Download or read book The Commissioning of the Hall B Beamline of Jefferson Lab for Coherently Producing a Beam of Linearly Polarized Photons written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The set of experiments forming the g8 run took place this past summer (06/04/01- 8/13/01) in Hall B of Jefferson Lab. These experiments made use of a beam of linearly-polarized photons produced through coherent bremsstrahlung and represent the first time such a probe has been employed at Jefferson Lab. Among the several new and upgraded Hall-B beamline devices commissioned prior to the production running of g8a were the photon tagger, the coherent bremsstrahlung facility (goniometer + an instrumented collimator), a photon profiler, and the PrimEx dipole + pair spectrometer telescopes. We essentially commissioned a new beam-line for photon running in Hall B. The scientific purpose of g8 is to improve the understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. With the high-quality beam of the tagged and collimated linearly-polarized photons arid the nearly complete angular coverage of the Hall-B spectrometer, we seek to extract the differential cross sections and polarization observables for the photoproduction of vector mesons and kaons at photon energies ranging between 1.1 and 2.25 GeV. For the first phase of g8, i.e. g8a, we collected approximately 1.8 billion triggers for 1.75 lte E_{vec-gamma} lte 2.25 GeV. In this paper, we report on the results of the commissioning of the beamline devices for the g8a run.
Download or read book Proceedings of the International Symposium Electromagnetic Interactions in Nuclear and Hadron Physics written by Mamoru Fujiwara and published by World Scientific. This book was released on 2002 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the following topics: (1) meson and hadron production by real and virtual photon interaction with nucleons and nuclei; (2) astrophysical studies via photoreactions and hadron reactions; (3) new technologies for the electromagnetic probes and detector development; (4) nuclear structure studies with electromagnetic probes; (5) fundamental symmetries with electromagnetic probes and related problems.The proceedings have been selected for coverage in: ? Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)
Download or read book GDH 2002 written by Marco Anghinolfi and published by World Scientific. This book was released on 2003 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing the proceedings of the GDH 2002 symposium, this is a review of results on the nucleon spin structure and related sum rules using real and virtual photons. Theoretical developments and high precision data from different laboratories are presented and discussed. The work offers a comprehensive picture of the nucleon spin studies from the perturbative domain down to the resonance and low momentum transfer region.
Download or read book Gdh 2002 Proceedings Of The Second International Symposium On The Gerasimov drell hearn Sum Rule And The Spin Structure Of The Nucleon written by Marco Anghinolfi and published by World Scientific. This book was released on 2003-06-13 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the GDH 2002 symposium. It is a review of the most recent results on the nucleon spin structure and related sum rules using real and virtual photons. The latest theoretical developments and the new high precision data from different laboratories are presented and discussed. The book provides a comprehensive picture of the nucleon spin studies from the perturbative domain down to the resonance and low momentum transfer region.
Download or read book International Conference on Charged and Neutral Particles Channeling Phenomena written by and published by . This book was released on 2004 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Polarized High Energy Photon Beam for Production of Exotic Mesons written by and published by . This book was released on 2012 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work describes design, prototyping and testing of various components of the Jefferson Lab Hall D photon beamline. These include coherent bremsstrahlung radiators to be used in this facility for generating the photon beam, a fine resolution hodoscope for the facility's tagging spectrometer, and a photon beam position sensor for stabilizing the beam on a collimator. The principal instrumentation project was the hodoscope: its design, implementation and beam testing will be thoroughly described. Studies of the coherent bremsstrahlung radiators involved X-ray characterization of diamond crystals to identify the appropriate line of manufactured radiators and the proper techniques for thinning them to the desired specification of the beamline. The photon beam position sensor project involved completion of a designed detector and its beam test. The results of these shorter studies will also be presented. The second part of this work discusses a Monte Carlo study of a possible photo-production and decay channel in the GlueX experiment that will be housed in the Hall D facility. Specifically, the [gamma] p → Xp → b1 [pi] → [omega] [pi]+1 [pi]-1 channel was studied including its Amplitude Analysis. This exercise attempted to generate a possible physics signal, complete with internal angular momentum states, and be able to reconstruct the signal in the detector and find the proper set of JPC quantum numbers through an amplitude fit. Derivation of the proper set of amplitudes in the helicity basis is described, followed by a discussion of the implementation, generation of the data sets, reconstruction techniques, the amplitude fit and results of this study.
Download or read book The Bremsstrahlung Tagged Photon Beam in Hall B at the Jefferson Laboratory written by and published by . This book was released on 2000 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe the design and commissioning of the photon tagging beamline installed in experimental Hall B at the Thomas Jefferson National Accelerator Facility. This system can tag photon energies over a range from 20% to 95% of the incident electron energy, and is capable of operation with beam energies up to 6.1 GeV. A single dipole magnet is combined with a hodoscope containing two planar arrays of plastic scintillators to detect energy-degraded electrons from a thin bremsstrahlung radiator.
Download or read book Jefferson Lab a Status Report written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thomas Jefferson National Accelerator Facility (Jefferson Lab; formerly known as CEBAF), operates a 4 GeV, 200[micro]A continuous wave (CW) electron accelerator that re-circulates the beam five times through two superconducting 400 MeV linacs. Electrons can be extracted from any of the five recirculation passes and beam can be simultaneously delivered to the three experimental halls. As the commissioning stage nears completion, the accelerator is becoming a fully operational machine. Experiments in Hall C have been underway since November 1995 with beam powers of over 300 kW at various energies. Hall A has received beam for spectrometer commissioning, while Hall B is expected to receive its first beam in the fall of 1996. Accelerator availability of greater than 70% during physics runs and excellent beam quality have contributed to making Jefferson Lab a world class laboratory for accelerator-based electromagnetic nuclear physics. With the high performance of the superconducting RF cavities, machine upgrades to 6 GeV, and eventually 8 to 10 GeV are now in the planning stages. Operational and commissioning details concerning all aspects of the machine will be discussed.
Download or read book A Linearly Polarized Photon Beam in the CEBAF Hall B March 1991 written by V.B. Ganenko and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Dynamics Activities at the Thomas Jefferson National Accelerator Facility Jefferson Lab written by and published by . This book was released on 1997 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Thomas Jefferson National Accelerator Facility (Jefferson Lab) has been funded by the US Navy to build an infra-red FEL driven by an energy-recovering compact SRF-based linear accelerator. The machine is to produce a 1 kW IR photon beam. The Jefferson Lab Accelerator Division is presently engaged in detailed design and beam dynamics studies for the driver accelerator. Principle beam dynamics and beam transport considerations include: (1) generation and transport of a high-quality, high-current, space-charge dominated beam; (2) the impact of coherent synchrotron radiation (CSR) during beam recirculation transport; (3) low-loss transport of a large momentum spread, high-current beam; (4) beam break up (BBU) instabilities in the recirculating accelerator; (5) impedance policing of transport system components; and (6) RF drive system control during energy recovery and FEL operation.
Download or read book Design and Commissioning of a Linearly Polarized Gamma ray Beam for Photofission Experiments written by Jasen L. Swanson and published by . This book was released on 2012 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: A polarized photon beamline has been established at the Idaho Accelerator Center for use in photofission experiments. A segmented Faraday cup was designed for monitoring the position of the electron beam. A collimation system was designed to capture a portion of the off-axis bremsstrahlung radiation in such a way that the photons sent into the experimental cell were polarized to the highest extent. A pair spectrometer was designed to be used as a relative photon flux monitor for normalization purposes, but it was found to be more useful in monitoring the stability of the beam. The polarization of the photon beam was determined using photodisintegration of the deuteron and looking at neutron asymmetries. Future experiments investigating photofission based applications which use prompt neutron signatures as a viable detection scheme for fissile material detection can now be conducted using the resulting linearly polarized gamma-ray beam.
Download or read book Status of the Jefferson Lab Polarized Beam Physics Program and Preparations for Upcoming Parity Experiments written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An ambitious nuclear physics research program continues at Jefferson Lab with Users at three experiment halls receiving reliable, highly polarized electrons at currents to 100 [micro]A. The polarized photoguns and drive lasers that contribute to Jefferson Lab's success will be described as well as significant events since PES2000. Typical of conditions at accelerators worldwide, success brings new challenges. Beam quality specifications continue to become more demanding as Users conduct more challenging experiments. In the months that follow this workshop, two parity violation experiments will begin at Jefferson Lab, G0 and HAPPEx2. The photogun requirements for these experiments will be discussed as well as our plans to eliminate/minimize systematic errors. Recent efforts to construct high power Ti-Sapphire drive lasers for these experiments also will be discussed.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book First E Photon Commissioning Results for the GlueX Experiment Hall D at CEBAF written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental Hall D, with flagship experiment GlueX, was constructed as part of the 12 GeV CEBAF upgrade. A new magnetically extracted electron beam line was installed to support this hall. Bremsstrahlung photons from retractable radiators, are delivered to the experiment through a series of collimators following a long drift to allow for beam convergence. Coherent Bremsstrahlung generated by interaction with a diamond radiator will achieve a nominal 40% linear polarization and photon energies between 8.5 and 9 GeV from 12.1 GeV electrons, which are then tagged or diverted to a medium power 60kW electron dump. The expected photon flux is 107-108 Hz. This paper discusses the experimental line design, commissioning experience gained since first beam in spring 2014, and the present results of beam commissioning by the experiment.
Download or read book Beam Quality at Jefferson Lab written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is a $600M CW electron accelerator in Newport News, Virginia. The machine is a recirculating, superconducting 5-pass linac initially commissioned for 4 GeV with a maximum beam power of 1 MW. With improvements in our RF cavity performance and an upgrade to magnet power supplies we are now capable of reliable operations at up to 5.7 GeV. We employ a three-laser photocathode gun to provide a CW electron beam with 80% polarization to three experimental endstations in currents ranging from 100 pA to 200 mA. Establishing clear criteria for beam quality and developing the means to verify and maintain beam quality is essential to a successful physics program.
Download or read book Beam Dynamics Activities at the Thomas Jefferson National Accelerator Facility Jefferson Lab written by David Douglas and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
