TUPMA —  Tuesday Posters (Madison)   (05-May-15   16:00—18:00)

Paper	Title	Page
TUPMA001	Progress of the R&D towards a diffraction limited upgrade of the Advanced Light Source	1840
	C. Steier, A. Anders, D. Arbelaez, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, A. Madur, H. Nishimura, J.R. Osborn, G.C. Pappas, L.R. Reginato, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, W.L. Waldron, E.J. Wallén, W. Wan LBNL, Berkeley, California, USA
	Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231. Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An R&D program funded by internal laboratory funds was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings (DLSR). It initially involves five areas, and focuses on the specific needs of soft x-ray facilities: vacuum system/NEG coating of small chambers, injection/pulsed magnets, RF systems/bunch lengthening, magnets/radiation production with advanced radiation devices, and beam physics design optimization. Some hardware prototypes have been built. The work will expand in the future to demonstrate necessary key technologies at the subsystem level or in beam tests and include new areas like photon beamline optics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA003	Microbunching Phenomena in LCLS-II	1843
	M. Venturini, C. F. Papadopoulos, J. Qiang LBNL, Berkeley, California, USA Y. Ding, P. Emma, Z. Huang, G. Marcus, A. Marinelli, Y. Nosochkov, T.O. Raubenheimer, L. Wang, M. Woodley SLAC, Menlo Park, California, USA
	Funding: Work supported by DOE, in part under Contract No. DE-AC02-05CH11231 and through the LCLS-II project. The microbunching instability has long been recognized as a potential limiting factor to the performance of X-ray FELs. It is of particular relevance in LCLS-II due, in part, to a layout that includes a long bypass beamline between the Linac and the undulators. Here we focus on two aspects of the instability that highlight the importance of 3D effects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA003
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA004	Synthesis of Ultra-Thin Single Crystal MgO/Ag/MgO Multilayer for Controlled Photocathode Emissive Properties	1846
	D.G. Velázquez, R.L. Seibert, L.K. Spentzouris, J. Terry, Z.M. Yusof Illinois Institute of Technology, Chicago, Illinois, USA
	Photocathode emission properties are critical for electron beam applications such as photoinjectors for free electron lasers (FEL) and energy recovery Linacs (ERL). We investigate whether emission properties of photocathodes can be manipulated through the engineering of the surface electronic structure. The multilayers described here have been predicted to have emission properties in correlation with the film thickness. This paper describes how ultra-thin multilayered MgO/Ag/MgO films in the crystallographic orientations (001) and (111) multilayers were synthesized and characterized. Preliminary results of work function measurements are provided. Films were grown by pulsed laser deposition at 130 °C for the (001) orientation and 210 °C for the (111) orientation at a background pressure of ~ 5×10-9 Torr. Epitaxial growth was monitored in-situ using reflection high-energy electron diffraction, which showed single crystal island growth for each stage of the multilayer formation. Photoelectron spectroscopy was used to track the chemical state transition from Ag to MgO during the deposition of successive layers. The Kelvin probe technique was used to measure the change in contact potential difference, and thus work function, for various MgO layer thicknesses in comparison with bare single crystal Ag(001)and Ag(111) thin films. The work function was observed to reduce with increasing thickness of MgO from 0 to 4 monolayers as much as 0.89 eV and 0.72 eV for the (001) and (111) orientations, respectively. Photoelectron spectra near the Fermi level revealed electron density shifts toward zero binding energy for the multilayered surfaces with respect to the clean Ag surfaces.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA004
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA007	Numerical Investigation of a Cascaded Longitudinal Space-Charge Amplifier at the Fermilab's Advanced Superconducting Test Accelerator	1850
	A. Halavanau, P. Piot Northern Illinois University, DeKalb, Illinois, USA P. Piot Fermilab, Batavia, Illinois, USA
	In a cascaded longitudinal space-charge amplifier (LSCA), initial density noise in a relativistic e-beam is amplified via the interplay of longitudinal space charge forces and properly located dispersive sections. This type of amplification process was shown to potentially result in large final density modulations * compatible with the production of broadband electromagnetic radiation. The technique was recently demonstrated in the optical domain **. In this paper we investigate, via numerical simulations, the performances of a cascaded LSCA beamline at the Fermilab's Advanced Superconducting Test Accelerator (ASTA). We especially explore the properties of the produced broadband radiation. Our studies have been conducted with an effective three-dimensional space-charge algorithm. * Dohlus, M. et al. Proc. SPIE 8779. doi:10.1117/12.2017369 ** Marinelli, A. et al. Phys. Rev. Lett. 110, 264802 (2013)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA008	Numerical Study of Three Dimensional Effects in Longitudinal Space-Charge Impedance	1853
	A. Halavanau, P. Piot Northern Illinois University, DeKalb, Illinois, USA P. Piot Fermilab, Batavia, Illinois, USA
	Longitudinal space-charge (LSC) effects are generally considered as detrimental in free-electron lasers as they can seed instabilities. Such "microbunching instabilities" were recently shown to be potentially useful to support the generation of broadband coherent radiation pulses. Therefore there has been an increasing interest in devising accelerator beamlines capable of sustaining this LSC instability as a mechanism to produce a coherent light source. To date most of these studies have been carried out with a one-dimensional impedance model for the LSC. In this paper we use a N-body "Barnes-Hut" algorithm * to simulate the 3D space charge force in the beam combined with Elegant ** and explore the limitation of the 1D model often used. * Barnes, J. & Hut, P., Nature 324, 446-449, 1986. ** Borland, M., Advanced Photon Source LS-287, 2000.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA008
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA010	Development of a Field-Emission Type S-band RF-Gun System for High Brightness Electron Source Applications	1856
	Y.-M. Shin Northern Illinois University, DeKalb, Illinois, USA N. Barov Far-Tech, Inc., San Diego, California, USA A.T. Green Northern Illinois Univerity, Dekalb, Illinois, USA
	Electron beams emitted from a cold cathode are thermally stable and mono-energetic with a small phase-space volume*. We have been developing a field-emission type RF-gun system for high brightness electron source applications, including electron scattering/diffraction and tunable coherent X-ray/THz generation. The system consists of a single-gap gun-cavity and an S-band klystron/modulator capable of powering the gun with up to 5.5 MW peak (PRR = 1 Hz, duration = 2.5 μs). The designed gun built with the symmetrised side-couplers has surface field on the cathode ranging 50 – 100 MV/m with 1.3 – 1.7 MW klystron-power and 1.2 field ratio (HFSS). ASTRA simulations also indicate that the gun produces the beam with transverse emittances of less than 1 mm-mrad with 10 – 20 pC bunch charge at 500 keV beam energy. Under the gun operating condition, particle tracking/PIC simulations (CST) show that a single-tip CNT field-emitter** produces short pulsed bunches (~ 1/10 RF-cycle) with small emittance ( 0.01 mm-mrad) and high peak current density ( 10,000 kA/cm2). After the gun is fully installed and commissioned, a CNT-tip cathode will be tested with RF-field emission. * N. De Jonge, J.-M. Bonard, Phil. Trans. R. Soc. Lond. A 362, 2239 (2004) ** G. S. Bocharov, and A. V. Eletskii, Nanomaterials 3, 393 (2013)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA012	Developing an Improved Pulsed Mode Operation for Duke Storage Ring Based FEL	1860
	S.F. Mikhailov, H. Hao, V. Popov, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DoE grant # DE-FG02-97ER41033 The Duke FEL and High Intensity Gamma-ray Source (HIGS) facility is operated with an e-beam from 0.24 to 1.2 GeV and a photon beam from 190 to 1060 nm. Currently, the energy range of the gamma-ray beam is from 1 MeV to about 100 MeV, with the maximum total gamma-ray flux about 3·1010 gammas per second around 10 MeV. The FEL is typically operated in quasi-CW mode. Some HIGS user experiments can benefit tremendously from a pulsed mode of FEL operation. For that purpose, a fast steering magnet was developed years ago to modulate the FEL gain. This FEL gain modulator decouples the e-beam from the FEL beam in the interaction region for most of time, but periodically allows a brief overlap of the electron and FEL beams. This allows us to build up a high peak power FEL pulse from a well-damped electron beam. However, the use of this gain modulator at low e-beam energies can dramatically limit e-beam current due to beam instability and poor injection. To overcome these shortcomings, we have successfully tested an RF frequency modulation technique to pulse the FEL beam. In this paper, we will describe this development, and report our preliminary results of this improved pulsed FEL operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA012
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA014	Extending OK5 Wiggler Operational Limit at Duke FEL/HIGS Facility	1863
	P.W. Wallace, M. Emamian, H. Hao, J.Y. Li, S.F. Mikhailov, V. Popov, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA J.Y. Li USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033 Since 2007 the HIGS facility has been operated to produce both linearly and circularly polarized gamma-ray beams using two FELs, the planar OK-4 FEL and helical OK-5 FEL. Presently, with the OK-5 FEL operating at 192 nm, we can produce circularly-polarized gamma-ray beams between 1 and 100 MeV for user applications. Gamma-ray production between 80 and 100 MeV required an extension of the OK-5 wiggler operation beyond the designed current limit of 3.0 kA. In 2009, we upgraded cooling and machine protection systems to successfully extend OK-5 operation to 3.5 kA. To realize HIGS gamma-ray operation beyond 100 MeV and ultimately toward 150 MeV (the pion-threshold energy), with various limitations of the VUV mirror technology, the OK-5 wigglers will need to be operated at an even higher current, between 3.6 and 4.0 kA. In this paper we present our technical solution to further extend the operation range of the OK-5 wigglers, and report our preliminary results with high-current wiggler operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA014
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA016	Light Source and Accelerator Physics Research Program at Duke University	1866
	Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033. The light source and accelerator physics research program at Duke Free-Electron Laser Laboratory (DFELL), TUNL, is focused on the development of the storage ring based free-electron lasers (FELs), and a state-of-the-art Compton gamma-ray source, the High Intensity Gamma-ray Source (HIGS) which is driven by the storage ring FEL. With a maximum total flux about 3·1010 gamma/s and a spectral flux of more than 1,000 gamma/s/eV around 10 MeV, the HIGS is the world's most intense Compton gamma-ray source. Operated in the energy range from 1 to 100 MeV, the HIGS is a premier Compton gamma-ray facility in the world for a variety of nuclear physics research programs, both fundamental and applied. In this paper, we will describe our ongoing light source development to produce gamma-ray beams in the higher energy range of 100 and 158 MeV. We will also provide a summary of our recent accelerator physics and FEL physics research activities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA016
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA017	Pulsed-wire Measurements for Insertion Devices	1869
	A. D'Audney, S. Biedronpresenter, S.V. Milton, S.A. Stellingwerff CSU, Fort Collins, Colorado, USA
	The performance of a Free Electron Laser (FELs) depends in part on the integrity of the magnetic field in the undulator. The magnetic field on the axis of the undulator is transverse and sinusoidally varying due to the periodic sequence of dipoles. The ideal trajectory of a relativistic electron bunch, inserted along the axis, is sinusoidal in the plane of oscillation. Phase errors are produced when the path of the electron is not the ideal sinusoidal trajectory, due to imperfections in the magnetic field. The result of such phase errors is a reduction of laser gain impacting overall FEL performance. A pulsed-wire method can be used to determine the profile of the magnetic field. This is achieved by sending a square current pulse through the wire, which will induce an interaction with the magnetic field. Measurement of the displacement in the wire over time using a motion detector yields the first or second integrals of the magnetic field. Dispersion in the wire can be corrected using algorithms resulting in higher accuracy. Once the fields are known, magnetic shims are placed where any corrections are needed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA018	An Improved Analytic Model of Electron Back-Bombardment in Thermionic Cathode RF Guns	1872
	J.P. Edelen, S. Biedron, J.R. Harris, S.V. Milton CSU, Fort Collins, Colorado, USA J.W. Lewellen LANL, Los Alamos, New Mexico, USA
	This paper describes work done at Colorado State University to improve upon the recent theory developed to predict the back-bombardment power in single-cell thermionic-cathode electron guns. The previous theory used a square-wave approximation of the time varying field to solve for the total kinetic energy deposited on the cathode due to the back-bombarded electrons. In addition the transit time factor was added as a correction to compensate for the non-sinusoidal field. By solving for the back-bombardment power using a sinusoidal field, the transit time factor can be removed and therefore a better overall model is produced. These alterations continue to accurately predict how back-bombardment varies as a function of the gun parameters and provides improvement when compared to the existing theory.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA019	Simulation and Analysis of Laser/Electron Beam interaction for use as a Free Electron Laser	1875
	J. Einstein, S. Biedron, H. Freund, S.V. Milton CSU, Fort Collins, Colorado, USA G. Dattoli ENEA C.R. Frascati, Frascati (Roma), Italy
	Through the use of simulation tools and theoretical analysis techniques, the Free Electron Laser process is investigated for a wiggler that is generated by an ultrafast laser system. The development and availability of such systems allows for novel FEL designs due to the high peak power of such lasers. Even though such high powers are possible, difficulties arise due to inhomogeneity in the laser pulse. This project looks at simulation results for a system with a realistic laser pulse profile and looks in to the pulse-shape effects on various system parameters. Models are presented for the expected behavior with important parameters noted, as well as highlighting possible difficulties that might occur experimentally. While head-on interaction has been proven experimentally for the short wavelength regime *, we believe that using a co-propagating laser can provide benefits that have currently been untested. This experimental setup is outlined in Lawler, J et al **, and we are currently simulating how the use of an ultrashort laser pulse as an electromagnetic wiggler will affect characteristics of the output radiation. * Laundy, D.; et al. NIM-A vol 689. pp 108-114. OCT 11 2012 ** Lawler, J.; et al. J. Phys. D: Appl. Phys. 46 (2013) 325501
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA020	PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons	1878
	A.H. Adeyemi, P.L. Gueye Hampton University, Hampton, Virginia, USA P.A. Adderley, M.M. Ali, H. Areti, J. F. Benesch, L.S. Cardman, J. Clark, S. Covert, C. Cuevas, A. Freyberger, S. Golge, J.M. Grames, P.L. Gueye, J. Hansknecht, P.L. Harrell, C. Hyde, R. Kazimi, Y. Kim, D. Machie, K.L. Mahoney, R.R. Mammei, J.L. McCarter, M.D. McCaughan, M. Poelker, M.L. Stutzman, R. Suleiman, C.-Y. Tsai, D.L. Turner, Y.W. Wang JLab, Newport News, Virginia, USA M.A. Baylac, E. Froidefond, M. Marton, J-F. Muraz, J-S. Real, E. J-M. Voutier LPSC, Grenoble Cedex, France P. Cole, D. Dale, T.A. Forest ISU, Pocatello, Idaho, USA O. Dadoun, A. Variola LAL, Orsay, France D. Dale, Y. Kim IAC, Pocatello, Idaho, USA EF. Fanchini INFN Genova, Genova, Italy S. Golge NCCU, , North Carolina, USA S. Golge, C. Hyde ODU, Norfolk, Virginia, USA J.L. McCarter UVa, Charlottesville, Virginia, USA C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA A. Variola IN2P3-CNRS, Orsay, France
	Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e−/e+ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA021	Optimization of an Improved SASE (iSASE) FEL	1881
	L. Gupta Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA K. Fang, J. Wu SLAC, Menlo Park, California, USA
	Funding: Supported by US DOE FWP-2013-SLAC-100164 and DOE SULI. In order to improve free electron laser technology for the future LCLSII at SLAC, a new strategy for creating radiation with increased temporal coherence is under development. The improved Self-Amplified Spontaneous Emission (iSASE) FEL utilizes phase shifters which allow for the spontaneously emitted radiation to interact with and stimulate more electrons to radiate coherently. Five phase shifters were simulated, with 34 normal-conducting undulators and focusing-defocusing quadrupoles as an LCLSII FEL lattice using the FEL software Genesis 1.3. Two general schemes, one providing a total phase shift of arbitrary distribution, the other providing a sequential or distributed phase shift, were simulated and optimized using a simulated annealing algorithm. The results suggest that the phase shifters must provide a total shift comparable to the bunch length, and the shifts must be distributed with one large shift, followed by smaller shifts. * J. Wu, A. Marinelli, C. Pellegrini, Proc. FEL2012, pp. 237, Japan (2012). ** J. Wu, et al., Proc. IPAC2013, pp. 2068, China (2013).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA022	CESR Upgrade as a High-Energy, High-Brightness X-Ray Light Source	1884
	J.P. Shanks, D. L. Rubin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Research supported by NSF grant DMR-1332208. The Cornell Electron Storage Ring (CESR) operates most of the year as the Cornell High Energy Synchrotron Source (CHESS). CESR was originally designed and operated as an electron/positron collider, circulating high-emittance beams in order to maximize luminosity. Beam lines were developed to extract x-rays from both electron and positron beams. The two beams share a common vacuum chamber, and are electrostatically separated to avoid collisions. The requirement to store counter-rotating beams significantly constrains the storage ring optics, limiting emittance and, beam current, and bunch distributions. The proposed upgrade eliminates two-beam operation in favor of a single optimized on-axis beam. Several new undulator-based beam lines are planned. The horizontal emittance is reduced in steps, first from 90nm to 20nm at 5.3 GeV, and then in a ring-wide upgrade to as low as 300 pm-rad at 6GeV. The low-emittance optics are based on multi-bend achromats with combined function bends. The details of the optics, apertures, and magnet parameters are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA023	Two-Dimensional Calculation of Channeling Radiation Spectrum for High-Brightness Hard X-Ray Production	1888
	W.D. Rush, J. Shi KU, Lawrence, Kansas, USA
	The channeling radiation spectrum is calculated without using the one-dimensional approximation in the planar channeling radiation model or the single-string approximation in the axial channeling radiation model. The obtained spectrum of the two-dimensional channeling radiaiton is significantly different from those previously calculated with the approximations. The calculation presented here is of the channeling radiation experiments conducted at Fermilab Advanced Superconducting Test Accelerator (ASTA) photoinjector with electron beam energies of 20-50 MeV and a diamond target. The computational method developed in this work can be applied to general cases of different crystals and beams with different energy and emittances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA023
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA025	X-Band RF Photoinjector for Laser Compton X-Ray and Gamma-Ray Sources	1891
	R.A. Marsh, G.G. Anderson, S.G. Anderson, C.P.J. Barty, D.J. Gibsonpresenter LLNL, Livermore, California, USA
	Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Extremely bright narrow bandwidth gamma-ray sources are expanding the application of accelerator technology and light sources in new directions. An X-band test station has been commissioned at LLNL to develop multi-bunch electron beams. This multi-bunch mode will have stringent requirements for the electron bunch properties including low emittance and energy spread, but across multiple bunches. The test station is a unique facility featuring a 200 MV/m 5.59 cell X-band photogun powered by a SLAC XL4 klystron driven by a Scandinova solid-state modulator. This paper focuses on its current status including the generation and initial characterization of first electron beam. Design and installation of the inverse-Compton scattering interaction region and upgrade paths will be discussed along with future applications.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA025
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA026	Status of the MaRIE X-FEL Accelerator Design	1894
	J.W. Lewellen, K. Bishofberger, B.E. Carlsten, L.D. Duffy, F.L. Krawczyk, Q.R. Marksteiner, D.C. Nguyen, S.J. Russell, R.L. Sheffield, N.A. Yampolsky LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the MaRIE program at Los Alamos National Laboratory, under contract DE-AC52-06NA25396 The Matter-Radiation Interactions in Extremes (MaRIE) facility is intended to probe and control the time-dependent properties of materials under extreme conditions. At its core, the “MaRIE 1.0” X-FEL is being designed to deliver pulse trains of ~1010 42 keV photons, with a minimum bunch spacing of 2.4 ns, enabling time-dependent studies particularly of mesoscale phenomena. The X-FEL accelerator is also intended to deliver a series of 2 nC electron bunches to enable electron radiography concurrently with the X-ray pulse train, so as to provide multi-probe capability to MaRIE. In 2014, the reference design for the MaRIE X-FEL 12 GeV driver linac was changed from an S-band normal-conducting to an L-band superconducting linac to accommodate pulse trains up to 100 μs in duration. This paper does not present a complete solution for the MaRIE linac design; rather it describes our current reference design, achieved parameters, areas of concern and paths towards mitigation of identified issues.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA026
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA028	Feasibility Study for an X-ray FEL Oscillator at the LCLS-II	1897
	T.J. Maxwell, J. Arthur, Y. Ding, W.M. Fawley, J.C. Frisch, J.B. Hastings, Z. Huang, J. Krzywinski, G. Marcus SLAC, Menlo Park, California, USA W.M. Fawley Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy K.-J. Kim, R.R. Lindberg, D. Shu, Yu. Shvyd'ko, S. Stoupin ANL, Argonne, Ilinois, USA
	Funding: This work supported in part under US Department of Energy contract DE-AC02-76SF00515. We show that a free-electron laser oscillator generating X-ray pulses with hard X-ray wavelengths of order 0.1 nm is feasible using the presently proposed FEL-quality electron beam within the space of existing LCLS-II infrastructure when combined with a low-loss X-ray crystal cavity. In an oscillator configuration driven by the 4 GeV energy electron beam lasing at the fifth harmonic, output x-ray bandwidths as small as a few meV are possible. The delivered average spectral flux is at least two orders of magnitude greater than present synchrotron-based sources with highly stable, coherent pulses of duration 1 ps or less for applications in Mössbauer spectroscopy and inelastic x-ray scattering.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA028
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA030	Narrowband Continuously Tunable Radiation in the 5 to 10 Terahertz Range by Inverse Compton Scattering	1901
	Z. Wu, K. Fang, M.-H. Wang, J. Wu SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy under Grants DE-AC02-76SF00515, DE-FG02-13ER41970 and by DARPA Grant N66001-11-1-4199. 5 to 10 THz has recently become the frontier of THz radiation sources development, pushed by the growing interests of spectroscopy and pump-probe material study in this frequency range. This spectrum “Gap” lies in between the several THz range covered by Electro-Optical crystal based THz generation, and the tens of THz range covered by the difference frequency generation method. The state-of-the-art EO crystal THz source using tilted pulse front technique has been able to reach ~ 100 MV/m peak field strength, large enough to be used in an inverse Compton scattering process to push these low energy photons to shorter wavelengths of the desired 5-10 THz range. The required electron beam energy is within 1~2 MeV, therefore a compact footprint of the whole system. The process would occur coherently granted the electron beam is bunched to a fraction of the radiation wavelengths (several microns). A system operating at KHz or even MHz repetition rate is possible given the low electron energy and thus low RF acceleration gradient required. This work will explore the scheme with design parameters and simulation results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA031	Dispersive Property of the Pulse Front Tilt of a Short Pulse Optical Undulator	1904
	M.-H. Wang, J. Wu, Z. Wupresenter SLAC, Menlo Park, California, USA
	Funding: Work supported by the US DOE No. DE-AC02-76SF00515. A short pulse laser can be used as an optical undulator to achieve a high-gain and high-brightness X-ray free electron laser (FEL) [1]. To extend the interaction duration of electron and laser field, the electron and the laser will propagate toward each other with an small angle. In addition, to maintain the FEL lasing resonant condition, the laser pulse shape need be flattened and the pulse front will be titled. Due to the short pulse duration, the laser pulse has a broad bandwidth. In this paper, we will first describe the method of generalized Gaussian beam propagation using ray matrix. By applying the Gaussian beam ray matrix, we can study the dispersive property after the pulse front of the short laser is tilted. The results of the optics design for the proposal of SLAC Compton scattering FEL are shown as an example in this paper. [1] C. Chang, et al.,“High-brightness X-ray free-electron laser with an optical undulator by pulse shaping”. Optics Express, Vol. 21, Issue 26, pp. 32013-32018 (2013).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA033	A Bunch Compression Method for Free Electron Lasers that Avoids Parasitic Compressions	1907
	S.V. Benson, D. Douglas, C. Tennant, F.G. Wilson JLab, Newport News, Virginia, USA D.C. Nguyen LANL, Los Alamos, New Mexico, USA
	Funding: This work was supported by U.S. DOE Contract No. DE-AC05-84-ER40150, the Air Force Office of Scientific Research, DOE Basic Energy Sciences. Virtually all existing high energy (>few MeV) linac-driven FELs compress the electron bunch length though the use of off-crest acceleration on the rising side of the RF waveform followed by transport through a magnetic chicane. This approach has at least three flaws: 1) it is difficult to correct aberrations- particularly RF curvature, 2) rising side acceleration exacerbates space charge-induced distortion of the longitudinal phase space, and 3) all achromatic "negative compaction" compressors create parasitic compression during the final compression process, increasing the CSR-induced emittance growth. One can avoid these deficiencies by using acceleration on the falling side of the RF waveform and a compressor with M56>0. This approach offers multiple advantages: 1) It is readily achieved in beam lines supporting simple schemes for aberration compensation, 2) Longitudinal space charge (LSC)-induced phase space distortion tends, on the falling side of the RF waveform, to enhance the chirp, and 3) Compressors with M56>0 can be configured to avoid spurious over-compression. We will discuss this bunch compression scheme in detail and give results of a successful beam test in April 2012 using the JLab UV Demo FEL
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA033
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA034	Control of Synchrotron Radiation Effects During Recirculation with Bunch Compression	1910
	D. Douglas, S.V. Benson, R. Li, C. Tennant JLab, Newport News, Virginia, USA G.A. Krafft, B. Terzić ODU, Norfolk, Virginia, USA C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Studies of beam quality preservation during recirculation * have been extended to generate a design of a compact arc providing bunch compression with positive momentum compaction ** and control of both incoherent and coherent synchrotron radiation (ISR and CSR) effects using the optics balance methods of diMitri et al.***. In addition, the arc/compressor generates very little micro-bunching gain. We detail the beam dynamical basis for the design, discuss the design process, give an example solution, and provide simulations of ISR and CSR effects. Reference will be made to a complete analysis of micro-bunching effects ****. * D. Douglas et al., these proceedings ** S. Benson et al., these proceedings *** S. diMitri et al., Phys. Rev. Lett. 110, 014801, 2 January 2013 **** C.Y. Tsai et al., these proceedings
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA035	Control of Synchrotron Radiation Effects during Recirculation	1913
	D. Douglas, S.V. Benson, A.S. Hofler, R. Kazimi, R. Li, Y. Roblin, C. Tennant JLab, Newport News, Virginia, USA G.A. Krafft, B. Terzić ODU, Norfolk, Virginia, USA C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Numerous proposals invoke recirculation and/or energy recovery for cost-performance optimization. These often encounter challenges with the beam-quality-degrading effects of incoherent and coherent synchrotron radiation (ISR and CSR). We describe a means of controlling of this degradation. The approach utilizes results by diMitri et al. *, and invokes behavior observed during simulations of the recirculation process. The method is based on the use of periodically isochronous 2nd-order achromats; this not only insures that the conditions for the suppression of CSR-driven emittance growth are met*, it also suppresses micro-bunching gain over a broad range of parameter space **. Details of specific designs will be presented, and a reference to an analysis of micro-bunching effects ** provided. A planned test of the CSR suppression mechanism in CEBAF will be described. *S. diMitri et al., Phys. Rev. Lett. 110, 014801, 2 January 2013. **C.Y. Tsai et al., these proceedings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA035
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA036	First e-/Photon Commissioning Results for the GlueX Experiment/Hall D at CEBAF	1916
	M.D. McCaughan, J. F. Benesch, Y. Roblin, T. Satogata JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. 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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA037	Commissioning of the 123 MeV Injector for 12 GeV CEBAF	1920
	Y.W. Wang, A.S. Hofler, R. Kazimi JLab, Newport News, Virginia, USA
	The injector energy needed to be raised from 67.5 MeV to 123 MeV to meet the energy requirement of the CEBAF 12 GeV upgrade. The ratio of the injector energy to the linac energy must remain 0.11284 at all times. Consequently, the injector was partially upgraded. The early injector, transport and acceleration from 130 keV to 6 MeV, is unchanged, but the downstream boost from 6 MeV to the final 123 MeV energy drove several changes. One of the two original CEBAF 25 MeV type cryomodules in the injector was upgraded to a 100 MeV capable one to provide more energy. Some trim magnets at the end of the injector were upgraded to compensate for the higher energy. The chicane region was expanded, and the full energy injector spectrometer was relocated to make room for the newly added Hall D line. Experience from the 6 GeV era indicated that the stray fields from the higher energy beam transport recombiners near the injection chicane adversely affect the injector orbit, so a study to understand and mitigate stray fields from the transport arc box supplies upgraded for 12 GeV led to shielding modifications for the beamline in the chicane region.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA038	Observation of Significant Quantum Efficiency Enhancement from a Polarized Photocathode with Distributed Brag Reflector	1923
	S. Zhang, M. Poelker, M.L. Stutzman JLab, Newport News, Virginia, USA Y. Chen, A. Moy SVT Associates, Eden Prairie, Minnesota, USA
	Funding: This project was supported by the U.S. DOE Basic Energy Sciences under contract No. DE-AC05-060R23177. Polarized photocathodes with higher Quantum efficiency (QE) would help to reduce the technological challenge associated with producing polarized beams at milliampere levels, because less laser light would be required, which simplifies photocathode cooling requirements. And for a given amount of available laser power, higher QE would extend the photogun operating lifetime. The distributed Bragg reflector (DBR) concept was proposed to enhance the QE of strained-superlattice photocathodes by increasing the absorption of the incident photons using a Fabry-Perot cavity formed between the front surface of the photocathode and the substrate that includes a DBR, without compromising electron polarization. Here we present recent results showing QE enhancement of a GaAs/GaAsP strained-superlattice photocathode made with a DBR structure. Typically, a GaAs/GaAsP strained-superlattice photocathode without DBR provides a QE of 1%, at a laser wavelength corresponding to peak polarization. In comparison, the GaAs/GaAsP strained-superlattice photocathodes with DBR exhibited an enhancement of over 2 when the incident laser wavelength was tuned to meet the resonant condition for the Fabry-Perot resonator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA041	On the Characterization of a CCR Source	1926
	A.V. Smirnov RadiaBeam, Santa Monica, California, USA
	Funding: US Department of Energy, contract # DE- SC-FOA-0000760 Peak and spectral brightness of a resonant long-range wakefield extractor are evaluated. It is shown that the brightness is dominated by beam density within the slow wave structure and antenna gain of the outcoupling. Far field radiation patterns and brightness of circular and high-aspect-ratio planar radiators are compared. A possibility to approach the diffraction limited brightness is demonstrated. Role of group velocity in designing of the Cherenkov source is emphasized. The approach can be applied for design and characterization of various structure-dominated sources (e.g., wakefield extractors with gratings or dielectrics, or FEL-Cherenkov combined sources) radiating into a free space using an antenna (from microwave to far infra-red regions). The high group velocity structures can be also effective as energy dechirpers and for diagnostics of microbunched relativistic electron beams.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA041
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA042	THz Radiation Generation in a Multimode Wakefield Structure	1929
	S.P. Antipov, S.V. Baryshev, C.-J. Jing, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA M.G. Fedurin BNL, Upton, Long Island, New York, USA W. Gai, D. Wang, A. Zholents ANL, Argonne, Illinois, USA
	Funding: Work supported by the Department of Energy SBIR program under Contract #DE-SC0009571 A number of methods for producing sub-picosecond beam microbunching have been developed in recent years. A train of these bunches is capable of generating THz radiation via multiple mechanisms like transition, Cherenkov and undulator radiation. We utilize a bunch train with tunable spacing to selectively excite high order TM0n - like modes in a multimode structure. In this paper we present experimental results obtained at the Accelerator Test Facility of Brookhaven National Laboratory.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA042
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA043	Experimental Test of Semiconductor Dechirper	1932
	S.P. Antipov, S.V. Baryshev, C.-J. Jing, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA S. Baturin LETI, Saint-Petersburg, Russia M.G. Fedurin, K. Kusche, C. Swinson BNL, Upton, Long Island, New York, USA W. Gai, S. Stoupin, A. Zholents ANL, Argonne, Illinois, USA
	Funding: Work supported by the Department of Energy SBIR program under Contract #DE-SC0006299 We report the observation of de-chirping of a linearly chirped (in energy) electron bunch by its passage through a 4 inch long rectangular waveguide loaded with two silicon bars 0.25 inch thick and 0.5 inch wide. Silicon being a semiconductor has a conductivity that allows it to drain the charge fast in case if some electrons get intercepted by the dechirper. At the same time the conductivity is low enough for the skin depth to be large (on the order of 1 cm) making the silicon loaded waveguide a slow wave structure supporting wakefields that dechirp the beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA043
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA047	Multipacting-free Quarter-wavelength Choke Joint Design for BNL SRF	1935
	W. Xu, S.A. Belomestnykhpresenter, I. Ben-Zvi, C.J. Liaw, G.T. McIntyre, K.S. Smith, R. Than, J.E. Tuozzolo, E. Wang, D. Weiss, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykhpresenter, I. Ben-Zvi Stony Brook University, Stony Brook, USA
	The BNL SRF gun cavity was operated well at CW mode up to 2 MV. However, the performance suffered due to multipacting in the quarter-wavelength choke-joint. A new multipacting-free cathode stalk was designed and will be conditioned. This paper will describes RF and thermal design of new cathode stalk and conditioning results. This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA048	Experimental and Simulational Result of Multipactors in 112 MHz QWR Injector	1938
	T. Xin Stony Brook University, Stony Brook, USA S.A. Belomestnykh, I. Ben-Zvi, J.C. Brutus, V. Litvinenko, I. Pinayev, J. Skaritka, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: This work was carried out at Brookhaven Science Associates, LLC under Contracts No. DE-AC02-98CH10886 and at Stony Brook University under grant DE-SC0005713 with the U.S. DOE. The first RF commissioning of 112 MHz QWR superconducting electron gun was done in late 2014. The coaxial Fundamental Power Coupler (FPC) and Cathode Stalk (stalk) were install and tested for the first time. During this experiment, we observed several multipacting barriers at varied gun voltage levels. The simulation work was done within the same range. The comparison between the experimental observation and the simulation results are presented in this paper. The observations during the test are consisted with the simulation predictions. We were able to overcome most of the multipacting barriers and reach 1.7 MV gun voltage under pulsed mode after several round of conditioning processes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA049	First Beam Commissioning at BNL ERL SRF Gun	1941
	W. Xu, Z. Altinbas, S.A. Belomestnykhpresenter, I. Ben-Zvi, S. Deonarine, D.M. Gassner, H. Hahn, L.R. Hammons, T. Hayes, J.P. Jamilkowski, P. K. Kankiya, D. Kayran, N. Laloudakis, R.F. Lambiase, V. Litvinenko, L. Masi, G.T. McIntyre, K. Mernick, T.A. Miller, G. Narayan, D. Phillips, V. Ptitsyn, T. Rao, T. Seda, F. Severino, B. Sheehy, K.S. Smith, A.N. Steszyn, T.N. Tallerico, R. Than, J.E. Tuozzolo, E. Wang, D. Weiss, M. Wilinski, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykhpresenter, I. Ben-Zvi, V. Litvinenko, V. Ptitsyn Stony Brook University, Stony Brook, USA
	Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. The 704 MHz superconducting RF gun successfully generated the first photoemission beam on Nov. 17 2014. This paper will report the latest results of SRF beam commissioning, including the SRF cavity performance, cathode QE measurements, and beam parameter measurements. The beam commissioning setup is described in the paper as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA050	NSLS-II Injector Commissioning and Initial Operation	1944
	E.B. Blum, B. Bacha, G. Bassi, J. Bengtsson, A. Blednykh, S. Buda, W.X. Cheng, J. Choi, J. Cupolo, R. D'Alsace, M.A. Davidsaver, J.H. De Long, L. Doom, D.J. Durfee, R.P. Fliller, M. Fulkerson, G. Ganetis, F. Gao, C. Gardner, W. Guo, R. Heese, Y. Hidaka, Y. Hu, M.P. Johanson, B.N. Kosciuk, S. Kowalski, S.L. Kramer, S. Krinsky, Y. Li, W. Louie, M.A. Maggipinto, P. Marino, J. Mead, J. Oliva, D. Padrazo, K. Pedersen, B. Podobedov, R.S. Rainer, J. Rose, M. Santana, S. Seletskiy, T.V. Shaftan, O. Singh, P. Singh, V.V. Smaluk, R.M. Smith, T. Summers, J. Tagger, Y. Tian, W.H. Wahl, G.M. Wang, G.J. Weiner, F.J. Willeke, L. Yang, X. Yang, E. Zeitler, E. Zitvogel, P. Zuhoski BNL, Upton, Long Island, New York, USA A. Akimov, P.B. Cheblakov, I.N. Churkin, A.A. Derbenev, S.M. Gurov, S.E. Karnaev, V.A. Kiselev, A.A. Korepanov, E.B. Levichev, S.V. Sinyatkin, A.N. Zhuravlev BINP SB RAS, Novosibirsk, Russia
	The injector for the National Synchrotron Light Source II storage ring consists of a 3 GeV booster synchrotron and a 200 MeV S-band linac. The linac was designed to produce either a single bunch with a charge of 0.5 nC of electrons or a train of bunches up to 300 ns long containing a total charge of 15 nC. The booster was designed to accelerate up to 15 nC each cycle. Linac commissioning was completed in April 2012. Booster commissioning was started in November 2013 and completed in March 2014. All of the significant design goals were satisfied including beam emittance, energy spread, and transport efficiency. While the maximum booster charge accelerated was only 10 nC this has proven to be more than sufficient for storage ring commissioning. The injector has operated reliably during storage ring operation since then. Results will be presented showing measurements of injector operating parameters achieved during commissioning and initial operation. Operating experience and reliability during the first year of NSLS-II operation will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA050
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA052	NSLS-II Radio Frequency Systems	1947
	J. Rose, F. Gao, B. Holub, J.G. Kulpin, C. Marques BNL, Upton, Long Island, New York, USA A. Goel ANL, Argonne, Ilinois, USA M. Yeddulla Varian Medical Systems, Inc., Palo Alto, California, USA
	Funding: Work supported by DOE contract DE-SC0012704 The National Synchrotron Light Source II is a 3 GeV X-ray user facility commissioned in 2014. The NSLS-II RF system consists of the master oscillator, digital low level RF controllers, linac, booster and storage ring RF sub-systems, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA052
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA053	Experience with First Turns Commissioning in NSLS-II Storage Ring	1950
	S. Seletskiy, G. Bassi, J. Bengtsson, A. Blednykh, E.B. Blum, W.X. Cheng, J. Choi, R.P. Fliller, W. Guo, R. Heese, Y. Hidaka, S.L. Kramer, Y. Li, B. Podobedov, T.V. Shaftan, G.M. Wang, F.J. Willeke, L. Yang, X. Yang BNL, Upton, Long Island, New York, USA
	In this paper we describe our experience with commissioning of the first turns in the NSLS-II storage ring. We discuss the problems that we encountered and show how applying a dedicated first turns commissioning software allowed us to diagnose and resolve these problems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA053
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA054	High Level Application for First Turns Commissioning in NSLS-II Storage Ring	1953
	S. Seletskiy, A. Blednykh, J. Choi, Y. Hidaka, B. Podobedov, G. Shen, L. Yang BNL, Upton, Long Island, New York, USA
	The typical problems occurring during commissioning of the first turns in the storage rings include shorted coils or reversed polarity of the magnets, cross-cabling of magnets power supplies and reversed polarity of BPMs. In this paper we describe a dedicated high level control application, which was created and utilized for commissioning of the first turns in NSLS-II storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA054
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA055	Analysis of Possible Beam Losses in the NSLS II Storage Ring	1956
	S. Seletskiy, R.P. Fliller, W. Guo, S.L. Kramer, Y. Li, B. Podobedov, T.V. Shaftan, W.H. Wahl, F.J. Willeke BNL, Upton, Long Island, New York, USA
	The NSLS-II accelerators are installed within radiation shielding walls that are designed to attenuate the radiation generated from an assumed beam loss power to a level of <0.5mrem/h at the outer surface of the bulk shield walls. Any operational losses greater than specified level are expected to be addressed by installing supplemental shielding near the loss point in order to attenuate the radiation outside the shield wall to the design level. In this paper we report the analysis of the electron beam mis-steering in the NSLS-II storage ring for the determination of supplementary shielding.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA056	Analysis of Possible Beam Losses in the NSLS II BSR Transfer Line	1959
	S. Seletskiy, R.P. Fliller, W. Guo, S.L. Kramer, Y. Li, B. Podobedov, T.V. Shaftan, W.H. Wahl, F.J. Willeke BNL, Upton, Long Island, New York, USA
	The NSLS-II accelerators are installed within 0.8 – 1 m thick radiation shielding walls. The safety considerations require attenuating the radiation generated from possible electron beam losses to a level of <0.5mrem/h at the outer surface of the bulk shield walls. Any operational losses greater than specified level shall be addressed by installing supplemental shielding near the loss point. In this paper we discuss simulation studies that identified potential beam loss locations. Results of these studies were used for identification of imposed radiation risks and for specification of the supplemental shielding design necessary to mitigate those risks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA056
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
TUPMA057	Commissioning of Active Interlock System for NSLS II Storage Ring	1962
	S. Seletskiy, C. Amundsen, J. Choi, J.H. De Long, K.M. Ha, C. Hetzel, H.-C. Hseuh, Y. Hu, P. Ilinski, S.L. Kramer, Y. Li, M.A. Maggipinto, J. Mead, D. Padrazo, T.V. Shaftan, G. Shen, O. Singh, R.M. Smith, W.H. Wahl, G.M. Wang, F.J. Willeke, L. Yang BNL, Upton, Long Island, New York, USA
	The NSLS-II storage ring is protected from possible damage from insertion devices (IDs) synchrotron radiation by a dedicated active interlock system (AIS). It monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope. In this paper we describe functional details of the AIS and discuss our experience with commissioning of the AIS for the first six IDs installed in the storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA057
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)