arXiv subjects

Lucien Cremaldi

Publications and source records attributed to Lucien Cremaldi.

13 recordsLinked to original sources

arXiv2025

The Imaging Time-of-Propagation Detector at Belle II

We report on the construction, operation, and performance of the Time-of-Propagation detector with imaging used for the Belle II experiment running at the Super-KEKB $e^+e^-$ collider. This detector is located in the central barrel region and uses Cherenkov light to provide particle identification among hadrons. The Cherenkov light is radiated in highly polished bars of synthetic fused silica (quartz) and transported to the ends of the bars via total internal reflection. One bar end is instrumented with finely segmented micro-channel-plate photomultiplier tubes to record the light, while the other end has a mirror attached to reflect the photons back to the instrumented end. Both the propagation times and hit positions of the Cherenkov photons are measured; these depend on the Cherenkov angle and together provide good discrimination among charged pions, kaons, and protons with momenta up to around 4 GeV/$c$. To date, the detector has been used to record and analyze almost 600 fb$^{-1}$ of Belle II data.

hep-ex↗

arXiv2017

Exploration of a High Luminosity 100 TeV Proton Antiproton Collider

New physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. We explore a 10$^{\,34}$ cm$^{-2}$ s$^{-1}$ luminosity, 100 TeV $p\bar{p}$ collider with 7$\times$ the energy of the LHC but only 2$\times$ as much NbTi superconductor, motivating the choice of 4.5 T single bore dipoles. The cross section for many high mass states is 10 times higher in $p\bar{p}$ than $pp$ collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per beam crossing, because lower beam currents can produce the same rare event rates. Events are more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller $β^{*}$ for higher luminosity. A Fermilab-like $\bar p$ source would disperse the beam into 12 momentum channels to capture more antiprotons. Because stochastic cooling time scales as the number of particles, 12 cooling ring sets would be used. Each set would include phase rotation to lower momentum spreads, equalize all momentum channels, and stochastically cool. One electron cooling ring would follow the stochastic cooling rings. Finally antiprotons would be recycled during runs without leaving the collider ring by joining them to new bunches with synchrotron damping.

physics.acc-ph↗

arXiv2016

Vibrations of Periodically Poled Lithium Niobate Bar with 0.3-mm Long Domains

The three dimensional vibrations in a periodically poled ZX-cut Lithium Niobate thin bar with 0.3-mm long domains are considered. The acoustical vibrations may be excited by the 1) longitudinal acousto-electric current when a radio frequency voltage is parallel to the x-axis, and 2) transverse electric field when a radio frequency voltage is parallel to the z-axis. The computations by the Final Element Method reveal all the three displacements along the x, y, and z crystallographic axes. The amplitudes may be different for two types of vibration excitations. The positions of peaks in admittance versus frequency correlate with the frequencies of maximum acoustic amplitudes. The superlattice with 0.3-mm long domains along the x-axis is fabricated in the z-cut 0.5-mm-thick wafer. The experimental data on the radio frequency admittance versus frequency is in agreement with the corresponding theoretical computations.

cond-mat.mtrl-sci↗

arXiv2016

Progress on Cherenkov Reconstruction in MICE

Two beamline Cherenkov detectors (Ckov-a,-b) support particle identification in the MICE beamline. Electrons and high-momentum muons and pions can be identified with good efficiency. We report on the Ckov-a,-b performance in detecting pions and muons with MICE Step I data and derive an upper limit on the pion contamination in the standard MICE muon beam.

physics.ins-det↗

arXiv2015

Final Muon Emittance Exchange in Vacuum for a Collider

We outline a plan for final muon ionization cooling with quadrupole doublets focusing onto short absorbers followed by emittance exchange in vacuum to achieve the small transverse beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low beta region occupied by a dense, low Z absorber. After final cooling, normalized xyz emittances of (0.071, 0.141, 2.4) mm-rad are exchanged into (0.025, 0.025, 70) mm-rad. Thin electrostatic septa efficiently slice the bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 microseconds, one quarter of a synchrotron oscillation period. A linear long wavelength RF bucket gives each bunch a different energy causing the bunches to drift until they merge into one bunch and can be captured in a short wavelength RF bucket with a 13% muon decay loss and a packing fraction as high as 87%.

physics.acc-ph↗

arXiv2013

Snowmass White Paper CMS Upgrade: Forward Lepton-Photon System

This White Paper outlines a proposal for an upgraded forward region to extend CMS lepton (e, mu) and photon physics reach out to 2.2<eta<5 for LHC and SLHC, which also provides better performance for the existing or new forward hadron calorimetry for jet energy and (eta, phi) measurements, especially under pileup/overlaps at high lumi, as LHC luminosity, energy and radiation damage increases.

physics.ins-det↗

arXiv2012

Double domain resonance in a periodically poled ferroelectric wafer

The periodically poled ferroelectric wafer is a two-dimensional phononic superlattice. The important applications of such a solid include novel ultrasonic transducers at the micro/nano-scale for low intensity ultra-sonography, ferroelectric data storage, and development of very high frequency chips for next generation communication and information technologies, and others. Usually, the transformations between the electrical and mechanical energies are required in the applications. In this work, we find the frequency characteristics for an effective acousto-electric interaction in a two-dimensional phononic superlattice inserted in LiNbO3 wafer.

cond-mat.mes-hall↗

arXiv2009

A Cherenkov Radiation Detector with High Density Aerogels

We have designed a threshold Cherenkov detector at the Rutherford-Appleton Laboratory to identify muons with momenta between 230 and 350 MeV/c. We investigated the properties of three aerogels for the design. The nominal indexes of refraction were n = 1.03, 1.07, 1.12, respectively. Two of the samples are of high density aerogel not commonly used for Cherenkov light detection. We present results of an examination of some optical properties of the aerogel samples and present basic test beam results.

physics.ins-det↗

arXiv2006

Working with Arrays of Inexpensive EIDE Disk Drives

In today's marketplace, the cost per Terabyte of disks with EIDE interfaces is about a third that of disks with SCSI. Hence, three times as many particle physics events could be put online with EIDE. The modern EIDE interface includes many of the performance features that appeared earlier in SCSI. EIDE bus speeds approach 33 Megabytes/s and need only be shared between two disks rather than seven disks. The internal I/O rate of very fast (and expensive) SCSI disks is only 50 per cent greater than EIDE disks. Hence, two EIDE disks whose combined cost is much less than one very fast SCSI disk can actually give more data throughput due to the advantage of multiple spindles and head actuators. We explore the use of 12 and 16 Gigabyte EIDE disks with motherboard and PCI bus card interfaces on a number of operating systems and CPUs. These include Red Hat Linux and Windows 95/98 on a Pentium, MacOS and Apple's Rhapsody/NeXT/UNIX on a PowerPC, and Sun Solaris on a UltraSparc 10 workstation.

hep-ex↗

arXiv2005

Simulation of Heavily Irradiated Silicon Pixel Sensors and Comparison with Test Beam Measurements

Charge collection measurements performed on heavily irradiated p-spray DOFZ pixel sensors with a grazing angle hadron beam provide a sensitive determination of the electric field within the detectors. The data are compared with a complete charge transport simulation of the sensor which includes signal trapping and charge induction effects. A linearly varying electric field based upon the standard picture of a constant type-inverted effective doping density is inconsistent with the data. A two-trap double junction model implemented in the ISE TCAD software can be tuned to produce a doubly-peaked electric field which describes the data reasonably well. The modeled field differs somewhat from previous determinations based upon the transient current technique. The model can also account for the level of charge trapping observed in the data.

physics.ins-det↗

arXiv2004

Work with Apple's Rhapsody Operating System which Allows Simultaneous UNIX Program Development, UNIX Program Execution, and PC Application Execution

Over the past decade, UNIX workstations have provided a very powerful program development environment. However, workstations are more expensive than PCs and Macintoshes and require a system manager for day-to-day tasks such as disk backup, adding users, and setting up print queues. Native commercial software for system maintenance and "PC applications" has been lacking under UNIX. Apple's new Rhapsody operating system puts the current MacOS on a NeXT UNIX foundation and adds an enhanced NeXTSTEP object oriented development environment called Yellow Box. Rhapsody simultaneously runs UNIX and commercial Macintosh applications such as word processing or spreadsheets. Thus a UNIX detector Monte Carlo can run for days in the background at the same time as a commercial word processing program. And commercial programs such as Dantz Retrospect are being made available to make disk backup easy under Rhapsody. Apple has announced that in 1999 they intend to be running Rhapsody, or MacOS X as it will be called in the commercial release, on all their newer computers. MacOS X may be of interest to those who have trouble hiring expert UNIX system managers; and to those who would prefer to have a single computer and operating system on their desktop that serves both the needs of UNIX program development and running commercial applications, simultaneously. We present our experiences running UNIX programs and Macintosh applications under the Rhapsody DR2 Developer Release.

hep-ex↗

arXiv2003

Ultrasonic Defect Modification in Irradiated Silicon

It is shown for the first time, that room temperature Ultrasonic Defect Manipulation (UDM) can significantly reduce the concentration of radiation defects in high resistivity silicon. Secondary Ion Mass Spectroscopy revealed that oxygen- and hydrogen- related chemical reactions in silicon are likely to occur under UDM at room temperature. Ultrasonically stimulated chemical reactions in solids can be an important source of energy, which is required for UDM.

cond-mat.mtrl-sci↗

arXiv2000

Search for Mixing and CP Violation in Charm Decays

Standard model mixing and CP violation are expected to be small in the charm sector. Some argue that only in the presence of new physics do we currently expect to observe these effects. Fermilab experiment E791 has the largest sample of reconstructed charm decays recorded to date. We have made an exhaustive search for D0 D0-bar mixing and CP violation in this data. We present the charm mixing limits on the mixing parameter r_mix using hadronic and semileptonic decays, and also present preliminary limits on the CP asymmetry parameter, A_CP, for Cabibbo suppressed decays.

hep-ex↗