The high momentum spectrometer drift chambers in hall c at. Cebaf large acceptance spectrometer clas is a nuclear and particle physics detector located in the experimental hall b at jefferson laboratory in newport news, virginia, united states. One of the important component of clas12 will be the central timeofflight system ctof. The g12 experiment used the cebaf large acceptance. Cebaf large acceptance spectrometer in hall b 1997 2012 7 polarized electron beam. May 27, 2014 a mixed electronpositron beam was produced from the primary electron beam in experimental hall b. The present pi spent most of his sabbatical year at cebaf, and 1 b. Pdf polarized targets for the clas detector at jefferson lab. We continued our background study through geant4 simulation developed for the test run design in order to. Photomultipliers for the electromagnetic shower calorimeter of the cebaf large acceptance spectrometer.
As a specific example, the cebaf large acceptance spectrometer is presented. Ba mecking, g adams, s ahmad, e anciant, m anghinolfi, b asavapibhop. Momentum corrections for charged particles photoproduced. Pdf driftchamber gas system controls development for. The clas cebaf large acceptance spectrometer eg1b experiment in hallb at jefferson laboratory utilized a polarized electron beam at various 1. Jefferson lab experimental hall b clasnotes all years. The large acceptance of clas allows for full azimuthal angle coverage over a large range of. Cebaf at jefferson lab will enable a new experimental program with substantial.
It is used to study the properties of the nuclear matter by the collaboration of over 200 physicists clas collaboration from many countries all around the world. Cebaf large acceptance spectrometer how is cebaf large acceptance spectrometer abbreviated. These measurements include data with linearly and circularly polarized taggedphoton beams, longitudinally and transversely polarized proton and deuterium targets, and recoil. Shms super high momentum spectrometer key features. Time of flight software for the clas12 particle detector. Cebaf large acceptance spectrometer clas 1 at the thomas jefferson national accelerator facility. Optimizing gas mixture composition for the rtpc detector for. The cebaf large acceptance spectrometer clas nasaads. Cebaf large acceptance spectrometer collab oration list d.
In contrast to the moderate acceptance spectrometers in halls a and c, hall b makes use of a large acceptance toroidal spectrometer the cebaf large acceptance spectrometer, clas. A new facility at jefferson laboratory to exploit real photon beams to study gluonic excitations. Photoproduction of scalar mesons using the cebaf large. The cebaf large acceptance spectrometer clas request pdf. Light readout system for the electromagnetic shower calorimeter of the cebaf large acceptance spectrometer. Fiducial volumes for photons detected in the forward. Preliminary results for the cross sections from a missing mass analysis are in good agreement with the said database 5. The region one drift chamber for the clas spectrometer. Spectrometer clas at jefferson lab with a liquid hydrogen target and a 4 5. Battaglieri infn ge a b c cebaf large acceptance spectrometer clas in hall b cryomodules in the accelerator tunnel an aerial view of the recirculating linear accelerator and 3 experimental halls. High power gainswitched diode laser master oscillator and. Uniqueness of cebaf depolarization factor typically about 0. Due to the luminosity constraint our kinematic coverage is limited to low q2 and high s longitudinal polarization of the virtual photon. This spectrometer will have similar properties as the hms, but with larger maximum central momentum 11 gevc and smaller minimum angle, 5.
The design, construction, and performance of the clas cherenkov threshold gas detector at jefferson lab is described. The present pi spent most of his sabbatical year 1 99 192 at cebaf, and serves as chair of the real. Measurement of single spin asymmetry and fifth structure. Thomas jefferson national accelerator facility jefferson lab is performing a large scale upgrade to the continuous electron beam accelerator facility cebaf to reach energies of 12gev. Hall b is installing a new large acceptance spectrometer, and hall a is upgrading its beamline to take advantage of the new energies. The ctof will provide detection and identification of charged particles emitted at. A fourier moment technique for extracting beam asymmetries from experimental data is described. The primary instrument in hall b at the continuous electron beam accelerator facility cebaf is the cebaf large acceptance spectrometer clas shown in fig. Baryon spectroscopy with polarization observables from clas. This apparatus will be replaced by a new spectrometer, clas12, shown in fig. However, there exists no photoproduction data on this particle. Electroproduction of hadrons at 6 gev using the cebaf large.
The cebaf large acceptance spectrometer clas is used to study photo and electroinduced nuclear and hadronic reactions by providing efficient detection of neutral and charged particles over a. The primary instrument in hall b is the cebaf large acceptance spectrometer clas 1 shown in figure 2. The cebaf large acceptance spectrometer clas sciencedirect. A rich detector for clas12 spectrometer sciencedirect. Sc h umac her carne gie mel lon university, pittsbur gh, p a 152 e. This work is part of a systematic study of neutral meson photoproduction from the proton and light nuclear targets over an incident photon energy range of 0. The spin structure functions g for the proton and the deuteron have been measured over a wide kinematic range in x and q using 1. The cebaf large acceptance spectrometer clas is a superconducting toroidal magnet with a large volume of drift chambers for charged particle tracking.
The cebaf large acceptance spectrometer clas is used to study photo and electroinduced nuclear and hadronic. The updated cebaf large acceptance spectrometer clas12 detector is being developed for the jlab upgrade program up to 12 gev. The cebaf large acceptance spectrometer clas performance l 1034 cm2 s1. Hall b was the home of the cebaf large acceptance spectrometer clas. Low energy photoproduction nuclear experiement hosted by university of bonn. Due to the luminosity constraint our kinematic coverage is limited to low q2 and high. Spectrometer capable of measuring particles up to 11 gev. Baryon spectroscopy with polarization observables from. The spaces between the coils are filled with three regions of drift chambers to track charged particles, cerenkov counters for electron. Cebaf is in the middle of an upgrade to increase the maximum beam energy from 5. Cebaf large acceptance spectrometer clas the tagging system at clas the frozenspin target frost jefferson laboratory in newport news, va the continuous electron beam accelerator facility cebaf can deliver a continuous electron beam up to 6 gev.
Energies up to e e 6 gev now up to 11 gev cebaf large acceptance spectrometer. The data set used was the e1f run from the cebaf large acceptance spectrometer clas at jefferson national lab. Cebaf large acceptance spectrometer how is cebaf large. The single spin asymmetry, a lt, and the polarized structure function. The dissertation of john theodore goetz is approved. The data set used was based on the rga run period from the recently upgraded cebaf large acceptance spectrometer clas12 in hall b at jefferson national lab jlab. Marc hand ceasaclay, d apniasphn, gifsuryvette ce dex, f r anc e f91191 h. We continued our background study through geant4 simula tion developed for the test, run design in order to find more background sources and. Comparison between simulations and data for neutral meson. Photoproduction of the f 2 1270 meson using the clas detector.
Driftchamber gas system controls development for the cebaf. The clas collaboration, the cebaf large acceptance spectrometer, nuclear instruments and methods 5033, 5 2003. Exclusive phi production beam spin asymmetry measurements. The clas12 spectrometer at jefferson laboratory white rose. Baryon spectroscopy, vector meson production, and the. This spectrometer provides efficient detection of charged and neutral particles over a large fraction of the full solid angle. The performance of these chambers depends on accurate monitoring and control of the mixture, flow rate, pressure, temperature, and contaminant levels of the gas. The upgrade of the continuous electron beam accelerator facility cebaf, located in je. Electroproduction of hadrons at 6 gev using the cebaf. In the analysis presented in this dissertation, the presence of the f01500 in the ks 0ks0 channel is investigated in photoproduction using the cebaf large acceptance spectrometer clas at the thomas jefferson national accelerator facility, also called jefferson lab jlab. The upgrade of continuous electron beam accelerator facility cebaf is undergo since 2010. A new ring imaging cherenkov rich detector is being developed to provide better kaon u,s pion u, d separation for clas12 in the 3 to 8 gevc momentum range. Aug 21, 2020 measurements of the beam spin asymmetry bsa of the exclusive electroproduction of the vector phi1020 meson through its decay into charged kaons have been performed.
Accelerator facility cebaf, which supplies beams of electrons to three experimental halls. The clas12 spectrometer at jefferson laboratory sciencedirect. Citeseerx document details isaac councill, lee giles, pradeep teregowda. A collaboration of about 30 institutions has designed, assembled, and commissioned clas in hall b at the thomas jefferson national accelerator facility. Baryon spectroscopy, vector meson production, and the physics. Timeofflight system for a ctof prototype counter with fine. Event display drift chambers electromagnetic calorimeters spectrometer in solenoidal magnetic field neutral particles reconstruction. Apr 11, 2020 the cebaf large acceptance spectrometer for operation at 12 gev beam energy clas12 in hall b at jefferson laboratory is used to study electroinduced nuclear and hadronic reactions.
The cebaf large acceptance spectrometer clas uses a novel experimental approach to exploit the physics opportunities presented by this novel accelerator. The cebaf large acceptance spectrometer clas is used to study photo and electroinduced nuclear and hadronic reactions by providing efficient detection of neutral and charged particles over a good fraction of the full solid angle. The sbs focuses on large acceptance detection, makes use of an existing magnet, and will utilize a detector package with stateofthe art gas electron multiplier gem tracking detectors. Pdf forward spectrometer for large acceptance experiments.
The cebaf large acceptance spectrometer for operation at 12 gev beam energy clas12 in hall b at jefferson laboratory is used to study. Cebaf large acceptance spectrometer clas12 in hall b is also undergoing a major upgrade to collect data at these high energies. Six superconducting coils produce a toroidal magnetic field around the beam axis. Forward spectrometer for large acceptance experiments in hall a at jefferson lab for the 12gev upgrade. Clas cebaf large acceptance spectrometer, located in hall b at jlab, has almost 4. May 11, 2003 the cebaf large acceptance spectrometer clas is used to study photo and electroinduced nuclear and hadronic reactions by providing efficient detection of neutral and charged particles over a good fraction of the full solid angle. Cebaf large acceptance spectrometer listed as clas. Both the scattered lepton and the recoil proton were detected by the cebaf large acceptance spectrometer clas. The photoproduction of vector mesons on various nuclei has been studied using the cebaf large acceptance spectrometer clas at jefferson laboratory. The experimental approach and some of the first physics results of clas will be discussed. Pdf driftchamber gas system controls development for the. Momentum corrections for charged particles photoproduced on. Driftchamber gas system controls development for the. Proton form factor puzzle and the cebaf large acceptance.
Clas12 is designed to enable higher luminosity operation with electron beams, up to 1035 cm. At the core of the upgrade, however, are the enhancements to the cebaf accelerator figure 1. Scattered electrons detected at large angle lead to high x, high q2 and low scattered energy e large acceptance spectrometer like mad matches the kinematics. Scattered electrons were detected in the cebaf large acceptance spectrometer, for 0. The performance of these chambers depends on accurate monitoring and control of the mixture, flow rate, pressure, temperature, and contaminant levels of.
After entering hall b, the cebaf electron beam strikes a radiator, which causes the. The thomas jefferson national accelerator facility scholarpedia. This device is a toroidal multigap magnetic spectrometer and is described in detail in the conceptual design report on cebaf basic experimental equipment 1. A superconducting toroidal magnet for the cebaf large. Each module consists of three adjustable mirrors of lightweight composite construction, a winston light collecting cone, a 5in. The data were taken at jefferson laboratory, using the hallb taggedphoton beam of energy between 0. Large acceptance detectors for electromagnetic nuclear physicinis. Spectrometer clas has proved that large acceptance devices can be. As part of this upgrade, the existing particle detector in experimental hall b, the continuous large acceptance spectrometer clas6, is being rebuilt. Oct 21, 2011 the continuous electron beam accelerator facility. Measurements with real photons at cebaf a large part of our effort this past year has gone into the planning and preparation for experiments with real photons at the cebaf large acceptance spectrometer clas. Exclusive studies on short range correlations in nuclei epj web of.
247 929 142 207 844 1019 708 1147 1373 773 83 707 1021 1322 903 1564 6 1550 793 526 338 1338 1156 354 1026 1320 1555 1075 1391 497 216 291 233 93 994 777