operational performance of the CERN omega ring imaging cerenkov detector
We discuss the design and construction of the Time Projection chambers (TPCs) of the Omega Ring Imaging Cerenkov Detector (RICH). Details are given of the TPC high voltage system and its monitoring and control. In addition, the operation and monitoring of the readout is described together with results of tests on the performance of the front end amplifiers. The operation of the RICH TPCs and electronics during the first data run of WA69, in 1984, is discussed together with relevant results from laboratory tests. Results from the preliminary analysis of a sample of data from the 1984 run are also presented.
58892392
LATEST BEAM TEST RESULTS FROM ATF2 WITH THE FONT ILC PROTOTYPE INTRA-TRAIN BEAM FEEDBACK SYSTEMS
We present the design and beam test results of a prototype beam-based digital feedback system for the Interaction Point of the International Linear Collider. A custom analogue front-end signal processor, FPGA-based digital signal processing boards, and kicker drive amplifier have been designed, built, deployed and tested with beam in the extraction line of the KEK Accelerator Test Facility (ATF2). The system was used to provide orbit correction to the train of bunches extracted from the ATF damping ring. The latency was measured to be approximately 140 ns.
54225329
DEVELOPMENT OF A FAST,SINGLE-PASS,MICRON-RESOLUTION BEAM POSITION MONITOR SIGNAL PROCESSOR:BEAM TEST RESULTS FROM ATF2
We present the design of a stripline beam position monitor (BPM) signal processor with low latency (c. 10ns) and micron-level spatial resolution in single-pass mode. Such a BPM processor has applications in singlepass beamlines such as those at linear colliders and FELs. The processor was deployed and tested at the Accelerator Test Facility (ATF2) extraction line at KEK, Japan. We report the beam test results and processor performance, including response, linearity, spatial resolution and latency.
59334407
DESIGN AND INITIAL RESULTS OF A TURN-BY-TURN BEAM POSITION MONITORING SYSTEM FOR MULTIPLE BUNCH OPERATION OF THE ATF DAMPING RING
An FPGA-based monitoring system has been developed to study multi-bunchbeam instabilities in the damping ring (DR) of the KEK Accelerator Test Facility (ATF), utilising a stripline beam position monitor(BPM) and existing BPM processor hardware. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1‐3 bunches in the DR. An overview of the system and initial results will be presented.
14475692
Latest Beam Test Results of the FONT4 ILC Intra-train Feedback System Prototype
We present the design and preliminary results of a prototype beam-based digital feedback system for the Interaction Point of the International Linear Collider. A custom analogue front-end processor, FPGA-based digital signal processing board, and kicker drive amplifier have been designed, built, and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The system was measured to have a latency of approximately 140 ns.
55766811
LATEST PERFORMANCE RESULTS FROM THE FONT5 INTRA-TRAIN POSITION AND ANGLE FEEDBACK SYSTEM AT ATF2
A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilise the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch timescales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. An overview of the hardware, and the latest results from beam tests at ATF2, will be presented. A total system latency as low as approximately 140 ns has been demonstrated.