• P.M. McIntyre, A. Sattarov
  Texas A&M University, College Station, Texas

Recent developments in the performance of superconductors and the design of high-field superconducting dipoles have opened the possibility to extend dipole field strength to ~25 Tesla in the arc dipoles of a future hadron collider. Design issues are presented for a concept of a Tripler upgrade of LHC, in which a second dual ring would be installed over the LHC ring in the same tunnel. Proton beams from LHC would be transferred to the Tripler midway through the LHC cycle and accelerated to ~20 TeV/beam for collisions. A number of obvious issues are explored. Synchrotron radiation power would be 80 times greater, but the critical energy would come as soft X-rays rather than hard UV, and so could be absorbed locally on ~150 K photon stops following each dipole so that total refrigeration power could perhaps be no more than that for LHC. Synchrotron damping would be dramatically enhanced in the Tripler compared to LHC, with damping times of ~one hour. Alternatives for beam transfer and low-beta insertions will be discussed. Like LHC, the Tripler would access new mass scales primarily through gluon fusion. The Tripler should reach about twice the mass scale attainable with LHC.

• D.A. Zakaryan, D.K. Kalantaryan
  YSU, Yerevan
• E.D. Gazazyan, K.A. Ispirian, M.K. Ispirian
  YerPhI, Yerevan

• M. Böge, B. Keil, A. Lüdeke, T. Schilcher
  PSI, Villigen

• M. Böge, J.T.M. Chrin, G. Ingold, B. Keil, J. Krempasky, T. Schilcher, V. Schlott, T. Schmidt, A. Streun
  PSI, Villigen

• G.A. Amatuni, Y.L. Martirosyan, R.H. Mikaelyan, V.M. Tsakanov, A. Vardanyan
  CANDLE, Yerevan

• J.Z. Xu, I. Vasserman
  ANL, Argonne, Illinois

In order to characterize the insertion devices at the Advanced Photon Source (APS) more efficiently, a new stretched-coil magnetic field integral measurement system has been developed. The system uses the latest state-of-the-art field programmable gate array (FPGA) technology to compensate the speed variations of the coil motions. Initial results demonstrate that the system achieves the system measurement accuracy of 0.15 Gauss centimeter (G-cm) in a field integral measurement of 600 G-cm, probably the world’s best accuracy of its kind.

• S.H. Kim
  ANL, Argonne, Illinois

An undulator with double-helix coils on a cylindrical beam tube is the classical method of producing a helical magnetic field. This type of device, however, can produce only circularly polarized radiation and has limited horizontal aperture for beam injection. A planar superconducting undulator SCU) unit of helical field, which generates horizontal and vertical fields perpendicular to the beam direction, is inserted in between the magnetic poles of a vertical-field unit. This paper analyzes the magnetic fields and a scaling law of the SCU. The angle of the coil windings for the inserted unit is analyzed to maximize the horizontal field Bx. The range of the optimum rotation angle, for the range of gap/period ratio 0.1 - 0.6, is calculated to 30 - 40 degrees.

• S.H. Kim, C. Doose, R. Kustom, E.R. Moog, I. Vasserman
  ANL, Argonne, Illinois

A superconducting undulator (SCU) with a period of 14.5 mm is under development at the Advanced Photon Source (APS). The undulator is designed to achieve a peak field on the beam axis of 0.8 T with an 8 mm pole gap and an average current density of 1 kA/mm2 in the NbTi coil. A 22-period half-section of a SCU has been fabricated. The SCU half-section was charged up to near the average critical current density jc of 1.4 kA/mm2, and the stability margin was measured by imposing external heat fluxes on the coil at 4.2 K in pool boiling LHe. The magnetic fields along the midplane of the SCU were measured using a Hall-probe field-mapping unit installed in a vertical dewar. The first test of a Nb3Sn short-section SCU reached an average current density of 1.45 kA/mm2, slightly higher than the jc for the NbTi SCU.

• A.A. Mikhailichenko
  Cornell University, Department of Physics, Ithaca, New York

• A.Y. Zelinsky, I.V. Drebot, Yu.N. Grigor'ev, O.D. Zvonarjova
  NSC/KIPT, Kharkov
• R. Tatchyn
  SLAC, Menlo Park, California

• J.A. Clarke, F.E. Hannon, D.J. Scott, B.J.A. Shepherd, N.G. Wyles
  CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire

• M.A. Palmer, J.A. Crittenden, J. Kandaswamy, A. Temnykh
  Cornell University, Department of Physics, Ithaca, New York
• T.I. O'Connell
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York

Installation of a radiative Bhabha luminosity monitor for CESR-c operation in 2004 required replacing a 40-mm aperture steel quadrupole magnet with one of aperture 75 mm, while maintaining field-quality tolerances at the level of a few parts in $10⁴. We present the design methodology using 2D- and 3D-finite-element field calculations, compare the calculated 3D integrals to flip-coil measurements, and discuss related mechanical tolerances.

• M.A. Shapiro, J.R. Sirigiri, R.J. Temkin
  MIT/PSFC, Cambridge, Massachusetts
• G. Shvets
  The University of Texas at Austin, Austin, Texas

We present the results of research on 3D metallic lattices operating at microwave frequencies for application in (1) accelerator structures with higher order mode suppression, (2) Smith-Purcell radiation beam diagnostics, and (3) polaritonic materials for laser acceleration. Electromagnetic waves in a 3D simple cubic lattice formed by metal wires are calculated using HFSS. The bulk modes in the lattice are determined using single cell calculations with different phase advances in all three directions. The Brillouin diagram for the bulk modes is presented and indicates the absence of band gaps in simple lattices except the band below the cutoff. Lattices with thin wires as well as with thick wires have been analyzed. The Brillouin diagram also indicates the presence of low frequency 3D plasmon mode as well as the two degenerate photon modes analogous to those in a 2D lattice. Surface modes for a semi-infinite cubic lattice are modeled as a stack of cells with different phase advances in the two directions along the surface. The surface modes are found for both the thin and thick wire lattices in the band below the cutoff. They demonstrate that the lattice acts as a negative dielectric constant material.

• M.C. Thompson, H. Badakov, J.B. Rosenzweig, G. Travish
  UCLA, Los Angeles, California
• M.J. Hogan, R. Ischebeck, R. Siemann, D.R. Walz
  SLAC, Menlo Park, California
• P. Muggli
  USC, Los Angeles, California
• A. Scott
  UCSB, Santa Barbara, California
• R.B. Yoder
  ,

An experiment is planned to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range. This new UCLA/SLAC collaboration will take advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., sz = 20 μm at Q = 3 nC). The electron beam will be focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 μm / OD = 325 μm and ID = 100 μm / OD = 325 μm. The pulse length of the electron beam will be varied in order to alter the accelerating gradient and probe the breakdown threshold of the dielectric structures. In addition to breakdown studies, we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain information about the strength of the accelerating fields. Status and progress on the experiment are reported.

• G.R. Werner
  CIPS, Boulder, Colorado
• J.R. Cary
  Tech-X, Boulder, Colorado

Photonic crystals (periodic dielectric structures with a lattice constant on the order of the wavelength of light) can have a wide range of properties. For instance, photonic crystals can be designed to be completely reflective within a certain bandwidth, thereby becoming a replacement for metal in accelerator structures such as waveguides and cavities. To see whether photonic crystals might find application in accelerators, and to design potential accelerator structures, we will need reliable computer simulations to predict fields and frequencies and other properties of photonic crystal structures. We propose to build photonic crystal structures in the microwave regime and test the validity of computer simulation against experiment. We can then explore more complex issues such as coupling to photonic crystal structures, higher-order mode rejection, and tunable photonic crystals.

• O. Yavas
  Ankara University, Faculty of Engineering, Tandogan, Ankara
• H.-H. Braun, R. Corsini
  CERN, Geneva
• S. Sultansoy
  Gazi University, Faculty of Science and Arts, Ankara

Main parameters of CLIC-LHC based FEL-Nucleus collider are determined. The matching of beam structures for maximum luminosity is studied. The advantages of the collider with respect to the traditional Nuclear Resonance Fluorescence (NRF) methods are presented considering (/Gamma-/Gamma(prime)) reactions. Determination of unknown decay width, spin and parity of excited levels is discussed for Pb nucleus.

• S. Sultansoy
  Gazi University, Faculty of Science and Arts, Ankara
• O. Cakir, A.K. Ciftci
  Ankara University, Faculty of Sciences, Tandogan/Ankara
• E. Recepoglu
  Turkish Atomic Energy Authority, Ankara
• O. Yavas
  Ankara University, Faculty of Engineering, Tandogan, Ankara

The construction of the ILC tangential to Tevatron ring will give opportunity to investigate electron-proton, positron-proton, electron-antiproton, positron-antiproton interactions at 1 TeV center of mass energy. The analysis of the lepton-hadron collisions in these energy region is very important both for understanding of strong interaction dynamics and for adequate interpretation of future LHC and VLHC data. In addition, ILC-Tevatron collider will provide a possibility to realize photon-hadron collisions in the same energy region using Compton backscattered laser photon of ILC electron beam. Main parameters of these colliders are estimated and their physics search potential is briefly discussed.

• B. Faatz
  DESY, Hamburg

• S. Khan
  BESSY GmbH, Berlin

The generation of ultrashort synchrotron radiation pulses by laser-induced energy modulation of electrons and their subsequent transverse displacement, now dubbed "femtoslicing," was demonstrated at the Advanced Light Source in Berkeley. More recently, a femtoslicing user facility was commissioned at the BESSY storage ring in Berlin, and another project is in progress at the Swiss Light Source. The paper reviews the principle of femtoslicing, its merits and shortcomings, as well as the variations of its technical implementation. Various diagnostics techniques to detect successful laser-electron interaction are discussed and experimental results are presented.

• S. Chouhan, D.A. Harder, G. Rakowsky, J. Skaritka, T. Tanabe
  BNL, Upton, Long Island, New York

In this work a new concept for the construction of planar variable polarization superconductive insertion device is presented. The construction of the device with 8 mm gap and magnetic period of 26 mm is described compared with permanent magnet insertion device with the same gap & period length, as well as with previously published concepts. Advantage of this design include: (1) electrical tunability for both right and left circular and elliptical, as well as linear vertical or horizontal, (2) it requires no compensation of unwanted vertical field component and (3) used only simple windings of superconductive wire in an interlaced pattern. As a first step towards the construction of full-length device we propose to build & test a short prototype that will serve as a proof of the concept for versatile variable polarization superconductor magnet.

• H. Schlarb
  DESY, Hamburg

• B.X. Yang, A.H. Lumpkin
  ANL, Argonne, Illinois

The Advanced Photon Source (APS) is a third generation hard x-ray source serving a large user community. In order to characterize the high-brilliance beams, the APS diagnostics beamlines have been developed into a full photon diagnostics suite. We will describe the design and capabilities of the APS visible light imaging line, the bend magnet x-ray pinhole camera, and a unique diagnostics undulator beamline. Their primary functions are to support the APS user operations by providing information on beam sizes (20 - 100 micrometers), divergence (3 – 25 microradians), and bunch length (20 – 50 ps). Through the use of examples, we will show how these complementary imaging tools are used to visualize the electron dynamics and investigate beam instabilities. Special emphasis will be put on the use of undulator radiation, which is uniquely suitable for time-resolved imaging of electron beam with high spatial resolution, and for measurements of longitudinal beam properties such as beam energy spread and momentum compaction.

• N.A. Moody, D.W. Feldman, P.G. O'Shea
  IREAP, College Park, Maryland
• K. Jensen
  NRL, Washington, DC

Photoinjector performance is a limiting factor in the continued development of high powered FELs and electron beam-based accelerators. Presently available photocathodes are plagued with limited efficiency and short lifetime in an RF-gun environment, due to contamination or evaporation of a photosensitive surface layer. An ideal photocathode should have high efficiency at long wavelengths, long lifetime in practical vacuum environments, and prompt emission. Cathodes with high efficiency typically have limited lifetime, and vice versa, and the needs of the photocathode are generally at odds with those of the drive laser. A potential solution is the low work function dispenser cathode, where lifetime issues are overcome by periodic in situ regeneration that restores the photosensitive surface layer, analogous to those used in the microwave power tube industry. This work reports on the fabrication techniques and performance of cesiated metal photocathodes and cesiated dispenser cathodes, with a focus on understanding and improving quantum efficiency and lifetime, and analyzing issues of emission uniformity. The efficiency versus coverage behavior of cesiated metals is discussed and closely matches that predicted by recent theory.*

*K. L. Jensen, et al., "Photoemission from Low Work Function Coated Metal Surfaces: A Comparison of Theory to Experiment" (this conference).

• V. Bharadwaj, Y.K. Batygin, R. Pitthan, D.C. Schultz, J. Sheppard, H. Vincke, J.W. Wang
  SLAC, Menlo Park, California
• J.G. Gronberg, W. Stein
  LLNL, Livermore, California

A positron source for the ILC can be designed using either a multi-GeV electron beam or a multi-MeV photon beam impinging on a metal target. The major issues are: the drive beam, choice of target material, the design of the target station, the capture section, the target vault, and beam transport to the damping ring. In this paper, positron source parameters for the various schemes are outlined and the advantages and disadvantages of each scheme are discussed.

• A. Bogomyagkov, V.E. Blinov, V.P. Cherepanov, V. Kiselev, E. Levichev, S.I. Mishnev, N.Yu. Muchnoi, S.A. Nikitin, I.B. Nikolaev, D.M. Nikolenko, A.G. Shamov, E. Shubin, A.N. Skrinsky, Yu.A. Tikhonov, D.K. Toporkov, G.M. Tumaikin
  BINP SB RAS, Novosibirsk

• H. Aksakal, A.K. Ciftci
  Ankara University, Faculty of Sciences, Tandogan/Ankara
• D. Schulte, F. Zimmermann
  CERN, Geneva

• J. Beebe-Wang, C. Montag
  BNL, Upton, Long Island, New York
• A. Deshpande
  Stony Brook University, Stony Brook
• D.J. Rondeau
  Binghamton University, State University of New York, Binghamton, New York
• B. Surrow
  MIT, Cambridge, Massachusetts

The eRHIC currently under study at BNL consists of an electron storage ring added to the existing RHIC complex. The interaction region of this facility has to provide the required low-beta focusing while accommodating the synchrotron radiation generated by beam separation close to the interaction point. In the current design, the synchrotron radiation caused by 10GeV electrons bent by low-beta triplet magnets will be guided through the interaction region and dumped 5m downstream. However, it is unavoidable to stop a fraction of the photons at the septum where the electron and ion vacuum system are separated. In order to protect the septum and minimize the backward scattering of the synchrotron radiation, an absorber and collimation system will be employed. In this paper, we first present the overview of the current design of the eRHIC interaction region with special emphasis on the synchrotron radiation. Then the initial design of the absorber and collimation system, including their geometrical and physical properties, will be described. Finally, our initial investigation of synchrotron radiation in the eRHIC interaction region, especially a simulation of the backward scattering from the absorber, will be presented.

• T. Takahashi, M. Izawa, S. Sakanaka, K. Umemori
  KEK, Ibaraki
• T. Koseki
  RIKEN/RARF/CC, Saitama

• D. Horan, E.E. Cherbak
  ANL, Argonne, Illinois

A 352-MHz fast-ferrite rf cavity tuner, manufactured by Advanced Ferrite Technology, was high-power tested on a single-cell copper rf cavity at the Advanced Photon Source. These tests measured the fast-ferrite tuner performance in terms of power handling capability, tuning bandwidth, tuning speed, stability, and rf losses. The test system comprises a single-cell copper rf cavity fitted with two identical coupling loops, one for input rf power and the other for coupling the fast-ferrite tuner to the cavity fields. The fast-ferrite tuner rf circuit consists of a cavity coupling loop, a 6-1/8” EIA coaxial line system with directional couplers, and an adjustable 360° mechanical phase shifter in series with the fast-ferrite tuner. A bipolar DC bias supply, controlled by a low-level rf cavity tuning loop consisting of an rf phase detector and a PID amplifier, is used to provide a variable bias current to the tuner ferrite material to maintain the test cavity at resonance. Losses in the fast-ferrite tuner are calculated from cooling water calorimetry. Test data will be presented.

• G.J. Waldschmidt, N.P. Di Monte, D. Horan, L.H. Morrison, G. Pile
  ANL, Argonne, Illinois

Higher-order-mode dampers were recently installed in the storage ring rf cavities at the Advanced Photon Source to eliminate longitudinal coupled-bunch instability. It was discovered that the 540-MHz cavity dipole mode created beam instability at beam currents in excess of 85 mA causing horizontal emittance blowup. Methods of compensating for the instability by detuning the cavities and adjusting the cavity water temperature were becoming more difficult at higher beam currents as tests were performed to prepare for eventual 300-mA beam current operation. Electric field passive dampers located on the median plane of each cavity were determined to be the most promising solution. Simulation models were created and verified with low-power testing of the dampers. High-power testing of the dampers as well as conditioning of the damper ceramic load were also performed at the APS 352-MHz rf test stand and compared with simulation results. Preliminary test results will be discussed.

• C. Wang, L.-H. Chang, S.-S. Chang, C.-T. Chen, F.-T. Chung, F.-Z. Hsiao, G.-Y. Hsiung, K.-T. Hsu, C.-C. Kuo, H.C. Li, M.-C. Lin, R.J. Lin, Y.K. Lin, G.-H. Luo, M.H. Tsai, J.Y. Yang, T.-T. Yang, M.-S. Yeh
  NSRRC, Hsinchu

• A.A. Mikhailichenko
  Cornell University, Department of Physics, Ithaca, New York

• A. Seryi
  SLAC, Menlo Park, California

• R.H.A. Farias, J.F. Citadini, M.J. Ferreira, J.G.R.S. Franco, A.F.A. Gouveia, L.C. Jahnel, L. Liu, R.T. Neuenschwander, X.R. Resende, P.F. Tavares, G. Tosin
  LNLS, Campinas
• N.P. Abreu
  UNICAMP, Campinas, São Paulo

We present the results of the commissioning of a 28-pole 2 T Hybrid Wiggler at the 1.37 GeV electron storage ring of the Brazilian Synchrotron Light Source. The wiggler will be used mainly for protein crystallography and was optimized for the production of 12 keV photons. The very high field and relatively large gap (22 mm) of this insertion device led to a magnetic design that includes large main and side magnets and heavily saturated poles. We present the results of the commissioning with beam, with special attention to the correction of the large linear tune-shift perturbations produced by the wiggler as well as on the reduction of beam lifetime at full energy. Since the injection at the LNLS storage ring is performed at 500 MeV we also focus on the effects of non-linearities and their impact on injection efficiency.

• S. Mayer, D. Forkel-Wirth, M. Fuerstner, H.G. Menzel, S. Roesler, C. Theis, H. Vincke
  CERN, Geneva

• Y. He, D.H. Rice
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
• Y. Li, M.A. Palmer
  Cornell University, Department of Physics, Ithaca, New York

A luminosity monitor using photons from radiative bhabha events at the CLEO interaction point (IP) has been installed in the Cornell Electron Storage Ring (CESR). A key vacuum and detector component is the photon window/converter whose uniformity and thickness are critical for determining the resolution of the total energy deposited in the segmented luminosity monitor. The window design must accommodate the operational requirements of the new monitor at CLEO-c beam energies of 1.5-2.5 GeV and also provide sufficient safety margin for operation at 5.3 GeV beam energies for Cornell High Energy Synchrotron Source (CHESS) running. During 5.3 GeV operation, intense stripes of synchrotron radiation from the interaction region superconducting quadrupole magnets as well as nearby bending magnets strike the window. During the course of window development, several materials and designs were evaluated. Thermal stresses were calculated using the finite element code ANSYS for various beam conditions to guide the cooling design. A window using aluminum alloy (6061-T6) was ultimately chosen to provide optimal performance for both CLEO-c and CHESS running conditions. The window has been in successful operation since September 2004.

• M. Fuerstner, I. Brunner, D. Forkel-Wirth, S. Mayer, H.G. Menzel, H. Vincke
  CERN, Geneva
• I. Floret
  Ecole d'ingénieurs de Genève, Genève

• A.L. Hillman, S.J. Pasky, N. Sereno, R. Soliday, J. Wang
  ANL, Argonne, Illinois

Operational goals for the APS facility include 97% availability and a mean time between unscheduled beam losses (faults) of 70 hours, with more than 5000 user hours of scheduled beam per year. To meet this objective, our focus has changed to maximizing the mean time between faults (MTBF). We have made various hardware and software improvements to better operate and monitor the injector power supply systems. These improvements have been challenging to design and implement in light of the facility operating requirements but are critical to maintaining maximum reliability and availability of beam for user operations. This paper presents actions taken as well as future plans to continue improving injector power supply hardware and software to meet APS user operation goals.

• Z.M. Yusof, M.E. Conde, W. Gai
  ANL, Argonne, Illinois

Using photons with energy that is less than the work function, we employ the Schottky effect to determine the field enhancement factor on the surface of a Mg photocathode. The Schottky effect is manifested via a shift in the threshold for photoemission as the amplitude of the RF in the photoinjector gun is varied. From the threshold condition, we can directly determine the field enhancement factor on the cathode surface. This is a viable technique to obtain the field enhancement factor of surfaces of other materials such as Nb and Cu.

• J. Smedley, T. Rao
  BNL, Upton, Long Island, New York
• P. Kneisel
  Jefferson Lab, Newport News, Virginia
• J.L. Langner, P. Strzyzewski
  The Andrzej Soltan Institute for Nuclear Studies, Centre Swierk, Swierk/Otwock
• R.S. Lefferts, A.R. Lipski
  SBUNSL, Stony Brook, New York
• J.S. Sekutowicz
  DESY, Hamburg

We present the results of our investigation of bulk, electroplated and vacuum deposited lead as suitable photocathode materials for superconducting RF injectors. The quantum efficiency of each sample is presented as a function of the wavelength of the incident light, from 310 nm to 190 nm. Quantum efficiencies of 0.3% have been obtained. Production of a niobium cavity with a lead-plated cathode is underway.

• V.M. Tsakanov
  CANDLE, Yerevan

• S. Sasaki
  ANL, Argonne, Illinois

Much work is underway to develop superconducting undulators in order to generate brilliant hard x-ray radiation at many synchrotron radiation facilities. However, in spite of many R&D efforts, it might take several years to reach this goal. On the other hand, the possibilities of cryogenic permanent magnet undulators are being investigated in order to provide an interim solution for hard x-ray users’ needs at Spring-8 and other facilities. However, although the in-vacuum undulator technology is well established, the in-vacuum gap-motion mechanism at a low temperature might cause major concerns regarding reliability and cost effectiveness. In this paper, the possibility for a cryogenic short-period staggered undulator was investigated. A simple model calculation by RADIA* shows that the effective undulator field is 0.825 T for a 15-mm-period staggered undulator at 6 mm gap with 1.36 T solenoid field. The pole material was assumed to be dysprosium, which has a saturation magnetization of 3.3 T at 77 K. The achievable maximum field of this simply structured device is close to that of a cryogenic permanent magnet undulator. We present calculated performances of cryogenic staggered undulators at various periods and gaps.

*O. Chubar, P. Elleaume, J. Chavanne, J. Synchrotron Radiat. 5, 481 (1998).

• D.J. Gibson, C.P.J. Barty, S.M. Betts, K. Crane, I. Jovanovic
  LLNL, Livermore, California

The PLEIADES (Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures) facility provides tunable short x-ray pulses with energies of 30-140 keV and pulse durations of 0.3 – 5 ps by scattering an intense, ultrashort laser pulse off a 35-75 MeV electron beam. Synchronization of the laser and electron beam is obtained by using a photoinjector gun, and using the same laser system to generate the electrons and the scattering laser. The Ti:Sapphire, chirped pulse amplification based 500 mJ, 50 fs, 810 nm scattering laser and the similar 300 μJ, 5 ps, 266 nm photoinjector laser systems are detailed. Additionally, an optical parametric chirped pulse amplification (OPCPA) system is studied as a replacement for part of the scattering laser front end. Such a change would significantly simplify the set-up the laser system by removing the need for active switching optics, as well as increase the pre-pulse contrast ratio which will be important when part of the scattering laser is used as a pump beam in pump-probe diffraction experiments using the ultrashort tunable x-rays generated as the probe.

• T. Honda, S. Asaoka, W.X. Cheng, K. Haga, K. Harada, Y. Hori, M. Izawa, T. Kasuga, Y. Kobayashi, H. Maezawa, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. Nogami, T. Obina, C.O. Pak, S. Sakanaka, Y. Sato, T. Shioya, M. Tadano, T. Takahashi, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto
  KEK, Ibaraki

• T. Mitsuhashi, A. Ueda
  KEK, Ibaraki

• T. Mitsuhashi, M.T. Tadano
  KEK, Ibaraki

• C.-C. Kuo, H.-P. Chang, C.-T. Chen, G.-H. Luo, H.-J. Tsai, M.-H. Wang
  NSRRC, Hsinchu

• G. Decker, N. Sereno
  ANL, Argonne, Illinois

A method for obtaining very short pulses using modulation of the accelerating voltage gradient is described and simulation results given. The idea is to operate the two rf stations with a phase separation adjusted so that the synchronous particle resides on the crest of one of the sources. Phase modulation of the on-crest system at twice the synchrotron frequency induces a longitudinal bunch shape oscillation with significantly reduced bunch length occurring twice each synchrotron period. Pulsed and steady-state operation will be discussed using various accelerator parameters.

• G. Decker, O. Singh
  ANL, Argonne, Illinois

The Advanced Photon Source has been in operation since 1996. Since that time, extensive incremental improvements to orbit stabilization systems have been made. This includes the addition of 80 channels of narrowband rf beam position monitors (bpm's), 40 channels of bending magnet photon bpm's, and most recently the inclusion of 36 insertion device photon bpm's into the orbit correction response matrix. In addition, considerable improvements have been made in the area of power supply regulation, both for the main multipole magnets and the steering corrector magnets. The present status of overall performance will be discussed, including long term pointing stability, reproducibility, and AC beam motion.

• J.B. Murphy, J. Bengtsson, R. Biscardi, A. Blednykh, G.L. Carr, W.R. Casey, S. Chouhan, S.B. Dierker, E. Haas, R. Heese, S. Hulbert, E.D. Johnson, C.C. Kao, S.L. Kramer, S. Krinsky, I.P. Pinayev, S. Pjerov, B. Podobedov, G. Rakowsky, J. Rose, T.V. Shaftan, B. Sheehy, J. Skaritka, N.A. Towne, J.-M. Wang, X.J. Wang, L.-H. Yu
  BNL, Upton, Long Island, New York

The National Synchrotron Light Source at BNL was the first dedicated light source facility and it has now operated for more than 20 years. During this time the user community has grown to more than 2400 users annually. To insure that this vibrant user community has access to the highest quality photon beams, the NSLS is pursuing the design of a new ultra-high brightness (~10E21) electron storage ring, tailored to the 0.3-20 KeV photon energy range. We present our preliminary design and review the critical accelerator physics design issues.

• D. Robin, J.M. Byrd, P. Fischer, P.A. Heimann, D.H. Kim, S. Kwiatkowski, D. Li, F. Sannibale, C. Steier, W. Wan, W. Wittmer, A. Zholents
  LBNL, Berkeley, California

A scheme is studied for producing ps length pulses of x-ray radiation from the Advanced Light Source (ALS) using two RF deflecting cavities. The cavities create vertical displacements of electrons correlated with their longitudinal position in the bunch. The two cavities separated by 180 degrees of vertical phase advance. This allows the vertical kick from one cavity to be compensated by the vertical kick of the other. The location of the cavities corresponds to the end of one straight section and the beginning of the following straight section. Halfway between the cavities a bending magnet source is located. The radiation from the bend can be compressed to ~1 ps in duration.

• M. Borland, V. Sajaev
  ANL, Argonne, Illinois

Recently, Zholents et al. proposed applying to the Advanced Photon Source an x-ray compression scheme based on a pair of crab cavities and asymmetric cut crystals. We have explored the feasibility and potential performance of this scheme through simulation. We used the code elegant to perform 6-D tracking, allowing us to characterize the emittance growth, which is mostly a result of sextupoles between the cavities. We also explored tolerances on alignment, phase, and voltage of the cavities; lifetime effects; tradeoffs between cavity frequency and voltage; and performance with slicing alone instead of compression. Our conclusion is that sub-picosecond rms x-ray pulse lengths should be feasible.

• W. Guo, M. Borland, K.C. Harkay, V. Sajaev, B.X. Yang
  ANL, Argonne, Illinois

The length of x-ray pulses generated by storage ring light sources is usually tens of picoseconds. For example, the value is 40 ps rms at the Advanced Photon Source (APS). Methods of x-ray pulse compression are of great interest at the APS. One possible method, per Zholents et al., is to tilt the electron bunch with deflecting rf cavities.* Alternately, we found that the electron bunch can develop a tilt after application of a vertical kick in the presence of nonzero chromaticity. After slicing, the x-ray pulse length is determined by the tilt angle and the vertical beam size. In principal, sub-picosecond pulses can be obtained at APS. To date we have observed 6 ps rms visible light pulses with a streak camera. Efforts are underway to attempt further compression of the x-ray pulse and to increase the brilliance. This method can be easily applied to any storage ring light sources to generate x-ray pulses up to two orders of magnitude shorter than the electron bunch length. In this paper, we will present the theory of bunch tilt, particularly the synchrobetatron coupling and decoherence beam dynamics, and the simulation and the experimental results will also be shown as verification.

*A. Zholents et al., NIM A 425, 385(1999).

• K. Dobashi
  NIRS, Chiba-shi
• M. Akemoto, H. Hayano, T. Higo, J.U. Urakawa
  KEK, Ibaraki
• F. Ebina, A. Fukasawa, T. Kaneyasu, H. Ogino, F. Sakamoto, M. Uesaka, Y. Yamamoto
  UTNL, Ibaraki

• M. Uesaka, T. Kaneyasu
  UTNL, Ibaraki
• K. Dobashi, M. Torikoshi
  NIRS, Chiba-shi

• V.K. Grishin
  MSU, Moscow

Using opportunity of X-ray emission, arising at process of fast charge interaction with media atomic electrons, for nano-object discovery and diagnostics in substances is discussed. This kind of of X-ray emission termed as polarization bremsstrahlung radiation (PB) depends very strongly on media structure. As result spectra of PB in a media containing nano-inhomogeneities (as fullerenes, nanotubes, composite structures as fullerites) reflex structural characteristics of last ones. Fullerenes in carbon soot as example of an amorphous substance with mentioned structure inhomogeneities are considered. It is shown that spectra of PB on fullerenes contain a series of oscillations which give the valuable information about single^- ore multilayers fullerene structures. The main peak of emission is placed in energy area of PB photons less than 1-1.5 keV. Here PB obtains a coherent character due to which one PB intensity is very high because it becomes to proportional square of all fullerene electrons number. Due to PB intensity depends weakly enough on observation angle, that permits to pick up PB signal from traditional bremsstrahlung radiation, and to facilitate measurement conditions.

• A. Doyuran, R.J. England, C. Joshi, J. Lim, J.B. Rosenzweig, S. Tochitsky, G. Travish, O. Williams
  UCLA, Los Angeles, California

An Inverse Compton Scattering (ICS) experiment, which will investigate nonlinear properties of scattering utilizing a terawatt CO2 laser system with various polarizations, is ongoing at the UCLA Neptune Laboratory. When the normalized amplitude of the incident laser’s vector potential a0 is larger than unity the scattering occurs in the nonlinear region; therefore, higher harmonics are also produced. ICS can be used, e.g., for a polarized positron source by striking a thin target (such as tungsten) with the polarized X-rays. As such, it is critical to demonstrate the production of polarized scattered photons and to investigate the ICS process as it enters the nonlinear regime. We present the description of the experimental set up and equipment utilized, including diagnostics for electron and photon beam detection. We present the current status of the experiment.

• T. Webb, L.C. DeVeaux, F. Harmon, J.E. Petrisko, R.J. Spaulding
  IAC, Pocatello
• R. Assink
  Sandia National Laboratories, Albuquerque, New Mexico
• W. Beezhold
  ISU, Pocatello, Idaho

• E.D. Gazazyan, K.A. Ispirian, A.T. Margaryan
  YerPhI, Yerevan
• D.K. Kalantaryan
  YSU, Yerevan
• E.M. Laziev
  CANDLE, Yerevan

• S.R. Marques, O.R. Bagnato, Bombacini, F.O. Bombacini, M.J. Ferreira, H. J. Onisto
  LNLS, Campinas

• T.C. Tseng, J.-R. Chen, H.C. Ho, C.-K. Kuan, C.J. Lin, S.Y. Perng, D.-J. Wang, J. Wang
  NSRRC, Hsinchu

• M.A. Palmer, D. L. Rubin, J.C. Smith
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
• M. Cravey, J. Napalitano
  RPI, Troy, New York
• V. Crede
  Cornell University, Department of Physics, Ithaca, New York
• K.L. Dooley
  Vassar, Poughkeepsie, New York
• H. Vogel
  CMU, Pittsburgh, Pennsylvania

The CLEO-c experiment at the Cornell Electron Storage Ring (CESR) is presently embarking on a multi-year exploration of charm and QCD physics in the 3-5 GeV center-of-mass energy range. In order to facilitate rapid optimization of machine parameters over this energy range, a luminosity monitor based on the measurement of radiative-bhabha photons coming from the CLEO-c interaction point (IP) has been designed and installed in the CESR ring. Key design criteria of the device include: better than 1% statistical measurements of the luminosity with a 1 Hz update rate over the full range of CESR-c operating conditions; bunch-by-bunch measurement capability; a large horizontal aperture to enable measurements under conditions ranging from single-bunch head-on collisions to multi-bunch collisions with a horizontal crossing angle of up to 4~mrad; and, a segmented readout to provide direct information on beam characteristics at the IP. We review the design and performance of this device and discuss its application to machine tuning and performance studies.

• T. Watanabe, M. Babzien, K. Kusche, V. Yakimenko
  BNL, Upton, Long Island, New York

• Y. Fukui, D. Cline, F. Zhou
  UCLA, Los Angeles, California
• A. Aryshev, V. Karataev, T. Muto, M. Tobiyama, J.U. Urakawa
  KEK, Ibaraki
• P.R. Bolton, M.C. Ross
  SLAC, Menlo Park, California
• R. Hamatsu
  TMU, Hatioji-shi,Tokyo
• G.A. Naumenko, A. Potylitsyn, A. Sharafutdinov
  Tomsk Polytechnic University, Physical-Technical Department, Tomsk

• J. Carter, I.V. Agapov, G.A. Blair, G.E. Boorman, C.D. Driouichi, F. Poirier, M.T. Price
  Royal Holloway, University of London, Surrey
• K. Balewski, H.-C. Lewin, S. Schreiber, K. Wittenburg
  DESY, Hamburg
• S.T. Boogert, S. Malton
  UCL, London
• N. Delerue, D.F. Howell
  OXFORDphysics, Oxford, Oxon
• T.  Kamps
  BESSY GmbH, Berlin

• S.F. Lin, H. Gao, P. Lu, B. Sun, J. Wang
  USTC/NSRL, Hefei, Anhui

Supported by Natural Science Foundation of China (10275062) and CAS Knowledge Innovation Project (KY4206).

• M. Masaki
  JASRI/SPring-8, Hyogo

• L.A. Dillon-Townes, C.P. Behre, M.E. Bevins, G.H. Biallas, D. Douglas, C.W. Gould, J.G. Gubeli, D.H. Kashy, R. Lassiter, L. Munk, G. Neil, M.D. Shinn, S. Slachtouski, D. Waldman
  Jefferson Lab, Newport News, Virginia

The beam transport vacuum components for the 10 kW Free Electron Laser (FEL) at Thomas Jefferson National Accelerator Facility (TJNAF) were designed to address 10 MeV electron beam characteristics and maintain an accelerator transport vacuum of 10^-9 torr. The components discussed include a novel zero length beam clipper, novel shielded bellows, one decade differential pumping stations with a 7.62 cm (3.0”) aperture, and a 50 kW beam dump. Incorporation of these accelerator transport components assist in establishing the environment needed for the electron beam to produce the optical light required to lase at 10 kW.

• Y. Li, Y. He, M.A. Palmer
  Cornell University, Department of Physics, Ithaca, New York

In order to improve luminosity tuning and maintenance for the CLEO-c high energy physics (HEP) program at the Cornell Electron Storage Ring (CESR), a luminosity monitor using photons from radiative Bhabha events has been installed in the CESR ring. Over 10 meters of CESR vacuum chambers near the interaction region were modified to accommodate this new device. The vacuum modifications were designed to meet two criteria. First, the new vacuum chambers had to provide sufficient horizontal and vertical aperture for photons originating from the IP over a wide range of colliding beam conditions. Secondly, the new vacuum chambers required adequate safety margins for operation at beam energies up to 5.3 GeV for Cornell High Energy Synchrotron Source running. In order to be certain that the vacuum modifications would not give rise to any localized pressure bumps, a detailed calculation of the expected vacuum pressure distribution due to synchrotron radiation flux was carried out. Careful design and planning enabled a successful installation and resumption of CESR operations in record time.

• Y. Suetsugu, H. Hisamatsu, K.-I. Kanazawa, N. Ohuchi, K. Shibata, M. Shirai
  KEK, Ibaraki

• G.R. White, G.R. White
  SLAC, Menlo Park, California

The luminosity performance of the ILC will be very sensitive to the parameters of the colliding bunches. Only some of these parameters can be measured using planned instrumentation. This analysis aims to access some of the colliding beam parameters not available by other means and to improve on the resolution of those that are. GUINEA-PIG is used to simulate the beam-beam interactions and produce beamstrahlung radiation (e+/e^- pairs and photons). These are tracked to a simulation of the low-angle Beam Calorimeter and a photon detector and event shapes are produced. A Taylor map is produced to transform from the event shapes to the simulated beam parameters. This paper reports on the progress of this analysis, examining the usefulness of the proposed fitting technique.

• V. Bharadwaj, R. Pitthan, J. Sheppard, H. Vincke, J.W. Wang
  SLAC, Menlo Park, California

In an ILC positron source, multi-GeV electrons or multi-MeV photons impinge on a metal target. In either case, the incoming beam power is hundreds of kilowatts. Various computer programs - such as FLUKA or MARS – can calculate how the incoming beam showers in the target and can track the particle showers through the positron source system. The incoming energy ends up as heat in the various positron source elements. This paper presents results from such calculations and their impact on the design of a positron source for the ILC.

• N.V. Mokhov, A.I. Drozhdin, M.A. Kostin
  Fermilab, Batavia, Illinois

Synchrotron radiation, spray from the dumps and extraction lines, beam-gas and beam halo interactions with collimators and other components in the ILC beam delivery system create fluxes of muons and other secondaries which can exceed the tolerable levels at a detector by a few orders of magnitude. It is shown that with a multi-stage collimation system, magnetized iron spoilers which fill the tunnel and a set of masks in the detector, one can hopefully meet the design goals. Results of modeling with the STRUCT and MARS15 codes of beam loss and energy deposition effects are presented in this paper. We concentrate on collimation system and mask design and optimization, short- and long-term survivability of the critical components (spoilers, absorbers, magnets, separators, dumps), dynamic heat loads and radiation levels in magnets and other components, machine-related backgrounds and damage in collider detectors, and environmental aspects (prompt dose, ground-water and air activation).

• D. Kraemer
  BESSY GmbH, Berlin

The user requests for an optimized 2nd generation FEL facility in the VUV to soft X-ray range demand for ultra short photon pulses (t = 20 fs) at a peak power of several GW. A high shot to shot reproducibility of the pulse shape and pulse power allowing for fs-synchronization for pump-probe experiments is feasible in a seeded FEL approach. Free selectable photon polarization and wavelength tuning is essential for any 2nd generation FEL source like the proposed BESSY-Soft X-ray FEL user facility. Freely selectable pulse repetition rates and freely selectable pulse patterns, including fast switching to different parallel operating FEL-Lines are necessary ingredients, feasible with a suitable injector in combination with a CW-superconducting linac. The status of the BESSY HGHG-FEL project will be reviewed.

• B.X. Yang
  ANL, Argonne, Illinois

The Linac Coherent Light Source (LCLS) is a fourth-generation light. Its proper operation requires a stringently controlled undulator field. The tolerance for the field parameter K is less than 1.5 × 10^-4 for all thirty-three undulator segments totaling 112 meters. Even with the high quality of the LCLS electron beam (x- and y-emittance ~ 44 pm, energy spread ~0.03%), the fluctuation of the electron energy (~0.05%) presents a serious challenge to measurement techniques based on electron or x-ray beams. We propose a differential measurement technique that makes use of the angle-integrated spontaneous radiation intensities from two undulator segments. When the x-ray beams emitted from the two undulator segments are separated but allowed to pass through the same monochromator, the two beam intensities will change almost identically with the change of electron beam energy. As a result, the intensity difference becomes a very sensitive and reliable measure of the difference of the two undulators’ K-parameters. Results of comprehensive numerical simulations show that differences in the range of delta-K/K ~ 10^-5 can be resolved, well within the tolerance for the LCLS operation.

• M.J. Ferreira, R.O. Ferraz, H.G. Filho, M.B. Silva
  LNLS, Campinas

We present the design of the vacuum chamber for the LNLS 2 T Hybrid Wiggler. The chamber is a 3 m long, 1.2 mm thick 316 SS tube, which was mechanically pressed into an elliptical shape from an originally round tube. In order to provide the necessary mechanical tolerances, the rather flexible tube is welded to lateral supports that run the complete length of the chamber. Special care has been given to the mechanical and magnetic characterization of the chamber and the inner surface of the chamber was NEG-coated at the ESRF. We present the installation procedure as well the vacuum conditioning charge evolution.

• C. Thongbai, V. Jinamoon, Mr. Kangrang, K. Kusoljariyakul, S. Rimjaem, J. Saisut, T. Vilaithong
  FNRF, Chiang Mai
• M.W. Rhodes, P. Wichaisirimongkol
  IST, Chiang Mai
• H. Wiedemann
  SLAC, Menlo Park, California

Femtosecond electron and photon pulses become a tool of interesting important to study dynamics at molecular or atomic levels. Such short pulses can be generated from a system consisting of an RF-gun with a thermionic cathode, an alpha magnet as a magnetic bunch compressor, and a linear accelerator. The femtosecond electron pulses can be used directly or used as sources to produce electromagnetic radiation of equally short pulses by choosing certain kind of radiation pruduction processes. At the Fast Neutron Research Facility (Thailand), we are especially interested in production of radiation in Far-infrared and X-ray regime. In the far-infrared wavelengths which are longer than the femtosecond pulse length, the radiation is emitted coherently producing intense radiation. In the X-ray regime, development of femtosecond X-ray source is crucial for application in ultrafast science.

• D. Dohan
  ANL, Argonne, Illinois

This paper presents a pragmatic global approach to data modeling a complex facility such as a particle accelerator. By successively partitioning the facility into collaborating subsystems, one eventually arrives at the component level–the point at which the subsystem is replaceable as a single unit. The fundamental goal of the model is to capture the dynamical relationships (i.e., the connections) that exist among the accelerator components. Components participate in one or more of three connection types: control, housing, and power. These connections are captured in a multi-hierarchical model capable of handling any component of the accelerator, from the macro scale (magnets, power supplies, racks, etc.) to the embedded scale (circuit board components), if desired. The connection approach has been used to model the signal flows between the component via their port connections. The result is a schema for a cable database that provides end-to-end signal tracing throughout the facility. The paper will discuss the multi-hierarchy nature of the model and its success in replacing the "Revision Controlled Drawing" approach to system documentation.

• Y. Liu, J.R. Beene, C.C. Havener, J. F. Liang
  ORNL, Oak Ridge, Tennessee
• A.C. Havener
  University of Tennessee, Knoxville, Tennessee

A novel method is described for selective suppression of isobar contaminants in negative radioactive ion beams. Negative ion beams extracted from an ion source were decelerated to low energies and injected into a gas-filled radio-frequency quadrupole (RFQ) ion guide where the ions were cooled and unwanted ions were selectively removed by non-resonant photodetachment with photons of sufficient energy. Simulation studies show that the laser-ion interaction time in a 40 cm long RFQ ion guide can be on the order of milliseconds, thus, high efficiency photodetachment is possible with commercially available CW lasers. There are a number of adjacent-Z species whose negative ions are such that photodetachment can be used to suppress the unwanted negative ion species while leaving the species of interest intact. Examples of particular interest include suppressing the 56Co- component in a mixed 56Ni- + 56Co- beam and the 17O- component in a mixed 17O- + 17F- beam. In a proof–of-principle experiment a CW Nd:YAG laser at 1064 nm wavelength was used to selectively remove Co- ions in the (Ni, Co) pair. With laser power on the order of 3 W, 95% of Co- beams were suppressed while only 10% of Ni- beams were neutralized in a He-filled RFQ guide.

• C. Vaccarezza, R. Cimino
  INFN/LNF, Frascati (Roma)
• A. Giglia, N. Mahne
  ELETTRA, Basovizza, Trieste
• S. Nannarone
  UNIMORE, Modena

• R. Soliday
  ANL, Argonne, Illinois

A new Tcl/Tk widget has been created to display MEDM screens inside a Tcl/Tk application. Tcl/Tk parses the MEDM input files and the appropriate widgets are created and linked to the associated process variables. One advantage of this approach is that an X-Windows emulator is not required to view and manipulate the MEDM screen under a Windows operating system. Another benefit is that the MEDM screen can now be tightly integrated into a scripting language to attach higher-level logic to various process variable manipulations. Further details and examples of the new widget will be discussed.

• R. Soliday, M. Borland
  ANL, Argonne, Illinois

Using sddspcas, a portable channel access server that is configured by SDDS input files, it is relatively simple to create process variables (PVs). It can be run in a standalone mode or it can be run so that the PVs are checked to ensure that they don’t conflict with other IOCs or portable channel access servers. It can also be run using the Run Control facility to prevent additional instances of the same sddspcas from being run. The SDDS configuration file provides the PV names, upper and lower limits, units, element counts if the PVs are waveforms, and the types of PVs. Valid types include various precision floats and integers as well as strings. One simple application of this program is that software developers can quickly test their code without requiring the coordination needed to update an IOC database to create PVs. Further details of the features, configuration, and applications of sddspcas will be discussed.

• K. Evans, M. Smith
  ANL, Argonne, Illinois

The EPICS PV Gateway has become a stable, high-performance application that provides access to process variables while minimizing the impact on critical IOCs and implementing additional access security. The additional access security typically prevents write access but is highly configurable. The Advanced Photon Source (APS) currently uses 40 Gateways running on 11 machines to provide access to the machine network from the offices and for the individual experimental teams. These include reverse Gateways that allow administration of all 40 APS Gateways from a single MEDM screen, even though the Gateways are running on separate networks. This administration includes starting, stopping, making and viewing reports, and viewing and editing access security files. There is one Gateway that provides process variable renaming. This paper provides an overview of the Gateways at the APS and describes the procedures that have been set up to use and administer them.

• G. Liu, X. Bao, C. Li, W. Li, J. Wang, Xie. Xie, K. Xuan
  USTC/NSRL, Hefei, Anhui
• J. Li
  DU/FEL, Durham, North Carolina

• G.J. Portmann
  LBNL, Berkeley, California
• W.J. Corbett, A. Terebilo
  SLAC, Menlo Park, California

Matlab is a matrix manipulation language originally developed to be a convenient language for using the LINPACK and EISPACK libraries. What makes Matlab so appealing for accelerator physics is the combination of a matrix oriented programming language, an active workspace for system variables, powerful graphics capability, built-in math libraries, and platform independence. A number of software toolboxes for accelerators have been written in Matlab – the Accelerator Toolbox (AT) for machine simulations, LOCO for accelerator calibration, Matlab Channel Access Toolbox (MCA) for EPICS connections, and the Middle Layer. This paper will describe the MiddleLayer software toolbox that resides between the high-level control applications and the low-level accelerator control system. This software was a collaborative effort between ALS and Spear but was written to easily port. Five accelerators presently use this software – Spear, ALS, CLS, and the X-ray and VUV rings at Brookhaven. The Middle Layer functionality includes energy ramp, configuration control, global orbit correction, local beam steering, insertion device compensation, beam-based alignment, tune correction, response matrices, and script-based physics studies.

• S.P. Karasyov, A.N. Dovbnja, L. Eran, Y.P. Melnik, Y. Ran'iuk, I.N. Shlyakhov
  NSC/KIPT, Kharkov
• A.J. Baratta
  Penn State University, University Park, Pennsylvania
• N.M. Kiryukhin
  ATSU, Kiev
• S.V. Trubnikov
  KhNU, Kharkov

A new concept for a two-step facility to increase the accuracy/reliability of detecting heavily shielded fissionable materials (FM) in marine containers is presented. The facility will detect FM in two steps. An existing dual-view; dual-energy X-ray scanner, which is based on 7 MeV electron accelerator, will select the suspicious places inside container. The linac with variable energy (up to 100 MeV) will be used for the second step. The technology will detect fissionable nuclei by gamma induced fission reactions and delayed neutron registration. A little-known Ukrainian experimental data obtained in Chernobil’ clean-up program will be presented to ground proposed concept. The theoretical calculations of neutron fluxes scale these results to marine container size. Modified GEANT code for electron/gamma penetration and authors’ own software for neutron yield/penetration are used for these calculations. Available facilities (X-ray scanners; linac; detectors), which will be used for concept proof, are described. The results of the first experiments by use variable energy linac are cited.