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Sample records for 8-gev h linac

  1. CERN's Linac4 cesiated surface H- source

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Aguglia, D.; Bertolo, S.; Briefi, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; David, N.; Chaudet, E.; Fantz, U.; Fink, D.; Garlasche, M.; Grudiev, A.; Guida, R.; Hansen, J.; Haase, M.; Hatayama, A.; Jones, A.; Kalvas, T.; Koszar, I.; Lallement, J.-B.; Lombardi, A.; di Lorenzo, F.; Machado, C.; Mastrostefano, C.; Mathot, S.; Mattei, S.; Moyret, P.; Nishida, K.; O'Neil, M.; Paoluzzi, M.; Raich, U.; Roncarolo, F.; Scrivens, R.; Steyaert, D.; Thaus, N.; Voulgarakis, G.

    2017-08-01

    Linac4 cesiated surface H- sources are routinely operated for the commissioning of the CERN's Linac4 and on an ion source test stand. Stable current of 40-50 mA are achieved but the transmission through the LEBT of 80% was below expectations and triggered additional beam simulation and characterization. The H- beam profile is not Gaussian and emittance measurements are larger than simulation. The status of ongoing development work is described; 36 mA H- and 20 mA D- beams were produced with a 5.5 mm aperture cesiated surface ion source. The emittances measured at the test stand are presented. During a preliminary test, the Linac4 proton source delivered a total beam intensity of 70 mA (p, H2+, H3+).

  2. H- ion sources for CERN's Linac4

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Aguglia, D.; Coutron, Y.; Chaudet, E.; Dallocchio, A.; Gil Flores, J.; Hansen, J.; Mahner, E.; Mathot, S.; Mattei, S.; Midttun, O.; Moyret, P.; Nisbet, D.; O'Neil, M.; Paoluzzi, M.; Pasquino, C.; Pereira, H.; Arias, J. Sanchez; Schmitzer, C.; Scrivens, R.; Steyaert, D.

    2013-02-01

    The specifications set to the Linac4 ion source are: H- ion pulses of 0.5 ms duration, 80 mA intensity and 45 keV energy within a normalized emittance of 0.25 mmmrad RMS at a repetition rate of 2 Hz. In 2010, during the commissioning of a prototype based on H- production from the plasma volume, it was observed that the powerful co-extracted electron beam inherent to this type of ion source could destroy its electron beam dump well before reaching nominal parameters. However, the same source was able to provide 80 mA of protons mixed with a small fraction of H2+ and H3+ molecular ions. The commissioning of the radio frequency quadrupole accelerator (RFQ), beam chopper and H- beam diagnostics of the Linac4 are scheduled for 2012 and its final installation in the underground building is to start in 2013. Therefore, a crash program was launched in 2010 and reviewed in 2011 aiming at keeping the original Linac4 schedule with the following deliverables: Design and production of a volume ion source prototype suitable for 20-30 mA H- and 80 mA proton pulses at 45 keV by mid-2012. This first prototype will be dedicated to the commissioning of the low energy components of the Linac4. Design and production of a second prototype suitable for 40-50 mA H- based on an external RF solenoid plasma heating and cesiated-surface production mechanism in 2013 and a third prototype based on BNL's Magnetron aiming at reliable 2 Hz and 80 mA H- operations in 2014. In order to ease the future maintenance and allow operation with Ion sources based on three different production principles, an ion source "front end" providing alignment features, pulsed gas injection, pumping units, beam tuning capabilities and pulsed bipolar high voltage acceleration was designed and is being produced. This paper describes the progress of the Linac4 ion source program, the design of the Front end and first ion source prototype. Preliminary results of the summer 2012 commissioning are presented. The outlook on

  3. Crossbar H-mode drift-tube linac design with alternative phase focusing for muon linac

    NASA Astrophysics Data System (ADS)

    Otani, M.; Futatsukawa, K.; Hasegawa, K.; Kitamura, R.; Kondo, Y.; Kurennoy, S.

    2017-07-01

    We have developed a Crossbar H-mode (CH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The CH-DTL accelerates muons from β = v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. The design and results are described in this paper.

  4. Interdigital H -mode drift-tube linac design with alternative phase focusing for muon linac

    NASA Astrophysics Data System (ADS)

    Otani, M.; Mibe, T.; Yoshida, M.; Hasegawa, K.; Kondo, Y.; Hayashizaki, N.; Iwashita, Y.; Iwata, Y.; Kitamura, R.; Saito, N.

    2016-04-01

    We have developed an interdigital H-mode (IH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The IH-DTL accelerates muons from β =v /c =0.08 to 0.28 at an operational frequency of 324 MHz. The output beam emittances are calculated as 0.315 π and 0.195 π mm mrad in the horizontal and vertical directions, respectively, which satisfies the experimental requirement.

  5. H- AND PROTON BEAM LOSS COMPARISON AT SNS SUPERCONDUCTING LINAC

    SciTech Connect

    Aleksandrov, Alexander V; Galambos, John D; Plum, Michael A; Shishlo, Andrei P

    2012-01-01

    A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H- and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H- + H- -> H- + H0 + e is presented. Earlier, a short description of these studies was presented in [1].

  6. Experimental investigation of plasma impedance in Linac4 H- source

    NASA Astrophysics Data System (ADS)

    Nishida, K.; Mattei, S.; Briefi, S.; Butterworth, A.; Grudiev, A.; Haase, M.; Jones, A.; Paoluzzi, M. M.; Voulgarakis, G.; Hatayama, A.; Lettry, J.

    2017-08-01

    CERN 's new particle accelerator Linac4 is part of the upgrade of the LHC accelerator chain. Linac4 is required to deliver 160 MeV H- beam to improve the beam brightness and luminosity in the Large Hadron Collider (LHC). The Linac4 H- source must deliver 40-50 mA, 45 keV H- beam in the RFQ acceptance. Since the RF power coupled to the H- source plasma is one of the important parameters that determines the quality of the H- beam, the experimental investigation of the dependence of the load impedance on the operational parameters is mandatory. In this study, we have measured the impedance of the H- source plasma varying the RF power coupled to the plasma and the condition of the hydrogen gas. Also, optical emission spectroscopy (OES) measurements have been carried out simultaneously with the impedance measurement in order to determine the plasma parameters. The determination of the plasma parameters allows us to compare the experimental results with the analytic model of the plasma parameters, which is useful to discuss the results from a physical point of view.

  7. Conversion of the AGS linac to H/sup -/ acceleration

    SciTech Connect

    Witkover, R.L.; Barton, D.S.; Reece, R.K.

    1983-01-01

    The AGS 200 MeV linac was converted to an H/sup -/ accelerator during the summer of 1982 using a magnetron-type source in the column of the second pre-injector pit. Because of the re-entrant electrode design, a 20 keV transport line was required to carry the beam to the first electrode. Several changes were made to the source which enhanced its performance over previous designs. The same H/sup -/ beam current is available at 2.75 times the duty factor with reduced deterioration of its output over several months of operation. The source, 750 keV transport, and linac modifications and performance will be presented.

  8. Autopilot regulation for the Linac4 H- ion source

    NASA Astrophysics Data System (ADS)

    Voulgarakis, G.; Lettry, J.; Mattei, S.; Lefort, B.; Costa, V. J. Correia

    2017-08-01

    Linac4 is a 160 MeV H- linear accelerator part of the upgrade of the LHC injector chain. Its cesiated surface H- source is designed to provide a beam intensity of 40-50mA. It is operated with periodical Cs-injection at typically 30 days intervals [1] and this implies that the beam parameters will slowly evolve during operation. Autopilot is a control software package extending CERN developed Inspector framework. The aim of Autopilot is to automatize the mandatory optimization and cesiation processes and to derive performance indicators, thus keeping human intervention minimal. Autopilot has been developed by capitalizing on the experience from manually operating the source. It comprises various algorithms running in real-time, which have been devised to: • Optimize the ion source performance by regulation of H2 injection, RF power and frequency. • Describe the performance of the source with performance indicators, which can be easily understood by operators. • Identify failures, try to recover the nominal operation and send warning in case of deviation from nominal operation. • Make the performance indicators remotely available through Web pages.Autopilot is at the same level of hierarchy as an operator, in the CERN infrastructure. This allows the combination of all ion source devices, providing the required flexibility. Autopilot is executed in a dedicated server, ensuring unique and centralized control, yet allowing multiple operators to interact at runtime, always coordinating between them. Autopilot aims at flexibility, adaptability, portability and scalability, and can be extended to other components of CERN's accelerators. In this paper, a detailed description of the Autopilot algorithms is presented, along with first results of operating the Linac4 H- Ion Source with Autopilot.

  9. Linac4 H{sup −} ion sources

    SciTech Connect

    Lettry, J. Aguglia, D.; Andersson, P.; Bertolo, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; David, N.; Chaudet, E.; Fink, D. A.; Garlasche, M.; Grudiev, A.; Guida, R.; Hansen, J.; Haase, M.; Jones, A.; Koszar, I.; Lallement, J.-B.; Lombardi, A. M.; Machado, C.; and others

    2016-02-15

    CERN’s 160 MeV H{sup −} linear accelerator (Linac4) is a key constituent of the injector chain upgrade of the Large Hadron Collider that is being installed and commissioned. A cesiated surface ion source prototype is being tested and has delivered a beam intensity of 45 mA within an emittance of 0.3 π ⋅ mm ⋅ mrad. The optimum ratio of the co-extracted electron- to ion-current is below 1 and the best production efficiency, defined as the ratio of the beam current to the 2 MHz RF-power transmitted to the plasma, reached 1.1 mA/kW. The H{sup −} source prototype and the first tests of the new ion source optics, electron-dump, and front end developed to minimize the beam emittance are presented. A temperature regulated magnetron H{sup −} source developed by the Brookhaven National Laboratory was built at CERN. The first tests of the magnetron operated at 0.8 Hz repetition rate are described.

  10. Neutron H*(10) estimation and measurements around 18MV linac.

    PubMed

    Cerón Ramírez, Pablo Víctor; Díaz Góngora, José Antonio Irán; Paredes Gutiérrez, Lydia Concepción; Rivera Montalvo, Teodoro; Vega Carrillo, Héctor René

    2016-11-01

    Thermoluminescent dosimetry, analytical techniques and Monte Carlo calculations were used to estimate the dose of neutron radiation in a treatment room with a linear electron accelerator of 18MV. Measurements were carried out through neutron ambient dose monitors which include pairs of thermoluminescent dosimeters TLD 600 ((6)LiF: Mg, Ti) and TLD 700 ((7)LiF: Mg, Ti), which were placed inside a paraffin spheres. The measurements has allowed to use NCRP 151 equations, these expressions are useful to find relevant dosimetric quantities. In addition, photoneutrons produced by linac head were calculated through MCNPX code taking into account the geometry and composition of the linac head principal parts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Beam physics of the 8-GeV H-minus linac

    SciTech Connect

    Carneiro, J.-P.; Mustapha, B.; Ostroumov, P.N.; /Argonne

    2008-11-01

    Fermilab is developing the concept and design of an 8-GeV superconducting H-minus linac with the primary mission of increasing the intensity of the Main Injector for the production of neutrino superbeams. The front-end of the linac up to 420 MeV operates at 325 MHz and accelerates beam from the ion source using a room temperature radio-frequency quadrupole followed by short CH type resonators and superconducting spoke resonators. In the high energy section, the acceleration is provided by the International Linear Collider (ILC)-style superconducting elliptical 1.3 GHz cavities. The beam physics for the linac is presented in this paper using two beam dynamics codes: TRACK and ASTRA.

  12. Beam physics of the 8-GeV H-minus linac.

    SciTech Connect

    Carneiro, J.-P.; Ostroumov, P. N.; Mustapha, B.; Physics; FNAL

    2009-07-21

    Fermilab is developing the concept and design of an 8-GeV superconducting H{sup -} linac with the primary mission of increasing the intensity of the Main Injector for the production of neutrino superbeams. The front-end of the linac up to 420 MeV operates at 325 MHz and accelerates the beam from the ion source using a room temperature radio-frequency quadrupole followed by short CH type resonators and superconducting spoke resonators. In the high-energy section, the acceleration is provided by superconducting elliptical 1.3 GHz cavities similar to the ones developed for the International Linear Collider (ILC). The beam physics for the linac is presented in this paper using two beam dynamics codes: TRACK and ASTRA.

  13. Optimization of the beam extraction systems for the Linac4 H{sup −} ion source

    SciTech Connect

    Fink, D. A.; Lettry, J.; Scrivens, R.; Steyaert, D.; Midttun, Ø.; Valerio-Lizarraga, C. A.

    2015-04-08

    The development of the Linac 4 and its integration into CERN’s acceleration complex is part of the foreseen luminosity upgrade of the Large Hadron Collider (LHC). The goal is to inject a 160 MeV H{sup −} beam into the CERN PS Booster (PSB) in order to increase the beam brightness by a factor of 2 compared to the 50 MeV proton linac, Linac 2, that is currently in operation. The requirements for the ion source are a 45 keV H{sup −} beam of 80 mA intensity, 2 Hz repetition rate and 0.5 ms pulse length within a normalized rms-emittance of 0.25 mm· mrad. The previously installed beam extraction system has been designed for an H{sup −} ion beam intensity of 20 mA produced by an RF-volume source with an electron to H{sup −} ratio of up to 50. For the required intensity upgrades of the Linac4 ion source, a new beam extraction system is being produced and tested; it is optimized for a cesiated surface RF-source with a nominal beam current of 40 mA and an electron to H{sup −} ratio of 4. The simulations, based on the IBSIMU code, are presented. At the Brookhaven National Laboratory (BNL), a peak beam current of more than 100 mA was demonstrated with a magnetron H{sup −} source at an energy of 35 keV and a repetition rate of 2 Hz. A new extraction system is required to operate at an energy of 45 keV; simulation of a two stage extraction system dedicated to the magnetron is presented.

  14. CERN’s Linac4 H{sup −} sources: Status and operational results

    SciTech Connect

    Lettry, J. Aguglia, D.; Andersson, P.; Bertolo, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; David, N.; Chaudet, E.; Fink, D.; Gil-Flores, J.; Garlasche, M.; Grudiev, A.; Guida, R.; Hansen, J.; Haase, M.; Jones, A.; Koszar, I.; Machado, C.; Mastrostefano, C.; and others

    2015-04-08

    Two volume sources equipped with DESY and CERN plasma generators and a low voltage electron dump were operated at 45 kV in the Linac4 tunnel and on a dedicated test stand. These volume sources delivered approximately 20 mA and ensured the commissioning of the Radio Frequency Quadrupole accelerator and of the first section of the Drift Tube Linac. CERN’s prototype of a cesiated surface source equipped with this electron dump was operated continuously from November 2013 to April 2014 on the ion source test stand and is being commissioned in the Linac4 tunnel. Before cesiation, the prototype conditioned in volume mode provided up to 30 mA H{sup −} beam. Short cesiations, of the order of 10 mg effectively reduced the intensity of co-extracted electrons down to 2 - 8 times the H{sup −} current; this cesiated surface operation mode delivered up to 60 mA H{sup −} beam. An H{sup −} beam of the order of 40 mA was sustained up to four weeks operation with 500 μs pulses at 1.2s spacing. A new extraction was designed to match these beam properties. A copy of BNL’s magnetron produced at CERN was tested at BNL and delivered at 40 kV H{sup −} beam exceeding Linac4’s nominal intensity of 80 mA. In this contribution, the performances, dynamic response to cesiation, stability and availability of these prototypes are described. The needed optimization of the emittance of H{sup −} beam above 40 mA is presented, which requires an evolution of the front end that encompasses implementation of a large ceramic insulator.

  15. Matching the laser generated p bunch into a crossbar-H drift tube linac

    NASA Astrophysics Data System (ADS)

    Almomani, A.; Droba, M.; Ratzinger, U.; Hofmann, I.

    2012-05-01

    Proton bunches with energies up to 30 MeV have been measured at the PHELIX laser. Because of the laser-plasma interactions at a power density of about 4×1019W/cm2, a total yield of 1.5×1013protons was produced. For the reference energy of 10 MeV, the yield within ±0.5MeV was exceeding 1010protons. The important topic for a further acceleration of the laser generated bunch is the matching into the acceptance of an rf accelerator stage. With respect to the high space charge forces and the transit energy range, only drift tube linacs seem adequate for this purpose. A crossbar H-type (CH) cavity was chosen as the linac structure. Optimum emittance values for the linac injection are compared with the available laser generated beam parameters. Options for beam matching into a CH structure by a pulsed magnetic solenoid and by using the simulation codes LASIN and LORASR are presented.

  16. H- Beam Loss and Evidence for Intrabeam Stripping in the LANSCE Linac

    SciTech Connect

    Rybarcyk, Lawrence J.; Kelsey, Charles T. IV; McCrady, Rodney C.; Pang, Xiaoying

    2012-05-15

    The LANSCE accelerator complex is a multi-beam, multi-user facility that provides high-intensity H{sup +} and H{sup -} particle beams for a variety of user programs. At the heart of the facility is a room temperature linac that is comprised of 100-MeV drift tube and 800-MeV coupled cavity linac (CCL) structures. Although both beams are similar in intensity and emittance at 100 MeV, the beam-loss monitors along the CCL show a trend of increased loss for H{sup -} that is not present for H{sup +}. This difference is attributed to stripping mechanisms that affect H{sup -} and not H{sup +}. We present the results of an analysis of H{sup -} beam loss along the CCL that incorporates beam spill measurements, beam dynamics simulations, analytical models and radiation transport estimates using the MCNPX code. The results indicate a significant fraction of these additional losses result from intrabeam stripping.

  17. Gas injection and fast pressure-rise measurements for the Linac4 H- source

    NASA Astrophysics Data System (ADS)

    Mahner, E.; Chiggiato, P.; Lettry, J.; Mattei, S.; O'Neil, M.; Neupert, H.; Pasquino, C.; Schmitzer, C.

    2013-02-01

    In the era of the Large Hadron Collider, the CERN injector complex comprising the 34 years old Linac2 with its primary proton source, is presently upgraded with a new linear accelerator for H- (Linac4). The design, construction, and test of volume production and cesiated RF-driven H- ion sources is presently ongoing with the final goal of producing an H- beam with 80 mA beam current, 45 keV beam energy, 500 μs pulse length, and a repetition rate of 2 Hz. In order to have quantitative information of the hydrogen gas density at the moment of plasma ignition the dynamic vacuum properties of the plasma generator were studied experimentally. We describe the experimental setup and present fast pressure-rise measurements for different parameters of the gas injection system, such as gas species (H2, He, N2, Ar), piezo valve voltage pulse length (200 - 500 μs), and injection pressure (400 - 2800 mbar). The obtained data are compared with a conductance model of the plasma generator.

  18. The BNL 200 MeV H sup minus linac: Performance and upgrades

    SciTech Connect

    Alessi, J.G.; Brennan, J.M.; Kponou, A.; LoDestro, V.; Montemurro, P.A.

    1990-01-01

    For the past two years the linac has had reliable operation from the new RFQ preinjector. The performance of this preinjector is described. There is a fast beam chopper in the transport line between the ion source and RFQ. By injecting narrow pulses into the AGS we can obtain an accurate linac energy measurement, or the detailed shape of the linac beam energy distribution, on a single pulse. Some general comment on the linac operation are also presented.

  19. RF low-level control for the Linac4 H{sup −} source

    SciTech Connect

    Butterworth, A. Grudiev, A.; Lettry, J.; Paoluzzi, M.; Schmitzer, C.; Nishida, K.

    2015-04-08

    The H{sup −} source for the Linac4 accelerator at CERN uses an RF driven plasma for the production of H{sup −}. The RF is supplied by a 2 MHz RF tube amplifier with a maximum power output of 100 kW and a pulse duration of up to 2 ms. The low-level RF signal generation and measurement system has been developed using standard CERN controls electronics in the VME form factor. The RF frequency and amplitude reference signals are generated using separate arbitrary waveform generator channels. The frequency and amplitude are both freely programmable over the duration of the RF pulse, which allows fine-tuning of the excitation. Measurements of the forward and reverse RF power signals are performed via directional couplers using high-speed digitizers, and permit the estimation of the plasma impedance and deposited power via an equivalent circuit model. The low-level RF hardware and software implementations are described, and experimental results obtained with the Linac4 ion sources in the test stand are presented.

  20. RF low-level control for the Linac4 H- source

    NASA Astrophysics Data System (ADS)

    Butterworth, A.; Grudiev, A.; Lettry, J.; Nishida, K.; Paoluzzi, M.; Schmitzer, C.

    2015-04-01

    The H- source for the Linac4 accelerator at CERN uses an RF driven plasma for the production of H-. The RF is supplied by a 2 MHz RF tube amplifier with a maximum power output of 100 kW and a pulse duration of up to 2 ms. The low-level RF signal generation and measurement system has been developed using standard CERN controls electronics in the VME form factor. The RF frequency and amplitude reference signals are generated using separate arbitrary waveform generator channels. The frequency and amplitude are both freely programmable over the duration of the RF pulse, which allows fine-tuning of the excitation. Measurements of the forward and reverse RF power signals are performed via directional couplers using high-speed digitizers, and permit the estimation of the plasma impedance and deposited power via an equivalent circuit model. The low-level RF hardware and software implementations are described, and experimental results obtained with the Linac4 ion sources in the test stand are presented.

  1. Performance of the SSC H{sup {minus}} rf volume ion source and linac injector

    SciTech Connect

    Saadatmand, K.; Hebert, J.E.; Okay, N.C.

    1993-09-01

    The Superconducting Super Collider (SSC) ion source is required to provide a 30-mA H{sup {minus}} beam at 35 keV with a normalized rms emittance ({var_epsilon}{sub n-rms}) of less than 0.18 {pi} mm-mrad. An rf-driven volume source was chosen for the commissioning of the SSC linear accelerator (Linac). The divergent ion source output beam is matched into the Radio Frequency Quadrupole accelerator (RFQ) by an electrostatic Low Energy Beam Transport (LEBT). The SSC Linac Injector (consisting of ion source, LEBT, and RFQ) is required to provide 25 mA of H{sup {minus}} beam (pulse width of 9.6--48 {mu}s at 10-Hz repetition rate) at 2.5 MeV with transverse normalized rms emittance ({var_epsilon}{sub t-n-rms}) of less than 0.2 {pi} mm-mrad and longitudinal normalized rms emittance ({var_epsilon}1) of less than 0.82*10{sup {minus}6} eV-s. The performance of our rf volume source and initial experimental results from the SSC Injector are discussed.

  2. Determination of discharge parameters via OES at the Linac4 H- ion source

    NASA Astrophysics Data System (ADS)

    Briefi, S.; Fink, D.; Mattei, S.; Lettry, J.; Fantz, U.

    2016-02-01

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (Te ≈ 1.2 eV, ne ≈ 1 × 1019 m-3, and nH/nH2 ≈ 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal "hockey-stick" rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients.

  3. Numerical simulation of the RF plasma discharge in the Linac4 H- ion source

    NASA Astrophysics Data System (ADS)

    Mattei, S.; Nishida, K.; Onai, M.; Lettry, J.; Tran, M. Q.; Hatayama, A.

    2017-08-01

    This paper presents a Particle-In-Cell Monte Carlo Collision simulation of the Radio-Frequency (RF) plasma heating in the Linac4 H- ion source at CERN. The model self-consistently takes into account the electromagnetic field generated by the RF coil, the external static magnetic fields and the resulting plasma response, including a kinetic description of the charged species (e-, H+, H2-, H3+, H-), as well as the atomic and molecular (vibrationally resolved) populations. The simulation is performed for the nominal operational condition of 40 kW RF power and 3 Pa H2 pressure. Results show that the plasma spatial distribution is non-uniform in the plasma chamber, with a density peak of ne = 5 . 1019 m-3 in the RF coil region. In the filter field region the electron density drops by two orders of magnitude, with a substantial reduction of the electron energy as well. This results in a ratio e/H- ≈ 1 in the extraction region. The vibrational population is characterized by a two temperature distribution, with the high vibrational states showing a factor 2 higher termperature. A very good agreement is found between the simulation results and optical emission spectroscopy measurement performed on a dedicated test stand at CERN.

  4. Plasma ignition and steady state simulations of the Linac4 H{sup −} ion source

    SciTech Connect

    Mattei, S. Lettry, J.; Grudiev, A.; Ohta, M.; Yasumoto, M.; Hatayama, A.

    2014-02-15

    The RF heating of the plasma in the Linac4 H{sup −} ion source has been simulated using a particle-in-cell Monte Carlo collision method. This model is applied to investigate the plasma formation starting from an initial low electron density of 10{sup 12} m{sup −3} and its stabilization at 10{sup 18} m{sup −3}. The plasma discharge at low electron density is driven by the capacitive coupling with the electric field generated by the antenna, and as the electron density increases the capacitive electric field is shielded by the plasma and induction drives the plasma heating process. Plasma properties such as e{sup −}/ion densities and energies, sheath formation, and shielding effect are presented and provide insight to the plasma properties of the hydrogen plasma.

  5. Influence of the cusp field on the plasma parameters of the Linac4 H- ion source

    NASA Astrophysics Data System (ADS)

    Briefi, S.; Mattei, S.; Lettry, J.; Fantz, U.

    2017-08-01

    When the H- ion source of CERN's Linac4 is operated in volume mode, a maximum of the extracted current is obtained at varying RF power. The power required for this maximum and its absolute value is strongly influenced by the cusp magnets installed at the source for electron confinement: without magnets, 15-20 mA are typically obtained at 20 kW whereas with magnets a factor of two more power is needed and 25-30 mA are achieved. In order to access the reasons behind the peaked performance with varying RF power and for determining the influence of the cusp field on the discharge, optical emission spectroscopy (OES) measurements of the atomic Balmer series and of the molecular Fulcher transition have been carried out. In all investigated cases, the gas temperature of the discharge has been virtually equal to the ambient temperature as the short discharge pulse length of 500 µs is not long enough for considerable heavy particle heating. When no cusp magnets are installed, the plasma parameters evaluated with the collisional radiative models Yacora H and Yacora H2 show a minimum in the electron temperature of 3.25 eV and a maximum in the electron density of 4×1019 m-3 and also in the vibrational excitation of the hydrogen molecule at 20 kW. Assessing the relevant production and destruction processes demonstrates that the H- yield is maximal at this point thereby explaining the optimum ion source performance. When the cusp magnets are applied, the same general trends are observed but the required RF power is a factor of two higher. The OES results indicate an optimum performance around 30 kW whereas the highest H- current is actually achieved around 40 kW. Furthermore, a higher H- yield is indicated without cusp magnets but a better ion source performance is observed with magnets. These differences can most likely be attributed to changing gradients in the plasma parameters which are not accessible by OES. Nevertheless, the obtained plasma parameters can be used as

  6. Stripping of H- beams by residual gas in the linac at the Los Alamos neutron science center

    SciTech Connect

    Mccrady, Rodney C; Ito, Takeyasu; Cooper, Martin D; Alexander, Saunders

    2010-09-07

    The linear accelerator at the Los Alamos Neutron Science Center (LANSCE) accelerates both protons and H{sup -} ions using Cockroft-Walton-type injectors, a drift-tube linac and a coupled-cavity linac. The vacuum is maintained in the range of 10{sup -6} to 10{sup -7} Torr; the residual gas in the vacuum system results in some stripping of the electrons from the H{sup -} ions resulting in beam spill and the potential for unwanted proton beams delivered to experiments. We have measured the amount of fully-stripped H{sup -} beam (protons) that end up at approximately 800 MeV in the beam switchyard at LANSCE using image plates as very sensitive detectors. We present here the motivation for the measurement, the measurement technique and results.

  7. Determination of discharge parameters via OES at the Linac4 H{sup −} ion source

    SciTech Connect

    Briefi, S.; Fink, D.; Mattei, S.; Lettry, J.; Fantz, U.

    2016-02-15

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (T{sub e} ≈ 1.2 eV, n{sub e} ≈ 1 × 10{sup 19} m{sup −3}, and n{sub H}/n{sub H{sub 2}} ≈ 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal “hockey-stick” rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients.

  8. CSNS LINAC DESIGN

    SciTech Connect

    FU, S.; FANG, S.; WEI, J.

    2006-08-21

    China Spallation Neutron Source has been approved in principle by the Chinese government. CSNS can provide a beam power of 100kW on the target in the first phase, and then 200kW in the second phase. The accelerator complex of CSNS consists of an H- linac of 81MeV and a rapid cycling synchrotron of 1.6GeV at 25Hz repetition rate. In the second phase, the linac energy will be upgraded to 132MeV and the average current will be doubled. The linac has been designed, and some R&D studies have started under the support from Chinese Academy of Sciences. The linac comprises a H- ion source, an RFQ and a conventional DTL with EMQs. This paper will present our major design results and some progresses in the R&D of the linac.

  9. Modeling of neutrals in the Linac4 H(-) ion source plasma: hydrogen atom production density profile and Hα intensity by collisional radiative model.

    PubMed

    Yamamoto, T; Shibata, T; Ohta, M; Yasumoto, M; Nishida, K; Hatayama, A; Mattei, S; Lettry, J; Sawada, K; Fantz, U

    2014-02-01

    To control the H(0) atom production profile in the H(-) ion sources is one of the important issues for the efficient and uniform surface H(-) production. The purpose of this study is to construct a collisional radiative (CR) model to calculate the effective production rate of H(0) atoms from H2 molecules in the model geometry of the radio-frequency (RF) H(-) ion source for Linac4 accelerator. In order to validate the CR model by comparison with the experimental results from the optical emission spectroscopy, it is also necessary for the model to calculate Balmer photon emission rate in the source. As a basic test of the model, the time evolutions of H(0) production and the Balmer Hα photon emission rate are calculated for given electron energy distribution functions in the Linac4 RF H(-) ion source. Reasonable test results are obtained and basis for the detailed comparisons with experimental results have been established.

  10. Status of the RF-driven H{sup −} ion source for J-PARC linac

    SciTech Connect

    Oguri, H. Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Ueno, A.; Shibata, T.

    2016-02-15

    For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then.

  11. Compact injector with alternating phase focusing-interdigital H-mode linac and superconducting electron cyclotron resonance ion source for heavy ion cancer therapy

    NASA Astrophysics Data System (ADS)

    Hayashizaki, Noriyosu; Hattori, Toshiyuki; Matsui, Shinjiro; Tomizawa, Hiromitsu; Yoshida, Toru; Isokawa, Katsushi; Kitagawa, Atsushi; Muramatsu, Masayuki; Yamada, Satoru; Okamura, Masahiro

    2000-02-01

    We have researched a compact medical accelerator with low investment and running cost for the popularization of heavy ion cancer therapy. As the first step, the compact injector system has been investigated for a Heavy Ion Medical Accelerator in Chiba at National Institute of Radiological Sciences. The proposed new injector system consists of a 6 MeV/u interdigital H-mode (IH) linac of 3.1 m long and a 18 GHz superconducting electron cyclotron resonance (ECR) (SC-ECR) ion source. The IH linac with high power efficiency is appropriate to a medical and industrial injector system. Its beam trajectory was simulated and a prototype has been constructed. The SC-ECR ion source has been designed to realize lightweight and low power consumption and the mirror field distribution was estimated.

  12. Analysis of electron energy distribution function in the Linac4 H{sup −} source

    SciTech Connect

    Mochizuki, S. Nishida, K.; Hatayama, A.; Mattei, S.; Lettry, J.

    2016-02-15

    To understand the Electron Energy Distribution Function (EEDF) in the Radio Frequency Inductively Coupled Plasmas (RF-ICPs) in hydrogen negative ion sources, the detailed analysis of the EEDFs using numerical simulation and the theoretical approach based on Boltzmann equation has been performed. It is shown that the EEDF of RF-ICPs consists of two parts, one is the low energy part which obeys Maxwellian distribution and the other is high energy part deviated from Maxwellian distribution. These simulation results have been confirmed to be reasonable by the analytical approach. The results suggest that it is possible to enhance the dissociation of molecules and the resultant H{sup −} negative ion production by reducing the gas pressure.

  13. Analysis of electron energy distribution function in the Linac4 H- source

    NASA Astrophysics Data System (ADS)

    Mochizuki, S.; Mattei, S.; Nishida, K.; Hatayama, A.; Lettry, J.

    2016-02-01

    To understand the Electron Energy Distribution Function (EEDF) in the Radio Frequency Inductively Coupled Plasmas (RF-ICPs) in hydrogen negative ion sources, the detailed analysis of the EEDFs using numerical simulation and the theoretical approach based on Boltzmann equation has been performed. It is shown that the EEDF of RF-ICPs consists of two parts, one is the low energy part which obeys Maxwellian distribution and the other is high energy part deviated from Maxwellian distribution. These simulation results have been confirmed to be reasonable by the analytical approach. The results suggest that it is possible to enhance the dissociation of molecules and the resultant H- negative ion production by reducing the gas pressure.

  14. Front end design of a multi-GeV H-minus linac.

    SciTech Connect

    Ostroumov, P. N.; Shepard, K. W.; Foster, G. W.; Gonin, I. V.; Romanov, G. V.; Physics; FNAL

    2005-01-01

    The proposed 8-GeV driver at FNAL [1] is based on {approx} 430 independently phased SC resonators. Significant cost savings are expected by using an rf power fan-out from high-power klystrons to multiple cavities. Successful development of superconducting (SC) multi-spoke resonators operating at {approx} 345-350 MHz provides a strong basis for their application in the front end of multi-GeV linear accelerators. Such a front-end operating at 325 MHz would enable direct transition to high-gradient 1300 MHz SC TESLA-style cavities at {approx} 400 MeV. The proposed front end consists of 5 sections: a conventional RFQ, room-temperature (RT) cross-bar H-type (CH) cavities, single-, double-and triple-spoke superconducting resonators. It is effective to use short RT CH-cavities between the RFQ and SC sections in the energy range 3-10 MeV as is discussed below.

  15. Emittance improvements of cesiated RF-driven H- ion source to enable 60 mA operation of high-energy and high-intensity LINACs by plasma impurity controls

    NASA Astrophysics Data System (ADS)

    Ueno, A.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Oguri, H.

    2017-08-01

    At the Japan Proton Accelerator Research Complex (J-PARC), the operation of a 400-MeV linear accelerator (LINAC) with an extraction H- ion beam intensity of 60 mA is under investigation. This intensity is 20 % higher than the 50 mA achieved by the J-PARC LINAC and about 50 % higher than those of operating similar LINACs in the world. Recently, the J-PARC cesiated RF-driven H- ion source successfully produces a beam enabling the 60 mA operation. A 66-mA beam with 95%-beam transverse normalized rms emittance of 0.23 πmm.mrad is produced by controlling the impurities of argon, nitrogen and water molecules in the hydrogen plasma and tuning rod-filter-field.

  16. Superconducting heavy-ion linac at Argonne

    SciTech Connect

    Aron, J.; Benaroya, R.; Bollinger, L.M.; Clifft, B.G.; Johnson, K.W.; Nixon, J.M.; Markovich, P.; Pardo, R.C.; Shepard, K.W.

    1981-01-01

    The design, status, and performance of the first operating superconducting heavy-ion accelerator, a linac used to boost the energies of beams from a 9-MV tandem, is summarized. When completed in 1981, the linac will consist of 24 independently-phased split-ring niobium resonators operating at 97 MHz. This linac is designed to provide 29 MV of acceleration. Because of the modular character of the system, the linac has been operable and useful since mid-1978, when a beam was accelerated through 2 units and the first nuclear-physics experiments were preformed. Now, 16 resonators are in use, and a beam has been accelerated for approx. 6000 h. Resonator performance has been remarkably stable, in spite of vacuum accidents, and the linac as a whole operates reliably without operators in attendance during nights and weekends. The ease and speed with which the beam energy can be changed is proving to be unexpectedly valuable to users.

  17. Design report of the laser system for notching H- beam at booster injection RF frequency in the 750-keV Linac

    SciTech Connect

    Yang, Xi; Ankenbrandt, Charles M.; /Fermilab

    2005-04-01

    With the requirement for more protons per hour from Booster, the radiation is a limiting factor. The most important periods in a Booster accelerating cycle are injection and transition crossing. The laser notching H{sup -} beam at the Booster injection RF frequency can make a bucket-to-bucket transfer from Linac to Booster possible, and this should remove most of the capture loss at injection and the early beam loss in the cycle. Besides that, the variation of the laser pulse length can change the notch length of the H{sup -} beam such that the bucket area filled by the beam can be controlled, and this can be applied to control the longitudinal emittance of the Booster beam.

  18. Modeling of neutrals in the Linac4 H{sup −} ion source plasma: Hydrogen atom production density profile and H{sub α} intensity by collisional radiative model

    SciTech Connect

    Yamamoto, T. Shibata, T.; Ohta, M.; Yasumoto, M.; Nishida, K.; Hatayama, A.; Mattei, S.; Lettry, J.; Sawada, K.; Fantz, U.

    2014-02-15

    To control the H{sup 0} atom production profile in the H{sup −} ion sources is one of the important issues for the efficient and uniform surface H{sup −} production. The purpose of this study is to construct a collisional radiative (CR) model to calculate the effective production rate of H{sup 0} atoms from H{sub 2} molecules in the model geometry of the radio-frequency (RF) H{sup −} ion source for Linac4 accelerator. In order to validate the CR model by comparison with the experimental results from the optical emission spectroscopy, it is also necessary for the model to calculate Balmer photon emission rate in the source. As a basic test of the model, the time evolutions of H{sup 0} production and the Balmer H{sub α} photon emission rate are calculated for given electron energy distribution functions in the Linac4 RF H{sup −} ion source. Reasonable test results are obtained and basis for the detailed comparisons with experimental results have been established.

  19. The RIA driver linac.

    SciTech Connect

    Shepard, K. W.

    2002-09-23

    The driver linac for the U.S. RIA project will be a 1.4 GV superconducting linac capable of accelerating the full mass range of ions from 900 MeV protons to 400 MeV/u uranium, and delivering a cw beam of 400 kW shared by at least two targets simultaneously. Elements of the linac are being developed at several U.S. laboratories. The current status of linac design and development is reviewed with emphasis on changes in the baseline design since the last linac conference.

  20. Effects of the extraction voltage applied by the puller-electrode on the H- extraction in the Linac4 negative ion source

    NASA Astrophysics Data System (ADS)

    Abe, S.; Nishioka, S.; Mattei, S.; Hatayama, A.; Lettry, J.

    2017-08-01

    In order to understand the H- extraction mechanism and investigate the effect of the extraction voltage applied by the puller-electrode on the H- extraction in the Linac4 negative ion source, we are developing a 2D3V-PIC (two dimensions in the real space and three dimensions in the velocity space, Particle in Cell) model with volume produced H- ions. It is shown that how to take the magnetic filter field direction is important for the 2D modeling to take into account the important 3D effect of electron E×B drift. It is also shown that the meniscus formation is not symmetric due to the electron E×B drift in the extraction region and the divergence of the H- beam is asymmetric. In order to make more quantitative comparison of the extracted H- and electron currents with the experiments and 3D modeling, further improvements, especially the electron loss along the magnetic filter field line will be needed.

  1. Development of high gradient IH linac

    NASA Astrophysics Data System (ADS)

    Isokawa, K.; Hattori, T.; Sasa, K.; Ito, T.; Hayashizaki, N.; Majima, S.; Osvath, E.; Dudu, D.; Yamada, S.

    We have studied Interdigital-H (IH)-type structures for application in heavy-ion inertial fusion (HIF) and other projects, at the Tokyo Institute of Technology (TIT). We have developed an IH linac with a high acceleration rate. It makes use of the fact that IH linacs have 5-10 times as high shunt impedance as Alvarez and RFQs in low and middle regions of energy [1-5]. We calculated trajectories of particles and made experiments by model cavities. Now an IH linac that we call high gradient IH linac is under construction. The calculated result of particle dynamics is that the transverse acceptance and an acceleration rate of this linac are 113π mm mrad and 5.5 MV/m, respectively. This linac is able to accelerate particles with a charge to mass ratio ( q/ A) greater than 1/16 from 219 keV/u up to 600 keV/u. The cavity length of this linac is 1120 mm. The frequency is 81 MHz.

  2. INR proton Linac operation and applications

    NASA Astrophysics Data System (ADS)

    Kravchuk, Leonid V.

    2006-06-01

    The INR Proton Linear Accelerator is presently under operation for about 2400 h per year with energy about 250 MeV and average current up to 150 μA. The Linac applications are mainly as follows: neutron and condensed matter research at spallation neutron source and neutron spectrometers, isotope production for medicine and industry, beam therapy. The experimental area description and the Linac operational experience are given in the paper.

  3. Magnet innovations for linacs

    SciTech Connect

    Halbach, K.

    1986-06-01

    It is possible to produce large magnetic fields at the aperture of permanent magnet quadrupoles, even when the magnetic aperture is very small. That, combined with their compactness, makes permanent magnet quadrupoles very powerful components of small aperture linacs. Results will be presented about past and present work on both fixed and variable strength permanent magnets suitable for use in and around linacs.

  4. Compendium of Scientific Linacs

    SciTech Connect

    Clendenin, James E

    2003-05-16

    The International Committee supported the proposal of the Chairman of the XVIII International Linac Conference to issue a new Compendium of linear accelerators. The last one was published in 1976. The Local Organizing Committee of Linac96 decided to set up a sub-committee for this purpose. Contrary to the catalogues of the High Energy Accelerators which compile accelerators with energies above 1 GeV, we have not defined a specific limit in energy. Microtrons and cyclotrons are not in this compendium. Also data from thousands of medical and industrial linacs has not been collected. Therefore, only scientific linacs are listed in the present compendium. Each linac found in this research and involved in a physics context was considered. It could be used, for example, either as an injector for high energy accelerators, or in nuclear physics, materials physics, free electron lasers or synchrotron light machines. Linear accelerators are developed in three continents only: America, Asia, and Europe. This geographical distribution is kept as a basis. The compendium contains the parameters and status of scientific linacs. Most of these linacs are operational. However, many facilities under construction or design studies are also included. A special mention has been made at the end for the studies of future linear colliders.

  5. Numerical simulation of electromagnetic fields and impedance of CERN LINAC4 H(-) source taking into account the effect of the plasma.

    PubMed

    Grudiev, A; Lettry, J; Mattei, S; Paoluzzi, M; Scrivens, R

    2014-02-01

    Numerical simulation of the CERN LINAC4 H(-) source 2 MHz RF system has been performed taking into account a realistic geometry from 3D Computer Aided Design model using commercial FEM high frequency simulation code. The effect of the plasma has been added to the model by the approximation of a homogenous electrically conducting medium. Electric and magnetic fields, RF power losses, and impedance of the circuit have been calculated for different values of the plasma conductivity. Three different regimes have been found depending on the plasma conductivity: (1) Zero or low plasma conductivity results in RF electric field induced by the RF antenna being mainly capacitive and has axial direction; (2) Intermediate conductivity results in the expulsion of capacitive electric field from plasma and the RF power coupling, which is increasing linearly with the plasma conductivity, is mainly dominated by the inductive azimuthal electric field; (3) High conductivity results in the shielding of both the electric and magnetic fields from plasma due to the skin effect, which reduces RF power coupling to plasma. From these simulations and measurements of the RF power coupling on the CERN source, a value of the plasma conductivity has been derived. It agrees well with an analytical estimate calculated from the measured plasma parameters. In addition, the simulated and measured impedances with and without plasma show very good agreement as well demonstrating validity of the plasma model used in the RF simulations.

  6. Numerical simulation of electromagnetic fields and impedance of CERN LINAC4 H- source taking into account the effect of the plasma

    NASA Astrophysics Data System (ADS)

    Grudiev, A.; Lettry, J.; Mattei, S.; Paoluzzi, M.; Scrivens, R.

    2014-02-01

    Numerical simulation of the CERN LINAC4 H- source 2 MHz RF system has been performed taking into account a realistic geometry from 3D Computer Aided Design model using commercial FEM high frequency simulation code. The effect of the plasma has been added to the model by the approximation of a homogenous electrically conducting medium. Electric and magnetic fields, RF power losses, and impedance of the circuit have been calculated for different values of the plasma conductivity. Three different regimes have been found depending on the plasma conductivity: (1) Zero or low plasma conductivity results in RF electric field induced by the RF antenna being mainly capacitive and has axial direction; (2) Intermediate conductivity results in the expulsion of capacitive electric field from plasma and the RF power coupling, which is increasing linearly with the plasma conductivity, is mainly dominated by the inductive azimuthal electric field; (3) High conductivity results in the shielding of both the electric and magnetic fields from plasma due to the skin effect, which reduces RF power coupling to plasma. From these simulations and measurements of the RF power coupling on the CERN source, a value of the plasma conductivity has been derived. It agrees well with an analytical estimate calculated from the measured plasma parameters. In addition, the simulated and measured impedances with and without plasma show very good agreement as well demonstrating validity of the plasma model used in the RF simulations.

  7. Measurements of the longitudinal beam parameters in the Fermilab Linac

    SciTech Connect

    Popovic, M.; Junck, K.; Kroc, T.; Mccrory, E.; Ostroumov, P.

    1994-08-01

    The Fermilab Linac Upgrade has increased the energy of the H{sup {minus}} linac from 201 to 401.5 MeV. This is achieved by replacing the last four 201.24 MHz drift-tube linac cavities with seven 804.96 MHz side-coupled cavity modules. Each accelerator module is powered with a 12 MW klystron-based power supply. The purpose of this report is to present a body of representative methods and data used to characterize longitudinal properties of the beam after each accelerating tank and module. These various methods proved useful in the commissioning of the Fermilab Linac Upgrade.

  8. LFSC - Linac Feedback Simulation Code

    SciTech Connect

    Ivanov, Valentin; /Fermilab

    2008-05-01

    The computer program LFSC (<Linac Feedback Simulation Code>) is a numerical tool for simulation beam based feedback in high performance linacs. The code LFSC is based on the earlier version developed by a collective of authors at SLAC (L.Hendrickson, R. McEwen, T. Himel, H. Shoaee, S. Shah, P. Emma, P. Schultz) during 1990-2005. That code was successively used in simulation of SLC, TESLA, CLIC and NLC projects. It can simulate as pulse-to-pulse feedback on timescale corresponding to 5-100 Hz, as slower feedbacks, operating in the 0.1-1 Hz range in the Main Linac and Beam Delivery System. The code LFSC is running under Matlab for MS Windows operating system. It contains about 30,000 lines of source code in more than 260 subroutines. The code uses the LIAR ('Linear Accelerator Research code') for particle tracking under ground motion and technical noise perturbations. It uses the Guinea Pig code to simulate the luminosity performance. A set of input files includes the lattice description (XSIF format), and plane text files with numerical parameters, wake fields, ground motion data etc. The Matlab environment provides a flexible system for graphical output.

  9. Linear Accelerator (LINAC)

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? A linear accelerator (LINAC) is the ... Therapy (SBRT) . top of page How does the equipment work? The linear accelerator uses microwave technology (similar ...

  10. Linear Accelerator (LINAC)

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? A linear accelerator (LINAC) is the ... Therapy (SBRT) . top of page How does the equipment work? The linear accelerator uses microwave technology (similar ...

  11. Physics design of front ends for superconducting ion linacs

    SciTech Connect

    Ostroumov, P.N.; Carneiro, J.-P.; /Fermilab

    2008-09-01

    Superconducting (SC) technology is the only option for CW linacs and is also an attractive option for pulsed linacs. SC cavities are routinely used for proton and H{sup -} beam acceleration above 185 MeV. Successful development of SC cavities covering the lower velocity range (down to 0.03c) is a very strong basis for the application of SC structures in the front ends of high energy linacs. Lattice design and related high-intensity beam physics issues in a {approx}400 MeV linac that uses SC cavities will be presented in this talk. In particular, axially-symmetric focusing by SC solenoids provides strong control of beam space charge and a compact focusing lattice. As an example, we discuss the SC front end of the H{sup -} linac for the FNAL Proton Driver.

  12. Physics design of front ends for superconducting ion linacs

    SciTech Connect

    Ostroumov, P.N.; Carneiro, J.P.; /Fermilab

    2009-01-01

    Superconducting (SC) technology is the only option for CW linacs and is also an attractive option for pulsed linacs. SC cavities are routinely used for proton and H{sup -} beam acceleration above 185 MeV. Successful development of SC cavities covering the lower velocity range (down to 0.03c) is a very strong basis for the application of SC structures in the front ends of high energy linacs. Lattice design and related high-intensity beam physics issues in a {approx}400 MeV linac that uses SC cavities will be presented in this talk. In particular, axially-symmetric focusing by SC solenoids provides strong control of beam space-charge and a compact focusing lattice. As an example, we discuss the SC front-end of the H{sup -} linac for the FNAL Proton Driver.

  13. Commissioning Experience for the SNS Linac

    SciTech Connect

    Aleksandrov, A.; Assadi, S.; Campisi, I.; Chu, P.; Cousineau, S.; Danilov, V.; Dodson, B.G.; Galambos, J.; Jeon, D.; Henderson, S.; Holtkamp, N.; Kravchuk, L.; Kim, S.; Plum, M.; Tanke, E.; Stockli, M.

    2005-06-08

    The Spallation Neutron Source accelerator systems will deliver a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H- injector, capable of producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. A 2.5 MeV beam from the Front End is accelerated to 86 MeV in a Drift Tube Linac, then to 185 MeV in a Coupled-Cavity Linac and then to 1 GeV in a Superconducting Linac. The staged beam commissioning of the accelerator complex is proceeding as component installation progresses. The Front End, Drift Tube Linac and part of the Coupled-Cavity Linac have been commissioned at ORNL. The primary design goals of peak current, transverse emittance and beam energy have been achieved. Results and status of the beam commissioning program will be presented.

  14. Progress in Induction Linacs

    SciTech Connect

    Caporaso, G J

    2000-09-27

    This presentation will be a broad survey of progress in induction technology over the past four years. Much work has been done on accelerators for hydrodynamic test radiography and other applications. Solid-state pulsers have been developed which can provide unprecedented flexibility and precision in pulse format and accelerating voltage for both ion and electron induction machines. Induction linacs can now be built which can operate with MHz repetition rates. Solid-state technology has also made possible the development of fast kickers for precision control of high current beams. New insulator technology has been developed which will improve conventional induction linacs in addition to enabling a new class of high gradient induction linacs.

  15. Linac-accelerator-radiosurgery.

    PubMed

    Sturm, V; Schlegel, W; Pastyr, O; Treuer, H; Voges, J; Müller, R P; Lorenz, W J

    1993-01-01

    A survey is given of the actual possibilities and limitations of the use of linear accelerators (Linac radiosurgery systems) for intra = cranial radiosurgery. Depending on the collimator size, spherical fields from 5-54 mm in diameter can be irradiated with dose gradients from 10% (large fields) to 20% (small fields) per millimeter distance between surface and treatment volume. This is comparable to the possibilities of Gamma-Knife and Proton-irradiation. Optimal mechanical adjustment of gantry and linac table are necessary for the required stability of the isocenter. Mechanical inaccuracy should be smaller than 0.8 mm. Advanced computerized 3D-treatment planning systems are indispensable prerequisites for accurate treatment and use of the flexibility of the linac system. Future developments are outlined.

  16. EXPERIENCE WITH THE SNS SC LINAC

    SciTech Connect

    Zhang, Yan; Aleksandrov, Alexander V; Allen, Christopher K; Campisi, Isidoro E; Cousineau, Sarah M; Danilov, Viatcheslav; Galambos, John D; Holmes, Jeffrey A; Jeon, Dong-O; Kim, Sang-Ho; Pelaia II, Tom; Plum, Michael A; Shishlo, Andrei P

    2008-01-01

    The SNS superconducting linac (SCL) is designed to deliver 1 GeV, up to 1.56-MW pulsed H- beams for neutron production. Commissioning of the accelerator systems was completed in June 2006, and the maximum beam energy achieved was approximately 952 MeV. In 2007, the SCL was successfully tuned for 1.01-GeV beam during a test operation. In the linac tune-up, phase scan signature matching, drifting beam measurement, and linac radio frequency cavity phase scaling were applied. In this paper, we will introduce the experiences with the SCL, including the tune-up, beam loss, and beam activation, and briefly discuss beam parameter measurements

  17. Special SLC linac developments

    SciTech Connect

    Seeman, J.T.; Sheppard, J.C.

    1986-04-01

    The linac of the SLAC Linear Collider (SLC) is required to accelerate several intense electron and positron bunches to high energy while maintaining their small transverse dimensions and energy spectra. Many of the linac systems have been upgraded to the new stringent SLC design criteria. The remaining systems will be completed in the summer of 1986. Special instruments and controls have been developed to monitor and manipulate these small but potent beams. A brief review of the SLC requirements is given. A broad survey of the recent development is made encompassing longitudinal and transverse wakefield reductions, Landau damping, energy and position feedback systems, beam diagnostic and beam current fluctuations.

  18. The ISS protontherapy LINAC

    NASA Astrophysics Data System (ADS)

    Picardi, L.; Ronsivalle, C.; Vignati, A.

    1997-02-01

    The TERA foundation stimulated in the past years a comparative study of compact proton accelerators for therapy and at the end of 1995 the Italian National Institute of Health (Istituto Superiore di Sanità, ISS) decided for the construction of a proton linac for its TOP (Terapia Oncologica con Protoni) project. The TOP-LINAC will be composed of a 7 MeV RFQ+DTL injector followed by a 7-65 MeV section of the innovative 3 GHz SCDTL structure and a 65-200 MeV variable energy SCL 3 GHz structure. A 5-cavity model of the SCDTL has been built and measured on a RF test bench while a 11-cavities prototype (accelerating until 12.5 MeV) is under construction and will be assembled within few months. The TOP LINAC whose construction will start at the end of 1996, will be the first linear accelerator dedicated to proton therapy, and the first 3 GHz proton linac. In this paper the accelerator design and the construction schedule will be presented, and the SCDTL structure RF measurements will be discussed.

  19. Designing self-matching linacs

    SciTech Connect

    Mills, R.S.; Crandall, K.R.; Farrell, J.A.

    1984-01-01

    The present trend in ion-linac design is to begin with a radio-frequency quadrupole (RFQ) linac followed by one or more drift-tube linac (DTL) tanks in which permanent-magnet quadrupoles are used for transverse focusing. The lack of adjustable elements (knobs) strongly suggests that one should seek linac designs with intertank matching solutions that are insensitive to beam currents and emittances, which can be accomplished if there are no sharp discontinuities in the focusing properties along the entire linac. Guidelines are presented for linac design and describe techniques for longitudinal as well as transverse matching between tanks. For a wide range of beam currents and emittances, a beam matched at the entrance to the RFQ should remain well matched throughout the entire linac.

  20. Recirculated and Energy Recovered Linacs

    SciTech Connect

    Geoffrey Krafft

    2003-05-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams from an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible from either a conventional linac, or from storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend from high power free-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  1. High power operational experience with the LANSCE Linac

    SciTech Connect

    Rybarcyk, Lawrence J

    2008-01-01

    The heart of the Los Alamos Neutron Science Center (LANSCE) is a pulsed linear accelerator that is used to simultaneously provide H+ and H- beams to several user facilities. This accelerator contains two Cockcroft-Walton style injectors, a 100-MeV drift tube linac and an 800-MeV coupled cavity linac. This presentation will touch on various aspects of the high power operation including performance, tune-up strategy, beam losses and machine protection.

  2. LINAC5 - A Quasi-Alvarez Linac for BioLEIR

    NASA Astrophysics Data System (ADS)

    Garland, J. M.; Lallement, J.-B.; Lombardi, A.

    2017-07-01

    LINAC5 is a new linac proposed for the acceleration of light ions with Q/A = 1/3 to 1/4 for medical applications within the BioLEIR (Low Energy Ion Ring) design study at CERN. We propose a novel quasi-Alvarez drift-tube linac (DTL) accelerating structure design for LINAC5, which can reduce the length of a more conventional DTL structure, yet allows better beam focussing control and flexibility than the inter-digital H (IH) structures typically used for modern ion acceleration. We present the main sections of the linac with total length ∼12 m, including a 202 MHz radio frequency quadrupole (RFQ) a matching medium energy beam transport (MEBT) and a 405 MHz quasi-Alvarez accelerating section with an output energy of 4.2 MeV/u. Permanent magnet quadrupoles are proposed for use in the quasi-Alvarez structure to improve the compactness of the design and increase the efficiency. Lattice design considerations, multi-particle beam dynamics simulations and RFQ and radio frequency (RF) cavity designs are presented.

  3. Superconducting energy recovery linacs

    DOE PAGES

    Ben-Zvi, Ilan

    2016-09-01

    High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

  4. Superconducting energy recovery linacs

    NASA Astrophysics Data System (ADS)

    Ben-Zvi, Ilan

    2016-10-01

    High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

  5. Compact, Integrated Photoelectron Linacs

    NASA Astrophysics Data System (ADS)

    Yu, David

    2000-12-01

    The innovative compact high energy iniector which has been developed by DULY Research Inc., will have wide scientific industrial and medical applications. The new photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injector and the linac. By focusing the beam with solenoid or permanent magnets, and producing high current with low emittance, extremely high brightness is achieved. In addition to providing a small footprint and improved beam quality in an integrated structure, the compact system considerably simplifies external subsystems required to operate the photoelectron linac, including rf power transport, beam focusing, vacuum and cooling. The photoelectron linac employs an innovative Plane-Wave-Transformer (PWT) design, which provides strong cell-to-cell coupling, relaxes manufacturing tolerance and facilitates the attachment of external ports to the compact structure with minimal field interference. DULY Research Inc. under the support of the DOE Small Business Innovation Research (SBIR) program, has developed, constructed and installed a 20-MeV, S-band compact electron source at UCLA. DULY Research is also presently engaged in the development of an X-band photoelectron linear accelerator in another SBIR project. The higher frequency structure when completed will be approximately three times smaller, and capable of a beam brightness ten times higher than the S-band structure.

  6. Superconducting linacs: some recent developments

    SciTech Connect

    Bollinger, L.M.

    1985-01-01

    The paper is a review of superconducting linacs that are of interest for heavy-ion acceleration. Most of the paper is concerned with energy boosters for projectiles from tandem electrostatic accelerators, the only application for which superconducting linacs are now used for heavy-ion acceleration. There is also a brief discussion of the concept of a superconducting injector linac being developed as a replacement of the tandem in a multi-stage acceleration system. Throughout, the emphasis is on the technology of the superconducting linac, including some attention to the relationships between resonator design parameters and accelerator performance characteristics. 21 refs., 14 figs., 3 tabs.

  7. 1-GeV Linac Upgrade Study at Fermilab

    SciTech Connect

    Popovic, M., Moretti, A., Noble, R., Schmidt, C. W., FNAL

    1998-09-01

    A linac injector for a new proton source complex at Fermilab is assumed to have a kinetic energy of 1 GeV. This linac would be sized to accelerate 100 mA of H{sup -} beam in a 200 microsecond pulse at a 15 Hz repetition rate. This would be adequate to produce {approximately}10{sup 14} protons per pulse allowing for future improvements of the new proton source complex. An alternate proposal is to add 600 MeV of side coupled cavity linac at 805 MHz to the existing 400 MeV Linac. This addition may either be in a new location or use the present Booster tunnel. A discussion of these possibilities will be given.

  8. Optimization of SRF Linacs

    SciTech Connect

    Powers, Tom

    2013-09-01

    This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project.[1] The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. The work was first published in an ICFA Beam Dynamics News Letter.[2] More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so. Additionally, program changes now allow one to model the costs associated with a linac that makes use of energy recovery mode of operation.

  9. New medical linacs

    NASA Astrophysics Data System (ADS)

    Schonberg, R. G.; Mishin, A. V.

    1997-02-01

    X-band linacs designed and manufactured by Schonberg Research Corporation that are currently used by two spin-off companies for radiation therapy systems. Accuray employs a basic 6 MeV design with 300 R/min nominal dose rate at 80 cm from a tungsten target. The designed stereoscopic radiosurgery system is known as the Cyberknife. The Cyberknife combines a treatment planning, imaging and treatment delivery features. The treatment delivery system enclosure incorporates an accelerator head, RF components, pulse transformer and electronics mounted on a robotic arm. Intraop Medical, Inc. has introduced a system for intraoperative radiation therapy (IORT) called Mobetron (Mobile Electron Beam Intraoperative Treatment System). Mobetron is based on a 12 MeV two section X-band linac also designed by Schonberg Research Corporation. The accelerator design permits smooth energy variation from 4 to 12 MeV, but will be used at 4 specific energies. A self-shielded concept is applied to the system design. It will be used in conventional operating rooms without added shielding.

  10. The 400 MeV Linac Upgrade at Fermilab

    SciTech Connect

    Noble, R.J.

    1992-12-01

    The Fermilab Linac Upgrade in planned to increase the energy of the H{sup {minus}} linac from 200 to 400 MeV. This is intended to reduce the incoherent space-charge tuneshift at injection into the 8 GeV Booster which limit either the brightness or the total intensity of the beam. The Linac Upgrade will be achieved by replacing the last four 201.25 MHs drift-tube linac (DTL) tanks which accelerate the beam from 116 to 200 MeV, with seven 805 MRs side-coupled cavity modules operating at an average axial field of about 7.5 MV/meter. This will allow acceleration to 400 MeV in the existing Linac enclosure. Each accelerator module will be driven with a 12 MW klystron-based rf power supply. Three of seven accelerator modules have been fabricated, power tested and installed in their temporary location adjacent to the existing DTL. All seven RF Modulators have been completed and klystron installation has begun. Waveguide runs have completed from the power supply gallery to the accelerator modules. The new linac will be powered in the temporary position without beam in order to verify overall system reliability until the laboratory operating schedule permits final conversion to 400 MeV operation.

  11. Design of heavy-ion APF-IH type linac for atomic physics and medical use

    NASA Astrophysics Data System (ADS)

    Hata, T.; Hattori, T.; Kashiwagi, H.; Takahashi, Y.; Yamamoto, K.; Matsui, S.; Dudu, D.; Osvath, E.; Vata, I.; Yamada, S.

    2002-04-01

    We have studied a compact heavy-ion linac for atomic physics and medical use. The design of the linac was based on using alternating-phase-focus (APF) and interdigital-H (IH) structures which give sufficient electric power efficiency. Thereby, it will be possible to design a small and high efficiency linac. The APF-IH linac was designed to accelerate ions from C 2+ to U 40+, from 30 to 300 keV/u and an operating frequency of 100 MHz. We made a half-scale cold model of this linac using orbit calculation and measured its RF characteristics. Then, we designed a APF-IH type linac using the results of the measurement.

  12. Low-charge-state linac

    SciTech Connect

    Shepard, K.W.; Kim, J.W.

    1995-08-01

    A design is being developed for a low-charge-state linac suitable for injecting ATLAS with a low-charge-state, radioactive beam. Initial work indicates that the existing ATLAS interdigital superconducting accelerating structures, together with the superconducting quadrupole transverse focussing element discussed above, provides a basis for a high-performance low-charge-state linac. The initial 2 or 3 MV of such a linac could be based on a normally-conducting, low-frequency RFQ, possibly combined with 24-MHz superconducting interdigital structures. Beam dynamics studies of the whole low-charge-state post-accelerator section were carried out in early FY 1995.

  13. SLAC Linac Preparations for FACET

    SciTech Connect

    Erickson, R.; Bentson, L.; Kharakh, D.; Owens, A.; Schuh, P.; Seeman, J.; Sheppard, J.C.; Stanek, M.; Wittmer, W.; Yocky, G.; Wienands, U.; /SLAC

    2011-02-07

    The SLAC 3km linear electron accelerator has been cut at the two-thirds point to provide beams to two independent programs. The last third provides the electron beam for the Linac Coherent Light Source (LCLS), leaving the first two-thirds available for FACET, the new experimental facility for accelerator science and test beams. In this paper, we describe this separation and projects to prepare the linac for the FACET experimental program.

  14. Induction Linac Pulsers

    SciTech Connect

    Faltens, Andris

    2011-01-07

    The pulsers used in most of the induction linacs evolved from the very large body of work that was done in the U.S. and Great Britain during the development of the pulsed magnetron for radar. The radar modulators started at {approx}100 kW and reached >10 MW by 1945. A typical pulse length was 1 {mu}s at a repetition rate of 1,000 pps. A very comprehensive account of the modulator development is Pulse Generators by Lebacqz and Glasoe, one of the Radiation Laboratory Series. There are many permutations of possible modulators, two of the choices being tube type and line type. In earlier notes I wrote that technically the vacuum tube pulser met all of our induction linac needs, in the sense that a number of tubes, in series and parallel if required, could produce our pulses, regulate their voltage, be useable in feed-forward correctors, and provide a low source impedance. At a lower speed, an FET array is similar, and we have obtained and tested a large array capable of >10 MW switching. A modulator with an electronically controlled output only needs a capacitor for energy storage and in a switched mode can transfer the energy from the capacitor to the load at high efficiency. Driving a full size Astron induction core and a simulated resistive 'beam load' we achieved >50% efficiency. These electronically controlled output pulses can produce the pulses we desire but are not used because of their high cost. The second choice, the line type pulser, visually comprises a closing switch and a distributed or a lumped element transmission line. The typical switch cannot open or stop conducting after the desired pulse has been produced, and consequently all of the initially stored energy is dissipated. This approximately halves the efficiency, and the original cost estimating program LIACEP used this factor of two, even though our circuits are usually worse, and even though our inveterate optimists often omit it. The 'missing' energy is that which is reflected back into the

  15. Lattice Design for the LHEC Recirculating Linac

    SciTech Connect

    Sun, Yipeng; Eide, Anders; Zimmermann, Frank; Adolphsen, Chris; /SLAC

    2011-05-20

    In this paper, we present a lattice design for the Large Hadron Electron Collider (LHeC) recirculating linac. The recirculating linac consists of one roughly 3-km long linac hosting superconducting RF (SRF) accelerating cavities, two arcs and one transfer line for the recirculation. In two passes through a pulsed SRF linac the electron beam can get a maximum energy of 140 GeV. Alternatively, in the Energy Recovery Linac (ERL) option the beam passes through a CW linac four times (two passes for acceleration and two for deceleration) for a maximum energy of 60 GeV.

  16. LINACS FOR FUTURE MUON FACILITIES

    SciTech Connect

    Slawomir Bogacz, Rolland Johnson

    2008-10-01

    Future Muon Colliders (MC) and Neutrino Factories (NF) based on muon storage rings will require innovative linacs to: produce the muons, cool them, compress longi-tudinally and ‘shape’ them into a beam and finally to rap-idly accelerate them to multi-GeV (NF) and TeV (MC) energies. Each of these four linac applications has new requirements and opportunities that follow from the na-ture of the muon in that it has a short lifetime (τ = 2.2 μsec) in its own rest frame, it is produced in a tertiary process into a large emittance, and its electron, photon, and neutrino decay products can be more than an annoy-ance. As an example, for optimum performance, the linac repetition rates should scale inversely with the laboratory lifetime of the muon in its storage ring, something as high as 1 kHz for a 40 GeV Neutrino Factory or as low as 20 Hz for a 5 TeV Muon Collider. A superconducting 8 GeV Linac capable of CW operation is being studied as a ver-satile option for muon production [1] for colliders, facto-ries, and muon beams for diverse purposes. A linac filled with high pressure hydrogen gas and imbedded in strong magnetic fields has been proposed to rapidly cool muon beams [2]. Recirculating Linear Accelerators (RLA) are possible because muons do not generate significant syn-chrotron radiation even at extremely high energy and in strong magnetic fields. We will describe the present status of linacs for muon applications; in particular the longitu-dinal bunch compression in a single pass linac and multi-pass acceleration in the RLA, especially the optics and technical requirements for RLA designs, using supercon-ducting RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed linac quadrupoles to allow the maximum number of passes. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  17. Superconducting radiofrequency linac development at Fermilab

    SciTech Connect

    Holmes, Stephen D.; /Fermilab

    2009-10-01

    As the Fermilab Tevatron Collider program draws to a close, a strategy has emerged of an experimental program built around the high intensity frontier. The centerpiece of this program is a superconducting H- linac that will support world leading programs in long baseline neutrino experimentation and the study of rare processes. Based on technology shared with the International Linear Collider, Project X will provide multi-MW beams at 60-120 GeV from the Main Injector, simultaneous with very high intensity beams at lower energies. Project X also supports development of a Muon Collider as a future facility at the energy frontier.

  18. An overview of LINAC ion sources

    SciTech Connect

    Keller, Roderich

    2008-01-01

    This paper discusses ion sources used in high-duty-factor proton and H{sup -} Linacs as well as in accelerators utilizing multi-charged heavy ions, mostly for nuclear physics applications. The included types are Electron Cyclotron Resonance (ECR) sources as well as filament and rf driven multicusp sources. The paper does not strive to attain encyclopedic character but rather to highlight major lines of development, peak performance parameters and type-specific limitations and problems of these sources. The main technical aspects being discussed are particle feed, plasma generation and ion production by discharges, and plasma confinement.

  19. High Frequency Linacs for Hadrontherapy

    NASA Astrophysics Data System (ADS)

    Amaldi, Ugo; Braccini, Saverio; Puggioni, Paolo

    The use of radiofrequency linacs for hadrontherapy was proposed about 20 years ago, but only recently has it been understood that the high repetition rate together with the possibility of very rapid energy variations offers an optimal solution to the present challenge of hadrontherapy: "paint" a moving tumor target in three dimensions with a pencil beam. Moreover, the fact that the energy, and thus the particle range, can be electronically adjusted implies that no absorber-based energy selection system is needed, which, in the case of cyclotron-based centers, is the cause of material activation. On the other side, a linac consumes less power than a synchrotron. The first part of this article describes the main advantages of high frequency linacs in hadrontherapy, the early design studies, and the construction and test of the first high-gradient prototype which accelerated protons. The second part illustrates some technical issues relevant to the design of copper standing wave accelerators, the present developments, and two designs of linac-based proton and carbon ion facilities. Superconductive linacs are not discussed, since nanoampere currents are sufficient for therapy. In the last two sections, a comparison with circular accelerators and an overview of future projects are presented.

  20. Commissioning of the LCLS LINAC

    SciTech Connect

    Loos, H.; Akre, R.; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Huang, Z.; Iverson, R.; Limborg-Deprey, C.; Miahnahri, A.; Molloy, S.; Nuhn, H.-D.; Turner, J.; Welch, J.; White, W.; Wu, J.; /SLAC /Stanford U., Appl. Phys. Dept.

    2010-06-11

    The Linac Coherent Light Source (LCLS) X-ray free electron laser project is currently under construction at the Stanford Linear Accelerator Center (SLAC). A new injector and upgrades to the existing accelerator were installed in two phases in 2006 and 2007. We report on the commissioning of the injector, the two new bunch compressors at 250MeV and 4.3 GeV, and transverse and longitudinal beam diagnostics up to the end of the existing linac at 13.6 GeV. The commissioning of the new transfer line from the end of the linac to the undulator is scheduled to start in November 2008 and for the undulator in March 2009 with first light to be expected in July 2009.

  1. RF characteristics of IHQ linac for heavy ion implantation

    NASA Astrophysics Data System (ADS)

    Ito, Takashi; Osvath, E.; Sasa, Kimikazu; Hayashizaki, Noriyosu; Isokawa, Katsushi; Schubert, H.; Hattori, Toshiyuki

    1998-04-01

    At Tokyo Institute of Technology (TIT), an Interdigital-H type Quadrupole (IHQ) linac has been constructed for application in high energy heavy ion implantation. The linac can accelerate particles with charge to mass ratio greater than 1/16 from 0.24 MeV up to 1.6 MeV (for 16O +). As a result of the low power test, the resonant frequency is 36.26 MHz, the shunt impedance is 252 MΩ/m and therefore, the required power to accelerate 16O + ion is 39.5 kW.

  2. Overview and status of RF systems for the SSC Linac

    SciTech Connect

    Mynk, J.; Grippe, J.; Cutler, R.I.; Rodriguez, R.

    1993-05-01

    The Superconducting Super Collider (SSC) Linear Accelerator (Linac) produces a 600-MeV, 35-{mu}s, H-beam at a 10-Hz repetition rate. The beam is accelerated by a series of RF cavities. These consist of a Radio Frequency Quadrupole (RFQ), two bunchers, and four Drift Tube Linac (DTL) tanks at 427.617 MHz, and two bunchers, nine side-coupled Linac modules, and an energy compressor at 1282.851 MHz. The RFQ amplifier and the low-frequency buncher cavity amplifiers use gridded tubes, while the other cavities use klystron amplifier systems. The RF control system consists of a reference line and cavity feedback and feedforward loops for each amplifier. The RF amplifier system for each of these accelerator cavities is described, and the current status of each system is presented.

  3. Argonne Tandem-Linac Accelerator System

    SciTech Connect

    Bollinger, L.M.

    1983-01-01

    Design considerations and operational experience for the existing heavy-ion accelerator consisting of a tandem injecting into a superconducting linac are summarized, with emphasis on the general features of the system. This introduction provides the basis for a discussion of the objectives and design of ATLAS, a larger tandem-linac system being formed by expanding the existing superconducting linac.

  4. Linac Energy Management for LCLS

    SciTech Connect

    Chu, Chungming; Iverson, Richard; Krejcik, Patrick; Rogind, Deborah; White, Greg; Woodley, Mark; /SLAC

    2012-07-05

    Linac Energy Management (LEM) is a control system program that scales magnet field set-point settings following a change in beam energy. LEM is necessary because changes in the number, phase, and amplitude of the active klystrons change the beam's rigidity, and therefore, to maintain constant optics, one has to change focusing gradients and bend fields accordingly. This paper describes the basic process, the control system application programs we developed for LEM, and some of the implementation lessons learned at the Linac Coherent Light Source (LCLS).

  5. Resonance effects of longitudinal HOMS in Project X linac

    SciTech Connect

    Yakovlev, V.; Vostrikov, A.; Gonin, I.; Khabiboulline, T.; Lunin, A.; Solyak, N.; Saini, a.; Sukhanov, A.; /Fermilab

    2011-03-01

    Results of analysis of losses due to excitation of longitudinal high order modes (HOMs) in the accelerating RF system of the CW proton linac of the Project X facility are presented. The necessity of HOM dampers in the superconducting (SC) cavities of the linac is discussed. Project X is a multi-MW proton source which is under development at Fermilab. The facility is based on a 3 GeV CW linac. The main fraction of H{sup -} beam from the linac is split into three parts for Mu2e experiment, kaon experiments, and another which is not yet decided. The layout of the linac is shown in Figure 1. It includes three sections based on 325 MHz single-spoke cavities, and a low-energy and a high-energy sections of 650 MHz elliptical cavities with geometrical beta of 0.61 and 0.9, respectively. The linac provides a beam with an average current of 1 mA and time structure (shown in Figure 2) devised to satisfy specific requirements of the experiments. Each bunch contains 9 {center_dot} 10{sup 7} H{sup -} ions. The bunch sequence frequency for the Mu2e experiment is 162.5 MHz with a total pulse duration of 100 ns and pulse repetition rate of 1 MHz. The bunch sequence frequency for Kaon and other experiments is 27.08 MHz. Figure 3 shows the idealized beam current spectrum, which contains harmonics of multiplies of 27.08 MHz and harmonics of multiplies of 1 MHz. The 5-cell 650 MHz cavities for Project X are currently under development. A critical design decision is to define the necessity of HOM dampers for these types of cavities.

  6. The upgrade of the Brookhaven Linac Isotope Producer (BLIP) and the BNL Linac

    SciTech Connect

    Mausner, L.F.; Alessi, J.G.

    1996-12-31

    An upgrade project was recently completed on the 200 MeV H{sup -} linac and the Brookhaven Linac Isotope Producer (BLIP) in order to improve radioisotope production capacity and reliability. The average beam current has increased from 60 {mu}A to 150 {mu}A. The increased average current is the result of increases in peak current, from 25 mA to 37 mA, pulse repetition rate, from 5 to 7.5 Hz, and pulse width, from 500 to 530 ps. To achieve this performance the 35 keV, 750 keV and 200 MeV beam transport were improved, the RF transmission lines and RF power supplies replaced. Improvements to the linac control system, and the optics and vacuum system of the 200 MeV transport were implemented. A BLIP the target cooling system was upgraded to 35 kW and automated, the targets, and target mechanical systems replaced with a more robust design, and the control system upgraded. With these enhancements BLIP is ready to address the lack of availability of accelerator produced medical and research isotopes.

  7. The Linac Coherent Light Source

    PubMed Central

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-01-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed. PMID:25931055

  8. The Linac Coherent Light Source

    DOE PAGES

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-05-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  9. The Linac Coherent Light Source

    SciTech Connect

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-04-21

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  10. The Linac Coherent Light Source

    SciTech Connect

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-05-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  11. PROGRESS IN DESIGN OF THE SNS LINAC

    SciTech Connect

    R. HARDEKOPF

    2000-11-01

    The Spallation Neutron Source (SNS) is a six-laboratory collaboration to build an intense pulsed neutron facility at Oak Ridge, TN. The linac design has evolved from the conceptual design presented in 1997 to achieve higher initial performance and to incorporate desirable upgrade features. The linac will initially produce 2-MW beam power using a combination of radio-frequency quadruple (RFQ) linac, drift-tube linac (DTL), coupled-cavity linac (CCL), and superconducting-cavity linac (SCL). Designs of each of these elements support the high peak intensity and high quality beam required for injection into the SNS accumulator ring. This paper will trace the evolution of the linac design, the cost and performance factors that drove architecture decisions, and the progress made in the R&D program.

  12. BEAM LOSS MECHANISMS IN HIGH INTENSITY LINACS

    SciTech Connect

    Plum, Michael A

    2012-01-01

    In the present operation of the Oak Ridge Spallation Neutron Source, 60-Hz, 825-us H beam pulses are accelerated to 910 MeV, and then compressed to less than a microsecond in the storage ring, to deliver 1 MW of beam power to the spallation target. The beam loss in the superconducting portion of the linac is higher than expected, and it has shown a surprising counter-intuitive correlation with quadrupole magnetic fields, with a loss minimum occurring when the quadrupoles are set to approximately half their design values. This behavior can now be explained by a recent set of experiments that show the beam loss is primarily due to intra-beam stripping. Beam halo is another important beam loss contributor, and collimation in the 2.5 MeV Medium Energy Beam Transport has proven to be an effective mitigation strategy. In this presentation, we will summarize these and other beam loss mechanisms that are important for high intensity linacs.

  13. Single Spoke Cavities for Low-energy Part of CW Linac of Project X.

    SciTech Connect

    Gonin, Ivan; Champion, Mark; Khabiboulline, Timergali; Lunin, Andrei; Perunov, Nikolay; Solyak, Nikolay; Yakovlev, Vyacheslav; /Fermilab

    2010-05-01

    In the low-energy part of the Project X H-linac three families of 325 MHz SC single spoke cavities will be used, having {beta} = 0.11, 0.21 and 0.4. Single spoke cavity was selected for the linac because of higher r/Q. Results of optimization of all cavities are presented. Results of the beam dynamics optimization for initial stage of the linac with beta=0.11 single spoke cavity are presented at poster MOPEC082 (this conference).

  14. Wakefields in SLAC linac collimators

    DOE PAGES

    Novokhatski, A.; Decker, F. -J.; Smith, H.; ...

    2014-12-02

    When a beam travels near collimator jaws, it gets an energy loss and a transverse kick due to the backreaction of the beam field diffracted from the jaws. The effect becomes very important for an intense short bunch when a tight collimation of the background beam halo is required. In the Linac Coherent Light Source at SLAC a collimation system is used to protect the undulators from radiation due to particles in the beam halo. The halo is most likely formed from gun dark current or dark current in some of the accelerating sections. However, collimators are also responsible formore » the generation of wake fields. The wake field effect from the collimators not only brings an additional energy jitter and change in the trajectory of the beam, but it also rotates the beam on the phase plane, which consequently leads to a degradation of the performance of the Free Electron Laser at the Linac Coherent Light Source. In this paper, we describe a model of the wake field radiation in the SLAC linac collimators. We use the results of a numerical simulation to illustrate the model. Based on the model, we derive simple formulas for the bunch energy loss and the average kick. We also present results from experimental measurements that confirm our model.« less

  15. PERFORMANCE OF THE SNS FRONT END AND WARM LINAC

    SciTech Connect

    Aleksandrov, Alexander V; Allen, Christopher K; Cousineau, Sarah M; Danilov, Viatcheslav; Galambos, John D; Holmes, Jeffrey A; Jeon, Dong-O; Pelaia II, Tom; Plum, Michael A; Shishlo, Andrei P; Stockli, Martin P; Zhang, Yan

    2008-01-01

    The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H{sup -} injector, capable of producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The 2.5 MeV beam from the Front End is accelerated to 87 MeV in the Drift Tube Linac, then to 186 MeV in a Coupled-Cavity Linac and finally to 1 GeV in the Superconducting Linac. With the completion of beam commissioning, the accelerator complex began operation in June 2006 and beam power is being gradually ramped up toward the design goal. Operational experience with the injector and linac will be presented including chopper performance, longitudinal beam dynamics study, and the results of a beam loss study.

  16. Status of the Linac Coherent Light Source

    SciTech Connect

    Galayda, John N.; /SLAC

    2011-11-04

    The Linac Coherent Light Source (LCLS) is a free electron laser facility in construction at Stanford Linear Accelerator Center. It is designed to operate in the wavelength range 0.15-1.5 nanometers. At the time of this conference, civil construction of new tunnels and buildings is complete, the necessary modifications to the SLAC linac are complete, and the undulator system and x-ray optics/diagnostics are being installed. The electron gun, 135 MeV injector linac and 250 MeV bunch compressor were commissioned in 2007. Accelerator commissioning activities are presently devoted to the achievement of performance goals for the completed 14 GeV linac.

  17. Design studies of SSC coupled cavity linac

    SciTech Connect

    Chang, C.R.; Bhandari, R.; Funk, W.; Raparia, D.; Watson, J.

    1991-05-01

    The SSC coupled cavity linac (CCL) will be a side coupled structure operating at 1284 MHz to accelerate a nominal 25 mA H{sup {minus}} beam from 70 MeV to 600 MeV. We present results of both cavity design and beam dynamic studies. Each accelerating cavity is optimized by SUPERFISH; coupled cavity characteristics in the region of low-, mid- and high-energies are checked by MAFIA-3D. MAFIA-3D was also used to design the bridge coupler systems. The beam dynamics and error analysis are simulated by CCLDYN and CCLTRACE. Possible future upgrade of the CCL to 1 GeV is also discussed. 2 refs., 6 figs.

  18. High duty factor plasma generator for CERN's Superconducting Proton Linac.

    PubMed

    Lettry, J; Kronberger, M; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, J-M; Küchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

    2010-02-01

    CERN's Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN's PS-Booster. Its ion source is a noncesiated rf driven H(-) volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H(-) during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the Large Hadron Collider. It consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H(-) during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H(-) plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the required heat dissipation and maintains the original functionality. Materials with higher thermal conductivity are selected and, wherever possible, thermal barriers resulting from low pressure contacts are removed by brazing metals on insulators. The AlN plasma chamber cooling circuit is inspired from the approach chosen for the cesiated high duty factor rf H(-) source operating at SNS.

  19. Linac4 low energy beam measurements with negative hydrogen ions

    NASA Astrophysics Data System (ADS)

    Scrivens, R.; Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T.

    2014-02-01

    Linac4, a 160 MeV normal-conducting H- linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H- beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  20. Linac4 low energy beam measurements with negative hydrogen ions

    SciTech Connect

    Scrivens, R. Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T.

    2014-02-15

    Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  1. Linac design for the European spallation source

    SciTech Connect

    Klein, H.

    1995-10-01

    A study group has started to develop a conceptual design for a European Spallation Source (ESS). This pulsed 5 MW source presently consists of a 1.334 GeV linac and two compressor rings. In the following mainly the high intensity linac part will be discussed, which has some features of interest for accelerators for transmutation of radioactive waste too.

  2. Dual-axis energy recovery linac.

    SciTech Connect

    Wang, C.-x.; Noonan, J.; Lewellen, J.

    2007-01-01

    In this paper we propose a new type of energy-recovery linac (ERL) for ERL applications. The envisioned dualaxis energy-recovery linac allows energy recovery of parallel beams, accelerating/decelerating along different axes, via the same dual-axis superconducting cavity. This new scheme offers many advantages over conventional ERLs in various applications. Preliminary feasibility considerations are presented.

  3. Induction linacs and pulsed power

    SciTech Connect

    Caporaso, G.J.

    1995-07-11

    Progress in electronic power conversion technology is making possible a new class of induction linacs that can operate at extremely high repetition rates. Advances in insulator technology, pulse forming line design and switching may also lead to a new type of high current accelerator with accelerating gradients at least an order of magnitude greater than those attainable today. The evolution of the induction accelerator pulsed power system will be discussed along with some details of these emerging technologies which are at the frontiers of accelerator technology.

  4. High gradient linac for proton therapy

    NASA Astrophysics Data System (ADS)

    Benedetti, S.; Grudiev, A.; Latina, A.

    2017-04-01

    Proposed for the first time almost 30 years ago, the research on radio frequency linacs for hadron therapy experienced a sparkling interest in the past decade. The different projects found a common ground on a relatively high rf operating frequency of 3 GHz, taking advantage of the availability of affordable and reliable commercial klystrons at this frequency. This article presents for the first time the design of a proton therapy linac, called TULIP all-linac, from the source up to 230 MeV. In the first part, we will review the rationale of linacs for hadron therapy. We then divided this paper in two main sections: first, we will discuss the rf design of the different accelerating structures that compose TULIP; second, we will present the beam dynamics design of the different linac sections.

  5. SNS LINAC RF control system.

    SciTech Connect

    Regan, A. H.; Kwon, S. I.; Prokop, M. S.; Rohlev, T. S.; Thomson, D. W.; Ma, H.

    2002-01-01

    The SNS linac RF control system (RFCS) is currently in development. A system is being installed in a superconducting test stand at Jefferson Laboratory presently. Two systems will soon be installed at Oak Ridge National Laboratory (ORNL) and more are due to be installed early next year. The RF control system provides field control for the entire SNS linac, including an RFQ and 6 DTL cavities at 402.5 MHz as well as three different types of cavities at of 805 MHz: 4 CCL cavities, 36 medium beta superconducting (SRF) cavities, and 45 high beta superconducting cavities. In addition to field control, it provides cavity resonance control, and incorporates high power protect functions. This paper will discuss the RFCS design to date, with emphasis on the challenges of providing a universal digital system for use on each of the individual cavity types. The RF control system hardware has been designed to minimize the amount of changes for all of the applications. Through software/firmware modification and changing a couple of frequency-dependent filters, the same control system design can be used for all five cavity types. The SNS is the first to utilize SRF cavities for a pulsed high-current proton accelerator, thereby making RF control especially challenging.

  6. Design of a 10 MeV normal conducting CW proton linac based on equidistant multi-gap CH cavities

    NASA Astrophysics Data System (ADS)

    Li, Zhi-Hui

    2015-09-01

    Continuous wave (CW) high current proton linacs have wide applications as the front end of high power proton machines. The low energy part of such a linac is the most difficult and there is currently no widely accepted solution. Based on the analysis of the focusing properties of the CW low energy proton linac, a 10 MeV low energy normal conducting proton linac based on equidistant seven-gap Cross-bar H-type (CH) cavities is proposed. The linac is composed of ten 7-gap CH cavities and the transverse focusing is maintained by quadrupole doublets located between the cavities. The total length of the linac is less than 6 meters and the average acceleration gradient is about 1.2 MeV/m. The electromagnetic properties of the cavities are investigated by Microwave Studio. At the nominal acceleration gradient the maximum surface electric field in the cavities is less than 1.3 times the Kilpatrick limit, and the Ohmic loss of each cavity is less than 35 kW. Multi-particle beam dynamics simulations are performed with Tracewin code, and the results show that the beam dynamics of the linac are quite stable, the linac has the capability to accelerate up to 30 mA beam with acceptable dynamics behavior. Supported by National Natural Science Foundation of China (11375122, 91126003)

  7. LYRAN: A program for the analysis of linac beam dynamics

    NASA Astrophysics Data System (ADS)

    Lu, J.-Q.; Ben-Zvi, I.; Cramer, J. G.

    1987-12-01

    The FORTRAN program LYRAN has been written for use in analyzing the beam dynamics of superconducting heavy ion linacs. The program is based on the program LYRA developed by A.H. Scholldorf at SUNY Stony Brook, but that original program has been extensively extended, modified, and restructed. LYRAN transports a group of input particles randomly distributed on a selected distribution function through linac elements which include rf accelerating and bunching elements, dipole and quadrupole magnets, electrostatic elements, and drift spaces. Second order corrections to dipole and quadrupole fields are included. A nonlinear optimization routine is incorporated, providing fast and efficient determination of accelerator configurations and parameter settings that provide desired beam properties. Beam envelope plotting is also included to provide a graphic display of beam characteristics.

  8. Multi-beam RFQ linac structure for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Hayashizaki, Noriyosu; Ishibashi, Takuya; Ito, Taku; Hattori, Toshiyuki

    2009-07-01

    Both the RF linear accelerator (linac) and the linear induction accelerator have been considered as injectors in a driver system for heavy ion fusion (HIF). In order to relax beam defocusing by space charge effect in the low-energy region, the accelerating beams that were merged and had their beam currents increased by the funnel tree system are injected into storage rings. A multi-beam linac that accelerates multiple beams in an accelerator cavity has the advantages of cost reduction and downsizing of the system. We modeled the multi-beam Interdigital-H type radio frequency quadruple (IH-RFQ) cavities with the different beam numbers and evaluated the electromagnetic characteristics by simulation. As a result, the reasonable ranges of their configuration were indicated for a practical use.

  9. Status and operation of the Linac4 ion source prototypes

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Aguglia, D.; Andersson, P.; Bertolo, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; Chaudet, E.; Gil-Flores, J.; Guida, R.; Hansen, J.; Hatayama, A.; Koszar, I.; Mahner, E.; Mastrostefano, C.; Mathot, S.; Mattei, S.; Midttun, Ø.; Moyret, P.; Nisbet, D.; Nishida, K.; O'Neil, M.; Ohta, M.; Paoluzzi, M.; Pasquino, C.; Pereira, H.; Rochez, J.; Sanchez Alvarez, J.; Sanchez Arias, J.; Scrivens, R.; Shibata, T.; Steyaert, D.; Thaus, N.; Yamamoto, T.

    2014-02-01

    CERN's Linac4 45 kV H- ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma, and pulsed high voltages are described. The first experimental results of two prototypes relying on 2 MHz RF-plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H- beam of 16-22 mA which has successfully been used for the commissioning of the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator, and chopper of Linac4.

  10. Status and operation of the Linac4 ion source prototypes.

    PubMed

    Lettry, J; Aguglia, D; Andersson, P; Bertolo, S; Butterworth, A; Coutron, Y; Dallocchio, A; Chaudet, E; Gil-Flores, J; Guida, R; Hansen, J; Hatayama, A; Koszar, I; Mahner, E; Mastrostefano, C; Mathot, S; Mattei, S; Midttun, Ø; Moyret, P; Nisbet, D; Nishida, K; O'Neil, M; Ohta, M; Paoluzzi, M; Pasquino, C; Pereira, H; Rochez, J; Sanchez Alvarez, J; Sanchez Arias, J; Scrivens, R; Shibata, T; Steyaert, D; Thaus, N; Yamamoto, T

    2014-02-01

    CERN's Linac4 45 kV H(-) ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma, and pulsed high voltages are described. The first experimental results of two prototypes relying on 2 MHz RF-plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H(-) beam of 16-22 mA which has successfully been used for the commissioning of the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator, and chopper of Linac4.

  11. A study of a test APF-IH type linac as an injector for cancer therapy

    NASA Astrophysics Data System (ADS)

    Hattori, T.; Yamamoto, K.; Hayashizaki, N.; Kashiwagi, H.; Takahashi, Y.; Hata, T.; Okada, S.; Sugita, T.; Aoki, M.; Okamura, M.; Yamada, S.; Osvath, E.; Dudu, D.; Vata, I.

    2002-04-01

    We are studying a heavy-ion interdigital H (IH) type linear accelerator as an injector for a cancer therapy synchrotron. The compact IH linac accelerates C 4+ ions from 65 keV/u up to 6 MeV/u with an alternating phase focus (APF) structure. The linac cavity is 3.1 m in length and operates at a frequency of 100 MHz. A test APF-IH linac was designed to accelerate C 4+ ions from 40 keV/u to 2 MeV/u with an operating frequency of 100 MHz. From particle orbit calculations, using an energy width of ±0.2%, this linac can accept a transverse emittance of 100 π mm mrad, a longitudinal phase of 35° and a beam intensity of several 100 μA. The test cavity has 1.4 m in length and 56 cm in diameter. We made a basic, half-scale model cavity of this linac and plan to measure its RF characteristics. Using the results of these measurements, a final design of this linac will be determined.

  12. Operating experience with the ALS linac

    SciTech Connect

    Selph, F.; Massoletti, D.

    1991-05-01

    The linac injector for the Advanced Light Source (ALS) at LBL was recently put into operation. Energy is 50 MeV, frequency 3 GHz. The electron gun delivers up to 6nC in a 3.0-ns bunch at 120 kV. A train of bunches is injected into a 1-Hz booster and accelerated to 1.5 GHz for storage ring injection. A magnetic analysis system is used for optimizing the linac. Measured beam properties from the gun and after acceleration in the linac are described. 9 refs., 3 figs.

  13. A cryomodule for the RIA driver linac.

    SciTech Connect

    Fuerst, J. D.; Shepard, K. W.

    2002-10-25

    We present a cryomodule design for the superconducting linacs for the proposed Rare Isotope Accelerator Facility (RIA). This paper discusses the design of a cryomodule for all the drift-tube-loaded superconducting cavities required for the machine. The same basic design will be used for the low and medium velocity sections of the driver linac and also for sections of the radioactive ion beam (RIB) linac. Fundamental design choices such as separate vs. common beam and insulating vacuum spaces are driven by the clean fabrication techniques required for optimum cavity performance. The design can be adapted to a variety of cavity geometries.

  14. INJECTOR LINAC FOR THE BNL SUPER NEUTRINO BEAM PROJECT.

    SciTech Connect

    RAPARIA, D.; ALESSI, J.; RUGGIERO, A.; WENG, W.T.

    2005-05-16

    BNL plans to upgrade the AGS proton beam power from the present 0.14 MW to higher than 1.0 MW and beyond for a neutrino facility. We have examined possible upgrade to the AGS accelerator complex that would meet the requirements of the proton beam of 1.0 MW for neutrino superbeam facility. The major contribution for the higher power is from the increase of the repetition rate of the AGS from 0.3 Hz to 2.5 Hz, with moderate increase from the intensity. To increase the AGS repetition rate we are proposing to replace booster with a 1.5 GeV linac. We will replace part of existing 200 MeV linac with coupled cavity structure from 116 MeV to 400 MeV and then add an additional 1.1 GeV superconducting linac to reach a final energy of 1.5 GeV for direct H{sup -} injection into the AGS. We will present possible choices for the upgrade and our choice and its design.

  15. Injector linac for the MESA facility

    SciTech Connect

    Heine, R.

    2013-11-07

    In this paper we present several possible configurations of an injector linac for the upcoming Mainz Energy-recovering Superconducting Accelerator (MESA) [1] and discuss their suitability for the project.

  16. Equipartitioning in a high current proton linac

    SciTech Connect

    Young, L.M.

    1997-08-01

    The code PARMILA simulates the beam transmission through the Accelerator for the Production of Tritium (APT) linac. The beam is equipartitioned when the longitudinal and transverse temperatures are equal. This paper explores the consequence of equipartitioning in the APT linac. The simulations begin with a beam that starts at the ion-source plasma surface. PARMILA tracks the particles from the RFQ exit through the 1.7-GeV linac. This paper compares two focusing schemes. One scheme uses mostly equal strength quadrupoles. The equipartitioning scheme uses weaker focusing in the high-energy portion of the linac. The RMS beam size with the equipartitioning scheme is larger, but the relative size of the halo is less than in the equal-strength design.

  17. Dark current model for ILC main linac

    SciTech Connect

    Solyak, N.; Romanov, G.; Mokhov, N.V.; Eidelman, Y.; Tam, Wai-Ming; /Indiana U.

    2008-06-01

    In the ILC Main Linac, the dark current electrons, generated in SRF cavity can be accelerated to hundreds of MeV before being kicked out by quadrupoles and thus will originate electromagnetic cascade showers in the surrounding materials. Some of the shower secondaries can return back into vacuum and be re-accelerated again. The preliminary results of simulation of the dark current generation in ILC cavity, its dynamics in linac are discussing in this paper.

  18. Advanced Light Source Linac subharmonic buncher cavities

    SciTech Connect

    Lo, C.C.; Taylor, B.; Lancaster, H.; Guigli, J.

    1989-03-01

    The Linear Accelerator (Linac) in the Advanced Light Source (ALS) is designed to provide either single or multiple bunches of 50 MeV electrons for the booster synchrotron. Three bunchers are used in the Linac. The 3 GHz S band buncher has been described elsewhere. This report deals with the two lower subharmonic bunchers. One operates at 124.914 MHz while the other operates at 499.654 MHz. 12 refs., 2 figs.

  19. Proposed FNAL 750 KeV Linac Injector Upgrade

    SciTech Connect

    Tan, C.Y.; Bollinger, D.S.; Schmidt, C.W.; /Fermilab

    2009-04-01

    The present FNAL linac H{sup -} injector has been operational since 1978 and consists of a magnetron H{sup -} source and a 750 keV Cockcroft-Walton Accelerator. The proposed upgrade to this injector is to replace the present magnetron source having a rectangular aperture with a circular aperture, and to replace the Cockcroft-Walton with a 200 MHz RFQ. Operational experience at other laboratories has shown that the upgraded source and RFQ will be more reliable and require less manpower than the present system.

  20. Simulation of large acceptance LINAC for muons

    SciTech Connect

    Miyadera, H; Kurennoy, S; Jason, A J

    2010-01-01

    There has been a recent need for muon accelerators not only for future Neutrino Factories and Muon Colliders but also for other applications in industry and medical use. We carried out simulations on a large-acceptance muon linac with a new concept 'mixed buncher/acceleration'. The linac can accept pions/muons from a production target with large acceptance and accelerate muon without any beam cooling which makes the initial section of muon-linac system very compact. The linac has a high impact on Neutrino Factory and Muon Collider (NF/MC) scenario since the 300-m injector section can be replaced by the muon linac of only 10-m length. The current design of the linac consists of the following components: independent 805-MHz cavity structure with 6- or 8-cm-radius aperture window; injection of a broad range of pion/muon energies, 10-100 MeV, and acceleration to 150 - 200 MeV. Further acceleration of the muon beam are relatively easy since the beam is already bunched.

  1. Experimental results of the laserwire emittance scanner for LINAC4 at CERN

    NASA Astrophysics Data System (ADS)

    Hofmann, Thomas; Boorman, Gary E.; Bosco, Alessio; Bravin, Enrico; Gibson, Stephen M.; Kruchinin, Konstantin O.; Raich, Uli; Roncarolo, Federico; Zocca, Francesca

    2016-09-01

    Within the framework of the LHC Injector Upgrade (LIU), the new LINAC4 is currently being commissioned to replace the existing LINAC2 proton source at CERN. After the expected completion at the end of 2016, the LINAC4 will accelerate H- ions to 160 MeV. To measure the transverse emittance of the H- beam, a method based on photo-detachment is proposed. This system will operate using a pulsed laser with light delivered via an optical fibre and subsequently focused onto the H- beam. The laser photons have sufficient energy to detach the outer electron and create H0/e- pairs. In a downstream dipole, the created H0 particles are separated from the unstripped H- ions and their distribution is measured with a dedicated detector. By scanning the focused laser beam across the H- beam, the transverse emittance of the H- beam can be reconstructed. This paper will first discuss the concept, design and simulations of the laser emittance scanner and then present results from a prototype system used during the 12 MeV commissioning of the LINAC4.

  2. A CONCEPTUAL 3-GEV LANSCE LINAC UPGRADE FOR ENHANCED PROTON RADIOGRAPHY

    SciTech Connect

    Garnett, Robert W; Rybarcyk, Lawrence J.; Merrill, Frank E.; O'Hara, James F.; Rees, Daniel E.; Walstrom, Peter L.

    2012-05-14

    A conceptual design of a 3-GeV linac upgrade that would enable enhanced proton radiography at the Los Alamos Neutron Science Center (LANSCE) is presented. The upgrade is based on the use of superconducting accelerating cavities to increase the present LANSCE linac output energy from 800 MeV to 3 GeV. The LANSCE linac currently provides negative hydrogen ion (H{sup -}) and proton (H{sup +}) beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. Required changes to the front-end, the accelerating structures, and to the RF systems to meet the new performance goals, and changes to the existing beam switchyard to maintain operations for a robust user program are also described.

  3. Acceleration test of TIT-IHQ linac for heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Takashi, Ito; Noriyosu, Hayashizaki; Shinjiro, Matsui; Kimikazu, Sasa; Schubert, H.; Osvath, E.; Toshiyuki, Hattori

    2000-03-01

    We have developed an interdigital-H quadrupole (IHQ) linac for industrial applications. This linac was designed to accelerate particles with charge to mass ratio greater than 1/16 from 21.8 up to 145 keV/u. The particles are focused by an electric quadrupole field exited by fingertips on the drift tubes. This IHQ linac was installed at Tokyo Institute of Technology in 1997 and some tests such as low power tuning and vacuum tests were done. Then, proton acceleration tests ware performed in 1998, and the proton beam was successfully accelerated up to the designed energy. As a result of this experiment, the effective shunt impedance was determined to be 210 MΩ/m, the required RF power consumption was 93 W and the beam transmission rate was about 9%. In this paper, the results of the high power acceleration test with H + ion are described.

  4. Analysis of beam loss mechanism in the Project X linac

    SciTech Connect

    Carneiro, J.-P.; Lebedev, V.; Nagaitsev, S.; Ostiguy, J.-F.; Solyak, N.; /Fermilab

    2011-03-01

    Minimization of the beam losses in a multi-MW H{sup -} linac such as ProjectX to a level below 1 W/m is a challenging task. The impact of different mechanism of beam stripping, including stripping in electric and magnetic fields, residual gas, blackbody radiation and intra-beam stripping, is analyzed. Other sources of beam losses are misalignements of beamline elements and errors in RF fields and phases. We present in this paper requirements for dynamic errors and correction schemes to keep beam losses under control.

  5. Title I Design Report: Fermilab Linac Upgrade

    SciTech Connect

    Fermilab,

    1990-02-01

    The Fermilab Linac Upgrade Project is motivated by the requirement to increase Collider luminosity which will increase the physics discovery potential of the Tevatron Collider. The Linac Upgrade is one of several steps which will increase the Collider luminosity. The basic accelerator physics motivation for the project is the following chain of logic. The existing Main Ring Accelerator has a fixed, relatively small admittance for 8 GeV protons injected from the Booster Accelerator. While it is demonstrably p088ible to increase the number of protons accelerated in the Booster, space charge effects at injection into the Booster from the Linac increase the emittance of the beam delivered from the Booster to the Main Ring beyond the available admittance of the Main Ring. An increase in the energy of the protons injected into the Booster, however, will reduce the emittance growth due to the space charge effects at injection. Therefore, for a given admittance into the Main Ring, a greater number of protons will be accelerated in the Booster with a matching emittance if the injection energy is raised. The goal of the Linac Upgrade is to double the output energy of the Linac from 200MeV to 400MeV.

  6. RFI-Based Ion Linac Systems

    NASA Astrophysics Data System (ADS)

    Swenson, Donald A.

    A new company, Ion Linac Systems, Inc., has been formed to promote the development, manufacture, and marketing of intense, RFI-based, Ion Linac Systems. The Rf Focused Interdigital (RFI) linac structure was invented by the author while at Linac Systems, LLC. The first step, for the new company, will be to correct a flaw in an existing RFI-based linac system and to demonstrate "good transmission" through the system. The existing system, aimed at the BNCT medical application, is designed to produce a beam of 2.5 MeV protons with an average beam current of 20 mA. In conjunction with a lithium target, it will produce an intense beam of epithermal neutrons. This system is very efficient, requiring only 180 kW of rf power to produce a 50 kW proton beam. In addition to the BNCT medical application, the RFI-based systems should represent a powerful neutron generator for homeland security, defence applications, cargo container inspection, and contraband detection. The timescale to the demonstration of "good transmission" is early fall of this year. Our website is www.ionlinacs.com.

  7. Application of RF Superconductivity to High Current Linac

    SciTech Connect

    Chan K.C.D.

    1998-09-13

    In 1997, the authors initiated a development program in Los Alamos for high-current superconducting proton-linac technology to build prototypes components of this linac to demonstrate the feasibility. The authors are building 700-MHz niobium cavities with elliptical shapes, as well as power couplers to transfer high RF power to these cavities. The cavities and power couplers will be integrated in cryostats as linac cryomodules. In this paper, they describe the linac design and the status of the development program.

  8. ARIEL e-LINAC: Commissioning and Development

    NASA Astrophysics Data System (ADS)

    Laxdal, R. E.; Zvyagintsev, V.

    2016-09-01

    A superconducting electron Linac (e-Linac) will be a part of the ARIEL facility for the production of radioactive ion beams (RIB) at TRIUMF. The e-Linac will consist of five 1.3GHz 9-cell cavities in three cryomodules delivering a 50MeV 10mA beam. The baseline operation will be single pass but a re-circulating ring is planned to allow either energy boost or energy recovery operation. The first stage of the accelerator which consists of two cryomodules has been successfully commissioned in 2014. The paper will discuss the superconducting radio-frequency (SRF) challenges of the accelerator. Cavities, crymodules and RF system design, preparation, and performance will be presented.

  9. Optics Simulations for the NLC Main Linac

    SciTech Connect

    Woodley, Mark D

    2001-06-15

    Focusing in the NLC main linac will be provided mainly by hybrid permanent magnet quadrupoles which have limited variability in strength. When the energy profile of the linac changes, due to normal cycling of rf sources, mismatches in the beam optics can be generated if the quadrupole strengths are not rescaled to the new energy profile. These mismatches can lead to emittance dilution. In addition, betatron phase advance changes caused by the mismatch can adversely affect the beam trajectory, leading to emittance dilution from dispersion and wakefields. This paper describes the results of simulations of these processes, undertaken in an attempt to determine whether or not rescaling of the quadrupoles will be necessary in the NLC main linac.

  10. Coupled-cavity drift-tube linac

    DOEpatents

    Billen, James H.

    1996-01-01

    A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the .pi.-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is .beta..lambda., where .lambda. is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a .pi./2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range.

  11. Energy Recovery Linacs for Commercial Radioisotope Production

    SciTech Connect

    Sy, Amy; Krafft, Geoffrey A.; Johnson, Rolland; Roberts, Tom; Boulware, Chase; Hollister, Jerry

    2015-09-01

    Photonuclear reactions with bremsstrahlung photon beams from electron linacs can generate radioisotopes of critical interest. An SRF Energy Recovery Linac (ERL) provides a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes in a more compact footprint and at a lower cost than those produced by conventional reactor or ion accelerator methods. Use of an ERL enables increased energy efficiency of the complex through energy recovery of the waste electron beam, high electron currents for high production yields, and reduced neutron production and shielding activation at beam dump components. Simulation studies using G4Beamline/GEANT4 and MCNP6 through MuSim, as well as other simulation codes, will design an ERL-based isotope production facility utilizing bremsstrahlung photon beams from an electron linac. Balancing the isotope production parameters versus energy recovery requirements will inform a choice of isotope production target for future experiments.

  12. Induced radioisotopes in a linac treatment hall.

    PubMed

    Vega-Carrillo, Héctor René; de Leon-Martinez, Héctor Asael; Rivera-Perez, Esteban; Luis Benites-Rengifo, Jorge; Gallego, Eduardo; Lorente, Alfredo

    2015-08-01

    When linacs operate above 8MV an undesirable neutron field is produced whose spectrum has three main components: the direct spectrum due to those neutrons leaking out from the linac head, the scattered spectrum due to neutrons produced in the head that collides with the nuclei in the head losing energy and the third spectrum due to room-return effect. The third category of spectrum has mainly epithermal and thermal neutrons being constant at any location in the treatment hall. These neutrons induce activation in the linac components, the concrete walls and in the patient body. Here the induced radioisotopes have been identified in concrete samples located in the hall and in one of the wedges. The identification has been carried out using a gamma-ray spectrometer.

  13. Neutron and photon spectra in LINACs.

    PubMed

    Vega-Carrillo, H R; Martínez-Ovalle, S A; Lallena, A M; Mercado, G A; Benites-Rengifo, J L

    2012-12-01

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10(-6) and 1 MeV. Neutron and the Bremsstrahlung spectra show the same features regardless of the linac voltage.

  14. S-Band Loads for SLAC Linac

    SciTech Connect

    Krasnykh, A.; Decker, F.-J.; LeClair, R.; /INTA Technologies, Santa Clara

    2012-08-28

    The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.

  15. ILC Linac R&D at SLAC

    SciTech Connect

    Adolphsen, C.; /SLAC

    2006-08-09

    Since the ITRP recommendation in August 2004 to use superconducting rf technology for a next generation linear collider, the former NLC Group at SLAC has been actively pursuing a broad range of R&D for this collider (the ILC). In this paper, the programs concerning linac technology are reviewed. Current activities include the development of a Marx-style modulator and a 10 MW sheet-beam klystron, operation of an L-band (1.3 GHz) rf source using an SNS HVCM modulator and commercial klystrons, design of a more efficient and less costly rf distribution system, construction of a coupler component test stand, fabrication of a prototype positron capture cavity, beam tests of prototype S-band linac beam position monitors and preparations for magnetic center stability measurements of a prototype SC linac quad.

  16. Progress of APT superconducting linac engineering development

    SciTech Connect

    Chan, K.C.D.; Campbell, B.M.; Gentzlinger, R.C.; Balleyguier, P.; Waynert, J.A.; Haynes, W.B.; Kelley, J.P.; Rusnak, B.; Safa, H.

    1998-12-31

    The authors initiated a program to develop superconducting (SC) RF for high-power proton linacs. These linacs are useful in accelerator-driven transmutation technologies and the Accelerator Production of Tritium (APT) Project. They are developing multicell niobium cavities with elliptical-cell shapes at 700 MHz. These cavities, unlike most elliptical cavities for electron accelerators, are designed to accelerate protons at {beta}<1. Coaxial power couplers are being developed to transmit high (250 kW) CW RF power to the cavities. The couplers will be tested both at ambient temperature and at cryogenic temperature (2K). Their power handling and thermal properties will be measured. The cavities and power couplers will be integrated into a prototype cryomodule. The cryomodule will be tested and characterized with RF under cryogenic conditions required for a high-power proton linac. This paper describes the status of this program.

  17. Coupled-cavity drift-tube linac

    DOEpatents

    Billen, J.H.

    1996-11-26

    A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the {pi}-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is {beta}{lambda}, where {lambda} is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range. 5 figs.

  18. INCREASED UNDERSTANDING OF BEAM LOSSES FROM THE SNS LINAC PROTON EXPERIMENT

    SciTech Connect

    Aleksandrov, Alexander V; Shishlo, Andrei P; Plum, Michael A; Lebedev, Valerie; Laface, Emanuele; Galambos, John D

    2013-01-01

    Beam loss is a major concern for high power hadron accelerators such as the Spallation Neutron Source (SNS). An unexpected beam loss in the SNS superconducting linac (SCL) was observed during the power ramp up and early operation. Intra-beam-stripping (IBS) loss, in which interactions between H- particles within the accelerated bunch strip the outermost electron, was recently identified as a possible cause of the beam loss. A set of experiments using proton beam acceleration in the SNS linac was conducted, which supports IBS as the primary beam loss mechanism in the SNS SCL.

  19. Beam position monitoring in the AGS Linac to Booster transfer line

    SciTech Connect

    Shea, T.J.; Brodowski, J.; Witkover, R.

    1991-01-01

    A beam position monitor system has been developed and used in the commissioning of Brookhaven's Linac to Booster transfer line. This line transports a chopped, RF modulated H- beam from the 200 MeV Linac to the AGS Booster. Over a 15dB dynamic range in beam current, the position monitor system provides a real-time, normalized position signal with an analog bandwidth of about 20 MHz. Seven directional coupler style pickups are installed in the line with each pickup sensing both horizontal and vertical position. Analog processing electronics are located in the tunnel and incorporate the amplitude modulation to phase modulation normalization technique. To avoid interference from the 200 MHz linac RF system, processing is performed at 400 MHz. This paper will provide a system overview and report results from the commissioning experience.

  20. Beam position monitoring in the AGS Linac to Booster transfer line

    SciTech Connect

    Shea, T.J.; Brodowski, J.; Witkover, R.

    1991-12-31

    A beam position monitor system has been developed and used in the commissioning of Brookhaven`s Linac to Booster transfer line. This line transports a chopped, RF modulated H- beam from the 200 MeV Linac to the AGS Booster. Over a 15dB dynamic range in beam current, the position monitor system provides a real-time, normalized position signal with an analog bandwidth of about 20 MHz. Seven directional coupler style pickups are installed in the line with each pickup sensing both horizontal and vertical position. Analog processing electronics are located in the tunnel and incorporate the amplitude modulation to phase modulation normalization technique. To avoid interference from the 200 MHz linac RF system, processing is performed at 400 MHz. This paper will provide a system overview and report results from the commissioning experience.

  1. An electron front end for the Fermilab multi-species 8 GeV SCRF linac

    SciTech Connect

    Philippe R.-G. Piot; G W Foster

    2004-07-08

    Fermilab is considering a 8 GeV superconducting linac whose primary mission is to serve as an intense H{sup -} injector for the main injector. This accelerator is also planned to be used for accelerating various other species (e.g. electrons, protons and muons). In the present paper we investigate the possibility of such a linac to accelerate high-brightness electron beam up to {approx} 7 GeV. We propose a design for the electron front end based on a photoinjector and consider the electron beam dynamics along the linac. Start-to-end simulations of the full accelerator for electrons are presented. Finally the potential applications of such an electron beam are outlined.

  2. Beam dynamics design of the muon linac high-beta section

    NASA Astrophysics Data System (ADS)

    Kondo, Y.; Hasegawa, K.; Otani, M.; Mibe, T.; Yoshida, M.; Kitamura, R.

    2017-07-01

    A muon linac development for a new muon g-2 experiment is now going on at J-PARC. Muons from the muon beam line (H line) at the J-PARC muon science facility are once stopped in a silica-aerogel target, and room temperature muoniums are evaporated from the aerogel. They are dissociated with lasers, then accelerated up to 212 MeV using a linear accelerator. For the accelerating structure from 40 MeV, disk-loaded traveling-wave structure is applicable because the particle beta is more than 0.7. The structure itself is similar to that for electron linacs, however, the cell length should be harmonic to the increase of the particle velocity. In this paper, the beam dynamics design of this muon linac using the disk-loaded structure (DLS) is described.

  3. Neutron sources based on medical Linac

    NASA Astrophysics Data System (ADS)

    Costa, M.; Durisi, E.; Monti, V.; Visca, L.; Zanini, A.; Giannini, G.

    2016-11-01

    The paper proposes the study of a novel photo-neutron source based on a medical high-energy electron Linac. Previous studies by the authors already demonstrated the possibility to obtain with this technique a thermal neutron flux of the order of 107 cm-2 s-1 . This paper shows possible Linac's setup and a new photo-converter design to reach a thermal neutron flux around 6×107 cm-2 s-1 , keeping a reasonable high quality of the beam with respect to fast neutron and gamma contaminations.

  4. Proton linacs for boron neutron capture therapy

    SciTech Connect

    Lennox, A.J. |

    1993-08-01

    Recent advances in the ability to deliver boron-containing drugs to brain tumors have generated interest in {approximately}4 MeV linacs as sources of epithermal neutrons for radiation therapy. In addition, fast neutron therapy facilities have been studying methods to moderate their beams to take advantage of the high cross section for epithermal neutrons on boron-10. This paper describes the technical issues involved in each approach and presents the motivation for undertaking such studies using the Fermilab linac. the problems which must be solved before therapy can begin are outlined. Status of preparatory work and results of preliminary measurements are presented.

  5. Linac Coherent Light Source Electron Beam Collimation

    SciTech Connect

    Wu, J.; Dowell, D.; Emma, P.; Limborg-Deprey, C.; Schmerge, J.F.; /SLAC

    2007-04-27

    This paper describes the design and simulation of the electron beam collimation system in the Linac Coherent Light Source (LCLS). Dark current is expected from the gun and some of the accelerating cavities. Particle tracking of the expected dark current through the entire LCLS linac, from gun through FEL undulator, is used to estimate final particle extent in the undulator as well as expected beam loss at each collimator or aperture restriction. A table of collimators and aperture restrictions is listed along with halo particle loss results, which includes an estimate of average continuous beam power lost. In addition, the transverse wakefield alignment tolerances are calculated for each collimator.

  6. Error analysis in post linac to driver linac transport beam line of RAON

    NASA Astrophysics Data System (ADS)

    Kim, Chanmi; Kim, Eun-San

    2016-07-01

    We investigated the effects of magnet errors in the beam transport line connecting the post linac to the driver linac (P2DT) in the Rare Isotope Accelerator in Korea (RAON). The P2DT beam line is bent by 180-degree to send the radioactive Isotope Separation On-line (ISOL) beams accelerated in Linac-3 to Linac-2. This beam line transports beams with multi-charge state 132Sn45,46,47. The P2DT beam line includes 42 quadrupole, 4 dipole and 10 sextupole magnets. We evaluate the effects of errors on the trajectory of the beam by using the TRACK code, which includes the translational and the rotational errors of the quadrupole, dipole and sextupole magnets in the beam line. The purpose of this error analysis is to reduce the rate of beam loss in the P2DT beam line. The distorted beam trajectories can be corrected by using six correctors and seven monitors.

  7. A Stability of LCLS Linac Modulators

    SciTech Connect

    Decker, F.-J.; Krasnykh, A.; Morris, B.; Nguyen, M.; /SLAC

    2012-06-13

    Information concerning to a stability of LCLS RF linac modulators is allocated in this paper. In general a 'pulse-to-pulse' modulator stability (and RF phase as well) is acceptable for the LCLS commission and FEL programs. Further modulator stability improvements are possible and approaches are discussed based on our experimental results.

  8. Vibrational Stability of NLC Linac accelerating structure

    SciTech Connect

    Le Pimpec, Frederic

    2002-09-25

    The vibration of components of the NLC linac, such as accelerating structures and girders, is being studied both experimentally and analytically. Various effects are being considered including structural resonances and vibration caused by cooling water in the accelerating structure. This paper reports the status of ongoing work.

  9. Design and simulation of C6+ hybrid single cavity linac for cancer therapy with direct plasma injection scheme

    NASA Astrophysics Data System (ADS)

    Lu, Liang; Hattori, Toshiyuki; Hayashizaki, Noriyosu

    2012-10-01

    A hybrid single cavity (HSC) linac, whose structure is formed by combining a radio frequency quadrupole (RFQ) structure and a drift tube (DT) structure into one interdigital-H (IH) cavity, has been developed over a span of a few years by our research team [1]. In the present work, several different structures of an HSC linac are analyzed in order to achieve an optimum cavity electric field distribution and to enhance beam transmission. The proposed HSC linac design is a direct injector linac for a heavy ion synchrotron for radiotherapy. This design also has potential as a neutron source in boron neutron capture therapy. According to our simulations, an HSC linac accelerated C6+ ions from 25 keV/u up to 2 MeV/u in 1800 mm for a 94 kW feeding power with a 100 MHz operation. The detailed HSC linac structure design and the results of the cavity electromagnetic field simulation are reported in this paper.

  10. CABOTO, a high-gradient linac for hadrontherapy.

    PubMed

    Verdú-Andrés, Silvia; Amaldi, Ugo; Faus-Golfe, Angeles

    2013-07-01

    The field of hadrontherapy has grown rapidly in recent years. At present the therapeutic beam is provided by a cyclotron or a synchrotron, but neither cyclotrons nor synchrotrons present the best performances for hadrontherapy. The new generation of accelerators for hadrontherapy should allow fast active energy modulation and have a high repetition rate, so that moving organs can be appropriately treated in a reasonable time. In addition, a reduction of the dimensions and cost of the accelerators for hadrontherapy would make the acquisition and operation of a hadrontherapy facility more affordable, which would translate into great benefits for the potential hadrontherapy patients. The 'cyclinac', an accelerator concept that combines a cyclotron with a high-frequency linear accelerator (linac), is a fast-cycling machine specifically conceived to allow for fast active energy modulation. The present paper focuses on CABOTO (CArbon BOoster for Therapy in Oncology), a compact, efficient high-frequency linac that can accelerate C(6+) ions and H2 molecules from 150-410 MeV/u in ∼24 m. The paper presents the latest design of CABOTO and discusses its performances.

  11. CABOTO, a high-gradient linac for hadrontherapy

    PubMed Central

    Verdú-Andrés, Silvia; Amaldi, Ugo; Faus-Golfe, Ángeles

    2013-01-01

    The field of hadrontherapy has grown rapidly in recent years. At present the therapeutic beam is provided by a cyclotron or a synchrotron, but neither cyclotrons nor synchrotrons present the best performances for hadrontherapy. The new generation of accelerators for hadrontherapy should allow fast active energy modulation and have a high repetition rate, so that moving organs can be appropriately treated in a reasonable time. In addition, a reduction of the dimensions and cost of the accelerators for hadrontherapy would make the acquisition and operation of a hadrontherapy facility more affordable, which would translate into great benefits for the potential hadrontherapy patients. The ‘cyclinac’, an accelerator concept that combines a cyclotron with a high-frequency linear accelerator (linac), is a fast-cycling machine specifically conceived to allow for fast active energy modulation. The present paper focuses on CABOTO (CArbon BOoster for Therapy in Oncology), a compact, efficient high-frequency linac that can accelerate C6+ ions and H2 molecules from 150–410 MeV/u in ∼24 m. The paper presents the latest design of CABOTO and discusses its performances. PMID:23824121

  12. New high power linacs and beam physics

    SciTech Connect

    Wangler, T.P.; Gray, E.R.; Nath, S.; Crandall, K.R.; Hasegawa, K.

    1997-08-01

    New high-power proton linacs must be designed to control beam loss, which can lead to radioactivation of the accelerator. The threat of beam loss is increased significantly by the formation of beam halo. Numerical simulation studies have identified the space-charge interactions, especially those that occur in rms mismatched beams, as a major concern for halo growth. The maximum-amplitude predictions of the simulation codes must be subjected to independent tests to confirm the validity of the results. Consequently, the authors compare predictions from the particle-core halo models with computer simulations to test their understanding of the halo mechanisms that are incorporated in the computer codes. They present and discuss scaling laws that provide guidance for high-power linac design.

  13. LLRF System Upgrade for the SLAC Linac

    SciTech Connect

    Hong, Bo; Akre, Ron; Pacak, Vojtech; /SLAC

    2012-07-06

    The Linac Coherent Light Source (LCLS) at SLAC is in full user operation and has met the stability goals for stable lasing. The 250pC bunch can be compressed to below 100fS before passing through an undulator. In a new mode of operation a 20pC bunch is compressed to about 10fS. Experimenters are regularly using this shorter X-ray pulse and getting pristine data. The 10fS bunch has timing jitter on the order of 100fS. Physicists are requesting that the RF system achieve better stability to reduce timing jitter. Drifts in the RF system require longitudinal feedbacks to work over large ranges and errors result in reduced performance of the LCLS. A new RF system is being designed to help diagnose and reduce jitter and drift in the SLAC linac.

  14. LINAC radiosurgery in skull base meningiomas.

    PubMed

    Deinsberger, R; Tidstrand, J; Sabitzer, H; Lanner, G

    2004-12-01

    LINAC radiosurgery has provided increasing access and changed treatment strategies in patients with benign skull base meningiomas in recent years. From January 1996 to January 2003, 37 patients with skull base meningiomas were treated with LINAC radiosurgery. A combination of the University of Florida system and the X Knife System, developed by Radionics, was used in all patients. Eight patients were treated by microsurgical resection before radiosurgery, in two patients tumor recurrence was treated and in 29 patients LINAC radiosurgery was the initial treatment procedure. The median treatment volume was 5.9 mL (0.7 to 22 mL) and the median given dose was 14.6 Gy (12.8 to 18 Gy) prescribed to the 80 percent isodose line. The follow-up period is between 12 and 96 months, median 66 months. 12 patients (32.4 %) showed a significant reduction in tumor size, in 11 patients (29.7 %) there was significantly less contrast enhancement and in 13 patients (35.1 %) the skull base meningioma was without any change. In one patient (2.8 %) there was tumor growth 48 months after radiosurgery, so the tumor control rate was 97.2 %. Two patients (5.6 %) showed neurological worsening after radiosurgery, whereas the symptoms were transient in one patient. LINAC radiosurgery offers us an effective treatment modality and changes treatment strategies in skull base meningiomas towards a less aggressive surgical approach. By combining microsurgery and radiosurgery we can achieve high tumor control rates with an acceptable low morbidity and a high level of quality of life.

  15. Linac radiosurgery as a tool in neurosurgery.

    PubMed

    Deinsberger, R; Tidstrand, J

    2005-04-01

    Stereotactic radiosurgery is a radiation technique that uses a high radiation dose focused on a stereotactic defined intracranial target in single fraction with high precision. In the 1980s, linear accelerators were introduced as a tool for radiosurgery beneath the already accepted gamma unit. Technique and mechanical precision of LINACs have become equal to the gamma unit and LINAC radiosurgery became more and more used recently. From January 1996 to August 2003 we have treated 237 patients with LINAC radiosurgery. A combination of the University of Florida system and the X Knife System, developed by Radionics, was used in all patients. A number of 110 patients had 161 brain metastases treated, whereas the local tumor control rate was 89.4%. The 1-year survival rate was 54.9% with a median survival of 54 weeks. In 55 patients we have treated 57 meningiomas, mostly located at the skull base (37 out of 55 patients). Local tumor control rate in our patients with skull base meningiomas at 5-year follow up was 97.2%. In this time period, we have also treated acoustic schwannoma, glioma, pituitary adenoma, arteriovenous malformations and patients with trigeminal neuralgia. LINAC radiosurgery has become a daily tool in neurosurgery and changed treatment strategies especially in the treatment of brain metastases and skull base meningiomas towards a less aggressive and multimodality approach. It is not only an alternative to open surgery, but also a very effective adjuvant treatment modality in many neuro-oncological patients, which helps us to enhance tumor control rate, minimize morbidity and increase postoperative quality of life.

  16. PHOTOCATHODES FOR THE ENERGY RECOVERY LINACS.

    SciTech Connect

    RAO, T.; BURRILL, A.; CHANG, X.Y.; SMEDLEY, J.; ET AL.

    2005-03-19

    This paper presents an overview of existing and emerging technologies on electron sources that can service various Energy Recovering Linacs under consideration. Photocathodes that can deliver average currents from 1 mA to 1 A, the pros and cons associated with these cathodes are addressed. Status of emerging technologies such as secondary emitters, cesiated dispenser cathodes, field and photon assisted field emitters and super lattice photocathodes are also reviewed.

  17. Photocathodes for the energy recovery linacs

    SciTech Connect

    Rao, T; Burrill, A; Chang, X Y; Smedley, J; Nishitani, T; Garcia, C Hernandez; Poelker, M; Seddon, E; Hannon, F E; Sinclair, C K; Lewellen, J; Feldman, D

    2005-03-19

    This paper presents an overview of existing and emerging technologies on electron sources that can service various Energy Recovering Linacs under consideration. Photocathodes that can deliver average currents from 1 mA to 1 A, the pros and cons associated with these cathodes are addressed. Status of emerging technologies such as secondary emitters, cesiated dispenser cathodes, field and photon assisted field emitters and super lattice photocathodes are also reviewed.

  18. [Linac based radiosurgery; a technical report].

    PubMed

    Hayashi, H; Asaga, A; Sakudoh, M; Hoshino, S; Katsuta, S; Akine, Y

    1992-07-01

    A method for highly dose-localized irradiation using a linear accelerator (linac) for a brain tumor has been developed. The method requires a linac, a computed tomography (CT) system, a CT simulator, and a treatment planning system for radiotherapy, with which most major radiotherapy centers are equipped. To immobilize a patient during irradiation, a custom-made device made of synthetic material which became flexible with heating was used. With the CT system and the CT simulator the target was identified and geometrical data for positioning the tumor at a point to which x-ray beams were directed (an isocenter of the linac) were obtained. By rotating a treatment couch it was made possible for the x-ray source to rotate around the isocenter on multiple planes. Dose distribution obtained with this method was compared to that of the gamma unit and found comparable. Since the method requires no invasive procedure, it appears suitable for treatment, with fractionated irradiation, of malignant tumors.

  19. Advanced RF power sources for linacs

    SciTech Connect

    Wilson, P.B.

    1996-10-01

    In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

  20. Experiments and prospects for induction linac drivers

    SciTech Connect

    Keefe, D.

    1986-12-01

    In the last three years, the US program in Heavy Ion Fusion has concentrated on understanding the induction linac approach to a power-plant driver. In this method it is important that the beam current be maximized throughout the accelerator. Consequently, it is crucial to understand the space-charge limit in the AG transport system in the linac and, also, to achieve current amplification during acceleration to keep pace with the kinematical increase of this limit with energy. Experimental results on both these matters and also on the use of multiple beams (inside the same accelerating structure) will be described. A new examination of the most attractive properties of the induction linac for a fusion driver has clearly pointed to the advantage of using heavy ions with a charge-state greater than unity - perhaps q = 3 may be an optimum. This development places even greater importance on understanding space-charge limits and mechanisms for emittance growth; also, it will require a new emphasis on the development of a suitable ion source.

  1. Multiple beam induction linac research at LBL

    SciTech Connect

    Garvey, T.; Eylon, S.; Fessenden, T.J.; Hahn, K.; Henestroza, E.; Keefe, D.

    1990-06-01

    We present results of progress on the LBL multiple beam induction linac experiment (MBE-4). This machine models the accelerator physics of the electric-focused portion of a driver for heavy ion inertial confinement fusion. Four beams of cesium ions are accelerated in common through twenty four induction gaps while being separately focused in individual electrostatic AG focusing channels. Early experiments have demonstrated current amplification in the linac, from 10 mA to 90 mA per beam. This is achieved both by acceleration (from 200 keV to 1 MeV) and by carefully controlled bunch compression. Recent experiments have concentrated on studies of beams extracted from an ion source which produces 5 mA cesium beams at emittances near 0.03 {pi} mm-mrad (normalized). Experiments and theory show a growth of emittance (by about a factor of 2) as these beams are accelerated through the linac. Results of recent measurements of the transverse emittance behavior of these strongly space-charge-dominated ion beams are reviewed and compared with theory. 9 refs., 3 figs.

  2. Wake fields in SLAC Linac Collimators

    SciTech Connect

    Novokhatski, Alexander; Decker, F. -J.; Smith, H.; Sullivan, M.

    2014-12-02

    When a beam travels near collimator jaws, it gets an energy loss and a transverse kick due to the backreaction of the beam field diffracted from the jaws. The effect becomes very important for an intense short bunch when a tight collimation of the background beam halo is required. In the Linac Coherent Light Source at SLAC a collimation system is used to protect the undulators from radiation due to particles in the beam halo. The halo is most likely formed from gun dark current or dark current in some of the accelerating sections. However, collimators are also responsible for the generation of wake fields. The wake field effect from the collimators not only brings an additional energy jitter and change in the trajectory of the beam, but it also rotates the beam on the phase plane, which consequently leads to a degradation of the performance of the Free Electron Laser at the Linac Coherent Light Source. In this paper, we describe a model of the wake field radiation in the SLAC linac collimators. We use the results of a numerical simulation to illustrate the model. Based on the model, we derive simple formulas for the bunch energy loss and the average kick. In addition, we also present results from experimental measurements that confirm our model.

  3. Experiments and prospects for induction linac drivers

    SciTech Connect

    Keefe D.

    1986-05-01

    In the last three years, the US program in Heavy Ion Fusion has concentrated on understanding the induction linac approach to a power-plant driver. In this method it is important that the beam current be maximized throughout the accelerator. Consequently, it is crucial to understand the space-charge limit in the AG transport system in the linac and, also, to achieve current amplification during acceleration to keep pace with the kinematical increase of this limit with energy. Experimental results on both these matters and also on the use of multiple beams (inside the same accelerating structure) will be described. A new examination of the most attractive properties of the induction linac for a fusion driver has clearly pointed to the advantage of using heavy ions with a charge-state greater than unity - perhaps q = 3 may be an optimum. This development places even greater importance on understanding space-charge limits and mechanisms for emittance growth; also, it will require a new emphasis on the development of a suitable ion source.

  4. A 2--4 nm Linac Coherent Light Source (LCLS) using the SLAC linac

    SciTech Connect

    Winick, H.; Bane, K.; Boyce, R.

    1993-05-01

    We describe the use of the SLAC linac to drive a unique, powerful. short wavelength Linac Coherent Light Source (LCLS). Operating as an FEL, lasing would be achieved in a single pass of a high peak current electron beam through a long undulator by self-amplified spontaneous emission (SASE). The main components are a high-brightness rf photocathode electron gun; pulse compressors; about 1/5 of the SLAC linac; and a long undulator with a FODO quadrupole focussing system. Using electrons below 8 GeV, the system would operate at wavelengths down to about 3 nm, producing {ge}10 GW peak power in sub-ps pulses. At a 120 Hz rate the average power is {approx} 1 W.

  5. SNS LINAC Wire Scanner System : Signal Levels and Accuracy.

    SciTech Connect

    Plum, M. A.; Christensen, W.; Myer, R. E.; Rose, C. R.

    2002-01-01

    The linac wire scanner system for the Spallation Neutron Source (SNS) at Oak Ridge, TN, USA, calls for 5 units in the medium energy beam transport (MEBT), 5 in the drift tube linac (DTL), and 10 in the coupled cavity linac (CCL). In this paper we present expected signal levels and an analysis of the error in the beam size measurement as functions of wire position and electrical signal errors.

  6. Analysis on linac quadrupole misalignment in FACET commissioning 2012

    SciTech Connect

    Sun, Yipeng; /SLAC

    2012-07-05

    In this note, the analysis on linac quadrupole misalignment is presented for the FACET linac section LI05-09 plus LI11-19. The effectiveness of the beam-based alignment technique is preliminarily confirmed by the measurement. Beam-based alignment technique was adopted at SLAC linac since SLC time. Here the beam-based alignment algorithms are further developed and applied in the FACET commissioning during 2012 run.

  7. SIMULATIONS OF A MUON LINAC FOR A NEUTRINO FACTORY

    SciTech Connect

    Kevin Beard, Alex Bogacz ,Slawomir Bogacz, Vasiliy Morozov, Yves Roblin

    2011-04-01

    The Neutrino Factory baseline design involves a complex chain of accelerators including a single-pass linac, two recirculating linacs and an FFAG. The first linac follows the capture and bunching section and accelerates the muons from about 244 to 900 MeV. It must accept a high emittance beam about 30 cm wide with a 10% energy spread. This linac uses counterwound, shielded superconducting solenoids and 201 MHz superconducting cavities. Simulations have been carried out using several codes including Zgoubi, OptiM, GPT, Elegant and G4beamline, both to determine the optics and to estimate the radiation loads on the elements due to beam loss and muon decay.

  8. Magnetic decoupling of the linac in a low field biplanar linac-MR system.

    PubMed

    St Aubin, J; Steciw, S; Fallone, B G

    2010-09-01

    The integration of a low field biplanar magnetic resonance (MR) imager and linear accelerator (linac) causes magnetic interference at the linac due to the MR fringe fields. In order to eliminate this interference, passive and active magnetic shielding designs are investigated. The optimized design of passive magnetic shielding was performed using the finite element method. The design was required to achieve no greater than a 20% electron beam loss within the linac waveguide and electron gun, no greater than 0.06 T at the multileaf collimator (MLC) motors, and generate a distortion of the main MR imaging volume of no greater than 300 ppm. Through the superposition of the analytical solution for a single current carrying wire loop, active shielding designs in the form of three and four sets of coil pairs surrounding the linac waveguide and electron gun were also investigated. The optimized current and coil center locations that yielded the best cancellation of the MR fringe fields at the linac were determined using sequential quadratic programming. Optimized passive shielding in the form of two steel cylinders was designed to meet the required constraints. When shielding the MLC motors along with the waveguide and electron gun, the thickness of the cylinders was less than 1 mm. If magnetically insensitive MLC motors are used, no MLC shielding would be required and the waveguide shield (shielding the waveguide and electron gun) became 1.58 mm thick. In addition, the optimized current and coil spacing for active shielding was determined for both three and four coil pair configurations. The results of the active shielding optimization produced no beam loss within the waveguide and electron gun and a maximum MR field distortion of 91 ppm over a 30 cm diameter spherical volume. Very simple passive and active shielding designs have been shown to magnetically decouple the linac from the MR imager in a low field biplanar linac-MR system. The MLC passive shielding produced

  9. Ion optics of the Linac--LEB transfer line

    SciTech Connect

    Bhandari, R.K.; Penner, S.

    1990-12-01

    This report describes the ion optical properties of a proposed transfer line to inject a nominal 25 mA H{sup {minus}} beam at 600 MeV from the Linac into the Low Energy Booster (LEB) synchrotron. Ion optical investigations have been carried out in detail using the TRANSPORT, TURTLE and TRACE 3-D codes. The calculations take account of linear space charge effects of up to 50 mA average beam current. These effects have been found to be quite appreciable, especially on the longitudinal phase space. Procedure for their evaluation and optimization are described. Effects of some imperfections in the beam line magnets have been studied. 6 refs., 19 figs., 4 tabs.

  10. First operation of the rf-focused interdigital linac structure

    NASA Astrophysics Data System (ADS)

    Joel Starling, W.; Swenson, Donald A.

    2007-08-01

    The new rf-focused interdigital (RFI) linac structure came into operation at the Linac Systems laboratory in May of 2006, after a multi-year development program supported by the US Department of Energy. The RFI linac structure is basically an interdigital (or Wideröe) linac structure with rf quadrupole focusing incorporated into each drift tube. The RFI prototype operates at 200-MHz and consists of an ECR ion source, an Einzel lens LEBT, a radial-strut, four-bar RFQ linac section to 0.75 MeV and an RFI linac section to a final energy of 2.5 MeV. The total length of the prototype is 2.2 m. The RFQ and RFI linac sections are resonantly coupled and require a total of 120 kW of rf power for cavity excitation. The energy of the accelerated beam was confirmed by requiring it to pass through a 2.25-MeV energy-degrading foil. The specifications for the RFI linac prototype were chosen to address the demanding Boron Neutron Capture Therapy medical application. There are, however, many other potential applications for the structure as it has efficiency and size advantages for both protons and heavy ions at a variety of energies and currents. To date, we have achieved a beam current of approximately 1 mA peak at a relatively low duty factor. We continue to improve the performance of the prototype structure on a daily basis as we better understand the optimal operational settings for the prototype system. Now that the first operational milestone for the RFI linac structure has been achieved, Linac Systems will vigorously pursue projects and partnerships for multiple applications such as compact and intense neutron sources, proton and carbon injector linacs for synchrotrons and PET isotope production.

  11. Conceptual design of the Project-X 1.3 GHz 3-8 GeV pulsed linac

    SciTech Connect

    Solyak, N.; Eidelman, Y.; Nagaitsev, S.; Ostiguy, J.-F.; Vostrikov, A.; Yakovlev, V.; /Fermilab

    2011-03-01

    Project-X, a multi-MW proton source, is under development at Fermilab. It enables a Long Baseline Neutrino Experiment via a new beam line pointed to DUSEL in Lead, South Dakota, and a broad suite of rare decay experiments. The initial acceleration is provided by a 3-GeV 1-mA CW superconducting linac. In a second stage, about 5% of the H{sup -} beam is accelerated up to 8 GeV in a 1.3 GHz SRF pulsed linac and injected into the Recycler/Main Injector complex. In order to mitigate problems with stripping foil heating during injection, higher current pulses are accelerated in the CW linac in conjunction with the 1 mA beam which is separated and further accelerated in the pulsed linac. The optimal current in the pulsed linac is discussed as well as the constraints that led to its selection. A conceptual design which covers optics and RF stability analysis is presented. Finally, the need for HOM damping is discussed.

  12. Commercial Superconducting Electron Linac for Radioisotope Production

    SciTech Connect

    Grimm, Terry Lee; Boulware, Charles H.; Hollister, Jerry L.; Jecks, Randall W.; Mamtimin, Mayir; Starovoitova, Valeriia

    2015-08-13

    The majority of radioisotopes used in the United States today come from foreign suppliers or are generated parasitically in large government accelerators and nuclear reactors. Both of these restrictions limit the availability of radioisotopes and discourage the development and evaluation of new isotopes and for nuclear medicine, science, and industry. Numerous studies have been recommending development of dedicated accelerators for production of radioisotopes for over 20 years (Institute of Medicine, 1995; Reba, et al, 2000; National Research Council, 2007; NSAC 2009). The 2015 NSAC Long Range Plan for Isotopes again identified electron accelerators as an area for continued research and development. Recommendation 1(c) from the 2015 NSAC Isotope report specifically identifies electron accelerators for continued funding for the purpose of producing medical and industrial radioisotopes. Recognizing the pressing need for new production methods of radioisotopes, the United States Congress passed the American Medical Isotope Production Act of 2012 to develop a domestic production of 99Mo and to eliminate the use of highly enriched uranium (HEU) in the production of 99Mo. One of the advantages of high power electron linear accelerators (linacs) is they can create both proton- and neutron-rich isotopes by generating high energy x-rays that knock out protons or neutrons from stable atoms or by fission of uranium. This allows for production of isotopes not possible in nuclear reactors. Recent advances in superconducting electron linacs have decreased the size and complexity of these systems such that they are economically competitive with nuclear reactors and large, high energy accelerators. Niowave, Inc. has been developing a radioisotope production facility based on a superconducting electron linac with liquid metal converters.

  13. Beam-based Feedback for the NLC Linac

    SciTech Connect

    Hendrickson, L

    2004-07-21

    The NLC linac train-by-train feedback system is designed to stabilize the beam trajectory, but is also a valuable element in the strategy for emittance preservation. New simulations employ improved strategies [1], allowing beam steering to be performed significantly less often than without the feedback system. Additional simulations indicate that the linac feedback can contribute towards successful operation at noisier sites.

  14. Induction linac drivers for commercial heavy-ion beam fusion

    SciTech Connect

    Keefe, D.

    1987-11-01

    This paper discusses induction linac drivers necessary to accelerate heavy ions at inertial fusion targets. Topics discussed are: driver configurations, the current-amplifying induction linac, high current beam behavior and emittance growth, new considerations for driver design, the heavy ion fusion systems study, and future studies. 13 refs., 6 figs., 1 tab. (LSP)

  15. MEIC Proton Beam Formation with a Low Energy Linac

    SciTech Connect

    Zhang, Yuhong

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  16. The Proposed NLC Linac LLRF System

    SciTech Connect

    Corredoura, Paul L.

    2000-07-07

    The proposed Next Linear Collider (NLC) contains linac systems operating at L,S,C, and X band. This paper describes a wideband modular low-level RF (LLRF) system applicable for all NLC pulsed RF systems. High speed digital IF techniques are used for both arbitrary klystron drive modulation and accurate RF vector detection. Measurement of relative beam to RF phase, beam loading compensation, and structure dipole modes for automated alignment are all handled by the system. Modern signal processing techniques are also described.

  17. An induction linac injector for scaled experiments

    SciTech Connect

    Rutkowski, H.L.; Faltens, A.; Pike, C.; Brodzik, D.; Johnson, R.M.; Vanecek, D. ); Hewett, D.W. )

    1991-04-01

    An injector is being developed at LBL that would serve as the front end of a scaled induction linac accelerator technology experiment for heavy ion fusion. The ion mass being used is in the range 10--18. It is a multi-beam device intended to accelerate up to 2 MeV with 500 mA in each beam. The first half of the accelerating column has been built and experiments with one carbon beam are underway at the 1 MeV level. 5 refs., 1 fig.

  18. Numerical simulation of coupler cavities for linacs

    SciTech Connect

    Ng, C.K.; Derutyer, H.; Ko, K.

    1993-04-01

    We present numerical procedures involved in the evaluation of the performance of coupler cavities for linacs. The MAFIA code is used to simulate an X-Band accelerator section in the time domain. The input/output coupler cavities for the structure arc of the symmetrical double-input design. We calculate the transmission properties of the coupler and compare the results with measurements. We compare the performance of the symmetrical double-input design with that of the conventional single-input type by evaluating the field amplitude and phase asymmetries. We also evaluate the peak field gradient in the computer.

  19. High density harp for SSCL linac

    SciTech Connect

    Fritsche, C.T.; Krogh, M.L.; Crist, C.E.

    1993-05-01

    AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities.

  20. Laser system for a subpicosecond electron linac.

    SciTech Connect

    Crowell, R. A.

    1998-09-25

    At the Argonne Chemistry Division efforts are underway to develop a sub-picosecond electron beam pulse radiolysis facility for chemical studies. The target output of the accelerator is to generate electron pulses that can be adjusted from 3nC in .6ps to 100nC in 45ps. In conjunction with development of the accelerator a state-of-the-art ultrafast laser system is under construction that will drive the linac's photocathode and provide probe pulses that are tunable from the UV to IR spectral regions.

  1. RF Control System for the NLC Linacs

    SciTech Connect

    Corredoura, Paul L.

    2000-08-23

    The proposed Next Linear Collider contains a large number of linac RF systems with new requirements for wideband klystron modulation and accurate RF vector detection. The system will be capable of automatically phasing each klystron and compensating for beam loading effects. Accelerator structure alignment is determined by detection of the beam induced dipole modes with a receiver similar to that used for measuring the accelerator RF and is incorporated into the RF system topology. This paper describes the proposed system design, signal processing techniques and includes preliminary test results.

  2. RF-chopper for the JHF proton linac

    NASA Astrophysics Data System (ADS)

    Fu, Shinian; Kato, Takao

    2000-02-01

    An RF-chopper possesses merits in both its high deflecting field and compactness. For this reason, it is suitable for chopping a high-current beam in a medium-energy beam-transport line (MEBT) of an ion linear accelerator. The JHF linac, as a high-current H - accelerator with an average current of up to 0.2 mA or higher in the second phase, took these advantages of the RF-chopper in its design. Two RF-deflecting cavities as the chopper will be used in the MEBT just downward of the 3-MeV 324-MHz RFQ. A 324-MHz RF-chopper cavity has been designed with optimization for a fast rise/fall time, which is an essential requirement for the chopper in a high-current accelerator in order to avoid radioactivity induced by the lost particles due to insufficient chopping during the transient time. The rise time can be less than 8 ns by means of a pair of ports with large coupling loops. In this paper, the details concerning the R&D of the RF-chopper are presented. Some RF properties calculated with MAFIA and HFSS codes have been compared with the test results of a cold-model cavity, showing good agreement. To cut down on the required RF-power, two RF-deflecting cavities are connected with a coaxial line in the design. The simulation and measurement of the coupled system exhibit a quick rise time that is almost the same as that of an independent cavity. The designed RF-chopper will be used in the JHF linac, which is under construction.

  3. Error studies for SNS Linac. Part 1: Transverse errors

    SciTech Connect

    Crandall, K.R.

    1998-12-31

    The SNS linac consist of a radio-frequency quadrupole (RFQ), a drift-tube linac (DTL), a coupled-cavity drift-tube linac (CCDTL) and a coupled-cavity linac (CCL). The RFQ and DTL are operated at 402.5 MHz; the CCDTL and CCL are operated at 805 MHz. Between the RFQ and DTL is a medium-energy beam-transport system (MEBT). This error study is concerned with the DTL, CCDTL and CCL, and each will be analyzed separately. In fact, the CCL is divided into two sections, and each of these will be analyzed separately. The types of errors considered here are those that affect the transverse characteristics of the beam. The errors that cause the beam center to be displaced from the linac axis are quad displacements and quad tilts. The errors that cause mismatches are quad gradient errors and quad rotations (roll).

  4. 10MeV 25KW industrial electron LINAC

    NASA Astrophysics Data System (ADS)

    Kamino, Y.

    1998-06-01

    A 10MeV 25KW plus class electron LINAC was developed for sterilisation of medical devices. The LINAC composed of a standing wave type single cavity prebuncher and a 2m electro-plated travelling wave guide uses a 5MW 2856MHz pulse klystron as an RF source and provides 25KW beam power at the Ti alloy beam window stably after the energy analysing magnet with 10MeV plus-minus 1 MeV energy slit. The practical maximum beam power reached 29 KW and this demonstrated the LINAC as one of the most powerful S-band electron LINACs in the world. The control of the LINAC is fully automated and the "One-Button Operation" is realised, which is valuable for easy operation as a plant system. 2 systems have been delivered and are being operated stably.

  5. RIA Superconducting Drift Tube Linac R & D

    SciTech Connect

    J. Popielarski; J. Bierwagen; S. Bricker; C. Compton; J. DeLauter; P. Glennon; T. Grimm; W. Hartung; D. Harvell; M. Hodek; M. Johnson; F. Marti; P. Miller; A. Moblo; D. Norton; L. Popielarski; J. Wlodarczak; R. C. York; A. Zeller

    2009-05-22

    Cavity and cryomodule development work for a superconducting ion linac has been underway for several years at the National Superconducting Cyclotron Laboratory. The original application of the work was the proposed Rare Isotope Accelerator. At present, the work is being continued for use with the Facility for Rare Isotope Beams (FRIB). The baseline linac for FRIB requires 4 types of superconducting cavities to cover the velocity range needed to accelerate an ion beam to 200 MeV/u: 2 types of quarter-wave resonator (QWR) and 2 types of half-wave resonator (HWR). Superconducting solenoids are used for focussing. Active and passive shielding is required to ensure that the solenoids’ field does not degrade the cavity performance. First prototypes of both QWR types and one HWR type have been fabricated and tested. A prototype solenoid has been procured and tested. A test cryomodule has been fabricated and tested. The test cryomodule contains one QWR, one HWR, one solenoid, and one super-ferric quadrupole. This report covers the design, fabrication, and testing of this cryomodule

  6. Features Of The J-PARC Linac

    SciTech Connect

    Kobayashi, Tetsuya

    2011-06-01

    Japan Proton Accelerator Research Complex (J-PARC) will be one of the highest intensity proton accelerators in the world aiming to realize 1 MW class of the beam power. The accelerator consists of a 400-MeV linac, a 3-GeV rapid-cycling synchrotron (RCS) and a main ring synchrotron (MR), and the accelerated beam is applied to several experimental facilities. The linac, which is the injector for the RCS, has about 50 cavity modules to accelerate the beam up to 400 MeV. The acceleration field error in all of them should be within {+-}1% in amplitude and {+-}1 degree in phase because the momentum spread of the RCS injection beam is required to be within 0.1%. For the cavity field stabilization, a high-stable optical signal distribution system is used as the RF reference, and sophisticated digital feedback and feed-forward system is working well in the low level RF control system. Consequently the providing beam to the RCS is very stable, and the beam commissioning and the experiments of the application facilities have been progressed steadily.

  7. Landau damping in the SLAC linac

    SciTech Connect

    Bane, K.L.F.

    1985-04-01

    In the SLC Landau damping can greatly stabilize the beam against changes in injection conditions into the linac. For example, by choosing phi/sub a/ = -15/sup 0/, n/sub a/ = 51, the jitter tolerances for 25% emittance growth can be relaxed by greater than a factor of 10, while sacrificing 1.6 GeV in final energy. Increasing the focusing, especially near the beginning of the linac, will lessen the energy penalty for a given amount of stability. For example, with the planned addition of more quads in sectors 2-4 the stability of the above example can be achieved at the cost of only 1.0 GeV in final energy. The simulations including machine errors indicate that the static residual emittance growth can be kept consistently below 30% with Landau damping, but that this would be difficult to achieve without Landau damping. It can be supposed that Landau damping will also stabilize the beam to magnet jitter, though a more thorough study of machine error effects still needs to be done. 9 refs., 4 figs., 1 tab.

  8. Beam commissioning for a superconducting proton linac

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Jun; He, Yuan; Jia, Huan; Dou, Wei-ping; Chen, Wei-long; Zhang, X. L.; Liu, Shu-hui; Feng, Chi; Tao, Yue; Wang, Wang-sheng; Wu, Jian-qiang; Zhang, Sheng-hu; Zhao, Hong-Wei

    2016-12-01

    To develop the next generation of safe and cleaner nuclear energy, the accelerator-driven subcritical (ADS) system emerges as one of the most attractive technologies. It will be able to transmute the long-lived transuranic radionuclides produced in the reactors of today's nuclear power plants into shorter-lived ones, and also it will provide positive energy output at the same time. The prototype of the Chinese ADS (C-ADS) proton accelerator comprises two injectors and a 1.5 GeV, 10 mA continuous wave (CW) superconducting main linac. The injector scheme II at the C-ADS demo facility inside the Institute of Modern Physics is a 10 MeV CW superconducting linac with a designed beam current of 10 mA, which includes an ECR ion source, a low-energy beam transport line, a 162.5 MHz radio frequency quadrupole accelerator, a medium-energy beam transport line, and a superconducting half wave resonator accelerator section. This demo facility has been successfully operating with an 11 mA, 2.7 MeV CW beam and a 3.9 mA, 4.3 MeV CW beam at different times and conditions since June 2014. The beam power has reached 28 kW, which is the highest record for the same type of linear accelerators. In this paper, the parameters of the test injector II and the progress of the beam commissioning are reported.

  9. WATER PURITY DEVELOPMENT FOR THE COUPLED CAVITY LINAC (CCL) AND DRIFT TUBE LINAC (DTL) STRUCTURES OF THE SPALLATION NEUTRON SOURCE (SNS) LINAC

    SciTech Connect

    D. KATONAK; J. BERNARDIN; S. HOPKINS

    2001-06-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the proton beam. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems. One of the primary components in the DTL and CCL water cooling systems, is a water purification system that is responsible for minimizing erosion, corrosion, scaling, biological growth, and hardware activation. The water purification system consists of filters, ion exchange resins, carbon beds, an oxygen scavenger, a UV source, and diagnostic instrumentation. This paper reviews related issues associated with water purification and describes the mechanical design of the SNS Linac water purification system.

  10. Space charge compensation in the Linac4 low energy beam transport line with negative hydrogen ions.

    PubMed

    Valerio-Lizarraga, Cristhian A; Lallement, Jean-Baptiste; Leon-Monzon, Ildefonso; Lettry, Jacques; Midttun, Øystein; Scrivens, Richard

    2014-02-01

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Transport using the package IBSimu [T. Kalvas et al., Rev. Sci. Instrum. 81, 02B703 (2010)], which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H(-) beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  11. High power test of an injector linac for heavy ion cancer therapy facilities

    NASA Astrophysics Data System (ADS)

    Lu, Liang; Hattori, Toshiyuki; Zhao, Huanyu; Kawasaki, Katsunori; Sun, Liangting; He, Yuan; Zhao, Hongwei

    2015-11-01

    A hybrid single cavity (HSC) linac, combined with radio frequency quadrupole and drift tube structure in a single interdigital-H cavity, operates with high rf power as a prototype injector for cancer therapy synchrotron. The HSC adopts a direct plasma injection scheme (DPIS) with a laser ion source. The input beam current of the HSC is designed to be 20 mA C6 + ions. According to simulations, the HSC can accelerate a 6-mA C6 + beam which meets the requirement of the particle number for cancer therapy (1 08 ˜9 ions/pulse ). The HSC injector with DPIS makes the existing multiturn injection system and stripping system unnecessary; what is more, it can also bring down the size of the beam pipe in existing synchrotron magnets, which can reduce the whole cost of the synchrotron. Details of the field measurements of the HSC linac and results of the high power test are reported in this paper.

  12. Space charge compensation in the Linac4 low energy beam transport line with negative hydrogen ions

    SciTech Connect

    Valerio-Lizarraga, Cristhian A.; Lallement, Jean-Baptiste; Lettry, Jacques; Scrivens, Richard; Leon-Monzon, Ildefonso; Midttun, Øystein

    2014-02-15

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Transport using the package IBSimu [T. Kalvas et al., Rev. Sci. Instrum. 81, 02B703 (2010)], which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H{sup −} beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  13. Results of LEBT/MEBT reconfiguration at BNL 200 MeV LINAC

    SciTech Connect

    Raparia,D.; Alessi, J.; Briscoe, B.; Fite, J.; Gould, O.; Kponou, A.; Lo Destro, V.; Okamura, M.; Ritter, J.

    2009-05-04

    The low energy (35 keV) and medium energy (750 keV) transport lines for both polarized and unpolarized H{sup -} have been reconfigured to reduce the beam emittance and beam losses out of the 200 MeV Linac. The medium energy line in the original layout was 7 m long, and had ten quadrupoles, two beam choppers, and three bunchers. The bunchers were necessary to keep the beam bunched at the entrance of the Linac. About 35% beam loss occurred, and the emittance growth was several fold. In the new layout, the 750 keV line is only 0.7 m long, with three quads and one buncher. We will present the experimental result of the upgrade.

  14. PHYSICS RESULTS OF THE NSLS-II LINAC FRONT END TEST STAND

    SciTech Connect

    Fliller R. P.; Gao, F.; Yang, X.; Rose, J.; Shaftan, T.; Piel, C

    2012-05-20

    The Linac Front End Test Stand (LFETS) was installed at the Source Development Laboratory (SDL) in the fall of 2011 in order to test the Linac Front End. The goal of these tests was to test the electron source against the specifications of the linac. In this report, we discuss the results of these measurements and the effect on linac performance.

  15. New high power 200 MHz RF system for the LANSCE drift tube linac

    SciTech Connect

    Lyles, J.; Friedrichs, C.; Lynch, M.

    1998-12-31

    The Los Alamos Neutron Science Center (LANSCE) linac provides an 800 MeV direct H{sup +} proton beam, and injects H{sup {minus}} to the upgraded proton storage ring for charge accumulation for the Short Pulse Spallation Source. Accelerating these interlaced beams requires high average power from the 201.25 MHz drift tube linac (DTL) RF system. Three power amplifiers have operated at up to three Megawatts with 12% duty factor. The total number of electron power tubes in the RF amplifiers and their modulators has been reduced from fifty-two to twenty-four. The plant continues to utilize the original design of a tetrode driving a super power triode. Further increases in the linac duty factor are limited, in part, by the maximum dissipation ratings of the triodes. A description of the system modifications proposed to overcome these limitations includes new power amplifiers using low-level RF modulation for tank field control. The first high power Diacrode{reg_sign} is being delivered and a new amplifier cavity is being designed. With only eight power tubes, the new system will deliver both peak power and high duty factor, with lower mains power and cooling requirements. The remaining components needed for the new RF system will be discussed.

  16. PERFORMANCE OF THE DIAGNOSTICS FOR NSLS-II LINAC COMMISSIONING

    SciTech Connect

    Fliller III, R.; Padrazo, D.; Wang, G.M.; Heese, R.; Hseuh H.-C.; Johanson, M.; Kosciuk, B.N.; Pinayev, I.; Rose, J.; Shaftan, T.; Singh, O.

    2011-03-28

    The National Synchrotron Light Source II (NSLS-II) is a state of the art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac, a 3-GeV booster synchrotron and associated transfer lines. The transfer lines not only provide a means to deliver the beam from one machine to another, they also provide a suite of diagnostics and utilities to measure the properties of the beam to be delivered. In this paper we discuss the suite of diagnostics that will be used to commission the NSLS-II linac and measure the beam properties. The linac to booster transfer line can measure the linac emittance with a three screens measurement or a quadrupole scan. Energy and energy spread are measured in a dispersive section. Total charge and charge uniformity are measured with wall current monitors in the linac and transformers in the transfer line. We show that the performance of the diagnostics in the transfer line will be sufficient to ensure the linac meets its specifications and provides a means of trouble shooting and studying the linac in future operation.

  17. Development of RF linac for high-current applications

    SciTech Connect

    Chan, K.C.D.; Lawrence, G.P.; Schneider, J.D.

    1997-12-31

    High-current proton linacs are promising sources of neutrons for material processing and research applications. Recently, a linac design that makes use of a combination of normal-conducting (NC) and superconducting (SC) linac technologies has been proposed for the US Accelerator Production of Tritium Project. As a result, a multi-year engineering development and demonstration (ED and D) program is underway. In this paper, the authors will describe the design and merits of the NC/SC hybrid approach. The scope, technology issues, and present status of the ED and D Program, and the participation of industry will also be described.

  18. Beam diagnostics for the Fermilab 400 meV Linac

    SciTech Connect

    McCrory, E. )

    1992-07-10

    The Fermilab 200 MeV Linac is scheduled to be upgraded to a 400 MeV Linac beginning in the Spring of 1993 [1]. We have designed beam diagnostics for the accelerator to expedite the commissioning and to facilitate the long-term reliability of the machine. These diagnostics include: stripline beam position monitors, resistive wall-current monitors, X-Y-U wire scanners, and various velocity and/or phase measurement devices, including bucnh-length detectors fashioned after the work at the INR in Moscow [2]. This paper will discuss these devices and our plans fot the commissioning of the new Linac using these diagnostics.

  19. Using basic electromagnetism to introduce LINAC4 (CERN)

    NASA Astrophysics Data System (ADS)

    Cid-Vidal, Xabier; Cid, Ramon; Vretenar, Maurizio

    2016-07-01

    The LHC is the last element of CERN’s accelerator complex, which is a succession of machines with increasingly higher energies. Everything starts in the 50 MeV linear accelerator (LINAC2), but a new linear accelerator, the 160 MeV LINAC4, will replace LINAC2 in 2018, upgrading LHC injectors to higher intensity and eventually increasing the luminosity of LHC. The aim of this article is briefly introducing this new accelerator, and presenting a simple application of some fundamental laws of magnetism to be taken to the secondary school classrooms.

  20. High-Performance Beam Simulator for the LANSCE Linac

    SciTech Connect

    Pang, Xiaoying; Rybarcyk, Lawrence J.; Baily, Scott A.

    2012-05-14

    A high performance multiparticle tracking simulator is currently under development at Los Alamos. The heart of the simulator is based upon the beam dynamics simulation algorithms of the PARMILA code, but implemented in C++ on Graphics Processing Unit (GPU) hardware using NVIDIA's CUDA platform. Linac operating set points are provided to the simulator via the EPICS control system so that changes of the real time linac parameters are tracked and the simulation results updated automatically. This simulator will provide valuable insight into the beam dynamics along a linac in pseudo real-time, especially where direct measurements of the beam properties do not exist. Details regarding the approach, benefits and performance are presented.

  1. The Australian magnetic resonance imaging-linac program.

    PubMed

    Keall, Paul J; Barton, Michael; Crozier, Stuart

    2014-07-01

    The Australian magnetic resonance imaging (MRI)-Linac program is a $16-million government-funded project to advance the science and clinical practice of exquisite real-time anatomical and physiological adaptive cancer therapy. The centerpiece of the program is a specifically designed 1-T open-bore MRI/6-MV linac system that is planned for delivery and completion of installation in 2014. Current scientific endeavors include engineering discovery in MRI component design, quantifying MRI and linac interactions, and developing image guidance and adaptation strategies. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Neutron Spectra in a 15 MV LINAC

    SciTech Connect

    Vega-Carrillo, H. R.; Chu, Wei-Han; Tung, Chuan-Jong; Lan, Jen-Hong

    2010-12-07

    Neutron spectra were calculated inside the treatment hall of a 15 MV LINAC, calculations were carried out using Monte Carlo methods. With a Bonner sphere spectrometer with pairs of thermoluminiscent dosimeters the neutron spectrum at 100 cm from the isocenter was measured and compared with the calculated spectrum. All the spectra in the treatment hall show the presence of evaporation and knock-on neutrons; also the room-return due to the hall features is shown. In the maze the large contribution are due to epithermal and thermal neutrons. A good agreement between the calculated and measured spectrum at 100 cm was noticed, from this comparison the differences are attributed to the water content in the concrete of the hall.

  3. Permanent-magnet quadrupoles in RFQ Linacs

    SciTech Connect

    Lysenko, W.P.; Wang, T.F.

    1985-10-01

    We investigated the possibility of increasing the current-carrying capability of radio-frequency quadrupole (RFQ) linear accelerators by adding permanentmagnet quadrupole (PMQ) focusing to the existing transverse focusing provided by the rf electric field. Increased transverse focusing would also allow shortening RFQ linacs by permitting a larger accelerating gradient, which is normally accompanied by an undesirable increased transverse rf defocusing effect. We found that PMQs were not helpful in increasing the transverse focusing strength in an RFQ. This conclusion was reached after some particle tracing simulations and some analytical calculations. In our parameter regime, the addition of the magnets increases the betatron frequency but does not result in improved focusing because the increased flutter more than offsets the gain from the increased betatron frequency.

  4. Recirculating Linac Accelerators For Future Muon Facilities

    SciTech Connect

    Yves Roblin, Alex Bogacz, Vasiliy Morozov, Kevin Beard

    2012-04-01

    Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of shortlived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discuss the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both m+ and m- species. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  5. Linac Coherent Light Source Longitudinal Feedback Model

    SciTech Connect

    Wu, Juhao; Emma, P.; Hendrickson, L.; /SLAC

    2005-06-15

    The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, it is critical to preserve the high quality of the electron beam during acceleration and compression. The peak current and final energy are very sensitive to system jitter. To minimize this sensitivity, a longitudinal feedback system on the bunch length and energy is required, together with other diagnostics and feedback systems (e.g., on transverse phase space). Here, we describe a simulation framework, which includes a realistic jitter model for the LCLS accelerator system, the RF acceleration, structure wakefield, and second order optics. Simulation results show that to meet the tight requirements set by the FEL, such a longitudinal feedback system is mandatory.

  6. Neutron Spectra in a 15 MV LINAC

    NASA Astrophysics Data System (ADS)

    Vega-Carrillo, H. R.; Chu, Wei-Han; Tung, Chuan-Jong; Lan, Jen-Hong

    2010-12-01

    Neutron spectra were calculated inside the treatment hall of a 15 MV LINAC, calculations were carried out using Monte Carlo methods. With a Bonner sphere spectrometer with pairs of thermoluminiscent dosimeters the neutron spectrum at 100 cm from the isocenter was measured and compared with the calculated spectrum. All the spectra in the treatment hall show the presence of evaporation and knock-on neutrons; also the room-return due to the hall features is shown. In the maze the large contribution are due to epithermal and thermal neutrons. A good agreement between the calculated and measured spectrum at 100 cm was noticed, from this comparison the differences are attributed to the water content in the concrete of the hall.

  7. Radiation processing with the Messina electron linac

    NASA Astrophysics Data System (ADS)

    Auditore, L.; Barnà, R. C.; De Pasquale, D.; Emanuele, U.; Loria, D.; Morgana, E.; Trifirò, A.; Trimarchi, M.

    2008-05-01

    In the last decades radiation processing has been more and more applied in several fields of industrial treatments and scientific research as a safe, reliable and economic technique. In order to improve existing industrial techniques and to develop new applications of this technology, at the Physics Department of Messina University a high power 5 MeV electron linac has been studied and set-up. The main features of the accelerating structure will be described together with the distinctive features of the delivered beam and several results obtained by electron beam irradiations, such as improvement of the characteristics of polymers and polymer composite materials, synthesis of new hydrogels for pharmaceutical and biomedical applications, reclaim of culture ground, sterilization of medical devices, development of new dosimeters for very high doses and dose rates required for monitoring of industrial irradiations.

  8. Energy Recovery Linacs for Light Source Applications

    SciTech Connect

    George Neil

    2011-04-01

    Energy Recovery Linacs are being considered for applications in present and future light sources. ERLs take advantage of the continuous operation of superconducting rf cavities to accelerate high average current beams with low losses. The electrons can be directed through bends, undulators, and wigglers for high brightness x ray production. They are then decelerated to low energy, recovering power so as to minimize the required rf drive and electrical draw. When this approach is coupled with advanced continuous wave injectors, very high power, ultra-short electron pulse trains of very high brightness can be achieved. This paper will review the status of worldwide programs and discuss the technology challenges to provide such beams for photon production.

  9. Computer optimization of a linac injector trajectory

    SciTech Connect

    Sawyer, C.; Detch, J.L. Jr.

    1984-01-01

    One can determine a computer prediction of the beam radius as a function of axial distance for a linac beam by providing a set of inputs to the computer code, ZFIELD. The trajectory may be improved by varying the magnet current values in the code, but repeated trails may still not attain the best trajectory. Starting with a set of points containing the desired trajectory, one may work the problem backwards and obtain the necessary magnet currents required by the trajectory. In the examples given, a portion of the trajectory is chosen to be parabolic. The trajectory information is used with a differential equation involving beam radius and its derivatives to yield the magnetic field as a function of axial position. Matrix methods are used to obtain the magnet currents from the magnetic field. 4 references, 6 figures.

  10. A new trajectory correction technique for linacs

    SciTech Connect

    Raubenheimer, T.O.; Ruth, R.D.

    1990-06-01

    In this paper, we describe a new trajectory correction technique for high energy linear accelerators. Current correction techniques force the beam trajectory to follow misalignments of the Beam Position Monitors. Since the particle bunch has a finite energy spread and particles with different energies are deflected differently, this causes chromatic'' dilution of the transverse beam emittance. The algorithm, which we describe in this paper, reduces the chromatic error by minimizing the energy dependence of the trajectory. To test the method we compare the effectiveness of our algorithm with a standard correction technique in simulations on a design linac for a Next Linear Collider. The simulations indicate that chromatic dilution would be debilitating in a future linear collider because of the very small beam sizes required to achieve the necessary luminosity. Thus, we feel that this technique will prove essential for future linear colliders. 3 refs., 6 figs., 2 tabs.

  11. A Program for Optimizing SRF Linac Costs

    SciTech Connect

    Powers, Thomas J.

    2013-04-01

    Every well-designed machine goes through the process of cost optimization several times during its design, production and operation. The initial optimizations are done during the early proposal stage of the project when none of the systems have been engineered. When a superconducting radio frequency (SRF) linac is implemented as part of the design, it is often a difficult decision as to the frequency and gradient that will be used. Frequently, such choices are made based on existing designs, which invariably necessitate moderate to substantial modifications so that they can be used in the new accelerator. Thus the fallacy of using existing designs is that they will frequently provide a higher cost machine or a machine with sub-optimal beam physics parameters. This paper describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK [1] several years ago while they were in the process of developing a conceptual design for the New Light Source project. The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs.

  12. A superconducting CW-LINAC for heavy ion acceleration at GSI

    NASA Astrophysics Data System (ADS)

    Barth, Winfried; Aulenbacher, Kurt; Basten, Markus; Dziuba, Florian; Gettmann, Viktor; Miski-Oglu, Maksym; Podlech, Holger; Yaramyshev, Stepan

    2017-03-01

    Recently the Universal Linear Accelerator (UNILAC) serves as a powerful high duty factor (25%) heavy ion beam accelerator for the ambitious experiment program at GSI. Beam time availability for SHE (Super Heavy Element)-research will be decreased due to the limitation of the UNILAC providing Uranium beams with an extremely high peak current for FAIR simultaneously. To keep the GSI-SHE program competitive on a high level and even beyond, a standalone superconducting continuous wave (100% duty factor) LINAC in combination with the upgraded GSI High Charge State injector is envisaged. In preparation for this, the first LINAC section (financed by HIM and GSI) will be tested with beam in 2017, demonstrating the future experimental capabilities. Further on the construction of an extended cryo module comprising two shorter Crossbar-H cavities is foreseen to test until end of 2017. As a final R&D step towards an entire LINAC three advanced cryo modules, each comprising two CH cavities, should be built until 2019, serving for first user experiments at the Coulomb barrier.

  13. Use of an INR-style bunch-length detector in the Fermilab Linac

    SciTech Connect

    McCrory, E.S.; Schmidt, C.W.; Feschenko, A.V.

    1993-08-01

    device to accurately measure the phase extent of a linac beam is being developed for use in the Fermilab 400 MeV Linac Upgrade. Prototypes have been and are being tested. We have attempted to improve the original design from the Institute for Nuclear Research in Moscow (INR) to increase the resolution for adequate operation at 805 MHz. The device incorporating a new arrangement of lens and deflector, reported previously, cannot achieve the desired resolution. This paper describes the operation and the strengths and weaknesses of the three types of bunch-length detectors (BLDs) and the measurements made at this time. The differences among these devices is delineated by the relative position of the rf deflector and the electrostatic einsel lens, as follows: INR--Lens before deflector; Fermilab--Lens after deflector; H- beam; and FNAL/INR--Lens and deflector combined. To satisfy the goals of commissioning the new linac, a resolution of about 5 picoseconds (1{degree} at 805 MHz) is desired.

  14. Design Features and Initial RF Performance of a Gradient Hardened 17 GHz TW Linac Structure

    SciTech Connect

    Haimson, J.; Mecklenburg, B.

    2009-01-22

    To avoid surface erosion damage and to assist in studying RF breakdown thresholds in 17 GHz TW linac structures, a gradient hardened structure has been fabricated with high temperature brazed and machined stainless steel surfaces located in the peak E-field region of the beam apertures and the peak H-field regions of the input coupler cavity. The microwave design parameters and physical dimensions of this 22 cavity, 120 degree phase advance structure were chosen to allow the high gradient performance to be compared against a similar design all-copper structure that has been tested in a dual ring, power recirculating amplifier system. The final design parameters of the gradient hardened structure are discussed; the influence of stainless steel RF losses on the power buildup of the resonant ring and on the structure gradient distribution are described; waveforms are shown of the unique ability of the power amplifier to rapidly quench RF breakdown discharges in the linac structure by automatically sensing and redirecting the RF source power to a matched load; and preliminary test results during high power RF processing of the gradient hardened linac structure are presented.

  15. Operation and expected performance of the NLC main linacs

    SciTech Connect

    Assmann, R.W.; Raubenheimer, T.O.

    1996-11-01

    The main linacs for the proposed Next Linear Collider (NLC) provide acceleration of up to 500 GeV per beam. The linacs operate in a regime where unavoidable imperfections and even natural ground motion cause significant emittance dilutions. In order to achieve the NLC luminosity goals, small emittance beams must be transported with an emittance growth of less than about 175% for the 1 TeV center-of-mass version of the NLC. In this paper the authors discuss the operation and the expected performance of the NLC main linacs. Under the assumption that the specified device tolerances are met, it is shown from detailed simulations that the linac emittance transport fulfills the NLC requirements.

  16. Possible use of the AGS linac for proton therapy

    SciTech Connect

    Alessi, J.G.; Chanana, A.; Dilmanian, F.A.; Lee, Y.Y.; Raparia, D.; Tuozzolo, J.; Wielopolski, L.

    1995-12-31

    The BNL 200 MeV linac presently provides beam for the AGS high energy physics program and for isotope production at the Brookhaven Linac Isotope Producer (BLIP) facility. There is now a proposal to develop a proton therapy facility which would also use the linac beam. Approximately 1% of the current in each linac beam pulse would be diverted from BLIP, down an existing transport line, to the proposed new facility. This paper focuses on the basic design of the facility, particularly the accelerator issues. The planned transport line layout is presented, along with a description of the energy and intensity control, and beam delivery systems. In the initial phase, we are planning one 360{degrees} vertical gantry and one horizontal treatment room.

  17. A Radiation shielding study for the Fermilab Linac

    SciTech Connect

    Rakhno, I.; Johnstone, C.; /Fermilab

    2006-02-01

    Radiation shielding calculations are performed for the Fermilab Linac enclosure and gallery. The predicted dose rates around the access labyrinth at normal operation and a comparison to measured dose rates are presented. An accident scenario is considered as well.

  18. Commissioning of the LCLS Linac and Bunch Compressors

    SciTech Connect

    Akre, R.; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma#, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Huang, Z.; Iverson, R.; Limborg-Deprey, C.; Loos, H.; Molloy, S.; Miahnahri, A.; Nuhn, H.-D.; Ratner, D.; Turner, J.; Welch, J.; White, W.; /SLAC

    2008-08-20

    The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) project under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through the first bunch compressor, was commissioned in the spring and summer of 2007. The second phase of commissioning, including the second bunch compressor and various main linac modifications, was completed in January through August of 2008. We report here on experience gained during this second phase of machine commissioning, including the injector, the first and second bunch compressor stages, the linac up to 14 GeV, and beam stability measurements. The final commissioning phase, including the undulator and the long transport line from the linac, is set to begin in December 2008, with first light expected in July 2009.

  19. Design of the driver linac for the Rare Isotope Accelerator.

    SciTech Connect

    Ostroumov, P. N.; Nolen, J. A.; Shepard, K. W.; Physics

    2006-01-01

    The proposed design of the Rare Isotope Accelerator (RIA) driver linac is a cw, fully superconducting, 1.4 GV linac capable of accelerating uranium ions up to 400 MeV/u and protons to 1 GeV with 400 kW beam power. An extensive research and development effort has resolved many technical issues related to the construction of the driver linac and other systems of the RIA facility. In particular, record intensities of heavy ion beams have been demonstrated with the ECR ion source VENUS at LBNL, the driver front end systems including two-charge-state Low Energy Beam Transport (LEBT) and RFQ are being tested, and a set of SC accelerating structures to cover velocity range from 0.02c to 0.7c have been developed and prototyped. Newly developed high-performance SC cavities will provide the required voltage for the driver linac using 300 cavities designed for six different geometrical betas.

  20. Effect of Cooling Water on Stability of NLC Linac Components

    SciTech Connect

    Le Pimpec, Frederic

    2002-11-01

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  1. Vibrational stability of NLC linac and final focus components

    SciTech Connect

    F. Le Pimpec et al.

    2003-02-06

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  2. Effect of cooling water on stability of NLC linac components

    SciTech Connect

    F. Le Pimpec et al.

    2003-02-11

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  3. Vibrational Stability of NLC Linac and Final Focus Components

    SciTech Connect

    Le Pimpec, Frederic

    2002-09-25

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structure and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. Design to properly decouple the structure vibrations from the linac quadrupoles is being pursued.

  4. Instability issues for the ESS linac and rings

    SciTech Connect

    Rees, G. H.

    1999-12-03

    Comments are made on beam instability issues in the ESS linac and rings. The topics of interest in the linac are halo generation in the absence and presence of machine imperfections, and also the stability of the momentum ramping of the output beam. In the case of the rings, the main concern is for fast coherent transverse instabilities due to the combined effect of coupled electron-proton oscillations and interaction with the wall impedances.

  5. Evolution of the 400 MeV linac design

    SciTech Connect

    MacLachlan, J.A.

    1987-11-09

    The basic premises of the conceptual design for the linac upgrade are pursued to establish lengths, gradients, power dissipation, etc., for the 400 MeV linac and matching section. The discussion is limited to accelerating and focusing components. Wherever values depend on the choice of the accelerating structure, the disk-and-washer structure is emphasized; the results are generally relevant to the side coupled cavity choice also.

  6. The booster linac for the New Delhi Pelletron

    SciTech Connect

    Potukuchi, P.N.; Roy, A.; Ajith Kumar, B.P.; Ghosh, S.; Sarkar, A.; Changrani, T.; Mehta, R.; Muralidhar, S.; Mehta, G.K.; Shepard, K.W.

    1993-10-01

    This paper describes the heavy ion booster linac project for the New Delhi tandem Pelletron accelerator. The superconducting linac will consist of all niobium quarter-wave coaxial-line cavities. A prototype of the accelerating structure has been designed and a room temperature model is tested for the electromagnetic and mechanical properties. Three prototype niobium cavities are nearing completion at the Argonne National Laboratory.

  7. Calculations of Operational and Residual Doses for the SNS Linac

    SciTech Connect

    Gallmeier, FX

    2001-08-13

    Dose profiles throughout the front-end building and the accelerator tunnel were calculated for the SNS linac system both for normal operation and after shut down of the facility based on normal operations beam losses. The calculated dose levels at an cylindrical envelope with 60 cm radius range from 0.08 to 10 rem/hr for the drift tube linac part, from 50-80 rem/hr for the coupled cavity linac part, from 1 to 20 rem/hr for the superconducting linac part, and from 70-200 rem/hr for the spare section extending after the linac. In the front-end building that houses the first 10 meters of the drift tube linac, dose levels of up to 500 mrem/hr were calculated that need to be reduced by adequate shielding, for example an ordinary concrete shield of up to 120 cm thickness. The shield thickness can be reduced by 25% using borated concrete or a layer of 20 cm borated polyethylene followed by ordinary concrete. The calculated residual dose levels in the accelerator tunnel are a factor of 2000-30 00 lower compared to the operational doses assuming a 30-year operations period and a 1hour decay period.

  8. Physics design of APT linac with normal conducting rf cavities

    SciTech Connect

    Nath, S.; Billen, J.H.; Stovall, J.E.; Takeda, Harunori; Young, L.M.

    1996-09-01

    The accelerator based production of tritium calls for a high-power, cw proton linac. Previous designs for such a linac use a radiofrequency quadrupole (RFQ), followed by a drift-tube linac (DTL) to an intermediate energy and a coupled-cavity linc (CCL) to the final energy. The Los Alamos design uses a high-energy (6.7 MeV) RFQ followed by the newly developed coupled-cavity drift-tube linac (CCDTL) and a CCL. This design accommodates external electromagnetic quadrupole lenses which provide a strong uniform focusing lattice from the end of the RFQ to the end of the CCL. The cell lengths in linacs of traditional design are typically graded as a function of particle velocity. By making groups of cells symmetric in both the CCDTL and CCL, the cavity design as well as mechanical design and fabrication is simplified without compromising the performance. At higher energies, there are some advantages of using superconducting rf cavities. Currently, such schemes are under vigorous study. This paper describes the linac design based on normal conducting cavities and presents simulation results.

  9. A novel electron gun for inline MRI-linac configurations

    SciTech Connect

    Constantin, Dragoş E. Fahrig, Rebecca; Holloway, Lois; Keall, Paul J.

    2014-02-15

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  10. A novel electron gun for inline MRI-linac configurations

    PubMed Central

    Constantin, Dragoş E.; Holloway, Lois; Keall, Paul J.; Fahrig, Rebecca

    2014-01-01

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  11. A novel electron gun for inline MRI-linac configurations.

    PubMed

    Constantin, Dragoş E; Holloway, Lois; Keall, Paul J; Fahrig, Rebecca

    2014-02-01

    This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Simple electron gun geometry modifications of a Varian 600 C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600 C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ± 15 cm along the axis of the 0.5 T magnet without capture

  12. A novel electron gun for inline MRI-linac configurations

    SciTech Connect

    Constantin, Dragoş E. Fahrig, Rebecca; Holloway, Lois; Keall, Paul J.

    2014-02-15

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  13. Status of the plasma generator of the superconducting proton linac

    SciTech Connect

    Kronberger, M.; Lettry, J.; Paoluzzi, M.; Pereira, H.; Arias, J. Sanchez; Schmitzer, C.; Scrivens, R.; Faircloth, D.

    2012-02-15

    In the framework of the superconducting proton linac (SPL) study at CERN, a new non-cesiated H{sup -} plasma generator driven by an external 2 MHz RF antenna has been developed and successfully operated at repetition rates of 50 Hz, pulse lengths of up to 3 ms, and average RF powers of up to 3 kW. The coupling efficiency of RF power into the plasma was determined by the cooling water temperatures and the analysis of the RF forward and reflected power and the antenna current and amounts to 50%-60%. The plasma resistance increases between 10 kW and 40 kW RF power from about 0.45 {Omega} to 0.65 {Omega}. Measurements of RF power dissipated in the ferrites and the magnets on a test bench show a 5-fold decrease of the power losses for the magnets when they are contained in a Cu box, thus validating the strategy of shielding the magnets with a high electrical conductivity material. An air cooling system was installed in the SPL plasma generator to control the temperatures of the ferrites despite hysteresis losses of several Watts.

  14. A modification of flattening filter free linac for IMRT.

    PubMed

    Tsiamas, P; Seco, J; Han, Z; Bhagwat, M; Maddox, J; Kappas, C; Theodorou, K; Makrigiorgos, M; Marcus, K; Zygmanski, P

    2011-05-01

    This study investigates the benefits of a modified flattening filter free (FFF) linac over the standard (STD) linac equipped with the flattening filter. Energy and angular spread of the electron beam of the FFF linac were modified. Modification of FFF beam parameters is explored to maximize the monitor unit efficiency and to minimize the head scatter in IMRT delivery for large target volumes or targets lying away from the central axis. The EGSnrc code is used to model FFF and STD linacs and study basic beam properties for both linac types in various beam configurations. Increasing energy of FFF linac results in similar beam attenuation properties and maximized dose rate compared to STD linac. Matching beam attenuation properties allows a more direct exploration of beam flatness of FFF linac in regard to IMRT delivery, especially away from the central axis where the effective dose rate is considerably smaller than the one at the central axis. Flatness of open beam dose profile of FFF linac is improved by increasing the angular spread of the electron beam. The resulting dose rate within the treatment field and outside of the field (peripheral dose) are characterized and compared to the unmodified FFF and STD linacs, In order to match beam penetration properties, the energy of FFF is adjusted from 6.5 to 8.0 MeV for small to medium field sizes and from 6.5 to 8.5 MeV for larger ones. Dose rate of FFF vs STD linac increased by a factor of 1.9 (6.5 MeV) and 3.4-4.1 (8.0-8.5 MeV). Adjusting the mean angular spread of the electron beam from 0 degrees to 5 degrees-10 degrees resulted in complete flattening of photon beam for field sizes between 10 x 10 cm2 and 15 x 15 cm2 and partial flattening for field sizes from 15 x 15 cm2 to 30 x 30 cm2. Values of angular spread > or =14 degrees are not recommended as they exceed the opening of the primary collimator, affecting the area at the edges of the field. FFF fields of sizes smaller than 6 x 6 cm2 are already flat and beam

  15. An induction linac developed for FEL application

    NASA Astrophysics Data System (ADS)

    de Mascureau, J.; Anthouard, Ph.; Bardy, J.; Eyharts, Ph.; Eyl, P.; Launspach, J.; Thevenot, M.; Villate, D.

    1992-07-01

    An induction linac is being studied and built at CESTA for FEL application. At first we studied the induction technology and namely the high-voltage (HV) generators and the induction cells. A HV generator designed to feed the cells with calibrated pulses (150 kV, 50 ns, δV/V < 1%) has been built using a resonant charging system and magnetic switches. This generator is planned for kHz repetition-rate operation. A prototype induction cell has also been built and tested with a cable generator. An electron injector (1.5 MeV, 1.5kA) has been designed and is now under test: it uses ten induction cells and a thermionic dispenser cathode. Numerical codes have been developed and simulations have been compared with experimental results for HV generators, induction cells, and the injector. An induction accelerating module has been studied and we plan to have the accelerator working at 3 MeV in 1992.

  16. Induction linac drivers: Prospects for the future

    SciTech Connect

    Keefe, D.

    1988-06-01

    This review is intended to place in perspective our current view of the parameter ranges for induction linac drivers that lead to attractive scenarios for civilian electrical power plants; there is a surprising degree of choice (a factor of two or so in most parameters) before any significant impact on the cost of energy results. The progress and goals of the US Heavy Ion Accelerator Research (HIFAR) program are reviewed. The step between the realization of the HIFAR goals and a full-scale driver is seen to be very large indeed and will require one or more significant intermediate steps which can be justified only by a commitment to advance the HIF method towards a true fusion goal. Historical anomalies in the way that fusion programs for both military and civilian applications are administered will need to be resolved; the absence of any presently perceived energy crisis results in little current sense of urgency to develop vigorous long-term energy solutions. 12 refs., 3 figs., 1 tab.

  17. Emittance and Phase Space Tomography for the Fermilab Linac

    SciTech Connect

    Garcia, F.G.G.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.M.; Moore, C.D.; Newhart, D.L.; /Fermilab

    2012-05-01

    The Fermilab Linac delivers a variable intensity, 400-MeV beam to the MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a deconvolution of the profile data. Preliminary measurements using this diagnostic section are reported here. These data represent a first-pass measurement of the Linac emittance based on various techniques. It is clear that the most accurate representation of the emittance is given by the 3-profile approach. Future work will entail minimizing the beam spot size on MW5 to test and possibly improve the accuracy of the 2-profile approach. The 95% emittance is {approx} 18{pi} in the vertical and {approx} 13{pi} in the horizontal, which is especially larger than anticipated - 8-10{pi} was expected. One possible explanation is that the entire Linac pulse is extracted into the MTA beamline and during the first few microseconds, the feed forward and RF regulation are not stable. This may result in a larger net emittance observed versus beam injected into Booster, where the leading part of the Linac beam pulse is chopped. Future studies will clearly entail a measurement of the emittance vs. pulse length. One additional concern is that the Linac phase space is most likely aperture-defined and non-elliptical in nature. A non-elliptical phase-space determination would require a more elaborate analysis and provide another explanation of the

  18. Design study on a medium-energy beam-transport line for the JHF proton linac

    NASA Astrophysics Data System (ADS)

    Fu, Shinian; Kato, Takao

    2001-01-01

    The JHF/JAERI linac is an injector of a 3-GeV ring. It consists of an H - ion source, a 3-MeV radio-frequency quadrupole linac, a 50-MeV drift-tube linac, a 200-MeV separated-type drift-tube linac and a 400-MeV ACS accelerator in its normal conducting section. As an intense beam linac with an average current of 0.2 mA (first stage) and higher in the second stage, the issue of decreasing beam losses is of prime importance. The MEBT between the RFQ and the DTL has been designed with a modified TRACE3-D code, aimed at perfect matching, clear chopping, a small emittance growth and sufficient space for beam measurements. The line consists of eight quadrupoles, two bunchers and two choppers with a total length of about 3 m. Multiparticle codes PARMILA and LINSAC were used to check the beam dynamics of the design. Mismatch due to errors in the elements of the MEBT or the input beam was also studied. A radio-frequency deflector (RFD) is adopted in the chopper. It is characterized by a high deflecting field and compactness. The RF-deflector cavity was designed using the MAFIA code and the electromagnetic field distribution, including fringe field, is applied in TRACE3-D simulation. It illustrates the effect of the beam tube in the cavity on large deflection. A deflection initiated by the RF-deflector is amplified more than twice by the following quadrupole. Owing to this merit, the required RF field of 1.6 MV/m is rather low to generate an adequate separation of 4.3 mm between chopped and unchopped beams at the beam stopper. By means of rapid changes in the RF amplitude and phase during the rise and fall time, the chopper has an equivalent rise and fall time of less than 3.1 ns. Beam losses during the transient time of the chopper are less than 0.08% at the exit of the 50-MeV DTL. An analysis of unstable particles in the coupled RF-deflectors shows no obvious difference from the case of an independent cavity.

  19. Fermilab 200 MeV linac control system hardware

    SciTech Connect

    Shea, M.F.

    1984-01-01

    This report is a description of the present Linac distributed control system that replaces the original Xerox computer and interface electronics with a network of 68000-based stations. In addition to replacing the obsolete Xerox equipment, goals set for the new system were to retain the fast response and interactive nature of the original system, to improve reliability, to ease maintenance, and to provide 15 Hz monitoring of all Linac parameters. Our previous experience with microcomputer installations showed that small, stand-alone control systems are rather straightforward to implement and have been proven to be reliable in operation, even in the severe environment of the 750-keV preaccelerator. The overall design of the Linac system incorporates the concept of many relatively small, stand-alone control systems networked together using an intercomputer communication network. Each station retains its local control system character but takes advantage of the network to allow an operator to interact with the entire Linac from any local console. At the same time, a link to the central computer system allows Host computers to also access parameters in the Linac.

  20. The Linac Coherent Light Source (LCLS)*

    NASA Astrophysics Data System (ADS)

    Winick, Herman

    2002-04-01

    Advances in technology make it possible to use the SLAC linac to drive the LCLS (1), a coherent x-ray source which will deliver sub-picosecond pulses at wavelengths down to 1.5 Angstroms with an instantaneous (peak) power up to 10 GW, corresponding to a brightness 10 orders of magnitude greater than x-ray beams from the most advanced synchrotron light sources. The LCLS operates on the principle of Self-Amplified Spontaneous Emission-SASE (2); i.e., coherent emission is achieved without an optical cavity by inducing a bunch-density modulation at the scale of the optical wavelength in a single pass of a high peak current, low emittance, 15 GeV electron beam through a 100m undulator. The LCLS, and a similar project planned at DESY in Hamburg, exploit recent technological developments; high-brightness rf photocathode electron guns, emittance preservation during acceleration and compression, precision undulator magnets, and high power x-ray optics. The unique properties of LCLS radiation enable new scientific opportunities in femtochemistry, nanoscale dynamics in condensed matter, atomic physics, biological imaging, plasma physics, and warm condensed matter. A collaboration including 4 US national labs (Argonne, Brookhaven, Lawrence Livermore, and Los Alamos) along with SLAC and UCLA is conducting r&d aiming for an LCLS construction start in 2004. 1. P.Emma; Proc. Part. Accel. Conf.(PAC2001); June 18-22, 2001. 2. R.Bonifacio, C.Pellegrini, L.Narducci; Optics Comm. 50,373(1984) *Supported by the Office of Basic Energy Sciences, US Dept. of Energy.

  1. Experimental RFQ as injector to the CERN Linac I

    SciTech Connect

    Boltezar, E.; Haseroth, H.; Pirkl, W.

    1981-01-01

    Since the successful development and testing of a radio-frequency quadrupole (RFQ) prototype at Los Alamos, the use of RFQs as injectors to the CERN linacs is being envisaged. As a pilot project, a 202.56-MHz RFQ for Linac I (Old Linac) is being built in close collaboration between Los Alamos and CERN. This project will be completed in about 15 months, a timescale imposed by other CERN programs. The CERN RFQ is based on the Los Alamos proven design approach, but will have to meet requirements of the existing CERN environment. The design characteristics of this accelerator are described, and some conclusions based on model work at CERN are given.

  2. Beam loading compensation for the NLC low frequency linacs

    SciTech Connect

    Li, Z.; Miller, R.; Farkas, D.; Raubenheimer, T.; Tang, H.; Yeremian, D.

    1997-03-01

    The NLC low rf linacs are heavily loaded by a beam of about 130 ns in macropulse length (90 bunches) and a current up to 2.75 Amps. Beam loading voltage generates a large energy spread along the bunch train. This energy spread is critical for lattice design and, if not properly compensated, induces emittance growth and in turn lowers the luminosity of the machine. In this paper, the authors study the {Delta}F and {Delta}T beam loading compensation techniques for the NLC low rf linacs. They will apply these methods to the NLC low rf linacs to demonstrate the efficacy of these methods. Finally, they discuss a hybrid {Delta}T + {Delta}F method to improve the efficiency of beam loading compensation.

  3. Thirty-five years of drift-tube linac experience

    SciTech Connect

    Knowles, H.B.

    1984-10-01

    The history of the drift-tube linear accelerator (linac) for the first 35 years of its existence is briefly reviewed. Both US and foreign experience is included. Particular attention is given to technological improvements, operational reliability, capital investment, and number of personnel committed to drift-tube linac (DTL) development. Preliminary data indicate that second- and third-generation (post-1960) DTLs have, in the US alone, operated for a combined total period of more than 75 machine-years and that very high reliability (>90%) has been achieved. Existing US drift-tube linacs represent a capital investment of at least $250 million (1983). Additional statistical evidence, derived from the proceedings of the last 11 linear accelerator conferences, supports the view that the DTL has achieved a mature technological base. The report concludes with a discussion of important recent advances in technology and their applications to the fourth generation of DTLs, many of which are now becoming operational.

  4. Heavy-ion acceleration with a superconducting linac

    SciTech Connect

    Bollinger, L.M.

    1988-01-01

    This year, 1988, is the tenth anniversary of the first use of RF superconductivity to accelerate heavy ions. In June 1978, the first two superconducting resonators of the Argonne Tandem-Linac Accelerator System (ATLAS) were used to boost the energy of a /sup 19/F beam from the tandem, and by September 1978 a 5-resonator linac provided an /sup 16/O beam for a nuclear-physics experiment. Since then, the superconducting linac has grown steadily in size and capability until now there are 42 accelerating structures and 4 bunchers. Throughout this period, the system was used routinely for physics research, and by now the total time with beam on target is 35,000 hours. Lessons learned from this long running experience and some key technical developments that made it possible are reviewed in this paper. 19 refs., 3 figs., 2 tabs.

  5. Solenoid-based focusing in a proton linac

    SciTech Connect

    Terechkine, I; DiMarco, J.; Schappert, W.; Sergatskov, d.; Tartaglia, M.; /Fermilab

    2010-09-01

    Development of solenoid-based focusing lenses for the transport channel of an R&D linac front end at FNAL (HINS linac) is in its final stage. Superconducting lenses for the room temperature RF section of the linac are assembled into individual cryostats and certified using a dedicated test stand. During this certification process, the optical axis of each lens relative to the cryogenic vessel is found in the warm and cold state. Lenses for the superconducting RF sections are ready for production, and development of a cryomodule (which contains multiple superconducting lenses and RF cavities) is in progress. Studies have been conducted to measure fringe magnetic field of a lens in the cryomodule, to investigate a laser-based method of alignment, and to evaluate the extent of beam quality degradation due to imperfections in lens construction and alignment. This report presents some results of these studies.

  6. R and D energy recovery LINAC at Brookhaven National Laboratory

    SciTech Connect

    Litvinenko,V.N.; Beavis, D.; Ben-Zvi, I.; Blaskiewicz, M.; Burrill, A.; Calaga, R.; Cameron, P.; Chang, X.; Drees, A.; Ganetis, G.; Gassner, D.; Hahn, H.; Hammons, L.; Hershcovitch, A.; Hseuh, H-C.; Jain, A.; Kayran, D.; Kewisch, J.; Lambiase, R.; Lederle, D.; Mahler, G.; McIntyre, G.; Meng, W.; Nehring, T.; Oerter, B.; Pai, C.; Pate, D.; Phillips, D.; Pozdeyev, E.; Rao, T.; Reich, J.; Roser, T.; Russo, T.; Smith, K.; Tuozzolo, J.; Weiss, D.; Williams, N.; Yip, K.; Zaltsman, A.; Favale, A.; Bluem, H.; Cole, M.; Holmes, D.; Rathke, J.; Schultheiss, T.; Todd, A.; Delayen, J.; Funk, L.; Phillips, L.; Preble, J.

    2008-06-23

    Collider Accelerator Department at BNL is in the final stages of developing the 20-MeV R and D energy recovery linac with super-conducting 2.5 MeV RF gun and single-mode super-conducting 5-cell RF linac. This unique facility aims to address many outstanding questions relevant for high current (up to 0.5 A of average current), high brightness energy-recovery linacs with novel ZigZag-type merger. Recent development in the R and D ERL plans include gun and 5-cell cavity (G5) test and possibility of using R and D ERL for proof-of-principle test of Coherent Electron Cooling at RHIC.

  7. Configuring the SLC linac for injection into PEP

    SciTech Connect

    Bane, K.L.F.

    1989-12-15

    From time to time the normal SLC physics program is to be interrupted so that beam can be delivered to PEP. In order that the switch to PEP injection (and the switch back again) can be accomplished quickly and easily, the gun, the damping rings, the linac phase ramp, the energy profile of the linac klystrons for the scavenger bunch, and the entire positron production system are to be kept the same as in the SLC configuration. What mainly remains to be changed is the linac klystron profile for the leading two bunches - those going to PEP. The new klystron profile must be such that it leaves these two beams (1) with final energies that match that of the storage ring and (2) with final energy spectra that fit within the energy aperture of the PEP transfer line. The conditions that need to be met in order to achieve these two goals are discussed in this note. 1 ref., 2 figs.

  8. A hot-spare injector for the APS linac.

    SciTech Connect

    Lewellen, J. W.

    1999-04-13

    Last year a second-generation SSRL-type thermionic cathode rf gun was installed in the Advanced Photon Source (APS) linac. This gun (referred to as ''gun2'') has been successfully commissioned and now serves as the main injector for the APS linac, essentially replacing the Koontz-type DC gun. To help ensure injector availability, particularly with the advent of top-up mode operation at the APS, a second thermionic-cathode rf gun will be installed in the APS linac to act as a hot-spare beam source. The hot-spare installation includes several unique design features, including a deep-orbit Panofsky-style alpha magnet. Details of the hot-spare beamline design and projected performance are presented, along with some plans for future performance upgrades.

  9. Alignment and steering scenarios for the APT linac

    SciTech Connect

    Stovall, J.E.; Gray, E.R.; Nath, S.; Takeda, H.; Wood, R.L.; Young, L.M.; Crandall, K.R.

    1996-09-01

    The Accelerator for the Production of Tritium (APT) requires a very high proton beam current (100 mA cw). Requirement for hands-on maintenance limits the beam spill to less than 0.2 nA/m along most of the linac. To achieve this, it is important to understand the effects of fabrication, installation and operational errors, establish realistic tolerances, and develop techniques for mitigating their consequences. A new code, PARTREX, statistically evaluates the effects of alignment, quadrupole field, and rf phase and amplitude errors in the linac. This paper reviews the effects of quadrupole misalignments and present two steering algorithms that minimize the potential for particle loss from the beam halo. These algorithms were tested on the 8-to-20 MeV portion of the APT linac.

  10. The rotating biplanar linac-magnetic resonance imaging system.

    PubMed

    Fallone, Biagio Gino

    2014-07-01

    We have successfully built linac-magnetic resonance imaging (MR) systems based on a linac waveguide placed between open MR planes (perpendicular) or through the central opening of one of the planes (parallel) to improve dosimetric properties. It rotates on a gantry to irradiate at any angle. Irradiation during MR imaging and automatic 2-dimensional MR image-based target tracking and automatic beam steering to the moving target have been demonstrated with our systems. The functioning whole-body system (0.6-T MR and 6-MV linac) has been installed in an existing clinical vault without removing the walls or the ceiling and without the need of a helium exhaust vent. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. DIAGNOSTIC TOOLS FOR BEAM HALO INVESTIGATION IN SNS LINAC

    SciTech Connect

    Aleksandrov, Alexander V; Blokland, Willem; Liu, Yun; Long, Cary D; Zhukov, Alexander P

    2012-01-01

    Uncontrolled beam loss is a major concern in the operation of a high intensity hadron linac. A low density cloud of particles with large oscillation amplitudes, so called halo, can form around the dense regular beam core. This halo can be a direct or indirect cause of beam loss. There is experimental evidence of halo growing in the SNS linac and limiting the further reduction of beam loss. A set of tools is being developed for detecting of the halo and investigating its origin and dynamics. The set includes high resolution emittance measurements in the injector, laser based emittance measurements at 1 GeV, and high resolution profile measurements along the linac. We will present our experience with useful measurement techniques and data analysis algorithms.

  12. Investigations of Slow Motions of the SLAC Linac Tunnel

    SciTech Connect

    Seryi, Andrei

    2000-08-31

    Investigations of slow transverse motion of the linac tunnel of the Stanford Linear Collider have been performed over period of about one month in December 1999--January 2000. The linac laser alignment system, equipped with a quadrant photodetector, allowed submicron resolution measurement of the motion of the middle of the linac tunnel with respect to its ends. Measurements revealed two major sources responsible for the observed relative motion. Variation of the external atmospheric pressure was found to be the most significant cause of short wavelength transverse motion of the tunnel. The long wavelength component of the motion has been also observed to have a large contribution from tidal effects. The measured data are essential for determination of parameters for the Next Linear Collider.

  13. The SLAC linac as used in the SLC collider

    SciTech Connect

    Seeman, J.T.; Abrams, G.; Adolphsen, C.; Atwood, W.; Bane, K.L.F.; Iverson, R.; Jacobsen, R.; Himel, T.M.; Jobe, R.K.; Lavine, T.L.

    1989-06-01

    The linac of the SLAC Linear Collider (SLC) must accelerate three high intensity bunches on each linac pulse from 1.2 GeV to 50 GeV with minimal increase of the small transverse emittance. The procedures and adjustments used to obtain this goal are outlined. Some of the accelerator parameters and components which interact are the beam energy, transverse position, component alignment, RF manipulation, feedback systems, quadrupole lattice, BNS damping, energy spectra, phase space matching, collimation, instrumentation and modelling. The method to bring these interdependent parameters collectively into specification has evolved over several years. This review is ordered in the sequence which is used to turn on the linac from a cold start and produce acceptable beams for the final focus and collisions. Approximate time estimates for the various activities are given. 21 refs.

  14. An energy recovery electron linac-on-ring collider

    SciTech Connect

    Merminga, L.; Krafft, G.A.; Lebedev, V.A.; Ben-Zvi, I.

    2000-09-14

    We present the design of high-luminosity electron-proton/ion colliders in which the electrons are produced by an Energy Recovering Linac (ERL). Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10{sup 33}(per nucleon) level have been proposed recently as a means for studying hadronic structure. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations (2) reduction of the synchrotron radiation load in the detectors (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at currents of a few hundred mA and multi-GeV energies. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored in the existing RHIC accelerator. Accelerator physics issues relevant to proton rings and energy recovery linacs are discussed and a list of required R and D for the realization of such a design is presented.

  15. Injector linac stability requirements for high precision experiments at MESA

    NASA Astrophysics Data System (ADS)

    Hug, F.; Heine, R.

    2017-07-01

    MESA is a recirculating superconducting accelerator under construction at Johannes Gutenberg-Universität Mainz. It will be used for high precision particle physics experiments in two different operation modes: external beam (EB) mode and energy recovery (ERL) mode. The operating beam current and energy in EB mode is 0.15 mA with polarized electrons at 155 MeV. In ERL mode an unpolarized beam of 1 mA at 105 MeV will be available. In a later construction stage of MESA the beam current in ERL-mode shall be upgraded to 10 mA. In order to achieve high beam stability and low energy spread in recirculating operation for external beam the acceleration in the main linac sections will be done on a certain phase with respect to the maximum of the accelerating field (off crest) while the return arcs provide longitudinal dispersion. On specific longitudinal working points this can result in a setting where any RF phase or magnitude jitters from main linac do not contribute to the resulting energy spread of the final beam at all. Then the resulting energy spread of the beam at the experiment is mostly determined by the beam properties provided by the injector linac. On the other hand the acceleration in ERL operation mode most likely needs to be done on crest of the accelerating field aiming for the highest efficiency in the energy recovering process albeit we are currently investigating different recirculation schemes for the ERL mode as well. Using on crest acceleration the achievable energy spread is determined by the longitudinal phase space properties behind the injector linac again but mostly by the bunch length of the beam injected to the main linac. Within this contribution we will investigate the requirements on the stability of the MESA injector linac MAMBO for achieving the experimental goals under both operating conditions.

  16. Study of the NLC Linac Optics Compatible with a Low Energy Scenario

    SciTech Connect

    Nosochkov, Yuri

    2002-02-27

    We explore the NLC linac optics compatible with a low energy scenario where initially only part of the full linac is installed. Optics modification suitable for a low energy beam running and upgrade to the nominal energy is discussed. Linac parameters and beam tolerances in the modified lattice are compared to the nominal design.

  17. Application of electron linacs in medicine, food sterilization and synchrotron light sources

    NASA Astrophysics Data System (ADS)

    Tran, Duc-Tien

    1989-04-01

    A review of the state of the art and new trends in electron linac technology is given with emphasis on three particular applications: radiotherapy, food sterilization and synchrotron light sources. The requirements on linac performances that these applications call for, namely energy variation flexibility, high power, high energy and low cost, will open linacs to new applications to come.

  18. High intensity proton linac activities at Los Alamos

    SciTech Connect

    Rusnak, B.; Chan, K.C.; Campbell, B.

    1998-09-01

    High-current proton linear accelerators offer an attractive alternative for generating the intense neutron fluxes needed for transmutations technologies, tritium production and neutron science. To achieve the fluxes required for tritium production, a 100-mA, 1700-MeV cw proton accelerator is being designed that uses superconducting cavities for the high-energy portion of the linac, from 211 to 1,700 MeV. The development work supporting the linac design effort is focused on three areas: superconducting cavity performance for medium-beta cavities at 700 MHz, high power rf coupler development, and cryomodule design. An overview of the progress in these three areas is presented.

  19. LINAC BEAM DYNAMICS SIMULATIONS WITH PY-ORBIT

    SciTech Connect

    Shishlo, Andrei P

    2012-01-01

    Linac dynamics simulation capabilities of the PyORBIT code are discussed. PyORBIT is an open source code and a further development of the original ORBIT code that was created and used for design, studies, and commissioning of the SNS ring. The PyORBIT code, like the original one, has a two-layer structure. C++ is used to perform time-consuming computations, and the program flow is controlled from a Python language shell. The flexible structure makes it possible to use PyORBIT also for linac dynamics simulations. A benchmark of PyORBIT with Parmila and the XAL Online model is presented.

  20. BEAM SIMULATIONS USING VIRTUAL DIAGNOSTICS FOR THE DRIVER LINAC

    SciTech Connect

    R. C. York; X. Wu; Q. Zhao

    2011-12-21

    End-to-end beam simulations for the driver linac have shown that the design meets the necessary performance requirements including having adequate transverse and longitudinal acceptances. However, to achieve reliable operational performance, the development of appropriate beam diagnostic systems and control room procedures are crucial. With limited R&D funding, beam simulations provide a cost effective tool to evaluate candidate beam diagnostic systems and to provide a critical basis for developing early commissioning and later operational activities. We propose to perform beam dynamic studies and engineering analyses to define the requisite diagnostic systems of the driver linac and through simulation to develop and test commissioning and operational procedures.

  1. ZDR - Simulation Studies of the NLC Main Linacs

    SciTech Connect

    Assmann, R.

    2005-01-26

    This study was published as part of the Next Linear Collider (NLC) Zeroth order Design Report (ZDR) [1]. It addresses the problems of transporting very small emittance beams in the main linacs of the NLC. Several mechanisms of emittance dilution and correction are calculated in detail. The results demonstrate the feasibility of the NLC main linac design under the assumption that the specified device tolerances are met. The full text of the ZDR is available on the WWW under http://www.slac.stanford.edu/accel/nlc/zdr/.

  2. Phase Transfer Measurements at the Jefferson Lab Recirculated Linacs

    SciTech Connect

    Geoffrey Krafft; J. Hovater; B. Bowling; M. Crofford

    2005-06-01

    Bunch length or longitudinal phase space distribution measurements are often used to evaluate if the electron beam meets RF criteria for a recirculated linac. Unfortunately, in many instances when the beam fails to meet the needed criteria, such measurements provide little guidance as to which machine element is problematic. All of the Jefferson Lab recirculated linacs have employed longitudinal phase transfer measurement systems to provide both useful information on the initial understanding of the dynamics of the longitudinal phase space in these accelerators, and much more useful diagnosis of out-of-specification performance of machine RF elements. These systems can provide precision transfer function measurements in time scales convenient for machine operations.

  3. Micro-SHINE Uranyl Sulfate Irradiations at the Linac

    SciTech Connect

    Youker, Amanda J.; Kalensky, Michael; Chemerisov, Sergey; Schneider, John; Byrnes, James; Vandegrift, George F.

    2016-08-01

    Peroxide formation due to water radiolysis in a uranyl sulfate solution is a concern for the SHINE Medical Technologies process in which Mo-99 is generated from the fission of dissolved low enriched uranium. To investigate the effects of power density and fission on peroxide formation and uranyl-peroxide precipitation, uranyl sulfate solutions were irradiated using a 50-MeV electron linac as part of the micro-SHINE experimental setup. Results are given for uranyl sulfate solutions with both high and low enriched uranium irradiated at different linac powers.

  4. Billion particle linac simulations for future light sources

    SciTech Connect

    Ryne, R. D.; Venturini, M.; Zholents, A. A.; Qiang, J.

    2008-09-25

    In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.

  5. SRF cavities for CW option of Project X Linac

    SciTech Connect

    Solyak, N.; Gonin, I.; Khabiboulline, T.; Lunin, A.; Perunov, N.; Yakovlev, V.; /Fermilab

    2009-09-01

    Alternative option of Project X is based on the CW SC 2GeV Linac with the average current 1mA. Possible option of the CW Linac considered in the paper includes low energy part consisted of a few families SC Spoke cavities (from 2.5 MeV to 466 MeV) and high energy part consisted of 2 types of elliptical cavities (v/c=0.81 and v/c=1). Requirements and designed parameters of cavities are considered.

  6. THE CONVENTIONAL FACILITIES REQUIREMENTS FOR THE SNS LINAC

    SciTech Connect

    P. TALLERICO; M. CROW; ET AL

    2001-06-01

    The Spallation Neutron Source (SNS) linac has a high gradient and 2 MW of beam power, and it therefore requires substantial RF power and cooling. There are 94 klystrons in its RF system, a large number for a proton linac. The optimization process and logic that lead to the klystron, transmitter, and power supply sizes is discussed. We also describe the requirements for building and tunnel area, electrical power, and water for this system. The trade-off decisions between low capital cost, low operating cost, and good maintainability are described.

  7. Neutron distribution and induced activity inside a Linac treatment room.

    PubMed

    Juste, B; Miró, R; Verdú, G; Díez, S; Campayo, J M

    2015-01-01

    Induced radioactivity and photoneutron contamination inside a radiation therapy bunker of a medical linear accelerator (Linac) is investigated in this work. The Linac studied is an Elekta Precise electron accelerator which maximum treatment photon energy is 15 MeV. This energy exceeds the photonuclear reaction threshold (around 7 MeV for high atomic number metals). The Monte Carlo code MCNP6 has been used for quantifying the neutron contamination inside the treatment room for different gantry rotation configuration. Walls activation processes have also been simulated. The approach described in this paper is useful to prevent the overexposure of patients and medical staff.

  8. Beam position monitor for energy recovered linac beams

    DOEpatents

    Powers, Thomas; Evtushenko, Pavel

    2017-06-06

    A method of determining the beam position in an energy recovered linac (ERL). The method makes use of in phase and quadrature (I/Q) demodulation techniques to separate the pickup signal generated by the electromagnetic fields generated by the first and second pass beam in the energy recovered linac. The method includes using analog or digital based I/Q demodulation techniques in order to measure the relative amplitude of the signals from a position sensitive beam pickup such as a button, strip line or microstripline beam position monitor.

  9. Design and construction of the main linac module for the superconducting energy recovery linac project at Cornell

    SciTech Connect

    Eichhorn, R.; Bullock, B.; He, Y.; Hoffstaetter, G.; Liepe, M.; O'Connell, T.; Quigley, P.; Sabol, D.; Sears, J.; Smith, E.; Veshcherevich, V.

    2014-01-29

    Cornell University has been designing and building superconducting accelerators for various applications for more than 50 years. Currently, an energy-recovery linac (ERL) based synchrotron-light facility is proposed making use of the existing CESR facility. As part of the phase 1 R and D program funded by the NSF, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/ BPM section. Pushing the limits, a high quality factor of the cavities (2⋅10{sup 10}) and high beam currents (100 mA accelerated plus 100 mA decelerated) are targeted. We will present the design of the main linac cryo-module (MLC) being finalized recently, its cryogenic features and report on the status of the fabrication which started in late 2012.

  10. LOW LOSS DESIGN OF THE LINAC AND ACCUMULATOR RING FOR THE SPALLATION NEUTRON SOURCE.

    SciTech Connect

    RAPARIA,D.

    2003-02-03

    The Spallation Neutron Source (SNS) is a second generation pulsed neutron source and is presently in the fourth year of a seven-year construction cycle at Oak Ridge National Laboratory. A collaboration of six national laboratories (ANL, BNL, LANL, LBNL, ORNL, TJNAF) is responsible for the design and construction of the various subsystems. The operation of the facility will begin in 2006 and deliver a 1.0 GeV, 1.4 MW proton beam with pulse length of 650 nanosecond at a repetition rate of 60 Hz, on a liquid mercury target. It consists of an RF volume H{sup -} source of 50 mA peak current at 6% duty; an all electrostatic Low-Energy Beam Transport (LEBT) which also serves as a first stage beam chopper with {+-} 25 ns rise/fall time; a 402.5 MHz, 4-vane Radio-Frequency Quadrupole (RFQ) for acceleration up to 2.5 MeV; a Medium Energy Beam Transport (MEBT) housing a second stage chopper (<{+-} 10ns rise/fall), an adjustable beam halo scraper, and diagnostics devices; a 6-tank Drift Tube Linac (DTL) with permanent magnet quadrupoles up to 87 MeV; an 805 MHz, 4-module, Side Coupled Cavity Linac (CCL) up to 186 MeV; an 805 MHz, superconducting RF (SRF) linac with eleven medium beta ({beta} = 0.61) cryo-modules and twelve high beta ({beta} = 0.81) cryo-modules accelerating the beam to the full energy; a High Energy Beam transport (HEBT) for diagnostics, transverse and longitudinal collimation, energy correction, painting and matching; an accumulator ring compressing the 1 GeV, 1 ms pulse to 650 ns for delivery onto the target through a Ring to Target Beam Transport (RTBT) with transverse collimators.

  11. Characterization of the radiation environment at the UNLV accelerator facility during operation of the Varian M6 linac

    NASA Astrophysics Data System (ADS)

    Hodges, M.; Barzilov, A.; Chen, Y.; Lowe, D.

    2016-10-01

    The bremsstrahlung photon flux from the UNLV particle accelerator (Varian M6 model) was determined using MCNP5 code for 3 MeV and 6 MeV incident electrons. Human biological equivalent dose rates due to accelerator operation were evaluated using the photon flux with the flux-to-dose conversion factors. Dose rates were computed for the accelerator facility for M6 linac use under different operating conditions. The results showed that the use of collimators and linac internal shielding significantly reduced the dose rates throughout the facility. It was shown that the walls of the facility, in addition to the earthen berm enveloping the building, provide equivalent shielding to reduce dose rates outside to below the 2 mrem/h limit.

  12. Conceptual Design for the New RPI 2020 Linac

    SciTech Connect

    Adolphsen, C.; Bane, K.; Dolgashev, V.; Jensen, A.; Haase, A.; Jongewaard, E.; Kemp, M.; Krasnykh, A.; Lewandowski, J.; Li, Z.; Neilson, J.; Pearson, C.; Tantawi, S.; Wang, J.; Yeremian, A. D.; Brand, P.; Danon, Y.; Epping, B.; Donovan, T.; Block, R.; Leinweber, G.

    2014-10-29

    The Rensselaer Polytechnic Institute (RPI) spectrometer is an installation based on an L-band linear accelerator designed and installed many decades ago. While this installation has served many important experiments over the decades, a new more powerful and more flexible linac to serve a wider range of experiments is envisioned as an upgrade to the existing installation by 2020.

  13. Critical design issues of high intensity proton linacs

    SciTech Connect

    Lawrence, G.P.

    1994-08-01

    Medium-energy proton linear accelerators are being studied as drivers for spallation applications requiring large amounts of beam powder. Important design factors for such high-intensity linacs are reviewed, and issues and concerns specific to this unprecedented power regime are discussed.

  14. Optimization of steering elements in the RIA driver linac.

    SciTech Connect

    Lessner, E. S.; Aseev, V. S.; Ostroumov, P. N.; Physics

    2005-01-01

    The driver linac of the projected RIA facility is a versatile accelerator, a 1.4-GV, CW superconducting (SC) linac designed to simultaneously accelerate several heavy-ion charge states, providing beams from proton to uranium at 400 MeV/u at power levels at a minimum of 100 kW and up to 400 kW for most beams. Acceleration of multiple-charge-state uranium beams places stringent requirements on the linac design. A steering algorithm was derived that fulfilled the driver's real estate requirements, such as placement of steering dipole coils on SC solenoids and of beam position monitors outside cryostats, and beam-dynamics requirements, such as coupling effects induced by the focusing solenoids. The algorithm has been fully integrated into the tracking code TRACK and it is used to study and optimize the number and position of steering elements that minimize the multiple-beam centroid oscillations and preserve the beam emittance under misalignments of accelerating and transverse focusing elements in the driver linac.

  15. An Energy Recovery Electron Linac On Ring Collider

    SciTech Connect

    Nikolitsa Merminga; Geoffrey Krafft; Valeri Lebedev; Ilan Ben-Zvi

    2001-09-01

    Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10{sup 33} (per nucleon) level have been proposed recently as a means for studying hadronic structure. Electron beam polarization appears to be crucial for many of the experiments. Two accelerator design scenarios have been examined in detail: colliding rings and recirculating linac-on-ring. Although the linac-on-ring scenario is not as well developed as the ring-ring scenario, comparable luminosities appear feasible. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations; (2) reduction of the synchrotron radiation load in the detectors; (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. This technology has been demonstrated at Jefferson Lab's IR FEL with cw current up to 5 mA and beam energy up to 50 MeV. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at higher currents (a few hundred mA) and higher energies (a few GeV) as well. The report begins with a brief overview of Jefferson Lab's experience with energy recovery and summarize its benefits. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented next. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored in the existing RHIC accelerator. Accelerator physics issues relevant to proton rings and energy recovery linacs are discussed next and a list of required R and D for the realization of such a design is presented.

  16. Passive tracking of linac clinical flow using radiofrequency identification technology.

    PubMed

    Harry, Taylor; Taylor, Matthew; Fletcher, Richard L; Mundt, Arno J; Pawlicki, Todd

    2014-01-01

    To analyze the implementation of a passive radiofrequency identification (RFID) clinical system and to evaluate the clinical workflow on 2 linear accelerators using the RFID technology. The clinical area of a typical radiation therapy center was equipped with RFID readers and antennae, which included linear accelerator (linac) treatment vaults. Both were dual energy linacs (6 and 15 MV). One linac was an iX with RapidArc (Varian Medical Systems, Inc, Palo Alto, CA) and the other was a TrueBeam (Varian Medical Systems, Inc, Palo Alto, CA). Patients were given an RFID transponder card on their first day of treatment. Location timestamps were collected when the patients entered and exited the linac vaults. Each fraction was categorized by treatment machine, treatment site (brain, head and neck, prostate, and other), and treatment type (static field intensity modulated radiation therapy [IMRT], RapidArc, and 3-dimensional [3D]). The Mann-Whitney nonparametric test was used to determine statistical significance between median times in the linac vault. A total of 4302 fractions from 144 patients were analyzed over a 10-month period. With minimal staff training, an approximately 70% read reliability was achieved. The median treatment time for all treatment fractions on the TrueBeam linac was 11.0 minutes (n = 1425) while the median time was 11.9 minutes (n = 1576) on the iX linac (P < .0001). Median times for the RapidArc cases was 10.9 minutes (n = 610) and 12.0 minutes (n = 1729) for IMRT cases (P < .0001). Median values for 3D delivery versus modulated delivery (RapidArc and IMRT) were 9.8 minutes (n = 315) and 11.7 minutes (n = 2339), P < .0001. Automatic remote reading of passive transponder cards is not without its challenges. However, with little or no clinical introduction, we experienced a read reliability that warrants further development. Our initial use of the system indicates that continual collection and analysis of workflow data may allow clinics to improve

  17. LINAC radiosurgery as single treatment in cerebral metastases.

    PubMed

    Deinsberger, R; Tidstrand, J

    2006-01-01

    Stereotactic radiosurgery is a radiation technique of high radiation dose focused on a stereotactic intracranial target in a single fraction with high precision. LINAC Radiosurgery has gained increasing relevance in the treatment of brain metastases since it was introduced by Sturm (1987). METHOD AND PATIENT SELECTION: From January 1996 to August 2003 110 patients were treated with LINAC Radiosurgery. A combination of the University of Florida system and the X Knife System developed by Radionics was used in all patients. Seventy patients had a single and 40 patients multiple metastatic lesions at the time of diagnosis and treatment. Overall 161 intracerebral metastases were treated. Median tumor volume was 3.1 ccm (0.3-15 ccm). Median radiation dose to the tumor margin was 1830 cGy (range 1100-2200 cGy) prescribed to the 80% isodose line. Whole brain radiation therapy with a total dose of 30 Gy in 10 fractions was performed in 35 patients because of multiple metastases and LINAC Radiosurgery was used as boost for recurrences. In 75 patients LINAC Radiosurgery was used as single treatment. The follow-up period was between 6 and 72 months. Local tumor control rate was 89.4%. Seventeen out of 161 metastases treated showed local recurrence. Eleven out of 75 patients treated with radiosurgery as single treatment developed distant recurrence and 3 out of 35 patients who were treated with whole brain radiation therapy (WBRT) and radiosurgery as boost. The 1-year survival rate is 54.9% with a median survival of 54 weeks. LINAC Radiosurgery is an effective and safe treatment modality in patients with cerebral metastases located in any area of the brain. WBRT should be preserved for patients with multiple metastases or be delayed until multiple recurrence occurs. Surgery is still the treatment of choice in metastases with mass effect and surgical accessible location.

  18. Experimental beam dynamics in the SLC (SLAC Linear Collier) linac

    SciTech Connect

    Steeman, J.T.; Campisi, I.E.; Herrmannsfeldt, W.; Lee, M.

    1987-01-01

    The component installation for the upgrade of the three-kilometer linac for the SLAC Linear Collider (SLC) was completed in late summer 1986. The system status and measurements of beam properties made during commissioning are described in this paper. In summary, a low-emittance electron beam from a damping ring has been accelerated through the linac and injected into the north SLC Arc with negligible loss. The maximum bunch intensity is 2.9 x 10 electrons/pulse. A peak particle energy of 53 GeV has been reached. Operation at 47 GeV is now routine. The energy and energy spectrum of the electron beam can be rapidly measured nondestructively at high energy. These signals will be used in a fast feedback system nearing completion. The electron beam can be centered in the accelerator to about 200 m rms. Slow feedback of the injection position and angle into the linac and injection into the north Arc are operational. Longitudinal and transverse wakefields have been measured and appear to be near expectations. Transverse position measurements at the end of the linac show a 120 m horizontal and a 30 m vertical (rms) jitter from pulse to pulse. The spot shape, including the transverse tails, also shows some jitter. The transverse position and shape fluctuations have several sources involving launch instabilities, chromatic effects, RF deflections and lattice mismatches. Continued improvements are expected. These parameter jitters would not preclude collisions. The measured invariant transverse emittances of the beam at 47 GeV are 2 x 10 V rm vertically and 12-25 x 10 V rm horizontally at 1 x 10 e . The horizontal emittance increases with beam intensity. Damped positrons have been injected into the linac, and trajectory correction is underway.

  19. Frequency choice of eRHIC SRF linac

    SciTech Connect

    Xu, W.; Ben-Zvi, I.; Roser, T.; Ptitsyn, V.

    2016-01-05

    eRHIC is a FFAG lattice based multipass ERL [1]. The eRHIC SRF linac has been decided to change from 422 MHz 5-cell cavity to 647 MHz 5-cell cavity. There are several considerations affecting the frequency choice for a high current multipass-ERL: the beam structure, bunch length, energy spread, beam-break-up (BBU) threshold, SRF loss considerations. Beyond the physics considerations, cost and complexity or risk is an important consideration for the frequency choice, especially when we are designing a machine to be built in a few years. Although there are some benefits of using a 422 MHz cavity for eRHIC ERL, however, there are some very critical drawbacks, including lack of facilities to fabricate a 422 MHz 5-cell cavity, very few facilities to process such a cavity and no existing facility to test the cavity anywhere. As the cavity size is big and its weight is large, it is difficult to handle it during fabrication, processing and testing and no one has experience in this area. As the cavity size is large, the cryomodule becomes big as well. All of these considerations drive the risk of building eRHIC ERL with 422 MHz cavities to a very high level. Therefore, a decision was made to change the frequency of main linac to be 647 MHz 5-cell cavities. This note will compare these two linacs: 422MHz 5-cell cavity linac and 647Mz 5-cell cavity SRF linac, from both practical point of view and physics point of view.

  20. The development of magnetic field measurement system for drift-tube linac quadrupole

    NASA Astrophysics Data System (ADS)

    Zhou, Jianxin; Kang, Wen; Yin, Baogui; Peng, Quanling; Li, Li; Liu, Huachang; Gong, Keyun; Li, Bo; Chen, Qiang; Li, Shuai; Liu, Yiqin

    2015-06-01

    In the China Spallation Neutron Source (CSNS) linac, a conventional 324 MHz drift-tube linac (DTL) accelerating an H- ion beam from 3 MeV to 80 MeV has been designed and manufactured. The electromagnetic quadrupoles (EMQs) are widely used in a DTL accelerator. The main challenge of DTLQ's structure is to house a strong gradient EMQ in the much reduced space of the drift-tube (DT). To verify the DTLQ's design specifications and fabrication quality, a precision harmonic coil measurement system has been developed, which is based on the high precision movement platform, the harmonic coil with ceramic frame and the special method to make the harmonic coil and the quadrupoles coaxial. After more than one year's continuous running, the magnetic field measurement system still performs accurately and stably. The field measurement of more than one hundred DTLQ has been finished. The components and function of the measurement system, the key point of the technology and the repeatability of the measurement results are described in this paper.

  1. Study of Effects of Failure of Beamline Elements and its Compensation in CW Superconducting Linac

    SciTech Connect

    Ostiguy, J.-F.; Solyak, N.; Yakovlev, V.P.; Mishra, C.S.; Ranjan, K.; Saini, A.; /Delhi U.

    2012-05-01

    Project-X is a proposed high intensity proton facility to be built at Fermilab in United States. The first stage consists of a superconducting linac (SC) operating in continuous wave (CW) mode to accelerate a H{sup -} beam from 2.1 MeV to 3 GeV. Failure of any beamline element during operations induces a downstream mismatch of the beam which is especially severe when the failure occurs at low energy. A large mismatch causes emittance growth and ultimately results in beam losses. In a worst case scenario, the operability of the machine may be affected and long downtime may be needed to replace the failed element. To minimize possible downtime, the optics can be designed in a way that allows local retuning to make the machine operable. This paper presents studies performed to investigate retuning scenarios after failure of an accelerating cavity or a focusing magnet at critical locations in the Project-X CW superconducting linac.

  2. Beam dynamic design of a high intensity injector for proton linac

    NASA Astrophysics Data System (ADS)

    Dou, Wei-Ping; Wang, Zhi-Jun; Jia, Fang-Jian; He, Yuan; Wang, Zhi; Lu, Yuan-Rong

    2016-08-01

    A compact room-temperature injector is designed to accelerate 100 mA proton beam from 45 keV to 4.06 MeV for the proposed high intensity proton linac at State Key Lab of Nuclear Physics and Technology in Peking university. The main feature is that the Radio Frequency Quadruple (RFQ) and the Drift Tube linac (DTL) sections are merged in one piece at the total length of 276 cm. The beam is matched in transverse directions with an compact internal doublet instead of an external matching section in between. The design has reached a high average accelerating gradient up to 1.55 MV/m with transmission efficiency of 95.9% at the consideration of high duty factor operation. The operation frequency is chose to be 200 MHz due to the already available RF power source. The injector combines a 150 cm long 4-vanes RFQ internal section from 45 keV to 618 keV with a 126 cm long H-type DTL section to 4.06 MeV. In general the design satisfy the challenges of the project requirements. And the details are presented in this paper.

  3. A Separated Function Drift-Tube Linac for the ISAC Project at TRIUMF

    NASA Astrophysics Data System (ADS)

    Laxdal, R. E.; Bricault, P. G.; Ries, T.; Gorelov, D. V.

    1997-05-01

    The ISAC radioactive ion beam facility under construction at TRIUMF combines an isotope-separator-on-line with a post accelerator. Required in the accelerator chain is a drift tube linac (DTL) capable of accelerating, in cw mode, unstable nuclei with A/q >= 1/6 from E=0.15 MeV/u to a final energy fully variable up to 1.5 MeV/u. A novel separated function DTL concept has been developed. Five independent interdigital H-type structures, each operating at 105 MHz and 0^circ synchronous phase, provide the acceleration, while quadrupole triplets and triple-gap spiral resonators placed between IH tanks provide periodic transverse and longitudinal focussing respectively. A square field computational model has been used to design and study the concept. In specific cases the model was verified by comparison with particle motion through computed three-dimensional realistic fields. Beam simulations show that the DTL can accelerate beams with little or no emittance growth over the complete energy range. MAFIA has been used to optimize the rf characteristics of the IH tanks. Design and fabrication of the first IH tank is underway. Results of the beam dynamics and MAFIA studies, as well as the final linac specifications are presented. In addition, the status of the DTL engineering is summarized.

  4. The main linac cavity for Cornell's energy recovery linac: Cavity design through horizontal cryomodule prototype test

    NASA Astrophysics Data System (ADS)

    Valles, N.; Liepe, M.; Furuta, F.; Gi, M.; Gonnella, D.; He, Y.; Ho, K.; Hoffstaetter, G.; Klein, D. S.; O'Connell, T.; Posen, S.; Quigley, P.; Sears, J.; Stedman, G. Q.; Tigner, M.; Veshcherevich, V.

    2014-01-01

    Future particle accelerators will require continuous wave operation of SRF cavities capable of supporting high beam currents. An example of this is the Energy Recovery Linac (ERL) at Cornell University, a next generation light source designed to run high currents (100 mA) with a high bunch repetition rate (1.3 GHz). Obtaining the beam emittance necessary to meet design specification requires strong damping of higher-order modes that can lead to beam breakup. We discuss the optimization and verification of the accelerating cavity. Next we show that an ERL constructed from the optimized cavity geometry - including realistic shape errors - can support beam currents in excess of 300 mA while still maintaining beam stability. A niobium prototype 7-cell cavity was fabricated and tested in a horizontal cryomodule. We show that the prototype cavity exceeds quality factor and gradient specifications of 2 ×1010 at 16.2 MV/m at 1.8 K by 50%, reaching Q =(3.0 ± 0.3) ×1010. The prototype cavity also satisfies all design constraints and has a higher order mode spectrum consistent with the optimized shape geometry. At 1.6 K, the cavity set a record for quality factor of a multicell cavity installed in a horizontal cryomodule reaching Q =(6.1 ± 0.6) ×1010.

  5. Beam-energy and laser beam-profile monitor at the BNL LINAC

    SciTech Connect

    Connolly, R.; Briscoe, B.; Degen, C.; DeSanto, L.; Meng, W.; Minty, M.; Nayak, S.; Raparia, D.; Russo, T.

    2010-05-02

    We are developing a non-interceptive beam profile and energy monitor for H{sup -} beams in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. Electrons that are removed from the beam ions either by laser photodetachment or stripping by background gas are deflected into a Faraday cup. The beam profile is measured by stepping a narrow laser beam across the ion beam and measuring the electron charge vs. transverse laser position. There is a grid in front of the collector that can be biased up to 125kV. The beam energy spectrum is determined by measuring the electron charge vs. grid voltage. Beam electrons have the same velocity as the beam and so have an energy of 1/1836 of the beam protons. A 200MeV H{sup -} beam yields 109keV electrons. Energy measurements can be made with either laser-stripped or gas-stripped electrons.

  6. Commissioning of the first drift tube linac module in the Ground Test Accelerator

    SciTech Connect

    Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Cole, R.; Connolly, R.; Denney, P.; Erickson, J.; Gilpatrick, J.D.; Ingalls, W.B.; Kersteins, D.; Kraus, R.; Lysenko, W.P.; McMurry, D.; Mottershead, C.T.; Power, J.; Rose, C.; Rusthoi, D.P.; Sandoval, D.P.; Schneider, J.D.; Smith, M.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

    1993-06-01

    The Ground Test Accelerator (GTA) has the objective of verifying much of the technology required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam-dynamics design of each major accelerator component as it is brought on-line. The major components are the 35-keV H{sup {minus}} injector, the 2.5-MeV radio-frequency quadrupole (RFQ), the intertank matching section (IMS), the 3.2 MeV first 2{beta}{lambda} drift tube linac (DTL-1) module, and the 24-MeV GTA with 10 DTL modules. Results from the DTL-1 beam experiments will be presented.

  7. Suppression of Microbunching Instability in the Linac Coherent Light Source

    SciTech Connect

    Huang, Z

    2004-03-02

    A microbunching instability driven by longitudinal space charge, coherent synchrotron radiation, and linac wakefields is studied for the linac coherent light source (LCLS) accelerator system. Since the uncorrelated (local) energy spread of electron beams generated from a photocathode rf gun is very small, the microbunching gain may be large enough to significantly amplify rf-gun generated modulations or even shot-noise fluctuations of the electron beam. The uncorrelated energy spread can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the free-electron laser performance. We study different damping options in the LCLS and discuss an effective laser heater to minimize the impact of the instability on the quality of the electron beam.

  8. Spectral fluence of neutrons generated by radiotherapeutic linacs.

    PubMed

    Králík, Miloslav; Šolc, Jaroslav; Vondráček, Vladimir; Šmoldasová, Jana; Farkašová, Estera; Tichá, Ivana

    2015-02-01

    Spectral fluences of neutrons generated in the heads of the radiotherapeutic linacs Varian Clinac 2100 C/D and Siemens ARTISTE were measured by means of the Bonner spheres spectrometer whose active detector of thermal neutrons was replaced by an activation detector, i.e. a tablet made of pure manganese. Measurements with different collimator settings reveal an interesting dependence of neutron fluence on the area defined by the collimator jaws. The determined neutron spectral fluences were used to derive ambient dose equivalent rate along the treatment coach. To clarify at which components of the linac neutrons are mainly created, the measurements were complemented with MCNPX calculations based on a realistic model of the Varian Clinac.

  9. MODEL BENCHMARK WITH EXPERIMENT AT THE SNS LINAC

    SciTech Connect

    Shishlo, Andrei P; Aleksandrov, Alexander V; Liu, Yun; Plum, Michael A

    2016-01-01

    The history of attempts to perform a transverse match-ing in the Spallation Neutron Source (SNS) superconduct-ing linac (SCL) is discussed. The SCL has 9 laser wire (LW) stations to perform non-destructive measurements of the transverse beam profiles. Any matching starts with the measurement of the initial Twiss parameters, which in the SNS case was done by using the first four LW stations at the beginning of the superconducting linac. For years the consistency between data from all LW stations could not be achieved. This problem was resolved only after significant improvements in accuracy of the phase scans of the SCL cavities, more precise analysis of all available scan data, better optics planning, and the initial longitudi-nal Twiss parameter measurements. The presented paper discusses in detail these developed procedures.

  10. RF CALIBRATION OF CEBAF LINAC CAVITIES THROUGH PHASE SHIFTS

    SciTech Connect

    Carpenter, Adam P.; Benesch, Jay F.; Slominski, Christopher J.

    2016-10-01

    This paper describes a new beam-based method of cavity energy gain calibration based on varying the cavity phase. This method can be fully automated and allows a larger range of momentum excursions during measurement than previous calibration approaches. Monte Carlo simulations suggest that a calibration precision of 2-3% could be realistically achieved using this method. During the commissioning of the Continuous Electron Beam Accelerator Facility's (CEBAF) energy upgrade to 12 GeV, 876 measurements were performed on 375 of the 400 linac cavities in Fall 2015 and applied December 2015. Linac optics appears to be closer to design as a result. The resulting ensemble proved to be 2% over the value needed to get the desired energy in the arcs. Continued offline analysis of the data has allowed for error analysis and better understanding of the process.

  11. PROSPECTS FOR A VERY HIGH POWER CW SRF LINAC

    SciTech Connect

    Robert Rimmer

    2010-06-01

    Steady development in SRF accelerator technology combined with the success of large scale installations such as CEBAF at Jefferson Laboratory and the SNS Linac at ORNL gives credibility to the concept of very high average power CW machines for light sources or Proton drivers. Such machines would be powerful tools for discovery science in themselves but could also pave the way to reliable cost effective drivers for such applications as neutrino factories, an energy-frontier muon collider, nuclear waste transmutation or accelerator driven subcritical reactors for energy production. In contrast to machines such as ILC that need maximum accelerating gradient, the challenges in these machines are mainly in efficiency, reliability, beam stability, beam loss and of course cost. In this paper the present state of the art is briefly reviewed and options for a multi-GeV, multi-MW CW linac are discussed.

  12. Assessment of Alternative RF Linac Structures for APT

    SciTech Connect

    1997-03-26

    The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties.

  13. Upgrade of the Brookhaven 200 MeV linac

    SciTech Connect

    Alessi, J.G.; Buxton, W.; Erickson, B.; Gould, O.

    1996-10-01

    The Brookhaven 200 MeV linac serves as the injector for the AGS Booster, as well as delivering beam to the Biomedical Isotope Resource Center. During the past year, many linac systems have been upgraded to allow operation at 2.5 times higher average current (150 {mu}A). This was achieved by an increase in rep-rate from 5 to 7.5 Hz, an increase in beam current from 25 mA to 37 mA, and a slight increase in pulse width to {approximately}530 {mu}s. Additional upgrades were made to improve reliability and modernize old systems. This paper describes improvements made in the 35 keV and 750 keV beam transport, 200 MeV beam transport, rf transmission line, rf power supplies, control systems, and instrumentation.

  14. Design of a Marx-Topology Modulator for FNAL Linac

    SciTech Connect

    Butler, T. A.; Garcia, F. G.; Kufer, M. R.; Pfeffer, H.; Wolff, D.

    2015-04-28

    The Fermilab Proton Improvement Plan (PIP) was formed in late 2011 to address important and necessary upgrades to the Proton Source machines (Injector line, Linac and Booster). The goal is to increase the proton flux by doubling the Booster beam cycle rate while maintaining the same intensity per cycle, the same uptime, and the same residual activation in the enclosure. For the Linac, the main focus within PIP is to address reliability. One of the main tasks is to replace the present hard-tube modulator used on the 200 MHz RF system. Plans to replace this high power system with a Marx-topology modulator, capable of providing the required waveform shaping to stabilize the accelerating gradient and compensate for beam loading, will be presented, along with development data from the prototype unit.

  15. Focusing solenoids for the HINS Linac front end

    SciTech Connect

    Terechkine, I.; Appollinari, G.; Di-Marco, J.; Huang, Y.; Orris, D.; Page, T.; Rabehl, R.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2008-10-01

    The low energy part of a linac for the High Intensity Neutrino Source (HINS) project at Fermilab will use superconducting solenoids as beam focusing elements (lenses). While the lenses for the conventional DTL-type accelerating section of the front end require individual cryostats, in the superconducting accelerating sections solenoids will be installed inside RF cryomodules. Some of the lenses in the conventional and in the superconducting sections are equipped with horizontal and vertical steering dipoles. Lenses for the DTL section are in the stage of production with certification activities ongoing at Fermilab. For the superconducting sections of the linac, a prototype lens has been built and tested. Each lens will be installed in the transport channel of the accelerator so that its magnetic axis is on the beamline. Corresponding technique has been developed at Fermilab and is used during the certification process. This report summarizes design features, parameters, and test results of the focusing lenses.

  16. Important aspects of linac beams for food irradiation

    NASA Astrophysics Data System (ADS)

    McKeown, J.; Jones, R. T.

    1987-04-01

    Linac based irradiators will require careful design before they can be routinely adopted for the radiation processing of food. The transverse emittance and energy spread from simple injectors provide a significant challenge to the design of a beam delivery system which must handle high power especially in photon mode. Any nonuniform current distribution at the plane of the product is further complicated by large dose variations near the air/product interface, even with simple geometries. The paper describes the use of methods developed at AECL to control and monitor linac behaviour as well as electron interactions at the product surface. It also reports on activation cross-section measurements and particularly on neutron yields from composite targets, designed to monitor the energy of accelerators used in food applications.

  17. Cavities and Cryomodules for the RIA Driver Linac

    SciTech Connect

    Fuerst, J.D.; Shepard, K.W.; Kedzie, M.; Kelly, M.P.

    2004-06-23

    We describe cavities, cryomodules, and associated subsystem concepts for the Rare Isotope Accelerator (RIA) driver linac baseline design. Some alternative concepts are also presented. Beams from protons to uranium are accelerated with superconducting RF cavities operating from 57.5 MHz to 805 MHz. Substantial cost reduction over the baseline design may be achieved by replacing three classes of elliptical cell structures operating at 2 K by two classes of three-spoke drift tube structures. Cavity count and tunnel length are reduced while efficient cooling at 4.5 K for all linac structures may be possible. Issues include RF power requirements, microphonics, clean handling techniques, separate cavity and insulating vacuum systems, and heat load.

  18. Beam-based alignment measurements of the LANSCE linac

    SciTech Connect

    McCrady, R. C.; Rybarcyk, L. J.

    2004-01-01

    We have made measurements of the alignment of the Los Alamos Neutron Science Center (LANSCE) Drift Tube linac (DTL) and Side Coupled linac (SCL) using beam position measurements and analyzing them with linear models. In the DTL, we varied the injection steering and focusing lattice strengths, measured the beam position after each DTL tank, and analyzed the data with a linear model using R-matrices that were either computed by the Trace-3D computer program or extracted from analysis of the data. The analysis model allowed for tank-to-tank misalignments. The measurements were made similarly in the SCL, where the analysis model allowed for misalignments of each quadrupole doublet lens. We present here the analysis techniques and the resulting beam-based alignment measurements.

  19. Longitudinal instability in heavy-ion-fusion induction linacs

    SciTech Connect

    Lee, E.P.

    1993-05-01

    A induction linac accelerating a high-current pulse of heavy ions at subrelativistic velocities is predicted to exhibit unstable growth of current fluctuations. An overview is given of the mode character, estimates of growth rates, and their application to an IFE driver. The present and projected effort to understand and ameliorate the instability is described. This includes particle-in-cell simulations, calculation and measurements of impedance, and design of feedback controls.

  20. Linac Coherent Light Source (LCLS) Design Study Report

    SciTech Connect

    Cornacchia, Massimo

    1998-12-04

    The Stanford Linear Accelerator Center, in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the wavelength range 1.5-15 {angstrom}. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. Starting in FY 1998, the first two-thirds of the SLAC linac will be used for injection into the B factory. This leaves the last one-third free for acceleration to 15 GeV. The LCLS takes advantage of this opportunity, opening the way for the next generation of synchrotron light sources with largely proven technology and cost effective methods. This proposal is consistent with the recommendations of the Report of the Basic Energy Sciences Advisory Committee (Synchrotron Radiation Light Source Working Group, October 18-19, 1997). The report recognizes that ''fourth-generation x-ray sources...will in all likelihood be based on the free electron laser concepts. If successful, this technology could yield improvements in brightness by many orders of magnitude.'' This Design Study, the authors believe, confirms the feasibility of constructing an x-ray FEL based on the SLAC linac. Although this design is based on a consistent and feasible set of parameters, some components require more research and development to guarantee the performance. Given appropriate funding, this R and D phase can be completed in 2 years.

  1. Monte Carlo simulations of photoneutron activation in a medical LINAC

    SciTech Connect

    Begin, Francois; Sellam, Addil; Nourreddine, Abdel-Mjid

    2015-07-01

    The first step of the present study was to simulate the γ-radioactivity produced by photoneutrons in the treatment head of a decommissioned medical LINAC. These results, obtained with MCNPX and CINDER'90, are then compared with γ-ray spectrometric measurements of parts of the treatment head. Our ultimate objective is to simulate the associated production by photonuclear reactions of pure β-emitters, which are more difficult to access experimentally than the γ-ray emitters. (authors)

  2. BEAM POSITION AND PHASE MONITORS FOR THE LANSCE LINAC

    SciTech Connect

    McCrady, Rodney C.; Gilpatrick, John D.; Watkins, Heath A.

    2012-04-11

    New beam-position and phase monitors are under development for the linac at the Los Alamos Neutron Science Center (LANSCE.) Transducers have been designed and are being installed. We are considering many options for the electronic instrumentation to process the signals and provide position and phase data with the necessary precision and flexibility to serve the various required functions. We'll present the various options under consideration for instrumentation along with the advantages and shortcomings of these options.

  3. Linac Coherent Light Source (LCLS) Conceptual Design Report

    SciTech Connect

    Nuhn, Heinz-Dieter

    2002-11-25

    The Stanford Linear Accelerator Center, in collaboration with Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, have collaborated to create a conceptual design for a Free-Electron-Laser (FEL) R&D facility operating in the wavelength range 1.5-15 {angstrom}. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. The first two-thirds of the SLAC linac are used for injection into the PEP-II storage rings. The last one-third will be converted to a source of electrons for the LCLS. The electrons will be transported to the SLAC Final Focus Test Beam (FFTB) Facility, which will be extended to house a 122-m undulator system. In passing through the undulators, the electrons will be bunched by the force of their own synchrotron radiation to produce an intense, spatially coherent beam of x-rays, tunable in energy from 0.8 keV to 8 keV. The LCLS will include two experiment halls as well as x-ray optics and infrastructure necessary to make use of this x-ray beam for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of constructing an x-ray FEL based on the SLAC linac.

  4. HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS

    SciTech Connect

    Deibele, Craig Edmond; Curry, Douglas E; Dickson, Richard W

    2012-01-01

    It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

  5. Simulation of waveguide FEL oscillator using RF linac

    SciTech Connect

    Kuruma, S.; Asakawa, M.; Imasaki, K.

    1995-12-31

    One dimensional multifrequency simulation code for waveguide mode FEL has been developed. Using this simulation code, we analyzed the spontaneous emission from electron micropulse from RF Linac. It is found that some parameters both high and low frequency waveguide modes are growing simultaneously, so the two radiation pulses are generated and amplified. And the experimental data for cavity length detuning of the radiation power are analyzed.

  6. Radiation protection of linac bunkers. A user-friendly approach.

    PubMed

    Sørensen, Thyge Holten; Olsen, Kjeld Jørgen; Behrens, Claus Flensted

    2015-07-01

    A well-known but complex formalism for the calculation of the leakage dose at the entrance of the linac maze was considered and simplified. These simplifications were based partly on the literature and partly on the authors' own measurements. The authors have included photon scatter originating from the irradiated patient in the formalism. A formalism for two different types of bunkers was developed, and the authors have obtained simple formulas to calculate the dose at the maze entrance for both bunker types.

  7. Commissioning the FELI linac and UV-FEL facility

    SciTech Connect

    Tomimasu, T.; Saeki, K.; Miyauchi, Y.

    1995-12-31

    The FELI 165-MeV linac and UV-FEL facility are in the commissioning, stage. A thermionic triode gun of the 6-MeV injector emits 500-ps pulses of 2.3A at 22.3125MHz. These pulses are compressed to 60AX 7ps by a 714-MHz prebuncher and a 2856-MHz buncher and seven ETL type accelerating waveguides with a length of 2.93m. The length of the linac including bending sections of two S-type BT systems for two undulators used for IR-FEL oscillations is 46m. The buncher and these accelerating waveguides are powered by two klystrons (E3729, 2856MHz, total 48MW, 24-{mu}s flat top long pulses). The flatness of our klystron modulator pulses is 0.067% at 24-{mu}s duration. An rf-ageing for new four accelerating waveguides will be started in May. An S-type BT line for 165-MeV beam from the linac will be installed in the end of April. A 2.68-m undulator ({lambda}u=4.0cm, N=67, Kmax gap length {ge}16mm) and an optical cavity (Lc=6.72m) will be installed early in July. The beam conditionings for UV-FEL experiments will be started in July.

  8. DESIGN OF THE SNS NORMAL CONDUCTING LINAC RF CONTROL SYSTEM

    SciTech Connect

    A. REGAN; ET AL

    2000-08-01

    The Spallation Neutron Source (SNS) is in the process of being, designed for operation in 2004. The SNS is a 1 GeV machine consisting of both a normal-conducting and super-conducting linac as well as a ring and target area The linac front end is a 402.5 MHz RFQ being developed by Lawrence Berkeley Lab. The DTL, being developed at Los Alamos National Laboratory, is also a copper structure operating at 402.5 MHz, with an 805 MHz CCL structure downstream of it. The expected output energy of the DTL is 87 MeV and that of the CCL is 185 MeV. The RF control system under development for the linac is based on the Low Energy Demonstration Accelerator's (LEDA) control system with some new features. This paper will discuss the new design approach and its benefits. Block diagrams and circuit specifics will be addressed. The normal conducting RF control system will be described in detail with reference to the super-conducting control system when appropriate.

  9. High-brightness beam diagnostics for the APS linac.

    SciTech Connect

    Lumpkin, A. H.

    1999-04-20

    The Advanced Photon Source (APS) injector includes an S-band linac with the capability to accelerate beams to 650 MeV. The linac has recently been upgraded with the installation of an rf thermionic gun in addition to the standard DC thermionic gun. The rf gun is predicted to have lower emittance (5{pi}mm mrad) and may be used to support the APS self-amplified spontaneous emission (SASE) experiments. The critical characterization of this gun's beam has begun with a beam diagnostics station at the end of the linac that can address beam transverse size, emittance, and bunch length (peak current). This station uses both an optical transition radiation (OTR) screen at 45{degree} to the beam direction and a Ce-doped YAG single crystal normal to the beam with a 45{degree} mirror behind it. The visible light images are detected by a Vicon CCD camera and a Hamamatsu C5680 synchroscan streak camera. Spatial resolution of about 30 {micro}m ({sigma}) and temporal resolution of 1 ps ({sigma}) have been demonstrated. Examples of rf gun beam characterization at 220 MeV are reported.

  10. Recent improvements to software used for optimization of SRF linacs

    SciTech Connect

    Powers, Tom J.

    2014-12-01

    This work describes a software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, where operation costs includes the cost of the electrical utilities but not the labor or other costs. The program includes estimates for the associated cryogenic facility, and controls hardware. The software interface provides the ability to vary the cost of the different aspects of the machine as well as to change the cryomodule and cavity types. Additionally, this work will describe the recent improvements to the software that allow one to estimate the costs of energy-recovery based linacs and to enter arbitrary values of the low field Q0 and Q0 slope. The initial goal when developing the software was to convert a spreadsheet format to a graphical interface and to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand tradeoffs. An example of how it was used to independently investigate cost optimization tradeoffs for the LCLS-II linac will also be presented.

  11. Ion sources for induction linac driven heavy ion fusion

    SciTech Connect

    Rutkowski, H.L.; Eylon, S.; Chupp, W.W.

    1993-08-01

    The use of ion sources in induction linacs for heavy ion fusion is fundamentally different from their use in the rf linac-storage rings approach. Induction linacs require very high current, short pulse extraction usually with large apertures which are dictated by the injector design. One is faced with the problem of extracting beams in a pulsed fashion while maintaining high beam quality during the pulse (low-emittance). Four types of sources have been studied for this application. The vacuum arc and the rf cusp field source are the plasma types and the porous plug and hot alumino-silicate surface source are the thermal types. The hot alumino-silicate potassium source has proved to be the best candidate for the next generation of scaled experiments. The porous plug for potassium is somewhat more difficult to use. The vacuum arc suffers from noise and lifetime problems and the rf cusp field source is difficult to use with very short pulses. Operational experience with all of these types of sources is presented.

  12. Electron Beam Focusing in the Linear Accelerator (linac)

    NASA Astrophysics Data System (ADS)

    Jauregui, Luis

    2015-10-01

    To produce consistent data with an electron accelerator, it is critical to have a well-focused beam. To keep the beam focused, quadrupoles (quads) are employed. Quads are magnets, which focus the beam in one direction (x or y) and defocus in the other. When two or more quads are used in series, a net focusing effect is achieved in both vertical and horizontal directions. At start up there is a 5% calibration error in the linac at Thomas Jefferson National Accelerator Facility. This means that the momentum of particles passing through the quads isn't always what is expected, which affects the focusing of the beam. The objective is to find exactly how sensitive the focusing in the linac is to this 5% error. A linac was simulated, which contained 290 RF Cavities with random electric fields (to simulate the 5% calibration error), and a total momentum kick of 1090 MeV. National Science Foundation, Department of Energy, Jefferson Lab, Old Dominion University.

  13. Design development of the SCDTL structure for the TOP linac

    NASA Astrophysics Data System (ADS)

    Picardi, L.; Ronsivalle, C.; Spataro, B.

    1999-04-01

    The Side Coupled Drift Tube Linac (SCDTL) is an attractive 3 GHz accelerating structure composed of short DTL tanks coupled together by side coupling cavities, in the course of development of the 200 MeV proton linear accelerator for proton therapy planned for the Terapia Oncologica con Protoni (TOP) program of the Italian National Institute of Health (Istituto Superiore di Sanità, ISS). The TOP Linac will be used to boost to 70 MeV the 7 MeV proton beam from a linac injector. Our main concern is to investigate in detail the characteristics of the structure in terms of RF properties of the accelerating mode, like longitudinal and transverse shunt impedance and quality factor, and of the other modes that cause the origin of the tank dispersion curve, in order to stabilize the behaviour under operating conditions. Calculations performed with the computer three-dimensional (3D) codes MAFIA and SOPRANO on the smallest unit of the system (a single DTL tank without coupling cavities) and experimental measurements made on a prototype have shown good agreement. Two possible supporting stem configurations (single stem and two stems 180° apart for each drift tube) were examined and a comparison of the results in both cases are discussed.

  14. Summary of the linac based radiation sources working group

    SciTech Connect

    Ben-Zvi, I.; Corbett, J.; Johnson, E.; Kim, K.J.; Sheffield, R.

    1992-10-01

    Technological advances have occurred in the past few years that have made linac based Free-Electron Lasers (FEL) promising candidates for the generation of short wavelength radiation. Although the FELs use undulators or wigglers, they produce stimulated radiation rather than the spontaneous emission found in insertion devices on the second and third generation sources of today. This stimulated emission process endows the FEL with properties presenting unique opportunities in many fields of science. Among these characteristics are: coherence, spectral brightness, peak power,high average power. Additional scope for experimental growth is provided by the flexible pulse structure of linac based sources, making possible developments in high resolution timing experiments. Invited presentations to the working group on linac based radiation sources covered various key subjects, aiming at establishing the ground work for various machine designs. Design issues of FEL light sources were worked out in a few sessions, including sub-group sessions. We have also discussed the question of R&D necessary for the development of high quality FEL light sources. A high priority was placed on laser photocathode rf gun development, emittance preservation and FEL mechanism studies. This report describes the technological foundation for high brightness beams, the design of FELs using these beams and recommendations for research and development in FEL physics.

  15. Summary of the linac based radiation sources working group

    SciTech Connect

    Ben-Zvi, I.; Corbett, J.; Johnson, E.; Kim, K.J.; Sheffield, R.

    1992-01-01

    Technological advances have occurred in the past few years that have made linac based Free-Electron Lasers (FEL) promising candidates for the generation of short wavelength radiation. Although the FELs use undulators or wigglers, they produce stimulated radiation rather than the spontaneous emission found in insertion devices on the second and third generation sources of today. This stimulated emission process endows the FEL with properties presenting unique opportunities in many fields of science. Among these characteristics are: coherence, spectral brightness, peak power,high average power. Additional scope for experimental growth is provided by the flexible pulse structure of linac based sources, making possible developments in high resolution timing experiments. Invited presentations to the working group on linac based radiation sources covered various key subjects, aiming at establishing the ground work for various machine designs. Design issues of FEL light sources were worked out in a few sessions, including sub-group sessions. We have also discussed the question of R D necessary for the development of high quality FEL light sources. A high priority was placed on laser photocathode rf gun development, emittance preservation and FEL mechanism studies. This report describes the technological foundation for high brightness beams, the design of FELs using these beams and recommendations for research and development in FEL physics.

  16. MBE-4: an induction linac experiment for heavy ion fusion

    SciTech Connect

    Fessenden, T.J.; Avery, R.T.; Brodzik, D.A.; Faltens, A.; Gough, D.E.; Henderson, T.F.; Judd, D.L.; Keefe, D.; Kim, C.; Laslett, L.J.

    1986-06-01

    The multiple-beam induction linac approach to a heavy ion fusion driver features continuous current amplification along the accelerator and a minimum of transverse beam manipulation from source to pellet. Current amplification and bunch length control require careful shaping of the accelerating voltages. This driver approach exploits developments in electron induction linac technology that have occurred within the last 15 years at LBL, LLNL and NBS. MBE-4 is a four beam induction linac that models much of the accelerator physics of the electrostatically focused section of a considerably longer induction accelerator. Four parallel Cs/sup +/ beams are electrostatically focussed and will be accelerated from 200 keV to approximately one MeV when the experiment is complete in the spring of 1987. The current in each of the four beams will increase from 10 to 40 mA due to both increase in beam speed and shortening of the bunch length. Results of experiments with the injector and first eight accelerating gaps are presented.

  17. Reliability and availability studies in the RIA driver linac.

    SciTech Connect

    Lessner, E. S.; Ostroumov, P. N.; Physics

    2005-01-01

    The Rare Isotope Accelerator (RIA) facility will include various complex systems and must provide radioactive beams to many users simultaneously. The availability of radioactive beams for most experiments at the fully-commissioned facility should be as high as possible within design cost limitations. To make a realistic estimate of the achievable reliability a detailed analysis is required. The RIA driver linac is a complex machine containing a large number of superconducting (SC) resonators and capable of accelerating multiple-charge-state beams [1]. At the pre-CDR stage of the design it is essential to identify critical facility subsystem failures that can prevent the driver linac from operating. The reliability and availability of the driver linac were studied using expert information and data from operating machines such as ATLAS, APS, JLab, and LANL. Availability studies are performed with a Monte-Carlo simulation code previously applied to availability assessments of the NLC facility [2] and the results used to identify subsystem failures that most affect the availability and reliability of the RIA driver, and guide design iterations and component specifications to address identified problems.

  18. Calculation of Nuclear Particles Production at High-Energy Photon Beams from a Linac Operating at 6, 10 and 15 MV.

    PubMed

    Marchesini, Renato; Bettega, Daniela; Calzolari, Paola; Pignoli, Emanuele

    2016-08-13

    Production of photonuclear particles in a tissue-equivalent medium has been calculated for linacs at 6, 10 and 15 MV from Varian TrueBeam. Based on the knowledge of bremsstrahlung fluence spectra and linac photon beam parameters, numerical integration was performed on the cross sections for photoparticle production of the constituent elements of tissue ((2)H,(12)C,(13)C,(16)O,(17)O,(18)O,(14)N,(15)N). At 15 MV, at the depth of photon maximum dose, the total absorbed dose due to neutrons, protons, alphas and residual nuclei from photon reactions in tissue (5.5E-05 Gy per Gy of photons) is comparable to that due to neutrons from accelerator head. Results reasonably agree with data reported in the literature using Monte Carlo models simulating linac head components. This work suggests a simple method to estimate the dose contributed by the photon-induced nuclear particles for high-energy photon beams produced by linacs in use, as it might be relevant for late stochastic effects.

  19. Alternative Main Linac BNS Configuration for Reduced IP Energy Spread (LCC-0139)

    SciTech Connect

    Tenenbaum, P

    2004-05-24

    We present a series of alternate BNS phase configurations for the 500 GeV CM NLC main linac in which the energy spread at the end of the linac is reduced from its nominal 0.25% value. The energy spectrum, achievable IP beam energy, energy bias, and linac stability are evaluated for the alternate cases. We conclude that the RMS energy spread and energy bias in the NLC can easily be reduced but that modest reductions in CM energy are required.

  20. Comparison of accelerating structures for the first cavity of the main part of the INR linac

    NASA Astrophysics Data System (ADS)

    Rybakov, I. V.; Kalinin, Y. Z.; Leontev, V. N.; Naboka, A. N.; Paramonov, V. V.; Serov, V. L.; Feschenko, A. V.

    2016-09-01

    For the beam power improvement of the hydrogen-ion INR linac replacement of the first four-section cavity in the main part of linac is required. Existent cavity is realized using DAW structure on 991 MHz operating frequency. The new cavity should at least not lose in parameters to the current structure and essential changes in other linac systems are not wish able. Parameters of accelerating structures possible for such application are compared.

  1. Electron linac for medical isotope production with improved energy efficiency and isotope recovery

    DOEpatents

    Noonan, John; Walters, Dean; Virgo, Matt; Lewellen, John

    2015-09-08

    A method and isotope linac system are provided for producing radio-isotopes and for recovering isotopes. The isotope linac is an energy recovery linac (ERL) with an electron beam being transmitted through an isotope-producing target. The electron beam energy is recollected and re-injected into an accelerating structure. The ERL provides improved efficiency with reduced power requirements and provides improved thermal management of an isotope target and an electron-to-x-ray converter.

  2. Discussion of superconducting and room-temperature high-intensity ion linacs

    SciTech Connect

    Jameson, R.A.

    1996-10-01

    The point of view taken in this discussion is that the basic technology base exists in all essential respects for both superconducting or room-temperature rf linac accelerators and associated power and control systems, and thus a project can make a choice between these technologies on overall system considerations. These include performance, cost, availability, flexibility, and upgradability. Large high-intensity neutron source proposals involving light-ion rf linacs in three categories are reviewed in this context. The categories arc cw linacs to high ({approximately}1 GeV) and low ({approximately}40 MeV) output energy, and pulsed linacs to energy {approximately}1 GeV.

  3. The Muon LINAC for the International Design Study of the Neutrino Factory

    SciTech Connect

    A. Kurup, C. Bontoiu, Morteza Aslaninejad, J. Pozimski, A. Bogacz, V.S. Morozov, Y.R. Roblin, K.B. Beard

    2011-09-01

    The first stage of muon acceleration in the Neutrino Factory utilises a superconducting linac to accelerate muons from 244 MeV to 900 MeV. The linac was split into three types of cryomodules with decreasing magnetic fields and increasing amounts of RF voltage but with the design of the superconducting solenoid and RF cavities being the same for all cryomodules. The current status of the muon linac for the International Design Study for the Neutrino Factory will be presented including a final lattice design of the linac and tracking simulations.

  4. The impact of linac output variations on dose distributions in helical tomotherapy

    PubMed Central

    Flynn, R T; Kissick, M W; Mehta, M P; Olivera, G H; Jeraj, R; Mackie, T R

    2009-01-01

    It has been suggested for quality assurance purposes that linac output variations for helical tomotherapy (HT) be within ±2% of the long-term average. Due to cancellation of systematic uncertainty and averaging of random uncertainty over multiple beam directions, relative uncertainties in the dose distribution can be significantly lower than those in linac output. The sensitivity of four HT cases with respect to linac output uncertainties was assessed by scaling both modelled and measured systematic and random linac output uncertainties until a dose uncertainty acceptance criterion failed. The dose uncertainty acceptance criterion required the delivered dose to have at least a 95% chance of being within 2% of the planned dose in all of the voxels in the treatment volume. For a random linac output uncertainty of 5% of the long-term mean, the maximum acceptable amplitude of the modelled, sinusoidal, systematic component of the linac output uncertainty for the four cases was 1.8%. Although the measured linac output variations represented values that were outside of the ±2% tolerance, the acceptance criterion did not fail for any of the four cases until the measured linac output variations were scaled by a factor of almost three. Thus the ±2% tolerance in linac output variations for HT is a more conservative tolerance than necessary. PMID:18184996

  5. High-Power Linac for the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Rej, D. J.

    2002-04-01

    The Spallation Neutron Source (SNS) will be the world’s most intense source of neutrons for fundamental science and industrial applications. Design and construction of this facility, located at Oak Ridge, is a joint venture between six DOE laboratories. Construction began in 1999 and is currently ahead of the scheduled 2006 completion date. Injecting a high-power, pulsed proton beam into a mercury target produces neutrons. In this talk, we review the physics requirements, design, and status of the construction of the 1-GeV, 1.4-MW average power RF linac for SNS. The accelerator consists of a drift tube linac (DTL), a coupled-cavity linac (CCL), and a superconducting rf (SRF) linac. The phase and quadrupole settings are set to avoid structure and parametric resonances, with coherent resonances posing minimal risk for emittance growth. The DTL is 37 m long and accelerates the ions to 87 MeV. The CCL is 55 m long and accelerates the ions to 186 MeV. The rf structure design and stability for both the DTL and CCL have been validated with scale models. The SRF linac has a modular design to accelerate ions to 1000 MeV, with a straightforward upgrade to 1.3 GeV at a later date. 3D particle-in-cell simulations of beam dynamics are performed to validate performance. The accelerator utilizes 93 MW of pulsed power operating continuously at 60-Hz with an 8factor. Approximately one hundred 402.5 or 805-MHz klystrons, with outputs between 0.55 and 5 MW, are used. The klystrons are powered by a novel converter-modulator that takes advantage of recent advances in IGBT switch plate assemblies and low-loss material cores for boost transformer. Beam diagnostics include position, phase, profile, and current monitors. They are designed to enable accurate beam steering and matching, and to minimize beam loss that would lead to activation and prevent hands-on maintenance.

  6. Evidence of a halo formation mechanism in the Spallation Neutron Source linac

    NASA Astrophysics Data System (ADS)

    Jeon, Dong-O.

    2013-04-01

    A new halo formation mechanism and its mitigation scheme [D. Jeon, J. Stovall, A. Aleksandrov, J. Wei, J. Staples, R. Keller, L. Young, H. Takeda, and S. Nath, Phys. Rev. ST Accel. Beams 5, 094201 (2002)PRABFM1098-440210.1103/PhysRevSTAB.5.094201] are verified experimentally through a series of emittance measurements performed during the drift tube linac tank 1 commissioning of the Spallation Neutron Source. This is a rare experiment evidence of a halo formation mechanism. As the simulation predicts, the emittance measurements clearly show a visible halo reduction as well as a significant rms emittance reduction when the proposed round beam optics is employed. The emittance measurement results are consistent with multiparticle simulations and also consistent with wire scanner results. These measurements serve as a valuable code benchmarking for a beam under an intense space charge effect.

  7. Status of the RF-driven H⁻ ion source for J-PARC linac.

    PubMed

    Oguri, H; Ohkoshi, K; Ikegami, K; Takagi, A; Asano, H; Ueno, A; Shibata, T

    2016-02-01

    For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then.

  8. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    NASA Astrophysics Data System (ADS)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  9. Progress in cavity and cryomodule design for the Project X linac

    SciTech Connect

    Champion, M.; Barbanotti, S.; Foley, M.; Ginsburg, S.; Gonin, I; Grimm, C.; Kerby, J.; Nagaitsev, S.; Nicol, T.; Peterson, T.; Ristori, L.; /Fermilab

    2011-03-01

    The continuous wave 3 GeV Project X Linac requires the development of two families of cavities and cryomodules at 325 and 650 MHz. The baseline design calls for three types of superconducting single-spoke resonators at 325 MHz having betas of 0.11, 0.22, and 0.42 and two types of superconducting five-cell elliptical cavities having betas of 0.61 and 0.9. These cavities shall accelerate a 1 mA H- beam initially and must support eventual operation at 4 mA. The electromagnetic and mechanical designs of the cavities are in progress and acquisition of prototypes is planned. The heat load to the cryogenic system is up to 25 W per cavity in the 650 MHz section, thus segmentation of the cryogenic system is a major issue in the cryomodule design. Designs for the two families of cryomodules are underway.

  10. Position sensitive counter development at the linac

    SciTech Connect

    Becker, J.A.

    1981-05-20

    In a novel application of the multiwire proportional counter we have imaged a collimated neutron beam. Although preliminary, the results are of sufficient import to be described here because of the potential wide application of the multiwire proportional counter to Laboratory problems. The counter was operated with a counting gas pressure of 20 Torr; the counting gas was pure C/sub 4/H/sub 10/. The radiator was a /sup 235/U foil. Under these conditions, the counter is (1) relatively insensitive to charged particles (other than fission fragments), (2) insensitive to ..gamma..-radiation, and (3) has an efficiency for the detection of fission fragments independent of incident neutron energy over a wide range of neutron energies.

  11. Parameter optimization in HN-IMRT for Elekta linacs.

    PubMed

    Worthy, Danielle; Wu, Qiuwen

    2009-04-28

    Planning and delivery in HN-IMRT has been challenging for the Elekta linac because of numerous machine limitations. Direct aperture optimization (DAO) algorithms have had success in simplifying the planning process and improving plan quality. Commercial adaptations of DAO allow for widespread use in many clinics; however clinical validation of these methods is still needed. In this work we evaluated Pinnacle3 commercial software for HN-IMRT on the Elekta linac. The purpose was to find a set of planning parameters that are applicable to most patients and optimal in terms of plan quality, delivery efficiency, and dosimetric accuracy. Four types of plans were created for each of 12 patients: ideal fluence optimization (FO), conventional two-step optimization (TS), segment weight optimization (SW), and direct machine parameter optimization (DMPO). Maximum number of segments (NS) and minimum segment area (MSA) were varied in DMPO. Results showed DMPO plans have the best optimization scores and dosimetric indices, and the most consistent IMRT output among patients. At larger NS (> or = 80), plan quality decreases with increasing MSA as expected, except for MSA<8 cm(2), suggesting presence of local minima in DMPO. Segment area and MUs can vary significantly between optimization methods and parameter settings; however, the quantity 'integral MU' remains constant. Irradiation time is linearly proportional to total plan segments, weakly dependent on MUs and independent of MSA. Dosimetric accuracy is independent of DMPO parameters. The superior quality of DMPO makes it the choice for HN-IMRT on Elekta linacs and its consistency allows development of 'class solutions'. However, planners should be aware of the local minima issue when pushing parameters to the limit such as NS<80 and MSA<8 cm(2). The optimal set of parameters should be chosen to balance plan quality and delivery efficiency based on a systematic evaluation of the planning technique and system constraints.

  12. Functional forms for photon spectra of clinical linacs

    NASA Astrophysics Data System (ADS)

    Ali, E. S. M.; Rogers, D. W. O.

    2012-01-01

    Specifying photon spectra of clinical linacs using a functional form is useful for many applications, including virtual source modelling and spectral unfolding from dosimetric measurements such as transmission data or depth-dose curves. In this study, 11 functional forms from the literature are compiled and quantitatively compared. A new function is proposed which offers improvements over existing ones. The proposed function is simple, physics-based and has four free parameters, one of which is the mean incident electron kinetic energy. A comprehensive benchmark set of validated, high-precision Monte Carlo spectra is generated and used to evaluate the strengths and limitations of different functions. The benchmark set has 65 spectra (3.5-30 MV) from Varian, Elekta, Siemens, Tomotherapy, Cyberknife and research linacs. The set includes spectra on- and off-axis from linacs with and without a flattening filter, and in treatment and imaging modes. The proposed function gives the lowest spectral deviations among all functions. It reproduces the energy fluence values in each bin for the benchmark set with a normalized root-mean-square deviation of 1.7%. The mean incident electron kinetic energy, maximum photon energy, most-probable energy and average energy are reproduced, on average, within 1.4%, 4.3%, 3.9% and 0.6% of their true values, respectively. The proposed function is well behaved when used for spectral unfolding from dosimetric data. The contribution of the 511 keV annihilation peak and the energy spread of the incident electron beam can be added as additional free parameters.

  13. TU-C-BRE-03: Aggregation of Linac Measurement Data

    SciTech Connect

    Kerns, J; Alvarez, P; Followill, D; Lowenstein, J; Molineu, A; Summers, P; Kry, S

    2014-06-15

    Purpose: Accurate data of linear accelerator radiation characteristics is important for treatment planning system commissioning as well as regular quality assurance of the machine. The RPC has performed site visits of numerous machines . Data gathered from Varian machines from the past 15 years are presented. The data collected can be used as a secondary check or when commissioning a new machine to verify that values are reasonable. Methods: Data from the past 15 years of RPC site visits was compiled and analyzed. Data was composed from measurements from approximately 400 Varian machines. Each dataset consists of several point measurements at various locations in a water phantom to measure percentage depth dose, output factors, including small MLC fields, off-axis factors, and wedge factors if applicable. Common statistical values are presented for each machine type. Where applicable, data was compared to other reference data given by the vendor or a select number of previous researchers. Results: Data is separated by energy and parameter and then analyzed by machine class. Data distributions of the parameter data were normal except occasionally at the tails. Distributions of the data for each class and parameter are tabulated to give not simply a singular reference value, but metrics about the distribution: 5th and 95th percentile values and the standard deviation as well as the median. Conclusion: The RPC has collected numerous data on Varian linacs and presented the finding of the past 15 years. The data can be used as a reference data set for physicists to compare against. A linac that deviates from the values does not necessarily indicate there is a problem as long as the treatment planning system correlates to the machine. Comparison of linac and treatment planning system data to external reference data can prevent serious treatment errors.

  14. A beam position monitor for the diagnostic line in MEBT2 of J-PARC linac

    NASA Astrophysics Data System (ADS)

    Miura, A.; Tamura, J.; Kawane, Y.

    2017-07-01

    In the linac of the Japan Proton Accelerator Research Complex (J-PARC), the neutral hydrogen (H0) beam from the negative hydrogen ion (H-) beam is one of key issues in mitigating beam losses. To diagnose H0 particles, we installed a set of beam-bump magnets to generate a chicane orbit of the H- beam. The beam position monitors (BPMs) in the beam line are used for orbit correction to maintain the beam displacement within 2.0 mm from the duct center. To measure the beam displacement under different drive currents of the beam-bump magnets, a new wide-range BPM was designed and manufactured to evaluate the horizontal beam position by using a correction function to compensate for non-linearity. We also employed the beam profile monitor (WSM: wire scanner monitor) to measure the H- beam profile, which helped us to compare the beam position measurements. In this paper, the design and the performance of the wide-range BPM are described. In addition, we present a comparison of the beam position measured by the BPM and the WSM.

  15. Charge neutralized low energy beam transport at Brookhaven 200 MeV linac

    SciTech Connect

    Raparia, D. Alessi, J.; Atoian, G.; Zelenski, A.

    2016-02-15

    The H{sup −} magnetron source provides about 100 mA H{sup −} beam to be match into the radio-frequency quadrupole accelerator. As H{sup −} beam traverses through low energy transport, it ionizes the residual gas and electrons are repelled and positive ions are trapped in the beam, due to negative potential of the beam, providing charge neutralization for the H{sup −} beam. The neutralization time for the critical density depends upon the background gas and its pressure. Critical density for xenon gas at 35 keV is about 43 times smaller than that of hydrogen and stripping cross section is only 5 times than that of hydrogen gas. We are using xenon gas to reduce neutralization time and to improve transmission through the 200 MeV linac. We are also using pulse nitrogen gas to improve transmission and stability of polarized H{sup −} beam from optically pumped polarized ion source.

  16. Phase-scan analysis results for the first drift tube linac module in the ground test accelerator: Data reproducibility and comparison to simulations

    SciTech Connect

    Johnson, K.F.; Sander, O.R.; Bolme, G.O.

    1995-05-01

    The Ground Test Accelerator (GTA) had the objective of producing a high-brightness, high-current H- beam. The major accelerator components were a 35 keV injector, a Radio Frequency Quadrupole, an intertank matching section, and a drift tube linac (DTL), consisting of 10 modules. This paper discusses the phase-scan technique which was used to experimentally determine the rf operating parameters for the commissioning and routine operation of the first DTL module.

  17. WE-D-BRD-01: Innovation in Radiation Therapy Delivery: Advanced Digital Linac Features

    SciTech Connect

    Xing, L; Wong, J; Li, R

    2014-06-15

    Last few years has witnessed significant advances in linac technology and therapeutic dose delivery method. Digital linacs equipped with high dose rate FFF beams have been clinically implemented in a number of hospitals. Gated VMAT is becoming increasingly popular in treating tumors affected by respiratory motion. This session is devoted to update the audience with these technical advances and to present our experience in clinically implementing the new linacs and dose delivery methods. Topics to be covered include, technical features of new generation of linacs from different vendors, dosimetric characteristics and clinical need for FFF-beam based IMRT and VMAT, respiration-gated VMAT, the concept and implementation of station parameter optimized radiation therapy (SPORT), beam level imaging and onboard image guidance tools. Emphasis will be on providing fundamental understanding of the new treatment delivery and image guidance strategies, control systems, and the associated dosimetric characteristics. Commissioning and acceptance experience on these new treatment delivery technologies will be reported. Clinical experience and challenges encountered during the process of implementation of the new treatment techniques and future applications of the systems will also be highlighted. Learning Objectives: Present background knowledge of emerging digital linacs and summarize their key geometric and dosimetric features. SPORT as an emerging radiation therapy modality specifically designed to take advantage of digital linacs. Discuss issues related to the acceptance and commissioning of the digital linacs and FFF beams. Describe clinical utility of the new generation of digital linacs and their future applications.

  18. Radio frequency linear accelerators for NDT applications: Basic overview of RF linacs

    SciTech Connect

    Hansen, H.J.

    1998-02-01

    High energy X-ray radiography can be an important part of a quality control program. In this article the author will present an overview of the technology found in a typical high energy X-ray source, the radio frequency (RF) linear accelerator. In NDT, linacs are used primarily for the inspection of thick sections of materials. Linacs are also used in applications such as high energy computed tomography of specimens greater than 1 m thick and cargo container inspection. Recent developments in reliable portable linacs are opening up other applications such as field inspection of pipelines, ships, bridges, and other civil infrastructure. The replacement of isotopes (such as Co-60) by the linac is an area for growth in the future. The shorter exposure times, improved image capabilities, and greatly reduced regulatory requirements of the linac make a persuasive argument for the replacement of isotopes with a portable linac. The linacs discussed here are those with X-ray energies from 1 to 20 MeV intended for use in NDT applications. The discussion will be in very broad terms; it will be impossible to discuss every variation in linac design. In addition, some topics have been necessarily simplified to increase the comprehensibility for a wider audience.

  19. Berkeley research program on ion-induction linacs for inertial fusion

    SciTech Connect

    Keefe, D.; Rosenblum, S.S.

    1982-03-01

    The following areas of research are described: (1) driver studies, (2) induction linac technology, (3) core materials, (4) insulators, (5) modulator-switches and pulse forming network, (6) induction linac accelerators and prototype modules, and (7) a high-temperature experiment. (MOW)

  20. Dedicated Linac for Radioneurosurgery at the National Institute of Neurology and Neurosurgery of Mexico

    NASA Astrophysics Data System (ADS)

    Celis-López, Miguel A.; Lárraga-Gutiérrez, José M.

    2003-09-01

    The objective is to present a description and the main clinical applications of this dedicated Linac for benign and malignant tumors in the central nervous system. The Novalis (BrainLab, Germany) is a 6 MV dedicated linac for a single high dose Radiosurgery (RS) and for fractionated doses in Stereotactic Radiotherapy with a high level of precision at the isocenter.

  1. Stability Study of ATF 80MeV Injector Linac

    SciTech Connect

    McCormick, Douglas

    2003-06-09

    A beam stability test was carried out at ATF 80 MeV injector linac. The test was performed by taking data of each monitor in pulse to pulse base. A data acquisition system which consists of a PC and a GPIB network was used for the test. In order to analyze the data, ''Correlation Plot'' method is used which is effective to find out some source of the observed beam fluctuation. This paper describes the result of the stability measurement and the comparison between ATF injector and SLC injector.

  2. Emittance and energy control in the NLC main linacs

    SciTech Connect

    Adolphsen, C.; Bane, K.L.F.; Kubo, K.; Raubenheimer, T.; Ruth, R.D.; Thompson, K.A.; Zimmermann, F.

    1995-06-01

    The authors discuss tolerances and correction schemes needed to control single- and multi-bunch emittance in the NLC main linacs. Specifications and design of emittance diagnostic stations will be presented. Trajectory correction schemes appropriate to simultaneously controlling the emittance of a multibunch train and the emittance of individual bunches within the train will be discussed. The authors discuss control of bunch-to-bunch energy spread using a ramped RF pulse generated by phase-modulating the SLED-II input. Tolerances on ions, wake fields, quadrupole alignment, and accelerating structure alignment will be given.

  3. Revisiting e- e- Switchover in the NLC Linac

    SciTech Connect

    Larsen, R.S.

    2004-06-22

    This paper is an extension of a talk given in December 1999 which discussed various options for reconfiguring magnets and power sources to convert the NLC to e{sup -}e{sup -} operation. At that time three different configurations were examined and a Directional Reversal model was recommended in order to avoid the difficulties of polarity reversal with permanent magnets anticipated in the main linac at that time. Since permanent magnets are no longer in the baseline, a Polarity Reversal scheme becomes more attractive.

  4. Improved Overhead Accounting in the NLC Main Linac

    SciTech Connect

    Tenenbaum, P.

    2004-06-10

    The NLC main linac contains 1,116 RF power units, of which 5% are considered ''spares'' for replacement of failed power units, make-up of the energy gain during an RF breakdown, and energy feedback. A more careful accounting for the effects of beam loading indicates that the NLC can operate with less BNS overhead and a smaller mean phase offset than was originally specified, and that as a consequence the total number of spares is actually about 7.9% of the total.

  5. Beam position monitor readout and control in the SLC linac

    SciTech Connect

    Bogart, J.; Phinney, N.; Ross, M.; Yaffe, D.

    1985-04-01

    A beam position monitoring system has been implemented in the first third of the SLC linac which provides a complete scan of the trajectory on a single beam pulse. The data is collected from the local micro-computers and viewed with an updating display at a console or passed on to application programs. The system must operate with interlaced beams so the scans are also interlaced, providing each user with the ability to select the beam, the update rate, and the attenuation level in the digitizing hardware. In addition each user calibrates the hardware for his beam. A description of the system architecture will be presented. 6 refs., 4 figs.

  6. A novel electron accelerator for MRI-Linac radiotherapy

    PubMed Central

    Whelan, Brendan; Gierman, Stephen; Holloway, Lois; Schmerge, John; Keall, Paul; Fahrig, Rebecca

    2016-01-01

    Purpose: MRI guided radiotherapy is a rapidly growing field; however, current electron accelerators are not designed to operate in the magnetic fringe fields of MRI scanners. As such, current MRI-Linac systems require magnetic shielding, which can degrade MR image quality and limit system flexibility. The purpose of this work was to develop and test a novel medical electron accelerator concept which is inherently robust to operation within magnetic fields for in-line MRI-Linac systems. Methods: Computational simulations were utilized to model the accelerator, including the thermionic emission process, the electromagnetic fields within the accelerating structure, and resulting particle trajectories through these fields. The spatial and energy characteristics of the electron beam were quantified at the accelerator target and compared to published data for conventional accelerators. The model was then coupled to the fields from a simulated 1 T superconducting magnet and solved for cathode to isocenter distances between 1.0 and 2.4 m; the impact on the electron beam was quantified. Results: For the zero field solution, the average current at the target was 146.3 mA, with a median energy of 5.8 MeV (interquartile spread of 0.1 MeV), and a spot size diameter of 1.5 mm full-width-tenth-maximum. Such an electron beam is suitable for therapy, comparing favorably to published data for conventional systems. The simulated accelerator showed increased robustness to operation in in-line magnetic fields, with a maximum current loss of 3% compared to 85% for a conventional system in the same magnetic fields. Conclusions: Computational simulations suggest that replacing conventional DC electron sources with a RF based source could be used to develop medical electron accelerators which are robust to operation in in-line magnetic fields. This would enable the development of MRI-Linac systems with no magnetic shielding around the Linac and reduce the requirements for optimization of

  7. Optical laser systems at the Linac Coherent Light Source

    DOE PAGES

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; ...

    2015-04-22

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  8. Rf breakdown studies in copper electron linac structures

    SciTech Connect

    Wang, J.W.; Loew, G.A.

    1989-03-01

    This paper presents a summary of rf breakdown-limited electric fields observed in experimental linac structures at SLAC and a discussion of how these experiments can be interpreted against the background of existing, yet incomplete, theories. The motivation of these studies, begun in 1984, is to determine the maximum accelerating field gradients that might be used safely in future e/sup /+-// colliders, to contribute to the basic understanding of the rf breakdown mechanism, and to discover if a special surface treatment might make it possible to supersede the field limits presently reachable in room temperature copper structures. 6 refs., 4 figs., 1 tab.

  9. HINS Linac front end focusing system R&D

    SciTech Connect

    Apollinari, G.; Carcagno, R.H.; Dimarco, J.; Huang, Y.; Kashikhin, V.V.; Orris, D.F.; Page, T.M.; Rabehl, R.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab /Argonne

    2008-08-01

    This report summarizes current status of an R&D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process.

  10. Induction Linac Systems Experiments for heavy ion fusion

    SciTech Connect

    Herrmannsfeldt, W.B.; Bangerter, R.O.

    1994-06-01

    The Lawrence Berkeley Laboratory and the Lawrence Livermore National Laboratory propose to build at LBL the Induction Linac Systems Experiments (ILSE), the next logical step toward the eventual goal of a heavy ion induction accelerator powerful enough to implode or drive inertial confinement fusion targets. Though much smaller than a driver, ILSE will be at full driver scale in several important parameters. Nearly all accelerator components and beam manipulations required for a driver will be tested. It is expected that ILSE will be built in stages as funds and technical progress allow. The first stage, called Elise will include all of the electrostatic quadrupole focused parts of ILSE.

  11. Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs

    NASA Astrophysics Data System (ADS)

    Amaldi, U.; Bonomi, R.; Braccini, S.; Crescenti, M.; Degiovanni, A.; Garlasché, M.; Garonna, A.; Magrin, G.; Mellace, C.; Pearce, P.; Pittà, G.; Puggioni, P.; Rosso, E.; Verdú Andrés, S.; Wegner, R.; Weiss, M.; Zennaro, R.

    2010-08-01

    Hadrontherapy with protons and carbon ions is a fast developing methodology in radiation oncology. The accelerators used and planned for this purpose are reviewed starting from the cyclotrons used in the thirties. As discussed in the first part of this paper, normal and superconducting cyclotrons are still employed, together with synchrotrons, for proton therapy while for carbon ion therapy synchrotrons have been till now the only option. The latest developments concern a superconducting cyclotron for carbon ion therapy, fast-cycling high frequency linacs and 'single room' proton therapy facilities. These issues are discussed in the second part of the paper by underlining the present challenges, in particular the treatment of moving organs.

  12. AMPERE AVERAGE CURRENT PHOTOINJECTOR AND ENERGY RECOVERY LINAC.

    SciTech Connect

    BEN-ZVI,I.; BURRILL,A.; CALAGA,R.; ET AL.

    2004-08-17

    High-power Free-Electron Lasers were made possible by advances in superconducting linac operated in an energy-recovery mode. In order to get to much higher power levels, say a fraction of a megawatt average power, many technological barriers are yet to be broken. We describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun employing a new secondary-emission multiplying cathode, an accelerator cavity, both capable of producing of the order of one ampere average current and plans for an ERL based on these units.

  13. Application of ``electronika 10 - 10'' electron linac for food irradiation

    NASA Astrophysics Data System (ADS)

    Migdał, W.; Maciszewski, W.; Gryzlow, A.

    1995-02-01

    The industrial electron linac "Elektronika 10 - 10" has been installed in Experimental Plant for Food Irradiation (INCT) in 1990. The accelerator is a prototype unit, prior the use for food treatment a period of optimization was involved in its experimental operation during 1993. The accelerator is capable to produce scanned beam of electrons with the energy 10 MeV and beam power of 10 kW. Radiation dose at minimal conveyer speed of 0.25 m/min reaches 50 kGy. The role of the plant is to promote food irradiation in Poland.

  14. Optical laser systems at the Linac Coherent Light Source

    PubMed Central

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E.; Fry, Alan R.

    2015-01-01

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS. PMID:25931064

  15. Optical laser systems at the Linac Coherent Light Source.

    PubMed

    Minitti, Michael P; Robinson, Joseph S; Coffee, Ryan N; Edstrom, Steve; Gilevich, Sasha; Glownia, James M; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E; Fry, Alan R

    2015-05-01

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump-probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump-probe experiments to be performed at LCLS.

  16. A novel electron accelerator for MRI-Linac radiotherapy.

    PubMed

    Whelan, Brendan; Gierman, Stephen; Holloway, Lois; Schmerge, John; Keall, Paul; Fahrig, Rebecca

    2016-03-01

    MRI guided radiotherapy is a rapidly growing field; however, current electron accelerators are not designed to operate in the magnetic fringe fields of MRI scanners. As such, current MRI-Linac systems require magnetic shielding, which can degrade MR image quality and limit system flexibility. The purpose of this work was to develop and test a novel medical electron accelerator concept which is inherently robust to operation within magnetic fields for in-line MRI-Linac systems. Computational simulations were utilized to model the accelerator, including the thermionic emission process, the electromagnetic fields within the accelerating structure, and resulting particle trajectories through these fields. The spatial and energy characteristics of the electron beam were quantified at the accelerator target and compared to published data for conventional accelerators. The model was then coupled to the fields from a simulated 1 T superconducting magnet and solved for cathode to isocenter distances between 1.0 and 2.4 m; the impact on the electron beam was quantified. For the zero field solution, the average current at the target was 146.3 mA, with a median energy of 5.8 MeV (interquartile spread of 0.1 MeV), and a spot size diameter of 1.5 mm full-width-tenth-maximum. Such an electron beam is suitable for therapy, comparing favorably to published data for conventional systems. The simulated accelerator showed increased robustness to operation in in-line magnetic fields, with a maximum current loss of 3% compared to 85% for a conventional system in the same magnetic fields. Computational simulations suggest that replacing conventional DC electron sources with a RF based source could be used to develop medical electron accelerators which are robust to operation in in-line magnetic fields. This would enable the development of MRI-Linac systems with no magnetic shielding around the Linac and reduce the requirements for optimization of magnetic fringe field, simplify design of

  17. Acceleration units for the Induction Linac Systems Experiment (ILSE)

    SciTech Connect

    Faltens, A.; Brady, V.; Brodzik, D.; Hansen, L.; Laslett, L.J.; Mukherjee, S.; Bubp, D.; Ravenscroft, D.; Reginato, L.

    1989-03-01

    The design of a high current heavy ion induction linac driver for inertial confinement fusion is optimized by adjusting the acceleration units along the length of the accelerator to match the beam current, energy, and pulse duration at any location. At the low energy end of the machine the optimum is a large number of electrostatically focused parallel beamlets, whereas at higher energies the optimum is a smaller number of magnetically focused beams. ILSE parallels this strategy by using 16 electrostatically focused beamlets at the low end followed by 4 magnetically focused beams after beam combining. 3 refs., 2 figs.

  18. The Development of the Linac Coherent Light Source RF Gun

    SciTech Connect

    Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of

  19. Energy-Recovery Linacs for Commercial Radioisotope Production

    SciTech Connect

    Johnson, Rolland Paul

    2016-11-19

    Most radioisotopes are produced by nuclear reactors or positive ion accelerators, which are expensive to construct and to operate. Photonuclear reactions using bremsstrahlung photon beams from less-expensive electron linacs can generate isotopes of critical interest, but much of the beam energy in a conventional electron linac is dumped at high energy, making unwanted radioactivation. The largest part of this radioactivation may be completely eliminated by applying energy recovery linac technology to the problem with an additional benefit that the energy cost to produce a given amount of isotope is reduced. Consequently, a Superconducting Radio Frequency (SRF) Energy Recovery Linac (ERL) is a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes at a cost lower than that of isotopes produced by reactors or positive-ion accelerators. A Jefferson Lab approach to this problem involves a thin photon production radiator, which allows the electron beam to recirculate through rf cavities so the beam energy can be recovered while the spent electrons are extracted and absorbed at a low enough energy to minimize unwanted radioactivation. The thicker isotope photoproduction target is not in the beam. MuPlus, with Jefferson Lab and Niowave, proposed to extend this ERL technology to the commercial world of radioisotope production. In Phase I we demonstrated that 1) the ERL advantage for producing radioisotopes is at high energies (~100 MeV), 2) the range of acceptable radiator thickness is narrow (too thin and there is no advantage relative to other methods and too thick means energy recovery is too difficult), 3) using optics techniques developed under an earlier STTR for collider low beta designs greatly improves the fraction of beam energy that can be recovered (patent pending), 4) many potentially useful radioisotopes can be made with this ERL technique that have never before been available in significant commercial quantities

  20. Measuring decay of praseodymium isotopes activated by a clinical LINAC

    NASA Astrophysics Data System (ADS)

    Boztosun, Ismail; Đapo, Haris; Karakoç, Mesut

    2016-10-01

    The decay of 140Pr produced by activation with a clinical LINAC was investigated. The sample was counted by a HPGe detector with 40% relative efficiency. Transitions created by beta decay of 140Pr were observed and corresponding energies lines and relative transition strengths were measured. In addition, half-life of 140Pr was obtained at 3.38 ± 0.06 min. The experimental results fitted nicely to the existing energy levels scheme of 140Pr. Notably, all results for transition energies are more accurate than the literature values, while the half-life and transition strengths showed accuracy similar to that of the literature.

  1. Dark Currents and Their Effect on the Primary Beam in an X-band Linac

    SciTech Connect

    Bane, K.L.F.; Dolgashev, V.A.; Raubenheimer, T.; Stupakov, G.V.; Wu, J.H.; /SLAC

    2005-05-27

    We numerically study properties of primary dark currents in an X-band accelerating structure. For the H60VG3 structure considered for the Next Linear Collider (NLC) we first perform a fairly complete (with some approximations) calculation of dark current trajectories. These results are used to study properties of the dark current leaving the structure. For example, at accelerating gradient of 65 MV/m, considering two very different assumptions about dark current emission around the irises, we find that the fraction of emitted current leaving the structure to be a consistent {approx} 1%. Considering that {approx} 1 mA outgoing dark current is seen in measurement, this implies that {approx} 100 mA (or 10 pC per period) is emitted within the structure itself. Using the formalism of the Lienard-Wiechert potentials, we then perform a systematic calculation of the transverse kick of dark currents on a primary linac bunch. The result is {approx} 1 V kick per mA (or per 0.1 pC per period) dark current emitted from an iris. For an entire structure we estimate the total kick on a primary bunch to be {approx} 15 V. For the NLC linac this translates to a ratio of (final) vertical beam offset to beam size of about 0.2. However, with the assumptions that needed to be made--particularly the number of emitters and their distribution within a structure--the accuracy of this result may be limited to the order of magnitude.

  2. Design of high-energy high-current linac with focusing by superconducting solenoids

    SciTech Connect

    Batskikh, G.I.; Belugin, V.M.; Bondarev, B.I.

    1995-10-01

    The advancement of MRTI design for 1.5 GeV and 250 mA ion CW linac was presented in a previous report. In this new linac version all the way from input to output the ions are focused by magnetic fields of superconducting solenoids. The ion limit current is far beyond the needed value. The linac focusing channel offers major advantages over the more conventional ones. The acceptance is 1.7 times as large for such focusing channel as for quadrupole one. Concurrently, a random perturbation sensitivity for such channel is one order of magnitude smaller than in quadrupole channel. These focusing channel features allow to decrease beam matched radius and increase a linac radiation purity without aperture growth. {open_quotes}Regotron{close_quotes} is used as high power generator in linac main part. But D&W cavities need not be divided into sections connected by RF-bridges which denuded them of high coupling factor.

  3. SU-E-J-200: Operation of An Electron Accelerator On An Integrated MR-Linac System

    SciTech Connect

    Harasimowicz, J; Roberts, D; Shinton, I; Sund, S; Kok, J; Overweg, J; Wang, H; Zhong, M

    2015-06-15

    Purpose: An integrated MRI guided radiotherapy system poses a challenge of operating a linear accelerator in the presence of a magnetic field as the magnetic force acting on the electrons could Result in radiation source displacement and subsequent reduction of dose output. It was the purpose of this work to test the performance of a linac in the presence of a 1.5T MRI system. Methods: The first experimental MRI guided radiotherapy system at UMC-Utrecht consisting of an Elekta linac rotating around a 1.5T Magnex magnet was examined. A passive magnetic shield was simulated, designed and installed to reduce the influence of the MRI magnet stray field on the electron beamline. The B field inside the shield was measured as a function of gantry angle and measurements of dose rate constancy upon gantry rotation were performed. Results: The magnitude of the magnetic field on the electron beam path without the shield was as high as 70G. It varied by up to 15G with gantry rotation due to the presence of metal beams in the bunker floor which resulted in dose output drop of up to 70% at certain gantry angles. With the prototype shield, field magnitude was reduced to well below 0.5G everywhere along the electron beam path. Field variation with gantry rotation was decreased to below 0.2G and enabled dose output of the linac to be recovered at all gantry angles. The homogeneity of the field inside the MRI magnet has not been compromised. Conclusion: It was demonstrated that the influence of the 1.5T magnet and the bunker design on the linac operation has been minimised. The performance will be further improved on the Elekta Atlantic system which incorporates a newly developed and optimised Philips magnet design and bunker construction. J Harasimowicz, D Roberts, I Shinton and S Sund are employed by Elekta Limited Crawley, H Wang and M Zhong are employed by Elekta Beijing Medical Systems Co. Ltd., J Overweg is employed by Philips Technologie GmbH Forschungslaboratorien.

  4. Analysis of an induction linac driver system for inertial fusion

    SciTech Connect

    Hovingh, J.; Brady, V.O.; Faltens, A.; Keefe, D.; Lee, E.P.

    1987-07-01

    A linear induction accelerator that produces a beam of energetic (5 to 20 GeV) heavy (130 to 210 amu) ions is a prime candidate as a driver for inertial fusion. Continuing developments in sources for ions with charge state greater than unity allow a potentially large reduction in the driver cost and an increase in the driver efficiency. The use of high undepressed tunes (sigma/sub 0/ approx. = 85/sup 0/) and low depressed tunes (sigma approx. = 8.5/sup 0/) also contributes to a potentially large reduction in the driver cost. The efficiency and cost of the induction linac system are discussed as a function of output energy and pulse repetition frequency for several ion masses and charge states. The cost optimization code LIACEP, including accelerating module alternatives, transport modules, and scaling laws, is presented. Items with large cost-leverage are identified as a guide to future research activities and development of technology that can yield substantial reductions in the accelerator system cost and improvement in the accelerator system efficiency. Finally, a cost-effective strategy using heavy ion induction linacs in a development scenario for inertial fusion is presented. 34 refs., 6 figs., 7 tabs.

  5. Linac cryogenic distribution system maintenance and upgrades at JLab

    SciTech Connect

    Dixon, K.; Wright, M.; Ganni, V.

    2014-01-29

    The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm{sup 3} of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

  6. Linac cryogenic distribution system maintenance and upgrades at Jlab

    SciTech Connect

    Dixon, Kelly D.; Wright, Mathew C.; Ganni, Venkatarao

    2014-01-01

    The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm{sup 3} of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

  7. Linac Coherent Light Source (LCLS) design study report

    SciTech Connect

    1998-04-01

    The Stanford Linear Accelerator Center (SLAC), in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the self-amplified spontaneous emission (SASE) mode in the wavelength range 1.5--15 {angstrom}. This FEL, called Linac Coherent Light Source (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. In this report, the Design Team has established performance parameters for all the major components of the LCLS and developed a layout of the entire system. Chapter 1 is the Executive Summary. Chapter 2 (Overview) provides a brief description of each of the major sections of the LCLS, from the rf photocathode gun, through the experimental stations and electron beam dump. Chapter 3 describes the scientific case for the LCLS. Chapter 4 provides a review of the principles of the FEL physics that the LCLS is based on, and Chapter 5 discusses the choice of the system's physical parameters. Chapters 6 through 10 describe in detail each major element of the system. Chapters 11 through 13 respectively cover undulator controls, mechanical alignment, and radiation issues.

  8. Recirculating Linac Acceleration - End-to-End Simulation

    SciTech Connect

    Alex Bogacz

    2010-03-01

    A conceptual design of a high-pass-number Recirculating Linear Accelerator (RLA) for muons is presented. The scheme involves three superconducting linacs (201 MHz): a single pass linear Pre-accelerator followed by a pair multi-pass (4.5-pass) 'Dogbone' RLAs. Acceleration starts after ionization cooling at 220 MeV/c and proceeds to 12.6 GeV. The Pre-accelerator captures a large muon phase space and accelerates muons to relativistic energies, while adiabatically decreasing the phase-space volume, so that effective acceleration in the RLA is possible. The RLA further compresses and shapes up the longitudinal and transverse phase-spaces, while increasing the energy. Appropriate choice of multi-pass linac optics based on FODO focusing assures large number of passes in the RLA. The proposed 'Dogbone' configuration facilitates simultaneous acceleration of both mu± species through the requirement of mirror symmetric optics of the return 'droplet' arcs. Finally, presented end-to-end simulation validates the efficiency and acceptance of the accelerator system.

  9. Linac cryogenic distribution system maintenance and upgrades at JLab

    NASA Astrophysics Data System (ADS)

    Dixon, K.; Wright, M.; Ganni, V.

    2014-01-01

    The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm3 of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

  10. Modulators for the S-band test linac at DESY

    SciTech Connect

    Bieler, M.; Choroba, S.; Hameister, J.; Lewin, H.

    1995-07-05

    The development of adequate modulators for high peak power klystrons is one of the focus points for linear collider R&D programs. For the DESY/THD S-band linear collider study 150 MW rf-pulse power at 50 Hz repetition rate and 3 {mu}s pulse duration is required [1]. Two different modulator schemes are under investigation. One is the conventional line type pulser, using a pulse forming network and a step up transformer, the other one is a hard tube pulser, using a dc power source at the full klystron voltage and a switch tube. This paper is focused on the modulator development for the S-band Test Linac at DESY. After a short overview over the test linac and a brief description of the 150 MW S-band klystron the circuitry of the line type pulse (LTP) is given. A hard tube pulser (HTP), which switches the high voltage directly from a storage capacitor to the klystron, has been built up at DESY. Circuitry and the results of the commissioning of the switch tube are reported. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  11. Modulators for the S-band test linac at DESY

    NASA Astrophysics Data System (ADS)

    Bieler, M.; Choroba, S.; Hameister, J.; Lewin, H.-Ch.

    1995-07-01

    The development of adequate modulators for high peak power klystrons is one of the focus points for linear collider R&D programs. For the DESY/THD S-band linear collider study 150 MW rf-pulse power at 50 Hz repetition rate and 3 μs pulse duration is required [1]. Two different modulator schemes are under investigation. One is the conventional line type pulser, using a pulse forming network and a step up transformer, the other one is a hard tube pulser, using a dc power source at the full klystron voltage and a switch tube. This paper is focused on the modulator development for the S-band Test Linac at DESY. After a short overview over the test linac and a brief description of the 150 MW S-band klystron the circuitry of the line type pulse (LTP) is given. A hard tube pulser (HTP), which switches the high voltage directly from a storage capacitor to the klystron, has been built up at DESY. Circuitry and the results of the commissioning of the switch tube are reported.

  12. High-Current Energy-Recovering Electron Linacs

    SciTech Connect

    Nikolitsa Merminga; David Douglas; Geoffrey Krafft

    2003-12-01

    The use of energy recovery provides a potentially powerful new paradigm for generation of the charged particle beams used in synchrotron radiation sources, high-energy electron cooling devices, electron-ion colliders, and other applications in photon science and nuclear and high-energy physics. Energy-recovering electron linear accelerators (called energy-recovering linacs, or ERLs) share many characteristics with ordinary linacs, as their six-dimensional beam phase space is largely determined by electron source properties. However, in common with classic storage rings, ERLs possess a high average-current-carrying capability enabled by the energy recovery process, and thus promise similar efficiencies. The authors discuss the concept of energy recovery and its technical challenges and describe the Jefferson Lab (JLab) Infrared Demonstration Free-Electron Laser (IR Demo FEL), originally driven by a 3548-MeV, 5-mA superconducting radiofrequency (srf) ERL, which provided the most substantial demonstration of energy recovery to date: a beam of 250 kW average power. They present an overview of envisioned ERL applications and a development path to achieving the required performance. They use experimental data obtained at the JLab IR Demo FEL and recent experimental results from CEBAF-ERL GeV-scale, comparatively low-current energy-recovery demonstration at JLab to evaluate the feasibility of the new applications of high-current ERLs, as well as ERLs' limitations and ultimate performance.

  13. RF system considerations for large high-duty-factor linacs

    SciTech Connect

    Lynch, M.T.; Ziomek, C.D.; Tallerico, P.J.; Regan, A.H.; Eaton, L.; Lawrence, G.

    1994-09-01

    RF systems are often a major cost item for linacs, but this is especially true for large high-duty-factor linacs (up to and including CW) such as the Accelerator for Production of Tritium (APT) or the Accelerator for Transmutation of nuclear Waste (ATW). In addition, the high energy and high average beam current of these machines (approximately 1 GeV, 100--200 mA) leads to a need for excellent control of the accelerating fields in order to minimize the possibility of beam loss in the accelerator and the resulting activation. This paper will address the key considerations and limitations in the design of the RF system. These considerations impact the design of both the high power RF components and the RF controls. As might be expected, the two concerns sometimes lead to conflicting design requirements. For example minimum RF operating costs lead to a desire for operation near saturation of the high power RF generators in order to maximize the operating efficiency. Optimal control of the RF fields leads to a desire for maximum overdrive capability in those same generators in order to respond quickly to disturbances of the accelerator fields.

  14. F-18 production with the TOP linac injector

    NASA Astrophysics Data System (ADS)

    Cianfarani, Cesidio; Cisbani, Evaristo; Orlandi, Gianluca; Frullani, Salvatore; Picardi, Luigi; Ronsivalle, Concetta

    2006-06-01

    ENEA and ISS (Italian National Institute of Health), are collaborating to develop a dedicated proton medical accelerator, TOP (Oncological Therapy with Protons) linac, consisting of a sequence of three pulsed linear accelerators. The 7 MeV injector can be used in three operating modes: Protontherapy and Radiobiology Mode—injecting low current proton beam into the TOP linac accelerating sections; Radioisotope Mode—generating an intense proton beam (8-10 mA, 50-100 μs, 30-100 Hz) to produce the positron-emitting radionuclide F18 for PET analyses. In the high current mode, at the exit of the injector the beam is guided through a magnetic quadrupoles channel to a target composed by a thin chamber (0.5 mm thick and 1 in. diameter) containing water enriched with O18. Production yield as well as total activity similar to these achieved with higher energy cyclotrons have been obtained. Environmental doses measured give indications on the shielding required for operation under current radioprotection regulations. Improvements are foreseen to optimize the production yield, the useful beam current and to better characterize gamma and neutron dose rates in the different operational modes.

  15. Delivery efficiency of an Elekta linac under gated operation.

    PubMed

    Cui, Guoqiang; Housley, David J; Chen, Fan; Mehta, Vivek K; Shepard, David M

    2014-09-08

    In this study, we have characterized the efficiency of an Elekta linac in the delivery of gated radiotherapy. We have explored techniques to reduce the beam-on delay and to improve the delivery efficiency, and have investigated the impact of frequent beam interruptions on the dosimetric accuracy of gated deliveries. A newly available gating interface was installed on an Elekta Synergy. Gating signals were generated using a surface mapping system in conjunction with a respiratory motion phantom. A series of gated deliveries were performed using volumetric modulated arc therapy (VMAT) treatment plans previously generated for lung cancer patients treated with stereotactic body radiotherapy. Baseline values were determined for the delivery times. The machine was then tuned in an effort to minimize beam-on delays and improve delivery efficiency. After that process was completed, the dosimetric accuracy of the gated deliveries was evaluated by comparing the measured and the planned coronal dose distributions using gamma index analyses. Comparison of the gated and the non-gated deliveries were also performed. The results demonstrated that, with the optimal machine settings, the average beam-on delay was reduced to less than 0.22 s. High dosimetric accuracy was demonstrated with gamma index passing rates no lower than 99.0% for all tests (3%/3 mm criteria). Consequently, Elekta linacs can provide a practical solution for gated VMAT treatments with high dosimetric accuracy and only a moderate increase in the overall delivery time.

  16. Alternate Tunings for the Linac Coherent Light Source Photoinjector

    SciTech Connect

    Limborg-Deprey, C.; Emma, P.; /SLAC

    2006-03-17

    The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser (FEL) project based on the SLAC linac. The LCLS Photoinjector beamline has been designed to deliver 10-ps long electron bunches of 1 nC with a normalized projected transverse emittance smaller than 1.2 mm-mrad at 135 MeV. Tolerances and regulation requirements are tight for this tuning. Half of the total emittance at the end of the injector comes from the ''cathode emittance'' which is 0.7 mm-mrad for our nominal 1nC tuning. As the ''cathode emittance'' scales linearly with laser spot radius, the emittance will be dramatically reduced for smaller radius, but this is only possible at lower charge. In particular, for a 0.2 nC charge, we believe we can achieve an emittance closer to 0.4 mm-mrad. This working point will be easier to tune and the beam quality should be much easier to maintain than for the 1 nC case. In the second half of this paper, we discuss optimum laser pulse shapes. We demonstrate that the benefits of the ellipsoidal shapes seem to be important enough so that serious investigations should be carried out in the production of such pulses.

  17. Spiral 2 Cryogenic System for The Superconducting LINAC

    NASA Astrophysics Data System (ADS)

    Ghribi, A.; Bernaudin, P.-E.; Bert, Y.; Commeaux, C.; Houeto, M.; Lescalié, G.

    2017-02-01

    SPIRAL 21 is a rare isotope accelerator dedicated to the production of high intensity beams (E = 40 MeV, I = 5 mA). The driver is a linear accelerator (LINAC) that uses bulk Niobium made quarter wave RF cavities. 19 cryomodules inclose one or two cavities respectively for the low and the high energy sections. To supply the 1300 W at 4.2 K required to cool down the LINAC, a cryogenic system has been set up. The heart of the latter is a 3 turbines geared HELIAL®LF (ALAT2) cold box that delivers both the liquid helium for the cavities and the 60 K Helium gaz for the thermal screens. 19 valve-boxes insure cryogenic fluid distribution and management. Key issues like cool down speed or cavity RF frequency stability are closely linked to the cryogenic system management. To overcome these issues, modelling and simulation efforts are being undertaken prior to the first cool down trials. In this paper, we present a status update of the Spiral 2 cryogenic system and the cool down strategy considered for its commissioning.

  18. Superconducting RF Linac Technology for ERL Light Sources

    SciTech Connect

    Tennant, Chris

    2005-08-01

    Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity's Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

  19. Dosimetric algorithm to reproduce isodose curves obtained from a LINAC.

    PubMed

    Estrada Espinosa, Julio Cesar; Martínez Ovalle, Segundo Agustín; Pereira Benavides, Cinthia Kotzian

    2014-01-01

    In this work isodose curves are obtained by the use of a new dosimetric algorithm using numerical data from percentage depth dose (PDD) and the maximum absorbed dose profile, calculated by Monte Carlo in a 18 MV LINAC. The software allows reproducing the absorbed dose percentage in the whole irradiated volume quickly and with a good approximation. To validate results an 18 MV LINAC with a whole geometry and a water phantom were constructed. On this construction, the distinct simulations were processed by the MCNPX code and then obtained the PDD and profiles for the whole depths of the radiation beam. The results data were used by the code to produce the dose percentages in any point of the irradiated volume. The absorbed dose for any voxel's size was also reproduced at any point of the irradiated volume, even when the voxels are considered to be of a pixel's size. The dosimetric algorithm is able to reproduce the absorbed dose induced by a radiation beam over a water phantom, considering PDD and profiles, whose maximum percent value is in the build-up region. Calculation time for the algorithm is only a few seconds, compared with the days taken when it is carried out by Monte Carlo.

  20. Dosimetric Algorithm to Reproduce Isodose Curves Obtained from a LINAC

    PubMed Central

    Estrada Espinosa, Julio Cesar; Martínez Ovalle, Segundo Agustín; Pereira Benavides, Cinthia Kotzian

    2014-01-01

    In this work isodose curves are obtained by the use of a new dosimetric algorithm using numerical data from percentage depth dose (PDD) and the maximum absorbed dose profile, calculated by Monte Carlo in a 18 MV LINAC. The software allows reproducing the absorbed dose percentage in the whole irradiated volume quickly and with a good approximation. To validate results an 18 MV LINAC with a whole geometry and a water phantom were constructed. On this construction, the distinct simulations were processed by the MCNPX code and then obtained the PDD and profiles for the whole depths of the radiation beam. The results data were used by the code to produce the dose percentages in any point of the irradiated volume. The absorbed dose for any voxel's size was also reproduced at any point of the irradiated volume, even when the voxels are considered to be of a pixel's size. The dosimetric algorithm is able to reproduce the absorbed dose induced by a radiation beam over a water phantom, considering PDD and profiles, whose maximum percent value is in the build-up region. Calculation time for the algorithm is only a few seconds, compared with the days taken when it is carried out by Monte Carlo. PMID:25045398

  1. Linac head scatter factor for asymmetric radiation field

    NASA Astrophysics Data System (ADS)

    Soubra, Mazen Ahmed

    1997-11-01

    The head scatter factor, Sh is an important dosimetric quantity used in radiation therapy dose calculation. It is empirically determined and its field size dependence reflects changes in photon scatter from components in the linac treatment head. In this work a detailed study of the physical factors influencing the determination of Sh was performed with particular attention given to asymmetric field geometries. Ionization measurements for 6 and 18 MV photon beams were made to examine the factors which determine Sh. These include: phantom size and material, collimator backscatter, non-lateral electronic equilibrium (LEE) conditions, electron contamination, collimator-exchange, photon energy, flattening filter and off-axis distance (OAD). Results indicated that LEE is not required for Sh measurements if electron contamination is minimized. Brass caps or polystyrene miniphantoms can both be used in Sh measurements provided the phantom thickness is large enough to stop contaminant electrons. Backscatter radiation effects into the monitor chamber were found to be negligible for the Siemens linac. It was found that the presence and shape of the flattening filter had a significant effect on the empirically determined value of Sh was also shown to be a function of OAD, particularly for small fields. For fields larger than 12×12 cm2/ Sh was independent of OAD. A flattening filter mass model was introduced to explain qualitatively the above results. A detailed Monte Carlo simulation of the Siemens KD2 linac head in 6 MV mode was performed to investigate the sources of head scatter which contribute to the measured Sh. The simulated head components include the flattening filter, the electron beam stopper, the primary collimator, the photon monitor chamber and the secondary collimators. The simulations showed that the scatter from the head of the Siemens linac is a complex function of the head components. On the central axis the flattening filter played the dominant role in

  2. Linac-based stereotactic radiotherapy and radiosurgery in patients with meningioma

    PubMed Central

    2014-01-01

    Background It was our purpose to analyze long-term clinical outcome and to identify prognostic factors after Linac-based fractionated stereotactic radiotherapy (Linac-based FSRT) and stereotactic radiosurgery (SRS) in patients with intracranial meningiomas. Materials and methods Between 10/1995 and 03/2009, 297 patients with a median age of 59 years were treated with FSRT for intracranial meningioma. 50 patients had a Grade I meningioma, 20 patients had a Grade II meningioma, 12 patients suffered from a Grade III tumor, and in 215 cases no histology was obtained (Grade 0). Of the 297 patients, 144 underwent FSRT as their primary treatment and 158 underwent postoperative FSRT. 179 patients received normofractionated radiotherapy (nFSRT), 92 patients received hypofractionated FSRT (hFSRT) and 26 patients underwent SRS. Patients with nFSRT received a mean total dose of 57.31 ± 5.82 Gy, patients with hFSRT received a mean total dose of 37.6 ± 4.4 Gy and patients who underwent SRS received a mean total dose of 17.31 ± 2.58 Gy. Results Median follow-up was 35 months. Overall progression free survival (PFS) was 92.3% at 3 years, 87% at 5 years and 84.1% at 10 years. Patients with adjuvant radiotherapy showed significantly better PFS-rates than patients who had been treated with primary radiotherapy. There was no significant difference between PFS-rates of nFSRT, hFSRT and SRS patients. PFS-rates were independent of tumor size. Patients who had received nFSRT showed less acute toxicity than those who had received hFSRT. In the Grade 0/I group the rate of radiologic focal reactions was significantly lower than in the atypical/malignant histology group. Conclusion This large study showed that FSRT is an effective and safe treatment modality with high PFS-rates for intracranial meningioma. We identified “pathological grading” and and “prior surgery” as significant prognostic factors. PMID:24650090

  3. Beam Dynamics Aspects of High Current Beams in a Superconducting Proton Linac

    NASA Astrophysics Data System (ADS)

    Bellomo, Giovanni; Pagani, Carlo; Pierini, Paolo

    1997-05-01

    High current CW proton linac accelerators have been recently proposed for nuclear waste transmutation and concurrent energy production. In most of the designs the high energy part (100 MeV up to 1-2 GeV) of the linac employs low frequency superconducting structures (352-700 MHz). Here we present beam dynamics issues for the high current (10-50 mA) beams in the superconducting section of such an accelerator, based on 352 MHz β-graded, LEP style cavities, as proposed at Linac 96(C. Pagani, G. Bellomo, P. Pierini, ``Linac96/Proceedings/Monday/MOP23/Paper.html>A High Current Proton Linac with 352 MHz SC Cavities'', Proceedings of the XVIII Int. Linear Acc. Conf., eds. C. Hill, M. Vretenar, CERN 96-07, 15 November 1996). In particular, smooth beam propagation along the linac has been reached with decreasing phase advances along the linac, and the design has been updated to match the beam dynamics results. Mismatching oscillations are discussed, as they are considered to cause beam halo and, consequently, beam losses.

  4. An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

    SciTech Connect

    Bradley, Joseph Thomas III; Rees, Daniel Earl; Scheinker, Alexander; Sheffield, Richard L.

    2015-05-04

    The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of the different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.

  5. Poster - Thur Eve - 42: Dynamic delivery quality assurance on Elekta linacs.

    PubMed

    Munger, P; Nicol, S

    2012-07-01

    Introduction Recently, Elekta linacs have gained the capability to deliver dynamic fields, such as sliding window IMRT or VMAT fields. Because of the potential complexity of such delivery modes, linac QA and patient-specific QA are of prime importance. The aim of this paper is to explain the fundamental concepts of this new mode of operation on Elekta linacs as well as to introduce the linear-α slit, a novel dynamic QA sequence which allows the performance of the delivery system to be objectively aassessed against dosimetric measurements. In the Elekta dynamic mode, dose rate can only take a limited number of discontinuous values. We have used the uniform slit, a simple slit moving at a constant speed across the field to verify how the linac selects leaf speed and dose rate for a given MU setting. Based on this, we expose the principles behind the linear-α slit, which exhibits two main characteristics: 1) it exercises the linac over a range of dose rates and 2) it produces a dose distribution which is theoretically equivalent to the uniform slit. Discrepancies between measurements of the linear-α slit and the uniform slit directly reflects problems with the delivery. The linear-α slit has been recently introduced in our routine monthly linac QA. We hope it will nicely complement patient-specific QA, and exising linac-QA. © 2012 American Association of Physicists in Medicine.

  6. Analysis of the LSC microbunching instability in MaRIE linac reference design

    SciTech Connect

    Yampolsky, Nikolai

    2016-09-22

    In this report we estimate the effect of the microbunching instability in the MaRIE XFEL linac. The reference design for the linac is described in a separate report. The parameters of the L1, L2, and L3 linacs as well as BC1 and BC2 bunch compressors were the same as in the referenced report. The beam dynamics was assumed to be linear along the accelerator (which is a reasonable assumption for estimating the effect of the microbunching instability). The parameters of the bunch also match the parameters described in the referenced report. Additionally, it was assumed that the beam radius is equal to R = 100 m and does not change along linac. This assumption needs to be revisited at later studies. The beam dynamics during acceleration was accounted in the matrix formalism using a Matlab code. The input parameters for the linacs are: RF peak gradient, RF frequency, RF phase, linac length, and initial beam energy. The energy gain and the imposed chirp are calculated based on the RF parameters self-consistently. The bunch compressors are accounted in the matrix formalism as well. Each chicane is characterized by the beam energy and the R56 matrix element. It was confirmed that the linac and beam parameters described previously provide two-stage bunch compression with compression ratios of 10 and 20 resulting in the bunch of 3kA peak current.

  7. Beam loss studies in high-intensity heavy-ion linacs

    NASA Astrophysics Data System (ADS)

    Ostroumov, P. N.; Aseev, V. N.; Mustapha, B.

    2004-09-01

    The proposed Rare Isotope Accelerator (RIA) Facility, an innovative exotic-beam facility for the production of high-quality beams of short-lived isotopes, consists of a fully superconducting 1.4GV driver linac and a 140MV postaccelerator. To produce sufficient intensities of secondary beams the driver linac will provide 400kW primary beams of any ion from hydrogen to uranium. Because of the high intensity of the primary beams the beam losses must be minimized to avoid radioactivation of the accelerator equipment. To keep the power deposited by the particles lost on the accelerator structures below 1 W/m, the relative beam losses per unit length should be less than 10-5, especially along the high-energy section of the linac. A new beam dynamics simulation code TRACK has been developed and used for beam loss studies in the RIA driver linac. In the TRACK code, ions are tracked through the three-dimensional electromagnetic fields of every element of the linac starting from the electron cyclotron resonance (ECR) ion source to the production target. The simulation starts with a multicomponent dc ion beam extracted from the ECR. The space charge forces are included in the simulations. They are especially important in the front end of the driver linac. Beam losses are studied by tracking a large number of particles (up to 106) through the whole linac considering all sources of error such us element misalignments, rf field errors, and stripper thickness fluctuations. For each configuration of the linac, multiple sets of error values have been randomly generated and used in the calculations. The results are then combined to calculate important beam parameters, estimate beam losses, and characterize the corresponding linac configuration. To track a large number of particles for a comprehensive number of error sets (up to 500), the code TRACK was parallelized and run on the Jazz computer cluster at ANL.

  8. Pulsed-focusing recirculating linacs for muon acceleration

    SciTech Connect

    Johnson, Rolland

    2014-12-31

    Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of

  9. Calculation of the Short-Range Longitudinal Wakefields in the NLC Linac

    SciTech Connect

    Bane, Karl LF

    1998-11-30

    Using two frequency domain and one time domain numerical approaches, we calculate the short-range longitudinal wakefield of the NLC linac accelerating structure, and find that the results agree to approximately 5%. We show that our results are consistent with an analytical formula for the impedance at high frequencies. We, in addition, obtain through fitting a simple formula for the short-range wakefield of a linac structure that can be useful in designing linear colliders. Finally, we demonstrate that for the NLC linac cavity the effects on the short-range wake of end conditions, tapering, and rounding of the irises are small.

  10. Micro-Radiography Using an Electron Linac Source and Ram Memory Chip Detectors

    DTIC Science & Technology

    1990-06-01

    comme source un accelerateur lineaire d’electron a impulsion ( LINAC ) et utilisant des memoires a circuits integres comme detecteur est etudiee dans ce...MICRO-RADIOGRAPHY USING AN ELECTRON LINAC SOURCE AND RAM MEMORY CHIP DETECTORS (U) by 00 T. Cousins, E.L Karam and J.R. Brisson ("NI DTIC.. ELECTE...Defence nationaie MICRO-RADIOGRAPHY USING AN ELECTRON LINAC SOURCE AND RAM MEMORY CHIP DETECTORS (U) by T. Cousins, E.L Karam and J.R. Brisson Nuclear

  11. Isac Sc-Linac Phase-II Helium Refrigerator Commissioning and First Operational Experience at Triumf

    NASA Astrophysics Data System (ADS)

    Sekachev, I.; Kishi, D.; Laxdal, R. E.

    2010-04-01

    ISAC Phase-II is an upgrade of the radioactive isotope superconducting linear accelerator, SC-linac, at TRIUMF. The Phase-I section of the accelerator, medium-beta, is operational and is cooled with a 600 W helium refrigerator, commissioned in March 2005. An identical refrigerator is being used with the Phase-II segment of the accelerator; which is now under construction. The second refrigerator has been commissioned and tested with the Phase-I section of the linac and is used for Phase-II linac development, including new SC-cavity performance tests. The commissioning of the Phase-II refrigeration system and recent operational experience is presented.

  12. Coherent Effects of High Current Beam in Project-X Linac

    SciTech Connect

    Sukhanov, A.; Lunin, A.; Yakovlev, V.; Gonin, I.; Khabiboulline, T.; Saini, A.; Solyak, N.; Yostrikov, A.

    2012-09-01

    Resonance excitation of longitudinal high order modes in superconducting RF structures of Project-X continuous wave linac is studied. We analyze regimes of operation of the linac with high beam current, which can be used to provide an intense muon source for the future Neutrino Factory or Muon Collider, and also important for the Accelerator-Driven Subcritical systems. We calculate power loss and associated heat load to the cryogenic system. Longitudinal emittance growth is estimated. We consider an alternative design of the elliptical cavity for the high energy part of the linac, which is more suitable for high current operation.

  13. Coherent Effects of High Current Beam in Project-X Linac

    SciTech Connect

    Sukhanov, Alexander; Yakovlev, Vyacheslav; Gonin, Ivan; Khabiboulline, Timergali; Lunin, Andrei; Saini, Arun; Solyak, Nikolay; Vostrikov, Alexander

    2013-04-01

    Resonance excitation of longitudinal high order modes in superconducting RF structures of Project-X continuous wave linac is studied. We analyze regimes of operation of the linac with high beam current, which can be used to provide an intense muon source for the future Neutrino Factory or Muon Collider, and also important for the Accelerator-Driven Subcritical systems. We calculate power loss and associated heat load to the cryogenic system. Longitudinal emittance growth is estimated. We consider an alternative design of the elliptical cavity for the high energy part of the linac, which is more suitable for high current operation.

  14. ELECTRON BEAM STABILITY REQUIREMENTS FOR LINAC-RING ELECTRON-ION COLLIDERS.

    SciTech Connect

    MONTAG, C.

    2005-05-16

    In recent years, linac-ring electron-ion colliders have been proposed at a number of laboratories around the world. While the linac-ring approach overcomes the beam-beam tuneshift limitation on the electron beam, it also introduces noise into the ion beam, via the beam-beam interaction with electron bunches of slightly fluctuating intensity and transverse size. The effect of these fluctuations is studied using a linearized model of the beam-beam interaction. Upper limits for the rms jitter amplitudes of electron beam parameters for various linac-ring electron-ion colliders are presented.

  15. Simultaneous optimization of the cavity heat load and trip rates in linacs using a genetic algorithm

    DOE PAGES

    Terzić, Balša; Hofler, Alicia S.; Reeves, Cody J.; ...

    2014-10-15

    In this paper, a genetic algorithm-based optimization is used to simultaneously minimize two competing objectives guiding the operation of the Jefferson Lab's Continuous Electron Beam Accelerator Facility linacs: cavity heat load and radio frequency cavity trip rates. The results represent a significant improvement to the standard linac energy management tool and thereby could lead to a more efficient Continuous Electron Beam Accelerator Facility configuration. This study also serves as a proof of principle of how a genetic algorithm can be used for optimizing other linac-based machines.

  16. Design study of a medical proton linac for neutron therapy

    SciTech Connect

    Machida, S.; Raparia, D.

    1988-08-26

    This paper describes a design study which establishes the physical parameters of the low energy beam transport, radiofrequency quadrupole, and linac, using computer programs available at Fermilab. Beam dynamics studies verify that the desired beam parameters can be achieved. The machine described here meets the aforementioned requirements and can be built using existing technology. Also discussed are other technically feasible options which could be attractive to clinicians, though they would complicate the design of the machine and increase construction costs. One of these options would allow the machine to deliver 2.3 MeV protons to produce epithermal neutrons for treating brain tumors. A second option would provide 15 MeV protons for isotope production. 21 refs., 33 figs.

  17. X-ray detectors at the Linac Coherent Light Source

    DOE PAGES

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; ...

    2015-04-21

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a newmore » generation of cameras under development at SLAC, is introduced.« less

  18. The linac coherent light source single particle imaging road map

    SciTech Connect

    Aquila, A.; Barty, A.; Bostedt, C.; Boutet, S.; Carini, G.; dePonte, D.; Drell, P.; Doniach, S.; Downing, K. H.; Earnest, T.; Elmlund, H.; Elser, V.; Gühr, M.; Hajdu, J.; Hastings, J.; Hau-Riege, S. P.; Huang, Z.; Lattman, E. E.; Maia, F. R.N.C.; Marchesini, S.; Ourmazd, A.; Pellegrini, C.; Schlichting, I.; Schroer, C.; Spence, J. C. H.; Vartanyants, I. A.; Wakatsuki, S.; Weis, W. I.; Williams, G. J.

    2015-07-01

    Intense femtosecond x-ray pulses from free-electron laser sources allow the imaging of individual particles in a single shot. Early experiments at the Linac Coherent Light Source (LCLS) have led to rapid progress in the field and, so far, coherent diffractive images have been recorded from biological specimens, aerosols, and quantum systems with a few-tens-of-nanometers resolution. In March 2014, LCLS held a workshop to discuss the scientific and technical challenges for reaching the ultimate goal of atomic resolution with single-shot coherent diffractive imaging. This paper summarizes the workshop findings and presents the roadmap toward reaching atomic resolution, 3D imaging at free-electron laser sources.

  19. A 300-nm compact mm-wave linac FEL design

    SciTech Connect

    Nassiri, A.; Kustom, R.L.; Kang, Y.W.

    1995-12-31

    Microfabrication technology offers an alternative method for fabricating precision, miniature-size components suitable for use in accelerator physics and commercial applications. The original R&D work at Argonne, in collaboration with the University of Illinois at Chicago, has produced encouraging results in the area of rf accelerating structure design, optical and x-ray masks production, deep x-ray lithography (LIGA exposures), and precision structural alignments. In this paper we will present a design study for a compact single pass mm-linac FEL to produce short wavelength radiation. This system will consists of a photocathode rf gun operated at 30 GHz, a 50-MeV superconducting constant gradient structure operated at 60 GHz, and a microundulator with 1-mm period. Initial experimental results on a scale model rf gun and microundulator will be presented.

  20. Linac Coherent Light Source: The first five years

    NASA Astrophysics Data System (ADS)

    Bostedt, Christoph; Boutet, Sébastien; Fritz, David M.; Huang, Zhirong; Lee, Hae Ja; Lemke, Henrik T.; Robert, Aymeric; Schlotter, William F.; Turner, Joshua J.; Williams, Garth J.

    2016-01-01

    A new scientific frontier opened in 2009 with the start of operations of the world's first x-ray free-electron laser (FEL), the Linac Coherent Light Source (LCLS), at SLAC National Accelerator Laboratory. LCLS provides femtosecond pulses of x rays (270 eV to 11.2 keV) with very high peak brightness to access new domains of ultrafast x-ray science. This article presents the fundamental FEL physics and outlines the LCLS source characteristics along with the experimental challenges, strategies, and instrumentation that accompany this novel type of x-ray source. The main part of the article reviews the scientific achievements since the inception of LCLS in the five primary areas it serves: atomic, molecular, and optical physics; condensed matter physics; matter in extreme conditions; chemistry and soft matter, and biology.

  1. SRF and RF systems for LEReC Linac

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Fedotov, A.; McIntyre, G.; Polizzo, S.; Smith, K.; Than, R.; Tuozzolo, J.; Veshcherevich, V.; Wu, Q.; Xiao, B.; Xu, W.; Zaltsman, A.

    2015-05-03

    The Low Energy RHIC electron Cooling (LEReC) is under development at BNL to improve RHIC luminosity at low energies. It will consist of a short electron linac and two cooling sections, one for blue and one for yellow rings. For the first stage of the project, LEReC-I, we will install a 704 MHz superconducting RF cavity and three normal conducting cavities operating at 9 MHz, 704 MHz and 2.1 GHz. The SRF cavity will boost the electron beam energy up to 2 MeV. The warm cavities will be used to correct the energy spread introduced in the SRF cavity. The paper describes layouts of the SRF and RF systems, their parameters and status.

  2. The linac coherent light source single particle imaging road map

    PubMed Central

    Aquila, A.; Barty, A.; Bostedt, C.; Boutet, S.; Carini, G.; dePonte, D.; Drell, P.; Doniach, S.; Downing, K. H.; Earnest, T.; Elmlund, H.; Elser, V.; Gühr, M.; Hajdu, J.; Hastings, J.; Hau-Riege, S. P.; Huang, Z.; Lattman, E. E.; Maia, F. R. N. C.; Marchesini, S.; Ourmazd, A.; Pellegrini, C.; Santra, R.; Schlichting, I.; Schroer, C.; Spence, J. C. H.; Vartanyants, I. A.; Wakatsuki, S.; Weis, W. I.; Williams, G. J.

    2015-01-01

    Intense femtosecond x-ray pulses from free-electron laser sources allow the imaging of individual particles in a single shot. Early experiments at the Linac Coherent Light Source (LCLS) have led to rapid progress in the field and, so far, coherent diffractive images have been recorded from biological specimens, aerosols, and quantum systems with a few-tens-of-nanometers resolution. In March 2014, LCLS held a workshop to discuss the scientific and technical challenges for reaching the ultimate goal of atomic resolution with single-shot coherent diffractive imaging. This paper summarizes the workshop findings and presents the roadmap toward reaching atomic resolution, 3D imaging at free-electron laser sources. PMID:26798801

  3. Physics design of rod type proton Radio Frequency Quadrupole linac

    NASA Astrophysics Data System (ADS)

    Das, C.; Dechoudhury, S.; Pandey, H. K.; Naik, V.; Chakrabarti, A.

    2017-02-01

    A Radio Frequency Quadrupole (RFQ) linac delivering 800 keV, 5 mA protons has been designed. It is envisaged as first injector of the proton driver that will be used for production of proton-rich radioactive beams in the proposed ANURIB facility. The option of rod-type structure at frequency of 80 MHz has been chosen owing to ease of mechanical fabrications and to avoid detrimental nearby dipole modes present in vane type structure. Optimization of parameters has been carried out for a viable length and power of RFQ in order to avoid any infrastructural complexity. Conventional method of keeping focusing factor and vane voltage constant along the length of RFQ has been adopted. Results of detailed beam dynamics and RF structure design, space charge induced effects and corroborative particle tracking with realistic 3D fields of modulated vane has been presented.

  4. The linac coherent light source single particle imaging road map

    DOE PAGES

    Aquila, A.; Barty, A.; Bostedt, C.; ...

    2015-07-01

    Intense femtosecond x-ray pulses from free-electron laser sources allow the imaging of individual particles in a single shot. Early experiments at the Linac Coherent Light Source (LCLS) have led to rapid progress in the field and, so far, coherent diffractive images have been recorded from biological specimens, aerosols, and quantum systems with a few-tens-of-nanometers resolution. In March 2014, LCLS held a workshop to discuss the scientific and technical challenges for reaching the ultimate goal of atomic resolution with single-shot coherent diffractive imaging. This paper summarizes the workshop findings and presents the roadmap toward reaching atomic resolution, 3D imaging at free-electronmore » laser sources.« less

  5. Development of a very-low-velocity superconducting linac

    SciTech Connect

    Shepard, K.W.

    1987-01-01

    Four types of superconducting accelerator structures are being developed for use in a low velocity positive-ion injector linac for the ATLAS heavy-ion accelerator. Prototypes of the first two of these have been tested. The structures are all variants of a quarter-wave line terminated with a four-gap interdigital drift-tube array. The two structure types so far tested operate at 48.5 mHz and have an active length of 10 cm (for the particle velocity - .008c type) and 16.5 cm (for the velocity - .014c type). Effective accelerating fields of 10 MV/m have been achieved with the 10 cm structure, corresponding to an effective accelerating potential of 1 MV. The 16.5 cm structure has been operated at field levels of 6 MV/m, also giving an effective potential of 1 MV. Prototypes of the remaining two resonant geometries are under construction.

  6. Nuclear structure and depletion of nuclear isomers using electron linacs

    SciTech Connect

    Carroll, J. J.; Litz, M. S.; Henriquez, S. L.; Burns, D. A.; Netherton, K. A.; Pereira, N. R.; Karamian, S. A.

    2013-04-19

    Long-lived nuclear excited states (isomers) have proven important to understanding nuclear structure. With some isomers having half-lives of decades or longer, and intrinsic energy densities reaching 10{sup 12} J/kg, they have also been suggested for a wide range of applications. The ability to effectively transfer a population of nuclei from an isomer to shorter-lived levels will determine the feasibility of any applications. Here is described a first demonstration of the induced depletion of a population of the 438 year isomer of {sup 108}Ag to its 2.38 min ground state, using 6 MeV bremsstrahlung from a modified medical electron linac. The experiment suggests refinements to be implemented in the future and how a similar approach might be applied to study induced depletion of the 1200 year isomer of {sup 166}Ho.

  7. Modification of a medical linac to a polymer irradiation facility

    NASA Astrophysics Data System (ADS)

    van Duijneveldt, W.; Botman, J. I. M.; Timmermans, C. J.; de Leeuw, R. W.

    1993-06-01

    A linear accelerator for X-ray therapy has been modified to generate a 5 MeV pulsed electron beam. The main objective is to irradiate polymeric materials in open air in order to alter their chemical and mechanical properties. To meet the radiation protection standards a shielding has been built round the target. Safety is guaranteed by a fail-safe secured programmable logic controller (PLC) monitored by a personal computer. The accelerator can be monitored and controlled by a graphics oriented and menu driven program running on the personal computer. In addition, a control panel has been designed and built to show warning signals and to set various linac parameters. A description of the accelerator modification and of the new control system is presented.

  8. Klystron modulator operation and upgrades for the APS linac

    SciTech Connect

    Russell, T.J.; Cours, A.

    1995-07-01

    The Advanced Photon Source (APS) linac requires five 100-MW modulators to achieve its required energy. In-house construction of these modulators was under an extremely compressed time schedule and, while the original design was successful, it had a few shortcomings. The operation of the modulators was hindered by excessively sensitive controls and overheating during the hot summer months. The system underwent minor changes that resulted in major improvements. Additionally, improvements have been made to the high voltage circuits to improve the rise time of the output pulse shape. reduce the initial ringing of the pulse, and enhance the reliability of the system. This paper will outline the changes and explain the results of the improvements.

  9. Beam transport for an SRF recirculating-linac FEL

    SciTech Connect

    Neuffer, D.; Douglas, D.; Li, Z.

    1995-12-31

    The beam transport system for the CEBAF UV Demo FEL includes a two-pan transport of the beam with acceleration from injector to wiggler, followed by energy recovery transport from wiggler to dump. From that contact we discuss the general problem of multi-pass energy-recovery beam transport for FELs. Tuneable, nearly-isochronous, large-momentum-acceptance import systems are required. The entire transport must preserve beam quality, particularly in the acceleration transport to the wiggler, and have low losses throughout the entire system. Issues such as injection and final energies, number of passes, linac focusing effects, beam separation, chronicity management, and stability constraints are critical. Various possible designs are discussed. Particle tracking results exploring the design options are also reported.

  10. A medical facility proposal to use the SSC linac

    NASA Astrophysics Data System (ADS)

    Warren Funk, L.

    1995-05-01

    A consortium organized by the Texas National Research Laboratory Commission (TNRLC) under a Department of Energy (DOE) grant proposes to build and operate a Regional Medical Technology Center (RMTC) to function as a combined medical radioisotope production complex and proton cancer therapy facility using the linear accelerator (linac) assets of the cancelled Superconducting Super Collider (SSC). The radioisotope production complex will serve as a domestic source of radioisotopes critically needed by the U.S. pharmaceutical industry and nuclear medicine facilities throughout North America. Presently, more than 70 percent of radioisotopes used in U.S. nuclear medicine procedures are produced outside the country. The Center's state-of-the-art proton cancer therapy facility will serve the Central United States, providing advanced capabilities and augmenting facilities in California and Massachusetts. Long-term, it is anticipated that the RMTC also will stimulate nuclear medicine research, advance medical diagnostic technologies, and generate new industrial applications of linear accelerator technology.

  11. A medical facility proposal to use the SSC linac

    SciTech Connect

    Funk, L.W.

    1994-12-31

    A consortium organized by the Texas National Research Laboratory Commission under a Department of Energy grant proposes to build and operate a Regional Medical Technology Center to function as a combined medical radioisotope production complex and proton cancer therapy facility using the Linear Accelerator (Linac) assets of the Superconducting Super Collider (SSC). The radioisotope production complex will serve as a domestic source of radioisotopes critically needed by the U.S. pharmaceutical industry and nuclear medicine facilities throughout North America. Presently, more than 70 percent of radioisotopes used in U.S. nuclear medicine procedures are produced outside the country. The Center`s state-of-the-art proton cancer therapy facility will serve the Central United States, providing advanced capabilities and augmenting facilities in California and Massachusetts. Long-term, it is anticipated that the RMTC also will stimulate nuclear medicine research, advance medical diagnostic technologies, and generate new industrial applications for linear accelerator technology.

  12. Tutorial on beam-based feedback systems for linacs

    SciTech Connect

    Hendrickson, L.; Allison, S.; Gromme, T.; Grossberg, P.; Himel, T.; Krauter, K.; MacKenzie, R.; Ross, M.; Sass, R.; Shoaee, H.

    1994-08-01

    A generalized fast feedback system stabilizes beams in the SLC. It performs measurements and modifies actuator settings to control beam states such as position, angle, energy and intensity on a pulse to pulse basis. An adaptive cascade feature allows communication between a series of linac loops, avoiding overcorrection problems. The system is based on the state space formalism of digital control theory. Due to the database-driven design, new loops are added without requiring software modifications. Recent enhancements support the monitoring and control of nonlinear states such as beam phase using excitation techniques. In over three years of operation, the feedback system has grown from its original eight loops to more than fifty loops, and it has been invaluable in stabilizing the machine.

  13. Energy stability in recirculating, energy-recovering linacs

    SciTech Connect

    Merminga, L.; Bisognano, J.J.; Delayen, J.R.

    1996-07-01

    Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields are investigated. Energy changes can cause beam loss on apertures, or, when coupled to M{sub 56}, phase oscillations. Both effects change the beam induced voltage in the cavities and can lead to unstable variations of the accelerating field. Stability analysis for small perturbations from equilibrium is performed and threshold currents are determined. Furthermore, the analytical model is extended to include amplitude and phase feedback, with the transfer function in the feedback path presently modeled as a low-pass filter. The feedback gain and bandwidth required for stability are calculated for the high power UV FEL proposed for construction at CEBAF. 4 refs.

  14. Energy recovery linacs in high-energy and nuclear physics

    SciTech Connect

    I. Ben-Zvi; Ya. Derbenev; V. Litvinenko; L. Merminga

    2005-03-01

    Energy Recovery Linacs (ERL) have significant potential uses in High Energy Physics and Nuclear Physics. We describe some of the potential applications which are under development by our laboratories in this area and the technology issues that are associated with these applications. The applications that we discuss are electron cooling of high-energy hadron beams and electron-nucleon colliders. The common issues for some of these applications are high currents of polarized electrons, high-charge and high-current electron beams and the associated issues of High-Order Modes. The advantages of ERLs for these applications are numerous and will be outlined in the text. It is worth noting that some of these advantages are the high-brightness of the ERL beams and their relative immunity to beam-beam disturbances.

  15. Ampere Average Current Photoinjector and Energy Recovery Linac

    SciTech Connect

    Ilan Ben-Zvi; A. Burrill; R. Calaga; P. Cameron; X. Chang; D. Gassner; H. Hahn; A. Hershcovitch; H.C. Hseuh; P. Johnson; D. Kayran; J. Kewisch; R. Lambiase; Vladimir N. Litvinenko; G. McIntyre; A. Nicoletti; J. Rank; T. Roser; J. Scaduto; K. Smith; T. Srinivasan-Rao; K.-C. Wu; A. Zaltsman; Y. Zhao; H. Bluem; A. Burger; Mike Cole; A. Favale; D. Holmes; John Rathke; Tom Schultheiss; A. Todd; J. Delayen; W. Funk; L. Phillips; Joe Preble

    2004-08-01

    High-power Free-Electron Lasers were made possible by advances in superconducting linac operated in an energy-recovery mode, as demonstrated by the spectacular success of the Jefferson Laboratory IR-Demo. In order to get to much higher power levels, say a fraction of a megawatt average power, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for a different application, that of electron cooling of high-energy hadron beams. I will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun employing a new secondary-emission multiplying cathode and an accelerator cavity, both capable of producing of the order of one ampere average current.

  16. Phase Noise Measurement in PEP II and the Linac

    SciTech Connect

    Getaneh, Mesfin

    2003-09-05

    The Goal of this project is to provide a measurement of the phase of the radio frequency (RF) relative to electron beam traveling down the Stanford Linear Accelerator Center (SLAC). Because the Main Drive Line (MDL) supplies the RF drive and phase reference for the entire accelerator system, the phase accuracy and amount of phase noise present in the MDL are very critical to the functionality of the accelerator. Therefore, a Phase Noise Measurement System was built to measure the phase noise in the liner accelerator (Linac) and PEP II. The system was used to determine the stability of the PEP II RF reference system. In this project a low noise Phase Locked Loop system (PLL) was built to measure timing jitter about sub picoseconds level. The phase noise measured in Master Oscillator using PLL indicates that phase noise is low enough for PEP II to run.

  17. Linac Coherent Light Source Undulator RF BPM System

    SciTech Connect

    Lill, R.M.; Morrison, L.H.; Waldschmidt, G.J.; Walters, D.R.; Johnson, R.; Li, Z.; Smith, S.; Straumann, T.; /SLAC

    2007-04-17

    The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL) when it becomes operational in 2009. The LCLS is currently in the construction phase. The beam position monitor (BPM) system planned for the LCLS undulator will incorporate a high-resolution X-band cavity BPM system described in this paper. The BPM system will provide high-resolution measurements of the electron beam trajectory on a pulse-to-pulse basis and over many shots. The X-band cavity BPM size, simple fabrication, and high resolution make it an ideal choice for LCLS beam position detection. We will discuss the system specifications, design, and prototype test results.

  18. High Gradient Accelerating Structures for Carbon Therapy Linac

    SciTech Connect

    Kutsaev, Sergey; Agustsson, R.; Faillace, L.; Goel, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.; Plastun, A.; Savin, E.

    2016-05-01

    Carbon therapy is the most promising among techniques for cancer treatment, as it has demonstrated significant improvements in clinical efficiency and reduced toxicity profiles in multiple types of cancer through much better localization of dose to the tumor volume. RadiaBeam, in collaboration with Argonne National Laboratory, are developing an ultra-high gradient linear accelerator, Advanced Compact Carbon Ion Linac (ACCIL), for the delivery of ion-beams with end-energies up to 450 MeV/u for 12C6+ ions and 250 MeV for protons. In this paper, we present a thorough comparison of standing and travelling wave designs for high gradient S-Band accelerating structures operating with ions at varying velocities, relative to the speed of light, in the range 0.3-0.7. In this paper we will compare these types of accelerating structures in terms of RF, beam dynamics and thermo-mechanical performance.

  19. Bunch shape monitor development in J-PARC linac

    NASA Astrophysics Data System (ADS)

    Miura, A.; Tamura, J.; Liu, Y.; Miyao, T.

    2017-07-01

    In the linac at the Japan accelerator research complex (J-PARC), we decided to use bunch shape monitors (BSMs) as phase-width monitors. Both centroid-phase set point at the frequency jump from SDTL (324 MHz) to ACS (972 MHz) and phase-width control are key issues for suppressing excess beam loss. BSM was designed and developed at the Institute for Nuclear Research, Russia. Because the BSM was first used between acceleration cavities, we need to improve it to protect it from the leakage-magnetic field of the quadrupole magnets and from outgassing impacts on the cavities. In this paper, we introduce these improvements to the BSM for the adoption of the location nearby the acceleration cavities.

  20. X-ray detectors at the Linac Coherent Light Source

    PubMed Central

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

    2015-01-01

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced. PMID:25931071

  1. Improved temperature regulation of APS linac RF components.

    SciTech Connect

    Dortwegt, R.

    1998-09-21

    The temperature of the APS S-Band linac's high-power rf components is regulated by water from individual closed-loop deionized (DI) water systems. The rf components are all made of oxygen-free high-conductivity copper and respond quickly to temperature changes. The SLED cavities are especially temperature-sensitive and cause beam energy instabilities when the temperature is not well regulated. Temperature regulation better than {+-} 0.1 F is required to achieve good energy stability. Improvements in the closed-loop water systems have enabled them to achieve a regulation of {+-} 0.05 F over long periods. Regulation philosophy and equipment are discussed and numerical results are presented.

  2. Spin motion of electrons in the SLC linac

    SciTech Connect

    Panofsky, W.K.H.

    1991-01-15

    It is generally expected that the depolarizing effects of the linear accelerator RF fields will be small. Recently Bill Atwood raised the question whether this conclusion is still correct in view of the fact that the particles in the SLC spend a larger fraction of their time at phase angles off crest'' due to BNS damping; since radial fields are in quadrature with the accelerating field this might imply that depolarizing effects are larger. On the other hand, because of the smaller emittance of the SLC relative to the earlier linac radial excursions would be smaller. The anticipation is therefore that the depolarizing effect will again be negligible but it might be worthwhile to update the early calculations of SLAC TN-63-97 revised. This paper discusses these updates.

  3. Spin motion of electrons in the SLC linac

    SciTech Connect

    Panofsky, W.K.H.

    1990-11-21

    It is generally expected that the depolarizing effects of the linear accelerator RF fields will be small. Recently Bill Atwood raised the question whether this conclusion is still correct in view of the fact that the particles in the SLC spend a larger fraction of their time at phase angles off crest'' due to BNS damping; since radial fields are in quadrature with the accelerating field this might imply that depolarizing effects are larger. On the other hand, because of the smaller emittance of the SLC relative to the earlier linac radial excursions would be smaller. The anticipation is therefore that the depolarizing effect will again be negligible but it might be worthwhile to update the early calculations of SLAC TN-63-97 revised in this paper.

  4. X-ray detectors at the Linac Coherent Light Source

    SciTech Connect

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

    2015-04-21

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced.

  5. Digitally Controlled Four Harmonic Buncher for FSU LINAC

    NASA Astrophysics Data System (ADS)

    Moerland, Daniel S.; Wiedenhoever, Ingo; Baby, Lagy T.; Caussyn, David; Spingler, David

    2012-03-01

    Florida State University's John D. Fox Superconducting Accelerator Laboratory is operating a Tandem-Linac system for heavy ion beams at energies of 5-10 MeV/u. Recently, the accelerator has been used as the driver for the radioactive beam facility RESOLUT, which poses new demands on its high-intensity performance and time-resolution. These demands motivated us to optimize the RF bunching system and to switch the bunch frequency from 48.5 to 12.125 MHz. We installed a four-harmonic resonant transformer to create 3-4 kV potential oscillations across a pair of wire-mesh grids. This setup is modulating the energy of the beam injected into the tandem accelerator, with the aim to create short bunches of beam particles. Asawtooth-like wave-form is created using the Fourier series method, by combining the basis sinusoidal wave of 12.125MHz and its 3 higher order harmonics, in a manner similar to the systems used at ATLAS [1] and other RF-accelerators. A new aspect of our setup is the use of a digital 1GHz function generator, which allows us to optimize and stabilize the synthesized waveform. The control system was realized using labview and integrated into the recently updated controls of the accelerator. We characterize the bunching quality achievedand discuss the optimization of the bunching wave-form. The bunching system has been successfully used in a number of Linac-experiments performed during 2011.[4pt][1] S. Sharamentov, J. Bogaty, B.E. Clifft, R. Pardo, UPGRADE OF THE ATLAS POSITIVE ION INJECTOR BUNCHING SYSTEM, Proceedings of 2005 Particle Accelerator Conference, Knoxville, Tennessee

  6. Design and development of a radio frequency quadrupole linac postaccelerator for the Variable Energy Cyclotron Center rare ion beam project.

    PubMed

    Dechoudhury, S; Naik, V; Mondal, M; Chatterjee, A; Pandey, H K; Mandi, T K; Bandyopadhyay, A; Karmakar, P; Bhattacharjee, S; Chouhan, P S; Ali, S; Srivastava, S C L; Chakrabarti, A

    2010-02-01

    A four-rod type heavy-ion radio frequency quadrupole (RFQ) linac has been designed, constructed, and tested for the rare ion beam (RIB) facility project at VECC. Designed for cw operation, this RFQ is the first postaccelerator in the RIB beam line. It will accelerate A/q < or = 14 heavy ions coming from the ion source to the energy of around 100 keV/u for subsequent acceleration in a number of Interdigital H-Linac. Operating at a resonance frequency of 37.83 MHz, maximum intervane voltage of around 54 kV will be needed to achieve the final energy over a vane length of 3.12 m for a power loss of 35 kW. In the first beam tests, transmission efficiency of about 90% was measured at the QQ focus after the RFQ for O(5+) beam. In this article the design of the RFQ including the effect of vane modulation on the rf characteristics and results of beam tests will be presented.

  7. Beam dynamics studies of the 8 GeV Linac at FNAL

    SciTech Connect

    Ostroumov, P.N.; Mustapha, B.; Carneiro, J.-P.; /Fermilab

    2008-11-01

    The proposed 8-GeV proton driver (PD) linac at FNAL includes a front end up to {approx}420 MeV operating at 325 MHz and a high energy section at 1300 MHz. A normal conducting RFQ and short CH type resonators are being developed for the initial acceleration of the H-minus or proton beam up to 10 MeV. From 10 MeV to {approx}420 MeV, the voltage gain is provided by superconducting (SC) spoke-loaded cavities. In the high-energy section, the acceleration will be provided by the International Linear Collider (ILC)-style SC elliptical cell cavities. To employ existing, readily available klystrons, an RF power fan out from high-power klystrons to multiple cavities is being developed. The beam dynamics simulation code TRACK, available in both serial and parallel versions, has been updated to include all known H-minus stripping mechanisms to predict the exact location of beam losses. An iterative simulation procedure is being developed to interact with a transient beam loading model taking into account RF feedback and feedforward systems.

  8. A laser-wire beam-energy and beam-profile monitor at the BNL linac

    SciTech Connect

    Connolly, R.; Degen, C.; DeSanto, L.; Meng, W.; Michnoff, R.; Minty, M.; Nayak, S.

    2011-03-28

    In 2009 a beam-energy monitor was installed in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. This device measures the energies of electrons stripped from the 40mA H{sup -} beam by background gas. Electrons are stripped by the 2.0x10{sup -7}torr residual gas at a rate of {approx}1.5x10{sup -8}/cm. Since beam electrons have the same velocities as beam protons, the beam proton energy is deduced by multiplying the electron energy by m{sub p}/m{sub e}=1836. A 183.6MeV H{sup -} beam produces 100keV electrons. In 2010 we installed an optics plates containing a laser and scanning optics to add beam-profile measurement capability via photodetachment. Our 100mJ/pulse, Q-switched laser neutralizes 70% of the beam during its 10ns pulse. This paper describes the upgrades to the detector and gives profile and energy measurements.

  9. Calculation of acceptance of high intensity superconducting proton linac for Project X

    SciTech Connect

    Saini, A.; Ranjan, K.; Solyak, N.; Mishra, S.; Yakovlev, V.; /Fermilab

    2011-03-01

    Project-X is the proposed high intensity proton facility to be built at Fermilab, US. Its Superconducting Linac, to be used at first stage of acceleration, will be operated in continuous wave (CW) mode. The Linac is divided into three sections on the basis of operating frequencies & six sections on the basis of family of RF cavities to be used for the acceleration of beam from 2.5 MeV to 3 GeV. The transition from one section to another can limit the acceptance of the Linac if these are not matched properly. We performed a study to calculate the acceptance of the Linac in both longitudinal and transverse plane. Investigation of most sensitive area which limits longitudinal acceptance and study of influence of failure of beam line elements at critical position, on acceptance are also performed.

  10. Effect of the transverse parasitic mode on beam performance for the ADS driver linac in China

    NASA Astrophysics Data System (ADS)

    Cheng, Peng; Pei, Shi-Lun; Wang, Jiu-Qing; Li, Zhi-Hui

    2015-05-01

    The ADS (Accelerator Driven subcritical System) driver linac in China is designed to run in CW (Continuous Wave) mode with 10 mA designed beam current. In this scenario, the beam-induced parasitic modes in the ADS driver linac may make the beam unstable or deteriorate the beam performance. To evaluate the parasitic mode effect on the beam dynamics systematically, simulation studies using the ROOT-based numerical code SMD have been conducted. The longitudinal beam instability induced by the HOMs (High Order Modes) and SOMs (Same Order Modes) has little effect on the longitudinal beam performance for the current ADS driver linac design based on the 10 MeV/325 MHz injector I from previous studies. Here the transverse parasitic mode (i.e., dipole HOM) effect on the transverse beam performance at the ADS driver linac exit is investigated. To more reasonably quantify the dipole mode effect, the multi-bunch effective emittance is introduced in this paper.

  11. First Considerations Concerning an Optimized Cavity Design for the Main Linac of BERLinPro

    SciTech Connect

    B. Riemann, T. Weis, W. Anders, J. Knobloch, A. Neumann, H.-W. Glock, C. Potratz, U. van Rienen, F. Marhauser

    2011-09-01

    The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW linac technology and expertise required to drive next-generation Energy Recovery Linacs. Strongly HOM-damped multicell 1.3 GHz cavities are required for the main linac. The optimization of the cavities presented here is primarily based on the CEBAF 1.5 GHz 5-cell high-current cavity design, including HOM waveguide couplers. The cavity was scaled to 1.3 GHz and extended to 7 cells. Modifications to the end group design have also been studied. An effort was also made to reduce the ratio Epk/Eacc while still permitting HOMs to propagate.

  12. Proposal for the use of the AGS linac for proton therapy

    SciTech Connect

    Alessi, J.G.; Chanana, A.; Dilmanian, F.A.; Lee, Y.Y.; Raparia, D.; Wielopolski, L.

    1994-10-01

    The BNL 200 MeV linac presently provides beam for the AGS high energy physics program and for isotope production at the Brookhaven Linac Isotope Producer (BLIP,) facility. There is now a proposal to develop a proton therapy facility which would also use the linac beam. Approximately 1% of the current in each linac beam pulse would be diverted from BLIP, down an existing transport line, to the proposed new facility. This paper focuses on the basic design of the facility, particularly the accelerator issues. The planned transport line layout is presented, along with a description of the energy and intensity control, and beam delivery systems. In the initial phase, we are planning one 360{degrees} vertical gantry and one horizontal treatment room.

  13. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    SciTech Connect

    Le Sage, G P

    2002-11-05

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the beam profile will be described.

  14. Proton linac for hospital-based fast neutron therapy and radioisotope production

    SciTech Connect

    Lennox, A.J.; Hendrickson, F.R.; Swenson, D.A.; Winje, R.A.; Young, D.E.; Rush Univ., Chicago, IL; Science Applications International Corp., Princeton, NJ; Fermi National Accelerator Lab., Batavia, IL )

    1989-09-01

    Recent developments in linac technology have led to the design of a hospital-based proton linac for fast neutron therapy. The 180 microamp average current allows beam to be diverted for radioisotope production during treatments while maintaining an acceptable dose rate. During dedicated operation, dose rates greater than 280 neutron rads per minute are achievable at depth, DMAX = 1.6 cm with source to axis distance, SAD = 190 cm. Maximum machine energy is 70 MeV and several intermediate energies are available for optimizing production of isotopes for Positron Emission Tomography and other medical applications. The linac can be used to produce a horizontal or a gantry can be added to the downstream end of the linac for conventional patient positioning. The 70 MeV protons can also be used for proton therapy for ocular melanomas. 17 refs., 1 fig., 1 tab.

  15. X-band Linac for a 6 MeV dual-head radiation therapy gantry

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Shin, Seung-Wook; Lee, Jongchul; Kim, Hui-Su; Lee, Byeong-No; Lee, Byung-Chul; Park, Hyung-dal; Song, Ki-back; Song, Ho-seung; Mun, Sangchul; Ha, Donghyup; Chai, Jong-Seo

    2017-04-01

    We developed a design for a 6 MeV X-band linear accelerator for radiation therapy in a dual-head gantry layout. The dual-head gantry has two linacs that can be operated independently. Each X-band linac accelerates electron bunches using high-power RF and generates X-rays for radiation therapy. It requires a versatile RF system and pulse sequence to accomplish various radiation therapy procedures. The RF system consists of 9.3 GHz, 2 MW X-band magnetron and associated RF transmission components. A test linac was assembled and operated to characterize its RF performance without beam. This paper presents these results along with a description of the gantry linacs and their operational requirements.

  16. The KONUS IH-DTL proposal for the GSI UNILAC poststripper linac replacement

    NASA Astrophysics Data System (ADS)

    Hähnel, H.; Ratzinger, U.; Tiede, R.

    2017-07-01

    Motivated by the necessary replacement of the GSI UNILAC poststripper linac, a compact and efficient linac design based on IH-type cavities has been developed. Using KONUS beam dynamics, it was possible to design a linac consisting of only five cavities that can be operated by the existing UNILAC RF amplifier structure. The transversal focusing scheme is based on magnetic quadrupole triplet lenses. The optimized design provides full transmission and low emittance growth for the design current of 15 emA U28+, accelerating the beam from 1.4 MeV/u to 11.4 MeV/u. Extensive error studies were performed to define tolerances and verify the stability of the design with respect to misalignment and injection parameters. The design provides a compact and cost effective alternative to a new Alvarez linac. With a total length of just 22.8 meters it will leave room for future energy upgrades in the UNILAC tunnel.

  17. Stereotactic radiosurgery for intracranial metastases: linac-based and gamma-dedicated unit approach.

    PubMed

    Alongi, Filippo; Fiorentino, Alba; Mancosu, Pietro; Navarria, Pierina; Giaj Levra, Niccolò; Mazzola, Rosario; Scorsetti, Marta

    2016-07-01

    For intracranial metastases, the role of stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy is well recognized. Historically, the first technology, for stereotactic device able to irradiate a brain tumor volume, was Gamma Knife® (GK). Due to the technological advancement of linear accelerator (Linac), there was a continuous increasing interest in SRS Linac-based applications. In those decades, it was assumed a superiority of GK compared to SRS Linac-based for brain tumor in terms of dose conformity and rapid fall-off dose close to the target. Expert commentary: Recently, due to the Linac technologic advancement, the choice of SRS GK-based is not necessarily so exclusive. The current review discussed in details the technical and clinical aspects comparing the two approaches for brain metastases.

  18. A Bunching Process Control in the Test Linac (S-band) DES

    NASA Astrophysics Data System (ADS)

    Kovalishin, A. S.; Kisselev, I. V.; Jonas, R.

    1997-05-01

    The structure of the control object of the S-band test linac - the electron gun, the focusing systems, two bunchers with RF transmitters and the autonomous systems for regulation of the amplitude, the phase and the resonans frequency of the cavities is presented. The mathematikal model is described with using of the automatic control theory methods for the bunching process and the practical results are presented. The control system of the S-band test linac is described.

  19. NOVEL METHODS FOR EXPERIMENTAL CHARACTERIZATION OF 3D SUPERCONDUCTING LINAC BEAM DYNAMICS

    SciTech Connect

    Shishlo, Andrei P

    2013-01-01

    This paper describes an approach to measure initial Twiss parameters in transverse and longitudinal directions at the entrance of a linac with independent short accelerating cavities. For the transverse plane the usual technique of transverse profiles is used, and for the longitudinal direction a recently developed non-intercepting method is applied. The new method is based on a beam position monitor amplitudes analysis. The applicability of the methods are discussed and demonstrated on an example of the Spallation Neutron Source superconducting linac.

  20. Status of the fluorescent screens and image processing for the APS linac

    SciTech Connect

    Berg, W.; Ko, K.

    1993-11-01

    Ten fluorescent screens and cameras determine the relative position and image profile of the beam in both the electron and positron linacs at the Advanced Photon Source (APS). The timing techniques used to capture the beam image allow direct synchronization to the electron gun trigger to minimize timing uncertainties. This paper discusses the design and status of the APS linac fluorescent screen assemblies and imaging system.

  1. HOM Consideration of 704 MHz and 2.1 GHz Cavities for LEReC Linac

    SciTech Connect

    Xiao, Binping; Belomestnykh, Sergey; Ben-Zvi, Ilan; Blaskiewicz, Michael; Brennan, Joseph; Brutus, Jean Clifford; Fedotov, Alexei; Hahn, Harald; McIntyre, Gary; Pai, Chien; Smith, Kevin; Tuozzolo, Joseph; Veshcherevich, Vadim; Wu, Qiong; Xin, Tianmu; Xu, Wencan; Zaltsman, Alex

    2016-06-01

    To improve RHIC luminosity for heavy ion beam energies below 10 GeV/nucleon, the Low Energy RHIC electron Cooler (LEReC) is currently under development at BNL. The Linac of LEReC is designed to deliver 2 MV to 5 MV electron beam, with rms dp/p less than 5·10⁻⁴. The HOM in this Linac is carefully studied to ensure this specification.

  2. Optical modeling of induction-linac driven free-electron lasers

    SciTech Connect

    Scharlemann, E.T.; Fawley, W.M.

    1986-03-31

    The free-electron laser (FEL) simulation code FRED, developed at Lawrence Livermore National Laboratory (LLNL) primarily to model single-pass FEL amplifiers driven by induction linear accelerators, is described. The main emphasis is on the modeling of optical propagation in the laser and on the differences between the requirements for modeling rf-linac-driven vs. induction-linac-driven FELs. Examples of optical guiding and mode cleanup are presented for a 50 ..mu..m FEL.

  3. Sci-Fri AM: YIS-09: The effect of magnetic interference on a coupled MR-linac system: Optimization of 3D FEM linac model.

    PubMed

    St Aubin, J; Steciw, S; Carlone, M; Fallone, B G

    2008-07-01

    The coupling of a 0.2T bi-planar Magnetic Resonance Imager and medical linear accelerator (linac) is proposed to provide real-time Image Guided Radiotherapy. This coupling necessitates the linac to be within the fringe fields of the bi-planar magnets causing magnetic interference. The design and optimization of the minimum required shielding is necessary to reduce the fringe field magnitudes to a point where a clinically useful radiation beam is produced. A first step to designing shielding is the full 3D radio-frequency modeling of the linac waveguide using the Finite Element Method. Various optimizations were performed on the linac model in order to achieve a desired resonant frequency, π/2 phase shift per cavity and other desired properties. An accelerating cavity (AC) and coupling cavity (CC) was first optimized in 3D to have identical resonant frequencies before the full 3D model was generated. In order to increase the capture efficiency of the injected electrons, the electric field in the first AC was reduced by shifting the first CC towards the gun end of the linac. The input waveguide AC dimensions were adjusted to account of the additional coupling iris and the last full AC had its gap length decreased. This work is the first step to determining the minimum magnetic shielding required to produce a clinically useful radiation beam from a coupled MR-Linac system. The fully optimized 3D model more accurately calculates the electric and magnetic field values since it includes the effects of coupling. © 2008 American Association of Physicists in Medicine.

  4. Superconducting resonator used as a phase and energy detector for linac setup

    NASA Astrophysics Data System (ADS)

    Lobanov, Nikolai R.

    2016-07-01

    Booster linacs for tandem accelerators and positive ion superconducting injectors have matured into standard features of many accelerator laboratories. Both types of linac are formed as an array of independently-phased resonators operating at room temperature or in a superconducting state. Each accelerating resonator needs to be individually set in phase and amplitude for optimum acceleration efficiency. The modularity of the linac allows the velocity profile along the structure to be tailored to accommodate a wide range charge to mass ratio. The linac setup procedure, described in this paper, utilizes a superconducting resonator operating in a beam bunch phase detection mode. The main objective was to derive the full set of phase distributions for quick and efficient tuning of the entire accelerator. The phase detector was operated in overcoupling mode in order to minimize de-tuning effects of microphonic background. A mathematical expression was derived to set a limit on resonator maximum accelerating field during the crossover search to enable extracting unambiguous beam phase data. A set of equations was obtained to calculate the values of beam phase advance and energy gain produced by accelerating resonators. An extensive range of linac setting up configurations was conducted to validate experimental procedures and analytical models. The main application of a superconducting phase detector is for fast tuning for beams of ultralow intensities, in particular in the straight section of linac facilities.

  5. WE-D-BRD-01: New Linac Designs for MR-Guided Therapy Systems

    SciTech Connect

    Baillie, D.

    2015-06-15

    The advantages that make MR highly desirable for in-room treatment guidance, i.e. soft-tissue visualization and physiological assessment of healthy/tumor tissues, are largely recognized in the research community. However, the MR absorption in practical clinical workflows is still hindered by lack of sufficient technological infrastructure. Recent advances have been made towards filling that gap such as the development of integrated therapy systems relying on an MR scanner and a radiation source (linac, Co-60) and/or brachytherapy. The session is intended to present new efforts and methods aimed at facilitating the adoption of MR guidance for treatment delivery. Specifically, the discussion will focus on a) linac designs for reduced footprint and seamless integration with MR/linac systems, b) tracking coils for brachytherapy applications, and c) procedures for the commissioning and monitoring of MR and MR/linac performance. Learning Objectives: Understand limitations and proposed solutions for linac designs and associated integration with MR/linac systems; Understand current issues with MR-guided brachytherapy procedures Understand the issues and needs for new MR commissioning and QC. License agreement with Modus Medical Devices to develop a phantom for the quantification of MR image distortions.

  6. Design of the NSLS-II Linac Front End Test Stand

    SciTech Connect

    Fliller III, R.; Johanson, M.; Lucas, M.; Rose, J.; Shaftan, T.

    2011-03-28

    The NSLS-II operational parameters place very stringent requirements on the injection system. Among these are the charge per bunch train at low emittance that is required from the linac along with the uniformity of the charge per bunch along the train. The NSLS-II linac is a 200 MeV linac produced by Research Instruments Gmbh. Part of the strategy for understanding to operation of the injectors is to test the front end of the linac prior to its installation in the facility. The linac front end consists of a 100 kV electron gun, 500 MHz subharmonic prebuncher, focusing solenoids and a suite of diagnostics. The diagnostics in the front end need to be supplemented with an additional suite of diagnostics to fully characterize the beam. In this paper we discuss the design of a test stand to measure the various properties of the beam generated from this section. In particular, the test stand will measure the charge, transverse emittance, energy, energy spread, and bunching performance of the linac front end under all operating conditions of the front end.

  7. Conceptual Design for Replacement of the DTL and CCL with Superconducting RF Cavities in the Spallation Neutron Source Linac

    SciTech Connect

    Champion, Mark S; Doleans, Marc; Kim, Sang-Ho

    2013-01-01

    The Spallation Neutron Source Linac utilizes normal conducting RF cavities in the low energy section from 2.5 MeV to 186 MeV. Six Drift Tube Linac (DTL) structures accelerate the beam to 87 MeV, and four Coupled Cavity Linac (CCL) structures provide further acceleration to 186 MeV. The remainder of the Linac is comprised of 81 superconducting cavities packaged in 23 cryomodules to provide final beam energy of approximately 1 GeV. The superconducting Linac has proven to be substantially more reliable than the normal conducting Linac despite the greater number of stations and the complexity associated with the cryogenic plant and distribution. A conceptual design has been initiated on a replacement of the DTL and CCL with superconducting RF cavities. The motivation, constraints, and conceptual design are presented.

  8. Magnetic shielding investigation for a 6 MV in-line linac within the parallel configuration of a linac-MR system.

    PubMed

    Santos, D M; St Aubin, J; Fallone, B G; Steciw, S

    2012-02-01

    In our current linac-magnetic resonance (MR) design, a 6 MV in-line linac is placed along the central axis of the MR's magnet where the MR's fringe magnetic fields are parallel to the overall electron trajectories in the linac waveguide. Our previous study of this configuration comprising a linac-MR SAD of 100 cm and a 0.5 T superconducting (open, split) MR imager. It showed the presence of longitudinal magnetic fields of 0.011 T at the electron gun, which caused a reduction in target current to 84% of nominal. In this study, passive and active magnetic shielding was investigated to recover the linac output losses caused by magnetic deflections of electron trajectories in the linac within a parallel linac-MR configuration. Magnetic materials and complex shield structures were used in a 3D finite element method (FEM) magnetic field model, which emulated the fringe magnetic fields of the MR imagers. The effects of passive magnetic shielding was studied by surrounding the electron gun and its casing with a series of capped steel cylinders of various inner lengths (26.5-306.5 mm) and thicknesses (0.75-15 mm) in the presence of the fringe magnetic fields from a commercial MR imager. In addition, the effects of a shield of fixed length (146.5 mm) with varying thicknesses were studied against a series of larger homogeneous magnetic fields (0-0.2 T). The effects of active magnetic shielding were studied by adding current loops around the electron gun and its casing. The loop currents, separation, and location were optimized to minimize the 0.011 T longitudinal magnetic fields in the electron gun. The magnetic field solutions from the FEM model were added to a validated linac simulation, consisting of a 3D electron gun (using OPERA-3d/scala) and 3D waveguide (using comsol Multiphysics and PARMELA) simulations. PARMELA's target current and output phase-space were analyzed to study the linac's output performance within the magnetic shields. The FEM model above agreed within 1

  9. Investigation of Positron Moderator Materials for Electron-Linac-Based Slow Positron Beamlines

    NASA Astrophysics Data System (ADS)

    Suzuki, Ryoichi; Ohdaira, Toshiyuki; Uedono, Akira; Cho, Yang; Yoshida, Sadafumi; Ishida, Yuuki; Ohshima, Takeshi; Itoh, Hisayoshi; Chiwaki, Mitsukuni; Mikado, Tomohisa; Yamazaki, Tetsuo; Tanigawa, Shoichiro

    1998-08-01

    Positron re-emission properties were studied on moderator materials in order to improve the positron moderation system of electron-linac-based intense slow positron beamlines. The re-emitted positron fraction was measured on tungsten, SiC, GaN, SrTiO3, and hydrogen-terminated Si with a variable-energy pulsed positron beam. The results suggested that tungsten is the best material for the primary moderator of the positron beamlines while epitaxially grown n-type 6H SiC is the best material for the secondary moderator. Defect characterization by monoenergetic positron beams and surface characterization by Auger electron spectroscopy were carried out to clarify the mechanism of tungsten moderator degradation induced by high-energy electron irradiation. The characterization experiments revealed that the degradation is due to both radiation-induced vacancy clusters and surface carbon impurities. For the restoration of degraded tungsten moderators, oxygen treatment at ˜900°C is effective. Furthermore, it was found that oxygen at the tungsten surface inhibits positronium formation; as a result, it can increase the positron re-emission fraction.

  10. Recent Developments in Nuclear Data Measurement capabilities at the Gaerttner LINAC Center at RPI

    NASA Astrophysics Data System (ADS)

    Danon, Y.; Daskalakis, A.; McDermott, B.; Thompson, N.; Youmans, A.; Block, R.; Barry, D.; Epping, B.; Leinweber, G.; Rapp, M.; Donovan, T.

    2016-03-01

    The Gaerttner LINAC Center at RPI uses a 60 MeV electron linear accelerator to produce short pulses of neutrons with duration of 5-5000 ns. The main research thrust at the Center is nuclear data for nuclear reactors and criticality safety applications. The Center includes several setups for time-of-flight measurements including neutron transmission, capture and scattering detectors, and a lead slowing-down spectrometer. Experiments were designed to produce neutron interaction cross sections that cover the energy range of 0.01 eV to 20 MeV. Recently added experiments include: setups for keV and fast neutron transmission, a C6D6 detector array for keV neutron capture measurements, and a fast neutron scattering system. Results discussed here include fast neutron scattering and angular distributions for natFe, iron capture measurements for incident neutrons from 1 keV to 2 MeV, fast neutron transmission through W and H2O samples, and keV transmission through Mo isotopes.

  11. Unfolding linac photon spectra and incident electron energies from experimental transmission data, with direct independent validation

    SciTech Connect

    Ali, E. S. M.; McEwen, M. R.; Rogers, D. W. O.

    2012-11-15

    Purpose: In a recent computational study, an improved physics-based approach was proposed for unfolding linac photon spectra and incident electron energies from transmission data. In this approach, energy differentiation is improved by simultaneously using transmission data for multiple attenuators and detectors, and the unfolding robustness is improved by using a four-parameter functional form to describe the photon spectrum. The purpose of the current study is to validate this approach experimentally, and to demonstrate its application on a typical clinical linac. Methods: The validation makes use of the recent transmission measurements performed on the Vickers research linac of National Research Council Canada. For this linac, the photon spectra were previously measured using a NaI detector, and the incident electron parameters are independently known. The transmission data are for eight beams in the range 10-30 MV using thick Be, Al and Pb bremsstrahlung targets. To demonstrate the approach on a typical clinical linac, new measurements are performed on an Elekta Precise linac for 6, 10 and 25 MV beams. The different experimental setups are modeled using EGSnrc, with the newly added photonuclear attenuation included. Results: For the validation on the research linac, the 95% confidence bounds of the unfolded spectra fall within the noise of the NaI data. The unfolded spectra agree with the EGSnrc spectra (calculated using independently known electron parameters) with RMS energy fluence deviations of 4.5%. The accuracy of unfolding the incident electron energy is shown to be {approx}3%. A transmission cutoff of only 10% is suitable for accurate unfolding, provided that the other components of the proposed approach are implemented. For the demonstration on a clinical linac, the unfolded incident electron energies and their 68% confidence bounds for the 6, 10 and 25 MV beams are 6.1 {+-} 0.1, 9.3 {+-} 0.1, and 19.3 {+-} 0.2 MeV, respectively. The unfolded spectra

  12. First MR images obtained during megavoltage photon irradiation from a prototype integrated linac-MR system.

    PubMed

    Fallone, B G; Murray, B; Rathee, S; Stanescu, T; Steciw, S; Vidakovic, S; Blosser, E; Tymofichuk, D

    2009-06-01

    The authors report the first magnetic resonance (MR) images produced by their prototype MR system integrated with a radiation therapy source. The prototype consists of a 6 MV linac mounted onto the open end of a biplanar 0.2 T permanent MR system which has 27.9 cm pole-to-pole opening with flat gradients (40 mT/m) running under a TMX NRC console. The distance from the magnet isocenter to the linac target is 80 cm. The authors' design has resolved the mutual interferences between the two devices such that the MR magnetic field does not interfere with the trajectory of the electron in the linac waveguide, and the radiofrequency (RF) signals from each system do not interfere with the operation of the other system. Magnetic and RF shielding calculations were performed and confirmed with appropriate measurements. The prototype is currently on a fixed gantry; however, in the very near future, the linac and MR magnet will rotate in unison such that the linac is always aimed through the opening in the biplanar magnet. MR imaging was found to be fully operational during linac irradiation and proven by imaging a phantom with conventional gradient echo sequences. Except for small changes in SNR, MR images produced during irradiation were visually and quantitatively very similar to those taken with the linac turned off. This prototype system provides proof of concept that the design has decreased the mutual interferences sufficiently to allow the development of real-time MR-guided radiotherapy. Low field-strength systems (0.2-0.5 T) have been used clinically as diagnostic tools. The task of the linac-MR system is, however, to provide MR guidance to the radiotherapy beam. Therefore, the 0.2 T field strength would provide adequate image quality for this purpose and, with the addition of fast imaging techniques, has the potential to provide 4D soft-tissue visualization not presently available in image-guided radiotherapy systems. The authors' initial design incorporates a

  13. Preliminary Analysis on Linac Oscillation Data LI05-19 and Wake Field Energy Loss in FACET Commissioning 2012

    SciTech Connect

    Sun, Yipeng; /SLAC

    2012-07-23

    In this note, preliminary analysis on linac ocsillation data in FACET linac LI05-09 plus LI11-19 is presented. Several quadrupoles are identified to possibly have different strength, compared with their designed strength in the MAD optics model. The beam energy loss due to longitudinal wake fields in the S-band linac is also analytically calculated, also by LITRACK numerical simulations.

  14. The Linac Coherent Light Source: Recent Developments and Future Plans

    DOE PAGES

    Schoenlein, R. W.; Boutet, S.; Minitti, M. P.; ...

    2017-08-18

    The development of X-ray free-electron lasers (XFELs) has launched a new era in X-ray science by providing ultrafast coherent X-ray pulses with a peak brightness that is approximately one billion times higher than previous X-ray sources. The Linac Coherent Light Source (LCLS) facility at the SLAC National Accelerator Laboratory, the world’s first hard X-ray FEL, has already demonstrated a tremendous scientific impact across broad areas of science. Here in this paper, a few of the more recent representative highlights from LCLS are presented in the areas of atomic, molecular, and optical science; chemistry; condensed matter physics; matter in extreme conditions;more » and biology. This paper also outlines the near term upgrade (LCLS-II) and motivating science opportunities for ultrafast X-rays in the 0.25–5 keV range at repetition rates up to 1 MHz. Future plans to extend the X-ray energy reach to beyond 13 keV (<1 Å) at high repetition rate (LCLS-II-HE) are envisioned, motivated by compelling new science of structural dynamics at the atomic scale.« less

  15. THE LINAC LASER NOTCHER FOR THE FERMILAB BOOSTER

    SciTech Connect

    Johnson, David E,; Duel, Kevin; Gardner, Matthew; Johnson, Todd; Slimmer, David; Patil, Screenvias; Tafoya, Jason

    2016-09-27

    In synchrotron machines, the beam extraction is accomplished by a combination of septa and kicker magnets which deflect the beam from an accelerator into another. Ideally the kicker field must rise/fall in between the beam bunches. However, in reality, an intentional beam-free time region (aka "notch") is created on the beam pulse to assure that the beam can be extracted with minimal losses. In the case of the Fermilab Booster, the notch is created in the ring near injection energy by the use of fast kickers which deposit the beam in a shielded collimation region within the accelerator tunnel. With increasing beam power it is desirable to create this notch at the lowest possible energy to minimize activation. The Fermilab Proton Improvement Plan (PIP) initiated an R&D project to build a laser system to create the notch within a linac beam pulse at 750 keV. This talk will describe the concept for the laser notcher and discuss our current status, commissioning results, and future plans.

  16. Beam-based Feedback for the Linac Coherent Light Source

    SciTech Connect

    Fairley, D.; Allison, S.; Chevtsov, S.; Chu, P.; Decker, F.J.; Emma, P.; Frisch, J.; Himel, T.; Kim, K.; Krejcik, P.; Loos, H.; Lahey, T.; Natampalli, P.; Peng, S.; Rogind, D.; Shoaee, H.; Straumann, T.; Williams, E.; White, G.; Wu, J.; Zelazney, M.; /SLAC

    2010-02-11

    Beam-based feedback control loops are required by the Linac Coherent Light Source (LCLS) program in order to provide fast, single-pulse stabilization of beam parameters. Eight transverse feedback loops, a 6 x 6 longitudinal feedback loop, and a loop to maintain the electron bunch charge were successfully prototyped in MATLAB for the LCLS, and have been maintaining stability of the LCLS electron beam at beam rates up to 30Hz. In the final commissioning phase of LCLS the beam will be operating at up to 120Hz. In order to run the feedback loops at beam rate, the feedback loops will be implemented in EPICS IOCs with a dedicated ethernet multi-cast network. This paper will discuss the design of the beam-based Fast Feedback System for LCLS. Topics include MATLAB feedback prototyping, algorithm for 120Hz feedback, network design for fast data transport, actuator and sensor design for single-pulse control and sensor readback, and feedback configuration and runtime control.

  17. Proton Driver Linac for the Frankfurt Neutron Source

    SciTech Connect

    Wiesner, C.; Chau, L. P.; Dinter, H.; Droba, M.; Heilmann, M.; Joshi, N.; Maeder, D.; Metz, A.; Meusel, O.; Noll, D.; Podlech, H.; Ratzinger, U.; Reichau, H.; Schempp, A.; Schmidt, S.; Schweizer, W.; Volk, K.; Wagner, C.; Mueller, I.

    2010-08-04

    The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum (FRANZ) will deliver high neutron fluxes in the energy range of 1 to 500 keV. The Activation Mode provides a high averaged neutron flux created by a cw proton beam of up to 5 mA, while in the Compressor Mode intense neutron pulses of 1 ns length are formed with a repetition rate of up to 250 kHz. The Compressor Mode is well-suited for energy-dependent neutron capture measurements using the Time-of-Flight method in combination with a 4{pi} BaF{sub 2} detector array. The design of the proton driver linac for both operation modes is presented. This includes the volume type ion source, the ExB chopper located in the low energy section, the RFQ-IH combination for beam acceleration and the bunch compressor. Finally, the neutron production at the lithium-7 target and the resulting energy spectrum is described.

  18. Identifying Longitudinal Jitter Sources in the LCLS Linac

    SciTech Connect

    Decker, Franz-Josef; Akre, Ron; Brachmann, Axel; Craft, Jim; Ding, Yuantao; Dowell, David; Emma, Paul; Frisch, Josef; Huang, Zhirong; Iverson, Richard; Krasnykh, Anatoly; Loos, Henrik; Nuhn, Heinz-Dieter; Ratner, Daniel; Smith, Tonee; Turner, James; Welch, James; White, William; Wu, Juhao; /SLAC

    2012-07-06

    The Linac Coherent Light Source (LCLS) at SLAC is an x-ray Free Electron Laser (FEL) with wavelengths of 0.15 nm to 1.5 nm. The electron beam stability is important for good lasing. While the transverse jitter of the beam is about 10-20% of the rms beam sizes, the jitter in the longitudinal phase space is a multiple of the energy spread and bunch length. At the lower energy of 4.3 GeV (corresponding to the longest wavelength of 1.5 nm) the relative energy jitter can be 0.125%, while the rms energy spread is with 0.025% five times smaller. An even bigger ratio exists for the arrival time jitter of 50 fs and the bunch duration of about 5 fs (rms) in the low charge (20 pC) operating mode. Although the impact to the experiments is reduced by providing pulse-by-pulse data of the measured energy and arrival time, it would be nice to understand and mitigate the root causes of this jitter. The thyratron of the high power supply of the RF klystrons is one of the main contributors. Another suspect is the multi-pacting in the RF loads. Phase measurements down to 0.01 degree (equals 10 fs) along the RF pulse were achieved, giving hints to the impact of the different sources.

  19. Vacuum system of the compact Energy Recovery Linac

    SciTech Connect

    Honda, T. Tanimoto, Y.; Nogami, T.; Takai, R.; Obina, T.; Asaoka, S.; Uchiyama, T.; Nakamura, N.

    2016-07-27

    The compact Energy Recovery Linac (cERL), a test accelerator to establish important technologies demanded for future ERL-based light sources, was constructed in late 2013 at KEK. The accelerator was successfully commissioned in early 2014, and demonstrated beam circulation with energy recovery. In the cERL vacuum system, low-impedance vacuum components are required to circulate high-intensity, low-emittance and short-bunch electron beams. We therefore developed ultra-high-vacuum (UHV)-compatible flanges that can connect beam tubes seamlessly, and employed retractable beam monitors, namely, a movable Faraday cup and screen monitors. In most parts of the accelerator, pressures below 1×10{sup −7} Pa are required to mitigate beam-gas interactions. Particularly, near the photocathode electron gun and the superconducting (SC) cavities, pressures below 1×10{sup −8} Pa are required. The beam tubes in the sections adjoining the SC cavities were coated with non-evaporable getter (NEG) materials, to reduce gas condensation on the cryo-surfaces. During the accelerator commissioning, stray magnetic fields from the permanent magnets of some cold cathode gauges (CCGs) were identified as a source of the disturbance to the beam orbit. Magnetic shielding was specially designed as a remedy for this issue.

  20. Design of the beryllium window for Brookhaven Linac Isotope Producer

    SciTech Connect

    Nayak, S.; Mapes, M.; Raparia, D.

    2015-11-01

    In the Brookhaven Linac Isotope Producer (BLIP) beam line, there were two Beryllium (Be) windows with an air gap to separate the high vacuum upstream side from low vacuum downstream side. There had been frequent window failures in the past which affected the machine productivity and increased the radiation dose received by workers due to unplanned maintenance. To improve the window life, design of Be window is reexamined. Detailed structural and thermal simulations are carried out on Be window for different design parameters and loading conditions to come up with better design to improve the window life. The new design removed the air gap and connect the both beam lines with a Be window in-between. The new design has multiple advantages such as 1) reduces the beam energy loss (because of one window with no air gap), 2) reduces air activation due to nuclear radiation and 3) increased the machine reliability as there is no direct pressure load during operation. For quick replacement of this window, an aluminum bellow coupled with load binder was designed. There hasn’t been a single window failure since the new design was implemented in 2012.

  1. Prospects for very-high-gradient linac-colliders

    SciTech Connect

    Wilson, P.B.

    1981-02-01

    The energy realistically attainable by an electron-positron storage ring is limited by the RF voltage and power requirements imposed by synchrotron radiation to about 100 GeV. To reach energies of 300 x 300 GeV and higher in a colliding beam machine of reasonable dimensions, we must look to the linac-collider operating at an energy gradient on the order of 100 MV/m. Proper choice of an RF structure or such a collider can minimize the total RF power requirement and the effects of longitudinal and transverse single-bunch beam loading. For an operating frequency in the range 4 to 6 GHz, the total RF power requirement for a 300 x 300 GeV collider with a luminosity of 10/sup 32/ cm/sup -2/s/sup -1/ accelerating 10/sup 11/ particles per bunch is on the order of 50 MW. To drive this collider, RF power sources are needed having a peak output power in the range 1-2 GW. Possibilities for attaining these peak power levels by direct generation and by energy storage and fast switching are discussed.

  2. Higher Order Mode Heating Analysis for the ILC Superconducting Linacs

    SciTech Connect

    Bane, K.L.F.; Nantista, C.; Adolphsen, C.; /SLAC

    2010-10-27

    The superconducting cavities and interconnects in the 11 km long linacs of the International Linear Collider (ILC) are designed to operate at 2K, where cooling costs are very expensive. It is thus important to minimize cryogenic heat loads. In addition to an unavoidable static load and the dynamic load of the fundamental 1.3 GHz accelerating rf, a further heat source is presented by the higher order mode (HOM) power deposited by the beam. Such modes will be damped by specially designed HOM couplers attached to the cavities (for trapped modes), and by ceramic dampers at 70K that are located between the eight or nine cavity cryomodules (for propagating modes). Brute force calculation of the higher frequency modes excited in a string of cryomodules is limited by computing capacity (see, e.g. [1]). M. Liepe has calculated {approx} 400 longitudinal TM modes in 3 superconducting cavities plus absorbers, up to 8 GHz [2]. Joestingmeier, et al., have used a ray tracing calculation to find the effect at higher frequencies, specifically in the range of tens of GHz and above [3]. In this report we present a scattering matrix approach, which we apply to an rf unit comprising 26 cavities and 3 absorbers. We perform calculations at sample frequencies (up to 20 GHz) to predict the effectiveness of the ceramic dampers in limiting HOM heat deposition at 2K.

  3. LANSCE Drift Tube Linac Water Control System Refurbishment

    SciTech Connect

    Marroquin, Pilar S.

    2011-01-01

    There are several refurbishment projects underway at the Los Alamos National Laboratory LANSCE linear accelerator. Systems involved are: RF, water cooling, networks, diagnostics, timing, controls, etc. The Drift Tube Linac (DTL) portion of the accelerator consists of four DTL tanks, each with three independent water control systems. The systems are about 40 years old, use outdated and non-replaceable equipment and NIM bin control modules, are beyond their design life and provide unstable temperature control. Insufficient instrumentation and documentation further complicate efforts at maintaining system performance. Detailed design of the replacement cooling systems is currently in progress. Previous design experience on the SNS accelerator water cooling systems will be leveraged, see the SNS DTL FDR. Plans call for replacement of water piping, manifolds, pumps, valves, mix tanks, instrumentation (flow, pressure and temperature) and control system hardware and software. This presentation will focus on the control system design with specific attention on planned use of the National Instruments Compact RIO platform with the Experimental Physics and Industrial Control system (EPICS) software toolkit.

  4. AVAILABILITY MODEL FOR THE SNS LINAC RF SYSTEM

    SciTech Connect

    Tallerico, P. J.; Rees, D. E.; Anderson, D. E.

    2001-01-01

    The Linac RF system is broken down into eight major components for this model. These components are: the klystrons, the waveguide, the water loads, the circulators, the converter/modulator, the transmitter, the window, and the low level RF (LLRF) controls. The mean time between failures (MTBF) for several of the components vary with voltage or klystron power level, and this variation is discussed below. In general, these MTBF's are design requirements supplied to the vendors of the subsystems, and verified at design reviews and by the experience at other accelerators. We assume that the scheduled operational time for the SNS is 6000 hours per year, and use this number to calculate the availability. We have to calculate the total down time during the 6000 hours of operation, and the availability is defined as one minus the unexpected down time for the year, divided by the number of operating hours in the year. Ideally, we would use distributions of MTBF's and MTTR's, since each failure will be different, but the equipment is not yet built, so the distributions are not available, and we make the assumption of constant MTBF and MTTR.

  5. AN AVAILABILITY MODEL FOR THE SNS LINAC RF SYSTEM

    SciTech Connect

    P. TALLERICO; D. REES; D. ANDERSON

    2001-06-01

    The Linac RF system is broken down into eight major components for this model. These components are: the klystrons, the waveguide, the water loads, the circulators, the converter/modulator, the transmitter, the window, and the low level RF (LLRF) controls. The mean time between failures (MTBF) for several of the components vary with voltage or klystron power level, and this variation is discussed below. In general, these MTBF's are design requirements supplied to the vendors of the subsystems, and verified at design reviews and by the experience at other accelerators. We assume that the scheduled operational time for the SNS is 6000 hours per year, and use this number to calculate the availability. We have to calculate the total down time during the 6000 hours of operation, and the availability is defined as one minus the unexpected down time for the year, divided by the number of operating hours in the year. Ideally, we would use distributions of MTBF's and MTTR's, since each failure will be different, but the equipment is not yet built, so the distributions are not available, and we make the assumption of constant MTBF and MTTR.

  6. MARS15 Simulation of Radiation Environment at the ESS Linac

    SciTech Connect

    Mokhov, N. V.; Eidelman, Yu. I.; Rakhno, I. L.; Tchelidze, L.; Tropin, I. S.

    2016-12-01

    Comprehensive studies with the MARS15(2016) Monte-Carlo code are described on evaluation of prompt and residual radiation levels induced by nominal and accidental beam losses in the 5-MW, 2-GeV European Spallation Source (ESS) Linac. These are to provide a basis for radiation shielding design verification through the accelerator complex. The calculation model is based on the latest engineering design and includes a sophisticated algorithm for particle tracking in the machine RF cavities as well as a well-established model of the beam loss. Substantial efforts were put in solving the deep-penetration problem for the thick shielding around the tunnel with numerous complex penetrations. It allowed us to study in detail not only the prompt dose, but also component and air activation, radiation loads on the soil outside the tunnel, and skyshine studies for the complicated 3-D surface above the machine. Among the other things, the newest features in MARS15 (2016), such as a ROOT-based beamline builder and a TENDL-based event generator for nuclear interactions below 100 MeV, were very useful in this challenging application

  7. Field stability in two-stem drift-tube linacs

    SciTech Connect

    Billen, J.H.; Spalek, G.; Shapiro, A.H.

    1988-01-01

    Drift tubes supported by two stems have been considered for cryogenic drift-tube linacs (DTLs) to reduce vibrations and to minimize drift-tube deflections upon cool down. We investigated rf properties of two-stem DTL structures at room temperature and low power. Even apart is inherently more stable against tuning errors than a similar structure with single stems. The increased stability is higher for DTLs with shorter drift tubes. Ordinary quarter-wavelength-long post couplers actually destabilize the two-stem DTL fields; the extra stem raises the post coupler frequency compared to the frequency of the same post coupler extended beyond the tank wall into coaxial stub tuners. Adjustment of the stub lengths tunes the post-coupler frequencies, but post-coupler lengths in the tank have no effect, which suggests a field pattern different from traditional post couplers. The stabilized DTL resembles multiple-stem DTLs in which the angle between stems is varied to achieve stabilization. Adjusting the coaxial stub length is mechanically simpler than changing the stem azimuth angle. 5 refs., 6 figs., 1 tab.

  8. Production of platinum radioisotopes at Brookhaven Linac Isotope Producer (BLIP)

    NASA Astrophysics Data System (ADS)

    Smith, Suzanne V.; McCutchan, Elizabeth; Gürdal, Gülhan; Lister, Christopher; Muench, Lisa; Nino, Michael; Sonzogni, Alexandro; Herman, Michal; Nobre, Gustavo; Cullen, Chris; Chillery, Thomas; Chowdury, Partha; Harding, Robert

    2017-09-01

    The accelerator production of platinum isotopes was investigated at the Brookhaven Linac Isotope Producer (BLIP). In this study high purity natural platinum foils were irradiated at 53.2, 65.7, 105.2, 151.9, 162.9 and 173.3.MeV. The irradiated foils were digested in aqua regia and then converted to their hydrochloride salt with concentrated hydrochloric acid before analyzing by gamma spectrometry periodically for at least 10 days post end of bombardment. A wide range of platinum (Pt), gold (Au) and iridium (Ir) isotopes were identified. Effective cross sections at BLIP for Pt-188, Pt-189, Pt-191 and Pt-195m were compared to literature and theoretical cross sections determined using Empire-3.2. The majority of the effective cross sections (<70 MeV) confirm those reported in the literature. While the absolute values of the theoretical cross sections were up to a factor of 3 lower, Empire 3.2 modeled thresholds and maxima correlated well with experimental values. Preliminary evaluation into a rapid separation of Pt isotopes from high levels of Ir and Au isotopes proved to be a promising approach for large scale production. In conclusion, this study demonstrated that with the use of isotopically enriched target material accelerator production of selected platinum isotopes is feasible over a wide proton energy range.

  9. Front end design of the RIA driver LINAC.

    SciTech Connect

    Kolomiets, A. A.; Asseev, V. N.; Ostroumov, P. N.; Pardo, R. C.; Physics; ITEP

    2003-01-01

    This paper describes the front end design for the RIA driver linac which is able to select, separate and accelerate in the RFQ the required ion species of one- or two-charge states. The front end consists of an ECR ion source located on a 100 kV platform, LEBT, RFQ and MEBT. The first section of the LEBT is an achromatic bending system for charge-to-mass analysis and selection. For the heaviest ions with masses above 180, the transport system is able to deliver to the entrance of the first buncher a two-charge-state beam with similar Twiss parameters for both charge states. In order to match two-charge-state ions with different mass to charge ratios, the straight section of the LEBT upstream of the RFQ will be placed on a high-voltage platform. A voltage /spl sim/30 kV is required in order to match velocities of ions with mass to charge ratio less than the design value and to maintain the possibility accelerating two charge states simultaneously. Several beam matching schemes in the transitions LEBT-RFQ and RFQ-MEBT have been studied.

  10. SU-E-T-270: Optimized Shielding Calculations for Medical Linear Accelerators (LINACs).

    PubMed

    Muhammad, W; Lee, S; Hussain, A

    2012-06-01

    The purpose of radiation shielding is to reduce the effective equivalent dose from a medical linear accelerator (LINAC) to a point outside the room to a level determined by individual state/international regulations. The study was performed to design LINAC's room for newly planned radiotherapy centers. Optimized shielding calculations were performed for LINACs having maximum photon energy of 20 MV based on NCRP 151. The maximum permissible dose limits were kept 0.04 mSv/week and 0.002 mSv/week for controlled and uncontrolled areas respectively by following ALARA principle. The planned LINAC's room was compared to the already constructed (non-optimized) LINAC's room to evaluate the shielding costs and the other facilities those are directly related to the room design. In the evaluation process it was noted that the non-optimized room size (i.e., 610 × 610 cm(2) or 20 feet × 20 feet) is not suitable for total body irradiation (TBI) although the machine installed inside was having not only the facility of TBI but the license was acquired. By keeping this point in view, the optimized INAC's room size was kept 762 × 762 cm 2. Although, the area of the optimized rooms was greater than the non-planned room (i.e., 762 × 762 cm 2 instead of 610 × 610 cm 2), the shielding cost for the optimized LINAC's rooms was reduced by 15%. When optimized shielding calculations were re-performed for non-optimized shielding room (i.e., keeping room size, occupancy factors, workload etc. same), it was found that the shielding cost may be lower to 41 %. In conclusion, non- optimized LINAC's room can not only put extra financial burden on the hospital but also can cause of some serious issues related to providing health care facilities for patients. © 2012 American Association of Physicists in Medicine.

  11. Attempted RIAPMTQ Benchmarking Study of the ANL RIA Low-Beta LinacDesign

    SciTech Connect

    Billen, J.; Qiang, J.; Wangler, T.

    2007-01-01

    The objective of this work is to compare the simulation results of the RIAPMTQ code with those of the ANL simulation code for the low-beta section of an ANL RIA Driver Linac design. However, the approach taken is not precisely that of a direct comparison of the two simulations of the same linac section, which is what one would normally expect to do. The reason is that the RFQ design approach used by the ANL codes and the LANL codes are approximately but not exactly the same, particularly at the ends of the RFQ, and it did not appear to be easy to make the two RFQ designs exactly identical. The effects on the beam of the different RFQ design approaches are not expected to be large, as long as the beam is properly matched at the transitions. What was done in the RIAPMTQ input file to compensate for the RFQ design difference was to use TRACE3D to adjust the four solenoid strengths and the two matching rf cavities in the MEBT (the beam transport system between the end of the RFQ and the beginning of the superconducting linac) to obtain the same match (Courant-Snyder parameters) into the superconducting linac as was obtained from the ANL code. We also matched the beam into the RFQ. The result is that we generate a RIAPMTQ input file for the low-beta section of the linac, which is not exactly identical to, but should be near to that of the ANL design. Then, what we wish to compare from the two codes are the rms emittances at the beginning of the superconducting linac, and the beam losses in the first or prestripper section of the superconducting (SC) linac. In this report, we describe the procedure and present the results. Section 2 gives the procedures and results, and Section 3 gives the summary.

  12. Comparative analyses of linac and Gamma Knife radiosurgery for trigeminal neuralgia treatments

    NASA Astrophysics Data System (ADS)

    Ma, L.; Kwok, Y.; Chin, L. S.; Yu, C.; Regine, W. F.

    2005-11-01

    Dedicated linac-based radiosurgery has been reported for trigeminal neuralgia treatments. In this study, we investigated the dose fall-off characteristics and setup error tolerance of linac-based radiosurgery as compared with standard Gamma Knife radiosurgery. In order to minimize the errors from different treatment planning calculations, consistent imaging registration, dose calculation and dose volume analysis methods were developed and implemented for both Gamma Knife and linac-based treatments. Intra-arc setup errors were incorporated into the treatment planning process of linac-based deliveries. The effects of intra-arc setup errors with increasing number of arcs were studied and benchmarked against Gamma Knife deliveries with and without plugging patterns. Our studies found equivalent dose fall-off properties between Gamma Knife and linac-based radiosurgery given a sufficient number of arcs (>7) and small intra-arc errors (<0.5 mm) were satisfied for linac-based deliveries. Increasing the number of arcs significantly decreased the variations in the dose fall-off curve at the low isodose region (e.g. from 40% to 10%) and also improved dose uniformity at the high isodose region (e.g. from 70% to 90%). As the number of arcs increased, the effects of intra-arc setup errors on the dose fall-off curves decreased. Increasing the number of arcs also reduced the integral dose to the distal normal brain tissues. In conclusion, linac-based radiosurgery produces equivalent dose fall-off characteristics to Gamma Knife radiosurgery with a high number of arcs. However, one must note the increased treatment time for a large number of arcs and isocentre accuracies.

  13. Technical Note: Development and performance of a software tool for quality assurance of online replanning with a conventional Linac or MR-Linac

    SciTech Connect

    Chen, Guang-Pei Ahunbay, Ergun; Li, X. Allen

    2016-04-15

    Purpose: To develop an integrated quality assurance (QA) software tool for online replanning capable of efficiently and automatically checking radiation treatment (RT) planning parameters and gross plan quality, verifying treatment plan data transfer from treatment planning system (TPS) to record and verify (R&V) system, performing a secondary monitor unit (MU) calculation with or without a presence of a magnetic field from MR-Linac, and validating the delivery record consistency with the plan. Methods: The software tool, named ArtQA, was developed to obtain and compare plan and treatment parameters from both the TPS and the R&V system database. The TPS data are accessed via direct file reading and the R&V data are retrieved via open database connectivity and structured query language. Plan quality is evaluated with both the logical consistency of planning parameters and the achieved dose–volume histograms. Beams in between the TPS and R&V system are matched based on geometry configurations. To consider the effect of a 1.5 T transverse magnetic field from MR-Linac in the secondary MU calculation, a method based on modified Clarkson integration algorithm was developed and tested for a series of clinical situations. Results: ArtQA has been used in their clinic and can quickly detect inconsistencies and deviations in the entire RT planning process. With the use of the ArtQA tool, the efficiency for plan check including plan quality, data transfer, and delivery check can be improved by at least 60%. The newly developed independent MU calculation tool for MR-Linac reduces the difference between the plan and calculated MUs by 10%. Conclusions: The software tool ArtQA can be used to perform a comprehensive QA check from planning to delivery with conventional Linac or MR-Linac and is an essential tool for online replanning where the QA check needs to be performed rapidly.

  14. Technical Note: Development and performance of a software tool for quality assurance of online replanning with a conventional Linac or MR-Linac.

    PubMed

    Chen, Guang-Pei; Ahunbay, Ergun; Li, X Allen

    2016-04-01

    To develop an integrated quality assurance (QA) software tool for online replanning capable of efficiently and automatically checking radiation treatment (RT) planning parameters and gross plan quality, verifying treatment plan data transfer from treatment planning system (TPS) to record and verify (R&V) system, performing a secondary monitor unit (MU) calculation with or without a presence of a magnetic field from MR-Linac, and validating the delivery record consistency with the plan. The software tool, named ArtQA, was developed to obtain and compare plan and treatment parameters from both the TPS and the R&V system database. The TPS data are accessed via direct file reading and the R&V data are retrieved via open database connectivity and structured query language. Plan quality is evaluated with both the logical consistency of planning parameters and the achieved dose-volume histograms. Beams in between the TPS and R&V system are matched based on geometry configurations. To consider the effect of a 1.5 T transverse magnetic field from MR-Linac in the secondary MU calculation, a method based on modified Clarkson integration algorithm was developed and tested for a series of clinical situations. ArtQA has been used in their clinic and can quickly detect inconsistencies and deviations in the entire RT planning process. With the use of the ArtQA tool, the efficiency for plan check including plan quality, data transfer, and delivery check can be improved by at least 60%. The newly developed independent MU calculation tool for MR-Linac reduces the difference between the plan and calculated MUs by 10%. The software tool ArtQA can be used to perform a comprehensive QA check from planning to delivery with conventional Linac or MR-Linac and is an essential tool for online replanning where the QA check needs to be performed rapidly.

  15. The Linac Coherent Light Source Photo-Injector Overview and Some Design Details

    SciTech Connect

    Dowell, D

    2004-09-27

    The Linac Coherent Light Source (LCLS) is a SASE free electron laser using the last 1/3 of the SLAC two mile linac to produce 1.5 to 15 angstrom x-rays in a 100 meter long undulator for use in a variety of x-ray science experiments. In order to satisfy the demanding electron beam requirements, a new 135 MeV photo-injector will be built in an existing, off-axis vault at the 2/3 point of the main linac. The injector accelerator consists of a BNL/SLAC/UCLA 1.6 cell S-band gun followed by two 3-meter long SLAC accelerator sections. The 6MeV beam from the gun is matched into the first accelerator section and accelerated to 135 MeV before injection onto the main linac axis with a 35 degree bend. Several modifications to the rf gun, linac and beamline as well as the inclusion of several diagnostics have been incorporated into the injector design to achieve the required 1.2 micron projected emittance at a charge of 1 nC. In addition, an inverse free electron laser, the laser heater, will be used to increase the uncorrelated energy spread to suppress coherent synchrotron radiation and longitudinal space charge instabilities in the main accelerator and bunch compressors. The configuration and function of the major injector components will be described.

  16. Progress update on cryogenic system for ARIEL E-linac at TRIUMF

    SciTech Connect

    Koveshnikov, A.; Bylinskii, I.; Hodgson, G.; Yosifov, D.

    2014-01-29

    TRIUMF is involved in a major upgrade. The Advanced Rare IsotopeE Laboratory (ARIEL) has become a fully funded project in July 2010. A 10 mA 50 MeV SRF electron linac (e-linac) operating CW at 1.3 GHz is the key component of this initiative. This machine will serve as a second independent photo-fission driver for Rare Isotope Beams (RIB) production at TRIUMF's Isotope Separator and Accelerator (ISAC) facility. The cryogens delivery system requirements are driven by the electron accelerator cryomodule design [1, 2]. Since commencement of the project in 2010 the cryogenic system of e-linac has moved from the conceptual design phase into engineering design and procurement stage. The present document summarizes the progress in cryogenic system development and construction. Current status of e-linac cryogenic system including details of LN{sub 2} storage and delivery systems, and helium subatmospheric (SA) system is presented. The first phase of e-linac consisting of two cryomodules, cryogens storage, delivery, and distribution systems, and a 600 W class liquid helium cryoplant is scheduled for installation and commissioning by year 2014.

  17. Installation and Commissioning of the Super Conducting RF Linac Cryomodules for the Erlp

    NASA Astrophysics Data System (ADS)

    Goulden, A. R.; Bate, R.; Buckley, R. K.; Pattalwar, S. M.

    2008-03-01

    An Energy Recovery Linac Prototype (ERLP) is currently being constructed at Daresbury Laboratory, (UK) to promote the necessary skills in science & technology, particularly in photocathode electron gun and Superconducting RF (SRF), to enable the construction of a fourth generation light source, based on energy recovery linacs-4GLS [1]. The ERLP uses two identical cryomodules, one as a booster Linac used to accelerate the beam to 8.5 MeV, the other as an Energy Recovery Linac (ERL) module with an energy gain of 26.5 MeV. Each module consists of two 9- cell cavities operating at a frequency of 1.3 GHz and a temperature of 2 K. As there is no energy recovery in the booster it requires a peak power of 53 kW; whereas the linac module only requires 8 kW. The RF power is supplied by Inductive Output Tube (IOT) amplifiers. The maximum heat load (or the cooling power) required in the SRF system is 180 W at 2 K and is achieved in two stages: a LN2 pre-cooled Linde TCF50 liquefier produces liquid helium at 4.5 K, followed by a 2 K cold box consisting of a JT valve, recuperator and an external room temperature vacuum pumping system. This presentation reports the experience gained during, installation, commissioning and the initial operation of the cryomodules.

  18. The SNS linac high power RF system design, status, and results

    SciTech Connect

    Rees, D. E.; Bradley, J. T. , III; Cummings, K. A.; Hardek, T. W.; Roybal, W. T.; Tallerico, P. J.

    2003-01-01

    The Spallation Neutron Source being built at the Oak Ridge National Lab in Tennessee requires a 1 GeV proton linac. Los Alamos has responsibility for the RF systems for the entire linac. The linac requires 3 distinct types of RF systems: 2.5-MW peak, 402.5 MHz, RF systems for the RFQ and DTL (7 systems total); 5-MW peak, 805 MHz systems for the CCL and the two energy corrector cavities (6 systems total); and 550-kW peak, 805 MHz systems for the superconducting sections (8 1 systems total). The design of the SNS Linac RF system was presented at the 2001 Particle Accelerator Conference in Chicago. Vendors have been selected for the klystrons (3 different vendors), circulators ( I vendor), transmitter (1 vendor), and high power RF loads (3 different vendors). This paper presents the results and status of vendor procurements, test results of the major components of the Linac RF system and our installation progress.

  19. An 805 MHz disk and washer structure for the Fermilab Linac Upgrade

    SciTech Connect

    Moretti, A.; Young, D.; Lee, G.; Mills, F.E.; Zhou, P.; Swenson, D.A.; Young, P.E.

    1988-10-03

    The Linac Upgrade program, a portion of the Tevatron Upgrade, calls for increasing the energy of the existing 200 MeV, 201.25 MHz linac to 400 MeV in order to reduce beam emittance degradation in the Booster. This is to be accomplished by replacing the last four Alvarez linac tanks with more efficient, higher gradient 805 MHz linac structure. One of the linac structures currently under study in a collaboration between Fermilab and SAIC is the Disk-and-Washer accelerating structure with bi-periodic tee supports, four per washer pair. This structure has a stop-band for the TM/sub 11/ mode (a problem in other designs) centered near the ..pi.. TM/sub 02/ accelerating mode frequency. A novel heat shrinking technique is used in the construction of a ten-cell one-meter long vacuum prototype structure. Description of the structure, testing techniques and test results are presented. 9 refs., 4 figs., 1 tab.

  20. Feasibility of using the linac real-time log data for VMAT treatment verification

    NASA Astrophysics Data System (ADS)

    Midi, N. S.; Zin, Hafiz M.

    2017-05-01

    This study investigates the feasibility of using the real-time log data from a linac to verify Volumetric Modulated Arc Therapy (VMAT) treatment. The treatment log data for an Elekta Synergy linac can be recorded at a sampling rate of 4 Hz using the service graphing tool on the linac control computer. A treatment plan that simulates a VMAT treatment was delivered from the linac and all the dynamic treatment parameters including monitor unit (MU), Multileaf Collimator (MLC) position, jaw position, gantry angle and collimator angle were recorded in real-time using the service graphing tool. The recorded raw data were extracted and analysed using algorithms written in Matlab (MathWorks, Natick, MA). The actual treatment parameters logged using the service graphing tool was compared to the prescription and the deviations were analysed. The MLC position errors travelling at the speed range from -3.25 to 5.92 cm/s were between -1.7 mm to 2.5 mm, well within the 3.5 mm tolerance value (AAPM TG-142). The discrepancies of other delivery parameters were also within the tolerance. The real-time linac parameters logged using the service graphing tool can be used as a supplementary data for patient specific VMAT pre-treatment quality assurance.

  1. MODEL AND BEAM BASED SETUP PROCEDURES FOR A HIGH POWER HADRON SUPERCONDUCTING LINAC

    SciTech Connect

    Shishlo, Andrei P

    2014-01-01

    This presentation will review methods for experimental determination of optimal operational set points in a multi-cavity superconducting high power hadron linac. A typical tuning process is based on comparison between measured data and the results of simulations from envelope and single-particle models. Presence of significant space charge effects requires simulation and measurement of bunch dynamics in 3 dimensions to ensure low loss beam transport. This is especially difficult in a superconducting linac where use of interceptive diagnostics is usually restricted because of the risk of SRF cavity surface contamination. The procedures discussed here are based on non-interceptive diagnostics such as beam position monitors and laser wires, and conventional diagnostics devices such as wire scanners and bunch shape monitors installed outside the superconducting linac. The longitudinal Twiss analysis based on the BPM signals will be described. The superconducting SNS linac tuning experience will be used to demonstrate problems and their solution for real world linac tune-up procedures

  2. Heavy-ion linac development for the U.S. RIA project.

    SciTech Connect

    Ostroumov, P. N.

    2002-01-29

    The Nuclear Science Community in the Unites States has unanimously concluded that developments in both nuclear science and its supporting technologies make building a world-leading Rare-Isotope Accelerator (RIA) facility for production of radioactive beams the top priority. The RIA development effort involves several US Laboratories (ANL, JLAB, LBNL, MSU, ORNL). The RIA Facility includes a CW 1.4 GeV driver linac and a 100 MV post-accelerator both based on superconducting (SC) cavities operating at frequencies from 48 MHz to 805 MHz. An initial acceleration in both linacs is provided by room temperature RFQs. The driver linac is designed for acceleration of any ion species; from protons up to 900 MeV to uranium up to 400 MeV/u. The novel feature of the driver linac is an acceleration of multiple charge-state heavy-ion beams in order to achieve 400 kW beam power. Basic design concepts of the driver linac are given. Several new conceptual solutions in beam dynamics, room temperature and SC accelerating structures for heavy ion accelerator applications are discussed.

  3. Linac based photofission inspection system employing novel detection concepts

    NASA Astrophysics Data System (ADS)

    Stevenson, John; Gozani, Tsahi; Elsalim, Mashal; Condron, Cathie; Brown, Craig

    2011-10-01

    Rapiscan Systems is developing a LINAC based cargo inspection system for detection of special nuclear material (SNM) in cargo containers. The system, called Photofission Based Alarm Resolution (PBAR) is being developed under a DHD/DNDO Advanced Technology Demonstration (ATD) program. The PBAR system is based on the Rapiscan Eagle P9000 X-ray system, which is a portal system with a commercial 9 MeV LINAC X-ray source. For the purposes of the DNDO ATD program, a conveyor system was installed in the portal to allow scanning and precise positioning of 20 ft ISO cargo containers. The system uses a two step inspection process. In the first step, the basic scan, the container is quickly and completely inspected using two independent radiography arrays: the conventional primary array with high spatial resolution and a lower resolution spectroscopic array employing the novel Z-Spec method. The primary array uses cadmium tungstate (CdWO 4) detectors with conventional current mode readouts using photodiodes. The Z-Spec array uses small plastic scintillators capable of performing very fast (up to 10 8 cps) gamma-ray spectroscopy. The two radiography arrays are used to locate high-Z objects in the image such as lead, tungsten, uranium, which could be potential shielding materials as well as SNM itself. In the current system, the Z-Spec works by measuring the energy spectrum of transmitted X-rays. For high-Z materials the higher end of the energy spectrum is more attenuated than for low-Z materials and thus has a lower mean energy and a narrower width than low- and medium-Z materials. The second step in the inspection process is the direct scan or alarm clearing scan. In this step, areas of the container image, which were identified as high Z, are re-inspected. This is done by precisely repositioning the container to the location of the high-Z object and performing a stationary irradiation of the area with X-ray beam. Since there are a large number of photons in the 9 MV

  4. Towards adaptive IMRT sequencing for the MR-linac

    NASA Astrophysics Data System (ADS)

    Kontaxis, C.; Bol, G. H.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2015-03-01

    The MRI linear accelerator (MR-linac) that is currently being installed in the University Medical Center Utrecht (Utrecht, The Netherlands), will be able to track the patient’s target(s) and Organ(s) At Risk during radiation delivery. In this paper, we present a treatment planning system for intensity-modulated radiotherapy (IMRT). It is capable of Adaptive Radiotherapy and consists of a GPU Monte Carlo dose engine, an inverse dose optimization algorithm and a novel adaptive sequencing algorithm. The system is able to compensate for patient anatomy changes and enables radiation delivery immediately from the first calculated segment. IMRT plans meeting all clinical constraints were generated for two breast cases, one spinal bone metastasis case, two prostate cases with integrated boost regions and one head and neck case. These plans were generated by the segment weighted version of our algorithm, in a 0 T environment in order to test the feasibility of the new sequencing strategy in current clinical conditions, yielding very small differences between the fluence and sequenced distributions. All plans went through stringent experimental quality assurance on Delta4 and passed all clinical tests currently performed in our institute. A new inter-fraction adaptation scheme built on top of this algorithm is also proposed that enables convergence to the ideal dose distribution without the need of a final segment weight optimization. The first results of this method confirm that convergence is achieved within the first fractions of the treatment. These features combined will lead to a fully adaptive intra-fraction planning system able to take into account patient anatomy updates during treatment.

  5. Towards adaptive IMRT sequencing for the MR-linac.

    PubMed

    Kontaxis, Charis; Bol, G H; Lagendijk, J J W; Raaymakers, B W

    2015-03-21

    The MRI linear accelerator (MR-linac) that is currently being installed in the University Medical Center Utrecht (Utrecht, The Netherlands), will be able to track the patient's target(s) and Organ(s) At Risk during radiation delivery. In this paper, we present a treatment planning system for intensity-modulated radiotherapy (IMRT). It is capable of Adaptive Radiotherapy and consists of a GPU Monte Carlo dose engine, an inverse dose optimization algorithm and a novel adaptive sequencing algorithm. The system is able to compensate for patient anatomy changes and enables radiation delivery immediately from the first calculated segment. IMRT plans meeting all clinical constraints were generated for two breast cases, one spinal bone metastasis case, two prostate cases with integrated boost regions and one head and neck case. These plans were generated by the segment weighted version of our algorithm, in a 0 T environment in order to test the feasibility of the new sequencing strategy in current clinical conditions, yielding very small differences between the fluence and sequenced distributions. All plans went through stringent experimental quality assurance on Delta4 and passed all clinical tests currently performed in our institute. A new inter-fraction adaptation scheme built on top of this algorithm is also proposed that enables convergence to the ideal dose distribution without the need of a final segment weight optimization. The first results of this method confirm that convergence is achieved within the first fractions of the treatment. These features combined will lead to a fully adaptive intra-fraction planning system able to take into account patient anatomy updates during treatment.

  6. Minimizing the magnetic field effect in MR-linac specific QA-tests: the use of electron dense materials

    NASA Astrophysics Data System (ADS)

    van Zijp, H. M.; van Asselen, B.; Wolthaus, J. W. H.; Kok, J. M. G.; de Vries, J. H. W.; Ishakoglu, K.; Beld, E.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2016-02-01

    To address the quality assurance (QA) of a MR-linac which is an MRI combined with a linear accelerator (linac), the traditional linac QA-tests need to be redesigned, since the presence of the static magnetic field in the MR-linac alters the electron trajectory. The latter causes the asymmetry in the dose kernel which is introduced by the magnetic field and hinders accurate geometrical QA-tests for the MR-linac. We introduced the use of electron dense materials (e.g. copper) to reduce the size of the dose kernel and thereby the magnetic field effect on the dose deposition. Two examples of QA-tests are presented in which the geometrical accuracy of the MR-linac was addressed; beam profile and star-shot measurements. The introduced setup was compared with a reference setup and both were tested on a conventional and the MR-linac. The results showed that the symmetry of the recorded beam profile was restored in presence of the copper material and that the isocenter size of the MR-linac can be determined accurately with the introduced star-shot setup. The use of electron dense materials is not limited to the presented QA-tests but has a broad application for beam-specific QA-tests in presence of a magnetic field.

  7. Minimizing the magnetic field effect in MR-linac specific QA-tests: the use of electron dense materials.

    PubMed

    van Zijp, H M; van Asselen, B; Wolthaus, J W H; Kok, J M G; de Vries, J H W; Ishakoglu, K; Beld, E; Lagendijk, J J W; Raaymakers, B W

    2016-02-07

    To address the quality assurance (QA) of a MR-linac which is an MRI combined with a linear accelerator (linac), the traditional linac QA-tests need to be redesigned, since the presence of the static magnetic field in the MR-linac alters the electron trajectory. The latter causes the asymmetry in the dose kernel which is introduced by the magnetic field and hinders accurate geometrical QA-tests for the MR-linac. We introduced the use of electron dense materials (e.g. copper) to reduce the size of the dose kernel and thereby the magnetic field effect on the dose deposition. Two examples of QA-tests are presented in which the geometrical accuracy of the MR-linac was addressed; beam profile and star-shot measurements. The introduced setup was compared with a reference setup and both were tested on a conventional and the MR-linac. The results showed that the symmetry of the recorded beam profile was restored in presence of the copper material and that the isocenter size of the MR-linac can be determined accurately with the introduced star-shot setup. The use of electron dense materials is not limited to the presented QA-tests but has a broad application for beam-specific QA-tests in presence of a magnetic field.

  8. LUX - A recirculating linac-based ultrafast X-ray source

    SciTech Connect

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2003-08-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.

  9. Thermionic RF Gun and Linac Pre-Injector for SPEAR3

    SciTech Connect

    Park, S.

    2003-08-11

    Preparations are underway to upgrade the Spear2 to the third generation light source. Installation of all the subsystems will start in April 2003. Although the Spear3 RF system is entirely different from the present form, the pre-injector gun/linac and booster synchrotron will remain the same even after the upgrade. The thermionic rf gun reliability and stability are to be improved to inject 500 mA of stored current in shortest possible time. When a top-up mode is enforced, where the stored beam decay is replenished to maintain the constant current and thus constant light intensity, the Spear3 will take injection every few minutes. In that case the gun, linac, and booster must stay on at all times. In this report we will describe some improvements made on the gun and linac in the recent past, as well as their present performance and future upgrade to be made.

  10. ARIEL e-linac. Electron linear accelerator for photo-fission

    NASA Astrophysics Data System (ADS)

    Koscielniak, Shane

    2014-01-01

    The design and implementation of a 1/2 MW beam power electron linear accelerator (e-linac) for the production of rare isotope beams (RIB) via photo-fission in the context of the Advanced Rare IsotopE Laboratory, ARIEL (Koscielniak et al. 2008; Merminga et al. 2011; Dilling et al., Hyperfine Interact, 2013), is described. The 100 % duty factor e-linac is based on super-conducting radiofrequency (SRF) technology at 1.3 GHz and has a nominal energy of 50 MeV. This paper provides an overview of the accelerator major components including the gun, cryomodules and cryoplant, high power RF sources, and machine layout including beam lines. Design features to facilitate operation of the linac as a Recirculating Linear Accelerator (RLA) for various applications, including Free Electron Lasers, are also noted.

  11. Beam Dynamics Study of X-Band Linac Driven X-Ray FELS

    SciTech Connect

    Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T.O.; Wu, J.; Sun, Y.; /SLAC

    2011-12-13

    Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described briefly. During the last 40 years, the photon wavelengths from linac driven FELs have been pushed shorter by increasing the electron beam energy and adopting shorter period undulators. Recently, the wavelengths have reached the X-ray range, with FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source) successfully providing users with soft and hard X-rays, respectively. FLASH uses a 1.2 GeV L-band (1.3 GHz) superconducting linac driver and can deliver 10-70 fs FWHM long photon pulses in a wavelength range of 44 nm to 4.1 nm. LCLS uses the last third of the SLAC 3 km S-band (2.856 GHz) normal-conducting linac to produce 3.5 GeV to 15 GeV bunches to generate soft and hard X-rays with good spatial coherence at wavelengths from 2.2 nm to 0.12 nm. Newer XFELs (at Spring8 and PSI) use C-band (5.7 GHz) normal-conducting linac drivers, which can sustain higher acceleration gradients, and hence shorten the linac length, and are more efficient at converting rf energy to bunch energy. The X-band (11.4 GHz) rf technology developed for NLC/GLC offers even higher gradients and efficiencies, and the shorter rf wavelength allows more versatility in longitudinal bunch phase space compression and manipulation. In the following sections, three different configurations of X-band linac driven XFELs are described that operate from 6 to 14 GeV. The first (LOW CHARGE DESIGN) has an electron bunch charge of only 10 pC; the second (OPTICS LINEARIZATION DESIGN) is based on optics

  12. PLIAC: A Pion Linac facility for 1-GEV pion physics at LAMPF

    SciTech Connect

    Spalek, G.; Thiessen, H.A.

    1991-12-31

    A design study for a Pion Linac (PILAC) at LAMPF is underway at Los Alamos. We present here a reference design for a system of pion source, linac, and high-resolution beam line and spectrometer that will provide 10{sup 9} pions per second on target and 200-keV resolution for the ({pi}{sup +}, K{sup +}) reaction at 0.92 GeV. A general-purpose beam line that delivers both positive and negative pions in the energy range 0.4--1.1 GeV is included, thus opening up the possibility of a broad experimental program as is discussed in this report. A kicker-based beam sharing system allows delivery of beam to both beamlines simultaneously with independent sign and energy control. Because the pion linac acts like an rf particle separator, all beams produced by PILAC will be free of electron (or positron) and proton contamination.

  13. PLIAC: A Pion Linac facility for 1-GEV pion physics at LAMPF

    SciTech Connect

    Spalek, G.; Thiessen, H.A.

    1991-01-01

    A design study for a Pion Linac (PILAC) at LAMPF is underway at Los Alamos. We present here a reference design for a system of pion source, linac, and high-resolution beam line and spectrometer that will provide 10{sup 9} pions per second on target and 200-keV resolution for the ({pi}{sup +}, K{sup +}) reaction at 0.92 GeV. A general-purpose beam line that delivers both positive and negative pions in the energy range 0.4--1.1 GeV is included, thus opening up the possibility of a broad experimental program as is discussed in this report. A kicker-based beam sharing system allows delivery of beam to both beamlines simultaneously with independent sign and energy control. Because the pion linac acts like an rf particle separator, all beams produced by PILAC will be free of electron (or positron) and proton contamination.

  14. Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

    SciTech Connect

    S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

    2012-07-01

    A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

  15. Predictive time-series modeling using artificial neural networks for Linac beam symmetry: an empirical study.

    PubMed

    Li, Qiongge; Chan, Maria F

    2017-01-01

    Over half of cancer patients receive radiotherapy (RT) as partial or full cancer treatment. Daily quality assurance (QA) of RT in cancer treatment closely monitors the performance of the medical linear accelerator (Linac) and is critical for continuous improvement of patient safety and quality of care. Cumulative longitudinal QA measurements are valuable for understanding the behavior of the Linac and allow physicists to identify trends in the output and take preventive actions. In this study, artificial neural networks (ANNs) and autoregressive moving average (ARMA) time-series prediction modeling techniques were both applied to 5-year daily Linac QA data. Verification tests and other evaluations were then performed for all models. Preliminary results showed that ANN time-series predictive modeling has more advantages over ARMA techniques for accurate and effective applicability in the dosimetry and QA field.

  16. Resonance Excitation of Longitudinal High Order Modes in Project X Linac

    SciTech Connect

    Khabiboulline, T.N.; Sukhanov, A.AUTHOR = Awida, M.; Gonin, I.; Lunin, A.AUTHOR = Solyak, N.; Yakovlev, V.; /Fermilab

    2012-05-01

    Results of simulation of power loss due to excitation of longitudinal high order modes (HOMs) in the accelerating superconducting RF system of CW linac of Project X are presented. Beam structures corresponding to the various modes of Project X operation are considered: CW regime for 3 GeV physics program; pulsed mode for neutrino experiments; and pulsed regime, when Project X linac operates as a driver for Neutrino Factory/Muon Collider. Power loss and associated heat load due to resonance excitation of longitudinal HOMs are shown to be small in all modes of operation. Conclusion is made that HOM couplers can be removed from the design of superconducting RF cavities of Project X linac.

  17. Beam physics design strategy for a high-current rf linac

    SciTech Connect

    Reiser, M.

    1995-10-01

    The high average beam power of an rf linac system for transmutation of nuclear waste puts very stringent requirements on beam quality and beam control. Fractional beam losses along the accelerator must be kept at extremely low levels to assure {open_quotes}hands-on{close_quotes} maintenance. Hence, halo formation and large-amplitude tails in the particle distribution due to beam mismatch and equipartitioning effects must be avoided. This implies that the beam should ideally be in near-perfect thermal equilibrium from injection to full energy - in contrast to existing rf linacs in which the transverse temperature, T {sub {perpendicular}}, is higher than the longitudinal temperature, T{sub {parallel}}. The physics and parameter scaling for such a system will be reviewed using the results of recent work on high-intensity bunched beams. A design strategy for a high-current rf linac with equilibrated beam will be proposed.

  18. A hospital-based proton linac for neutron therapy and radioisotope production

    SciTech Connect

    Lennox, A.J.

    1988-10-01

    Fermilab's Alvarez proton linac has been used routinely for neutron therapy since 1976. The Neutron Therapy Facility (NTF) operates in a mode parasitic to the laboratory's high energy physics program, which uses the linac as an injector for a synchrotron. Parasitic operation is possible because the linac delivers /approximately/1.2 /times/ 10/sup 13/ protons per pulse at a 15 Hz rate, while the high energy physics program requires beam at a rate not greater than 0.5 Hz. Protons not needed for physics experiments strike a beryllium target to produce neutrons for neutron therapy. Encouraging clinical results from NTF have led to a study of the issues involved in providing hospitals with a neutron beam of the type available at Fermilab. This paper describes the issues addressed by that study. 12 refs., 1 fig., 1 tab.

  19. Optimizing the average longitudinal phase of the beam in the SLC linac

    SciTech Connect

    Bane, K.L.F.

    1989-09-01

    The relation of the beam's average linac phase, {phi}{sub 0}, to the final energy spectrum in the SLC linac has been studied by many people over the years, with much of the work left unpublished. In this note we perform a somewhat thorough in vestigation of the problem. First we describe the calculation method, and discuss some common features of the energy spectrum. Then we calculate the value of {phi}{sub 0} that minimizes {delta}{sub rms} for the conceivable range of bunch population and bunch lengths of the SLC linac. This is followed by luminosity calculations, including the sensitivity of luminosity to variations in {phi}{sub 0}. Finally we suggest a practical method of implementing the proper phase setting on the real machine.

  20. BEAM DYNAMICS STUDIES FOR A COMPACT CARBON ION LINAC FOR THERAPY

    SciTech Connect

    Plastun, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.

    2016-05-01

    Feasibility of an Advanced Compact Carbon Ion Linac (ACCIL) for hadron therapy is being studied at Argonne National Laboratory in collaboration with RadiaBeam Technologies. The 45-meter long linac is designed to deliver 109 carbon ions per second with variable energy from 45 MeV/u to 450 MeV/u. S-band structure provides the acceleration in this range. The carbon beam energy can be adjusted from pulse to pulse, making 3D tumor scanning straightforward and fast. Front end accelerating structures such as RFQ, DTL and coupled DTL are designed to operate at lower frequencies. The design of the linac was accompanied with extensive end-to-end beam dynamics studies which are presented in this paper.