LINAC2014 - List of Keywords (proton)

Paper	Title	Other Keywords	Page
MOPP001	First Experimental Results for the Superconducting Half-Wave Resonators for PXIE	cavity, niobium, cryomodule, accelerating-gradient	46
	Z.A. Conway, A. Barcikowski, G.L. Cherry, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.W.T. MacDonald, R.C. Murphy, P.N. Ostroumov, T. Reid, K.W. Shepard ANL, Argonne, Illinois, USA
	Funding: This work was supported by the U.S. Department of energy, Offices of High-Energy Physics and Nuclear Physics, under Contract No. DE-AC02-76-CH03000 and DE-AC02-06CH11357. The first pair of superconducting niobium half-wave resonators operating at 162.5 MHz for the FNAL PIP-II project are complete and this poster reports the cold test results. These cavities are optimized to accelerate protons/H⁻ from 2 to 10 MeV and build upon optimized electromagnetic designs and processing techniques developed at Argonne for the Intensity Upgrade of the ATLAS superconducting heavy ion accelerator.

MOPP015	High Energy Electron Radiography Experiment Research Based on Picosecond Pulse-width Bunch	experiment, electron, linac, quadrupole	76
	Q.T. Zhao, S. Cao, R. Cheng, X.K. Shen, Z.M. Zhang, Y.T. Zhao IMP, Lanzhou, People's Republic of China Y.-C. Du TUB, Beijing, People's Republic of China W. Gai ANL, Argonne, Illinois, USA
	A new scheme is proposed that high energy electron beam as a probe is used for time resolved imaging measurement of high energy density materials, especially for high energy density matter and inertial confinement fusion. The first picosecond pulse-width electron radiography experiment was achieved by Institute of Modern Physics, Chinese Academy of Sciences and Tinghua University (THU), based on THU Linear electron accelerator (LINAC). It is used for principle test and certifying that this kind of LINAC with ultra-short pulse electron bunch can be used for electron radiography. The experiment results, such as magnifying factor and the imaging distortion, are consistent with the beam optical theory well. The 2.5 um RMS spatial resolution has been gotten with magnifying factor 46, with no optimization the imaging lens section. It is found that in the certain range of magnifying factor, the RMS spatial resolution will get better with bigger magnifying factor. The details of experiment set up, results, analysis and discussions are presented here.
	Poster MOPP015 [2.866 MB]

MOPP026	Actively Cooled RF Power Coupler : Theoretical and Experimental Studies	cryomodule, cryogenics, cavity, linac	111
	R. Bonomi, V. Parma CERN, Geneva, Switzerland
	In cryostats for Super-conducting Radio Frequency Cavities, the heat loads introduced by the high-power RF couplers represent an important fraction of the overall static thermal budget. Working at low operating temperature benefits from a reduced surface resistance (low dynamic losses) but is penalized by the high refrigeration cost. The external conductor of RF coaxial couplers provides a direct conduction path from ambient to cryogenic temperature plus is heated by resistive power deposition. Heat interception is therefore essential to contain heat in-leaks: a double-walled external conductor with a properly designed gas cooling effectively reduces heat loads to the cold bath by 1 order of magnitude. This paper presents the thermal design of the RF power coupler of the Superconducting Proton Linac (SPL) at CERN, featuring a helium vapour cooling between 4.5 K and ambient temperature. Numerical models, which can be used as design tools for other applications, have been developed to assess efficiency and thermal performance. A full-size mock-up cooled by nitrogen has been built for experimental validation. Comparison between calculations and measurements is presented and discussed.

MOPP038	Longitudinal Bunch Profile Monitoring at the ESS Linac	linac, simulation, neutron, target	143
	I. Dolenc Kittelmann, B. Cheymol ESS, Lund, Sweden
	The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5MW, 2GeV proton linac. This high intensity linac will among other beam instrumentation require longitudinal bunch profile monitors. These shall be used during the commissioning phase and start-up periods for beam dynamics optimization and beam loss reduction. The paper focuses on the preliminary studies concerning the longitudinal bunch profile monitoring at the ESS linac.

MOPP059	Study and Design of the High Power RF Coupler for the CH-Cavity of the Fair pLINAC	coupling, cavity, linac, resonance	187
	F. Maimone, G. Clemente, W. Vinzenz GSI, Darmstadt, Germany
	At GSI a proton Linac has been designed and developed in order to provide a 70 MeV proton beam for the FAIR facility. The pLINAC consists of an RFQ followed by six CH-DTL accelerating cavities and the electromagnetic field inside each cavity is generated by seven Klystrons providing up to 2.8 MW power at 325.224 MHz. The high power RF coupling between the Klystron and the accelerating CH-cavity has been studied and an inductive coupling loop has been designed. The coupler insertion inside the cavity and the rotation angle with respect to the magnetic field lines have been adjusted and the results of the analysis of the coupler positioning are presented. A prototype coupler is under construction and the measurement of RF coupling with the CH-cavity is scheduled within this year.

MOPP063	Development of a Pepper Pot Emittance Measurement Device for FRANZ	emittance, ion, ion-source, plasma	199
	B. Klump, U. Ratzinger, W. Schweizer, K. Volk IAP, Frankfurt am Main, Germany
	Funding: This work is supported by HGS-HIRe Within the FRANZ project [] on the Institute of Applied Physics, University Frankfurt, a robust and simple pepper pot emittance measurement device for high beam power densities is developed. To use the device directly behind the ion source, a high robustness against HV breakdowns is necessary. This paper gives an overview on experimental setup, on the analysis method and on imaging properties of the screen. Furthermore, the implemented software-based evaluation method is shown. It concludes with a preliminary emittance measurement on the high current ion source for FRANZ. [] U. Ratzinger et al., “intense Pulsed Neutron Source FRANZ in the 1-500 keV Range“, Proc. ICANS-XVIII, Dongguan, April 2007, p.210

MOPP064	R&D of the 17 MeV MYRRHA Injector	emittance, cavity, rfq, linac	202
	D. Mäder, M. Basten, D. Koser, H.C. Lenz, N.F. Petry, H. Podlech, A. Schempp, M. Schwarz, M. Vossberg IAP, Frankfurt am Main, Germany C. Zhang GSI, Darmstadt, Germany
	Funding: Project supported by the EU, FP7 MAX, Contract No. 269565 MYRRHA is designed as an accelerator driven system (ADS) for transmutation of long-lived radioactive waste. The challenge of the linac development is the very high reliability of the accelerator to limit the thermal stress inside the reactor. With the concept of parallel redundancy the injector will supply a cw proton beam with 4 mA and 17 MeV to the main linac. The new MYRRHA injector layout consists of a very robust beam dynamics design with low emittance growth rates. Sufficient drift space provides plenty room for diagnostic elements and increases the mountability. Behind a 4-Rod-RFQ and a pair of two-gap QWR rebunchers at 1.5 MeV the protons are matched into the CH cavity section. A focussing triplet between the rebunchers ensures an ideal transversal matching into the doublet lattice. Each of the 7 RT CH structures has a constant phase profile and does not exceed thermal losses of 29 kW/m. The transition to the 5 SC CH cavities with constant beta profile is at 5.9 MeV. For a safe operation of the niobium resonators the electric and magnetic peak fields are defined below 25 MV/m and 57 mT respectively.
	Poster MOPP064 [4.024 MB]

MOPP065	Investigations of Space-Charge Compensation in Low-Energy Beam Transport (LEBT) Sections Using a Particle-in-Cell Code	electron, ion, simulation, space-charge	205
	D. Noll, M. Droba, O. Meusel, U. Ratzinger, K. Schulte, C. Wiesner IAP, Frankfurt am Main, Germany
	Among the advantages of magnetostatic LEBT sections is the possibility for compensation of space charge by electrons in the case of positively charged ion beams. In the past, it has been shown that the distribution of these compensation electrons can lead to unwanted emittance growth. However, the distribution of electrons especially in the presence of the magnetic fields of the focussing lenses is difficult to predict. To improve the understanding of the influence on the beam, models for the relevant processes namely residual gas ionization using realistic cross sections as well as secondary electron production on surfaces have been implemented in a particle-in-cell code. In this contribution, we will present the code used as well as first results for two model systems as an example.

MOPP078	RF Power Systems for the FAIR Proton Linac	klystron, linac, electronics, cavity	236
	J. Lesrel, C. Joly IPN, Orsay, France E. Plechov, A. Schnase, G. Schreiber, W. Vinzenz GSI, Darmstadt, Germany
	In the framework of collaboration between the FAIR project, GSI, and CNRS, the IPNO lab is in charge of providing the high power RF components for a cavity test stand and for the planned FAIR proton Linac. This Linac will be connected to the existing GSI synchrotron SIS18 for serving as an injector for the new FAIR facility. The 70 MeV FAIR proton Linac design contains a 3 MeV RFQ, and a DTL based on Cross-bar H-mode cavities (CH). It will operate with pulsed RF at 325.224 MHz with a width of 200 μs and a repetition rate of 4 Hz. The planned RF systems of the proton Linac will be presented as well as the description of the test stand. The first power test results are obtained with a Thales klystron developed jointly with CNRS. Three solid state amplifiers made by Sigmaphi Electronics for the bunchers will also be described in this paper.

MOPP080	Beam Dynamics Study for RAON Superconducting Linac	linac, ion, lattice, quadrupole	239
	H. Jang, H.J. Kim IBS, Daejeon, Republic of Korea J.G. Hwang KNU, Deagu, Republic of Korea B.H. Oh POSTECH, Pohang, Kyungbuk, Republic of Korea
	Rare Isotope Science Project (RISP) in Korea is going to build an ion accelerator, RAON which can generate and accelerate various stable ions such as uranium, proton, xenon and rare isotopes such as tin, nickel. Linear accelerators of RAON adopted superconducting RF cavities and warm quadruple doublet structure. In RAON, there are two low energy linacs which can accelerate the Uranium beam from 0.5MeV/u to 17.5MeV/u, charge stripping sections and one high energy linac which can accelerate the Uranium beam up to 200MeV/u. Due to the diversity of planned ions and isotopes, their A/q range lies widely from 1 to 8. As a result, the research related with linac lattice design and beam dynamics is one of the important topics to build RAON. In this presentation the current status of RAON linac lattice design and the beam dynamics simulation results for acceleration of various ions will be described.

MOPP084	Nondestructive Diagnostics of Proton Beam Halo and Transverse Bunch Position by Cerenkov Slow Wave Structures	simulation, diagnostics, monitoring, electron	251
	S.V. Kuzikov, M.B. Goykhman, A.V. Gromov, A.V. Palitsin, Yu.V. Rodin, A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia
	An appearance of the halo around bunch of particles is very undesirable destructive phenomenon in high-intensity proton accelerators. We suggest using built-in short BWO section in form of the corrugated metallic waveguide, in order to control particle distribution in real time. In BWO low velocity proton bunch has synchronism with slow spatial harmonic of TM01 wave. Fields of slow harmonic sharply grow in direction from axis to walls and rf power, generated by flying bunch of the given charge, critically depends on transverse bunch size. Results of the simulation, carried out for 20 pC proton bunch of 10 ps duration, show that in 5 GHz BWO of 30 cm length the output rf pulse of several nanosecond duration is varied from mW- level (for 1 mm transverse bunch size) to several tens of mW (for bunch of 20 mm radius). This power level is high enough to control halo appearance in each single proton bunch. The producible rf power in a BWO is also dependent on bunch deflection from axis. This effect we plan to use, in order to provide transverse bunch position monitoring by means of two additional rectangular slow wave section which have corrugations on mutually perpendicular walls.
	Poster MOPP084 [0.732 MB]

MOPP088	MUNES a Compact Neutron Source for BNCT and Radioactive Wastes Characterization	neutron, rfq, target, quadrupole	261
	A. Pisent, P. Colautti, E. Fagotti INFN/LNL, Legnaro (PD), Italy
	At INFN LNL (Legnaro Italy) it has been built a high intensity Radio Frequency Quadrupole (RFQ) structure, able to produce a 5 MeV proton beam of 30 mA. Coupled with a Be target such a beam can generate a neutron flux of 10¹⁴ n/s, with a spectrum centered in the MeV region (that has been recently characterized in detail at LNL accelerators). This neutron flux can be moderated to generate a thermal or epithermal source for BNCT with very little contamination of energetic form energetic neutron and gamma. Since the approval of MUNES project (in 2012) the high technology issues related to a compact neutron source to be installed in an Hospital environment have been faced. In particular for the powering of the accelerating structure an innovative system, completely based on solid state amplifiers, has been developed and ordered to industry. An outline of MUNES design and the status of the project will be given in the paper.

MOPP099	Compact Proton Injector for Synchrotrons	rfq, linac, cavity, quadrupole	291
	A.D. Kovalenko, A.V. Butenko JINR, Dubna, Moscow Region, Russia A. Kolomiets, A.S. Plastun ITEP, Moscow, Russia
	Compact linac comprising two sections of different RFQ structures was designed. The first section is conventional RFQ with output energy 3 MeV whereas the second one is RFQ with trapezoidal modulation of vanes. The linac output energy is 8 MeV. The both structures operate at frequency of 352 MHz. The total length of machine is less than 8 m. The output pulsed beam current is of 40 mA. The design is suitable for both as NICA injection complex and proton superconducting medical synchrotron.

MOPP124	Development of a 3 MeV Prototype RFQ Structure for High Intensity Proton Linac for ISNS	rfq, vacuum, ion, operation	345
	S.C. Joshi, A. Chaturvedi, S.K. Chauhan, K.K. Das, G.V. Kane, S.V. Kokil, B. Oraon, S. Raghvendra, N.K. Sharma RRCAT, Indore (M.P.), India
	Raja Ramanna Centre for Advanced Technology (RRCAT) has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. A 3 MeV Radio Frequency Quadrupole (RFQ) will be used as front end of the pulsed proton linac. A full scale prototype RFQ structure has been designed and fabricated to validate the physics design and manufacturing procedures. The total of 3.46 meter has been divided in three segments for ease in machining. The fabricated RFQ structure has been assembled for low power RF characterization. The RFQ frequency and field tuning exercise is being carried out using 48 stub tuners. The paper will also present the engineering design aspects and fabrication issues for the full scale RFQ structure.

MOPP125	Comparison of Normal Conducting High Energy Accelerating Structures for a Moderate Operating Frequency	coupling, linac, Windows, impedance	348
	V.V. Paramonov RAS/INR, Moscow, Russia
	The progress in the CERN Linac 4 project confirms the very attractive possibility for single frequency high intensity high energy normal conducting hadron linac. The important part of such linac is the accelerating structure for high energy part. Parameters of possible accelerating structures, referring to PIMS, at operating frequency 352 MHz are considered for proton energy up to 600 MeV. The set of parameters, such as dimensions, RF efficiency, field stability, cooling capability, vacuum conductivity, are considered and compared.

MOPP129	Status of the FETS Project	rfq, emittance, ion-source, ion	361
	A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.M.H. Alsari, M. Aslaninejad, J.K. Pozimski, P. Savage Imperial College of Science and Technology, Department of Physics, London, United Kingdom J.J. Back University of Warwick, Coventry, United Kingdom G.E. Boorman, A. Bosco, S.M. Gibson Royal Holloway, University of London, Surrey, United Kingdom R.T.P. D'Arcy, S. Jolly UCL, London, United Kingdom M. Dudman, J.K. Pozimski STFC/RAL, Chilton, Didcot, Oxon, United Kingdom D.C. Plostinar STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The Front End Test Stand (FETS) under construction at RAL is a demonstrator for front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, high energy physics proton drivers etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty factor, FETS consists of a high brightness ion source, magnetic low energy beam transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium energy beam transport (MEBT) containing a high speed beam chopper and non-destructive laser diagnostics. This paper describes the current status of the project and future plans.

MOPP134	Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening	cavity, simulation, linac, vacuum	373
	J. Rodnizki, Y. Ben Aliz, A. Grin, Z. Horvitz, A. Perry, L. Weissman Soreq NRC, Yavne, Israel G.K. Davis JLab, Newport News, Virginia, USA J.R. Delayen ODU, Norfolk, Virginia, USA
	The SARAF Prototype Superconducting Module (PSM) houses six 176 MHz Half Wave Resonators(HWR). The PSM accelerates protons and deuterons from 1.5 MeV/u to 4 and 5.6 MeV. The HWRs are highly sensitive to the coolant liquid Helium pressure fluctuations which limit the available beam power to 2kW per cavity out of 4kW RF amplifier and coupler and so might limit the available beam current to 2mA depending on the output energy. The flat shape of the cavity along the beam line in the area of the high electric field generates the high sensitivity of the Eigen mode frequency to helium pressure. The evaluated cavity sensitivity is full consistent with the measured values. It was explored that the tuning system (the fog structure) has a significant contribution to the cavity sensitivity. By using ribs or by modifying the rigidity of the fog we may reduce the HWR sensitivity by a factor of 3. This analysis is applied to study the stresses on the cavity during cool down and warm up to avoid plastic deformation as the Niobium yield is an order of magnitude lower in room temperature.

MOPP137	Design Progress of the MYRRHA Low Energy Beam Line	rfq, emittance, solenoid, ion	381
	R. Salemme, L. Medeiros Romão, D. Vandeplassche Studiecentrum voor Kernenergie - Centre d'Étude de l'énergie Nucléaire (SCK•CEN), Mol, Belgium M.A. Baylac, D. Bondoux, F. Bouly, J.-M. De Conto, E. Froidefond LPSC, Grenoble Cedex, France J.-L. Biarrotte IPN, Orsay, France D. Uriot CEA/DSM/IRFU, France
	The MYRRHA project, a flexible spectrum neutron irradiation facility, is designed according to the Accelerator Driven System (ADS) reactor concept. The MYRRHA driver consists of a high power superconducting proton LINAC. A prototype of the front end injector is being built up into a test platform conceived to experimentally address its design issues. Currently, the ECR proton source has been industrially procured. LPSC Grenoble designed the subsequent Low Energy Beam Transport (LEBT) section. Right before the RFQ, a short section hosts an electrostatic beam chopper producing carefully controlled beam interruptions. In this paper the status of the LEBT design with the associated beam instrumentation is reviewed. Future experimental plans including LEBT beam characterization and optimization of the beam transmission are presented.

TUIOB02	Beam Commissioning of the 100 MeV KOMAC Linac	DTL, linac, operation, klystron	413
	Y.-S. Cho KAERI, Daejon, Republic of Korea
	Funding: This work was supported by the Ministry of Science, ICT & Future Planning of the Korean Government. The operation of the 100MeV proton linear accelerator for multipurpose application started in July, 2013 at KOMAC (Korea Multipurpose Accelerator Complex), KAERI (Korea Atomic Energy Research Institute). Also, the operation of the two beam lines, one is for 20MeV beam and the other for 100MeV beam, started in order to supply proton beams to users. The accumulated operation time was 2,290 hours and the proton beam was supplied to 937 samples in 2013. In addition to the beam service, the effort to increase the beam power is continuing in 2014. Beam commissioning and operation status of the linac will be presented in this talk.
	Slides TUIOB02 [7.200 MB]

TUPP039	Accuracy Determination of the ESS MEBT Emittance Measurements	emittance, scattering, quadrupole, linac	519
	B. Cheymol, A. Ponton ESS, Lund, Sweden
	The European Spallation Source MEBT will be equipped with a full set of diagnostics in order to characterize the bean properties before the injection in the DTL. The 6D phase space of the beam shall be characterize during the commissioning of the normal conducting as well as on regular basis during retuning phase of the machine. In this paper we will discuss the accuracy of the transverse emittance measurement that will be performed with the slit-grid method. The slit geometric parameters have been determined in order to achieve the required resolution and sensitivity. Scattering effects at the slit have been considered to determine the emittance measurement accuracy.

TUPP045	Beam Physics Challenge in FRIB Driver Linac	linac, ion, focusing, acceleration	532
	Y. Yamazaki, N.K. Bultman, A. Facco, Z.Q. He, M. Ikegami, M.J. Johnson, S.M. Lidia, F. Marti, G. Pozdeyev, K. Saito, J. Wei, X. Wu, Y. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA
	Funding: *Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The Facility for Rare Isotope Beams driver linac provides CW beams of all the stable ions (from protons to uranium) with a beam power of 400 kW and a minimum beam energy of 200 MeV/u in order to produce a wide variety of rare isotopes, mainly for nuclear physics study. The low beam emittances, both transverse and longitudinal, are key performance requirements, together with beam stability. These are required for efficiently separating one isotope from another, the reason for choosing this linac configuration. Multi-charge states (five charge states for the uranium case) are accelerated for maximizing the beam current, while keeping the low emittances. The efficient acceleration of high beam currents from 0.5 MeV/u through the superconducting linac is, needless to say, one of the biggest challenges. The beam power is more than 200 times higher than existing similar SC heavy ion linac. In particular, the SC cavities are difficult to protect from heavy ion beam damage, which can be 30 times larger locally than a proton beam with the same beam power. Other challenges peculiar to the FRIB linac will be presented, together with the solutions.

TUPP055	Progress on Euclid SRF Conical Half-Wave Resonator Project	cavity, niobium, vacuum, SRF	547
	E.N. Zaplatin FZJ, Jülich, Germany T.L. Grimm Niowave, Inc., Lansing, Michigan, USA A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Funding: This Work is supported by the DOE SBIR Program, contract # DE-SC0006302. Euclid conical Half-Wave Resonator (cHWR) project develops 162.5 MHz β=v/c=0.11 accelerator structure for the high-intensity proton accelerator complex proposed at Fermi National Accelerator Laboratory. The main idea of this project is to provide a self-compensation cavity design together with its helium vessel to minimize the resonant frequency dependence on external loads. A unique cavity side-tuning option is also under development. Niowave, Inc. proposed a complete cavity production procedure including preparation of technical drawings, processing steps and resonator high-gradient tests to demonstrate such possibility for the private company. Here we present the procedure of the cavity and helium vessel fabrication, cavity preparation and initial experimental results.

TUPP056	High Current Proton Beam Operation at GSI UNILAC	ion, linac, operation, ion-source	550
	W.A. Barth, A. Adonin, P. Gerhard, M. Heilmann, R. Hollinger, W. Vinzenz, H. Vormann GSI, Darmstadt, Germany
	A significant part of the experimental program at FAIR is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR Proton LINAC will deliver a pulsed proton beam of up to 35 mA of 36 μs duration at a repetition rate of 4 Hz. The current GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not dedicated for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown, that the UNILAC is able to provide for sufficient high intensities of CH3-beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach results in up to 2 mA of proton intensity at a maximum beam energy of 20 MeV, 100 μs pulse duration and a rep. rate of 4 Hz. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 17% of the FAIR requirements.

TUPP063	Improvements of the LORASR Code and their Impact on Current Beam Dynamics Designs	linac, DTL, focusing, quadrupole	569
	R. Tiede, D. Mäder, N.F. Petry, H. Podlech, U. Ratzinger, C. Zhang IAP, Frankfurt am Main, Germany
	LORASR is a multi-particle tracking code optimized for the beam dynamics design of ‘Combined Zero Degree Structure (KONUS)’ lattices, which can benefit from an adapted input file structure and code architecture. Recent code developments focused on the implementation of tools for machine error studies and loss profile investigations, including also steering correction strategies. These tools are a stringent necessity for the design of high intensity linacs. Thus, the abilities of the present LORASR release allow performing a manifold of checks and optimizations before finalizing the layouts of KONUS-based or conventional linacs. Two representative examples are the MAX-MYRRHA Injector and the GSI FAIR Facility Proton Linac, both under development with strong participation of IAP, Frankfurt University. This paper presents the status of the LORASR code development with focus on the new features and illustrates the impact on current designs by examples taken from the above-mentioned projects.

TUPP073	Study of the ACS Cavity Without a Bridge Cavity	cavity, linac, coupling, alignment	596
	F. Naito, K. Takata KEK, Ibaraki, Japan H. Ao, K. Hasegawa, K. Hirano, T. Morishita, N. Ouchi JAEA/J-PARC, Tokai-mura, Japan
	J-PARC has installed the Annular-ring Coupled Structure (ACS) linac to increase the beam energy up to 400 MeV. One ACS module is composed of two accelerating tanks which are coupled by the bridge cavity. The bridge cavity simplifies the handling of the multi-tank system. While it is possible to feed the RF power into the each tanks directly with the power divider and the phase shifter instead of the bridge cavity. The rf properties of the ACS linac with the direct rf-power supply system has been measured by using the low power model made of aluminum. The measured results are described in the paper.
	Slides TUPP073 [5.042 MB]

TUPP097	100-MeV Proton Beam Phase Measurement by Using Stripline BPM	linac, DTL, simulation, coupling	656
	H.S. Kim, Y.-S. Cho, H.-J. Kwon KAERI, Daejon, Republic of Korea
	Funding: This work is supported by Ministry of Science, ICT & Future Planning of the Korean Government. In Korea Multipurpose Accelerator Complex (KOMAC), a 100-MeV proton linac, which is composed of a proton injector based on the microwave ion source, 3-MeV RFQ with a four-vane type and 100-MeV DTL with electromagnetic quadrupoles has been developed and currently provides the proton beam to users for various applications. To increase the beam power up to the design value, several improvements are required including the fine adjustment of the RF set-point during the operation. A stripline BPM is used for the beam phase measurement, where the pickup signals from four electrodes are combined by using the RF combiner, then mixed with 300 MHz LO reference signal resulting in 50 MHz IF signal which is processed by digital IQ demodulation method. In this paper, the details of the beam phase measurement setup and results will be presented.

TUPP103	The Beam Envelope Control in SC Linac for the Proton Radiotherapy	linac, controls, cavity, simulation	665
	A.V. Samoshin, I.A. Ashanin, S.M. Polozov MEPhI, Moscow, Russia
	Proton cancer therapy is conventionally based on normal conducting synchrotrons and cyclotrons. The high electrical power consumption and especial devices necessary to energy variation are main problems of such facilities. Superconducting linacs based on short identical independently phased cavities have a seriously progress and it's development allow to propose their using for medical application. High accelerating gradient and small capacity losses nearly 10^-4 Vt/m are main advantages in advance of normal conducting facilities, the energy variation can be realized by means of RF field amplitude and phase variation in a number of cavities. Besides linac structures are lack of unwieldy magnetic system, simplicity of input and output of particles and high current densities. The parameters choose and the optimization for SC linac structure with energy up to 240 MeV and envelope control will discuss in this paper. The simulation was done using BEAMDULAC-SCL code. The study of beam dynamics will direct to realize the energy variation in range 150-240 MeV with beam quality preservation. A.V. Samoshin. Proc. of LINAC2012, Tel-Aviv, Israel, TUPB069, p. 630 - 632

TUPP109	Cryogenic Testing of High-Velocity Spoke Cavities	cavity, cryogenics, acceleration, linac	677
	C.S. Hopper, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA J.R. Delayen, H. Park JLab, Newport News, Virginia, USA
	Spoke-loaded cavities are being investigated for the high-velocity regime. The relative compactness at low-frequency makes them attractive for applications requiring, or benefiting from, 4 K operation. Additionally, the large velocity acceptance makes them good candidates for the acceleration of high-velocity protons and ions. Here we present the results of cryogenic testing of a 325 MHz, β0 = 0.82 single-spoke cavity and a 500 MHz, β0 = 1 double-spoke cavity.

WEIOB01	Chopping High-Intensity Ion Beams at FRANZ	ion, rfq, ion-source, solenoid	765
	C. Wiesner, M. Droba, O. Meusel, D. Noll, O. Payir, U. Ratzinger, P.P. Schneider IAP, Frankfurt am Main, Germany
	The accelerator-driven Frankfurt Neutron Source FRANZ is under construction at the science campus of Frankfurt University. Its Low-Energy Beam Transport (LEBT) line also serves as test stand for transport and chopping experiments with high-intensity ion beams. The high-current proton source was tested successfully with dc currents above 200 mA . The LEBT section consisting of four solenoids and a 250 kHz, 120 ns chopper was successfully commissioned using a helium test beam at low beam currents. Transport simulations including space-charge compensation and measurements are discussed. Simulations and experimental results of the novel LEBT chopper using a Wien-filter type field array and pulsed electrode voltages of up to ±6kV will be presented.
	Slides WEIOB01 [7.925 MB]

WEIOB02	SARAF Phase-I Proton / Deuteron Linac Beam Operation Status	operation, target, rfq, neutron	770
	A. Kreisel, A. Arenshtam, Y. Ben Aliz, D. Berkovits, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I.G. Gertz, A. Grin, S. Halfon, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, J. Luner, I. Mor, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, D. Vartsky, L. Weissman, E. Zemach Soreq NRC, Yavne, Israel
	SARAF Phase-I linac is the first accelerator to demonstrate acceleration of variable energy 2 mA CW proton beam. Such intense beam is used in SARAF Phase-I to irradiate a liquid lithium jet target for nuclear astrophysics studies. Several improvements were necessary to allow beam operation with such high current. The improvements include a DC bias that was introduced on the cavity RF coupler to reduce coupler heating. A new slow chopper was commissioned to enable increase the current by increasing the duty cycle with fewer changes in the beam optics. A beam dump was developed to allow beam studies of a 2 mA CW proton beam. The beam dump is based on tungsten pins which distributes, by radiation, the high beam power over a large area which is then easily water cooled. While most of beam tuning is done using a low intensity pilot beam, some nondestructive methods were studied to monitor the high intensity beam. These include a current transformer and a residual gas monitor (RGM) to monitor beam transverse distribution. Additional valuable information about the beam current and energy is gained from measurements of the nuclear reaction products of the proton on lithium targets.
	Slides WEIOB02 [3.027 MB]

THPP015	Status of the FAIR Proton Source and LEBT	linac, ion, diagnostics, ion-source	863
	N. Chauvin, O. Delferrière, Y. Gauthier, P. Girardot, J.L. Jannin, A. Lotode, N. Misiara, J. Neyret, F. Senée, C.S. Simon, O. Tuske CEA/IRFU, Gif-sur-Yvette, France R. Berezov, J. Fils, P. Forck, R. Hollinger, V. Ivanova, C. Ullmann, W. Vinzenz GSI, Darmstadt, Germany A. Maugueret CEA/DSM/IRFU, France
	The unique Facility for Antiproton and Ion Research – FAIR will deliver stable and rare isotope beams covering a huge range of intensities and beam energies. A significant part of the experimental program at FAIR is dedicated to antiproton physics that requires an ultimate number 7x10¹⁰ cooled pbar/h. The high-intensity proton beam that is necessary for antiproton production will be deliver by a dedicated 75 mA/70 MeV proton linac. The injector section of this accelerator is composed by an ECR source, delivering a pulsed 100 mA H⁺ beam (4 Hz) at 95 keV and a low energy beam transport (LEBT) line required to match the beam for the RFQ injection. The proposed design for the LEBT is based on a dual solenoids focusing scheme. A dedicated chamber containing several diagnostics (Alisson scanner, Wien filter, SEM grid, Iris, Faraday Cup) will be located between the two solenoids. At the end of the beam line, an electrostatic chopper system is foreseen to inject up to 50μseconds long beam pulses into the RFQ. The status of LEBT simulations, design and fabrication of the FAIR proton injector will be presented.

THPP040	A Compact High-Frequency RFQ for Medical Applications	rfq, linac, cavity, quadrupole	935
	M. Vretenar, A. Dallocchio, V.A. Dimov, M. Garlaschè, A. Grudiev, A.M. Lombardi, S.J. Mathot, E. Montesinos, M.A. Timmins CERN, Geneva, Switzerland
	In the frame of a new program for medical applications, CERN has designed and is presently constructing a compact 750 MHz Radio Frequency Quadrupole to be used as injector for hadron therapy linacs. The RFQ reaches an energy of 5 MeV in only 2 meters; it is divided into four standardized modules of 500 mm, each equipped with 12 tuner ports and one RF input. The inner quadrant radius is 46 mm and the RFQ has an outer diameter of 134 mm; its total weight is only 220 kg. The beam dynamics and RF design have been optimized for reduced length and minimum RF power consumption; construction techniques have been adapted for future industrial production. The multiple RF ports are foreseen for using either 4 solid-state units or 4 IOT’s as RF power sources. Although hadron therapy requires only a low duty cycle, the RFQ has been designed for 5% duty cycle in view of other uses. This extremely compact and economical RFQ design opens several new perspectives for medical applications, in particular for PET isotopes production in hospitals with two coupled high-frequency RFQs reaching 10 MeV and for Technetium production for SPECT tomography with two RFQs followed by a DTL.

THPP044	ESS Normal Conducting Linac Status and Plans	linac, rfq, DTL, vacuum	948
	A. Ponton, B. Cheymol, R. De Prisco, M. Eshraqi, R. Miyamoto, E. Sargsyan ESS, Lund, Sweden G. Bourdelle, M. Desmons, A. France, O. Piquet, B. Pottin CEA/DSM/IRFU, France I. Bustinduy, P.J. González, J.L. Muñoz, I. Rueda, F. Sordo ESS Bilbao, Bilbao, Spain L. Celona, S. Gammino, L. Neri INFN/LNS, Catania, Italy M. Comunian, F. Grespan, A. Pisent, C. R. Roncolato INFN/LNL, Legnaro (PD), Italy P. Mereu INFN-Torino, Torino, Italy
	The ESS Normal Conducting (NC) linac is composed of an ion source, a Low Energy Beam Transport line, a Radio Frequency Quarupole (RFQ), a Medium Energy Beam Transport Line (MEBT) and a Drift Tube Linac (DTL). It creates, bunches and accelerates the proton beam up to 90 MeV before injecting into the superconducting linac which will deliver a 5 MW beam onto the neutron production target. The construction of the NC linac is part of a broad collaboration involving experts of various Labs in Europe. The technical chalenges and the collaboration strategy for the NC linac will be presented.

THPP061	RF Design of a Novel S-Band Backward Traveling Wave Linac for Proton Therapy	coupling, linac, accelerating-gradient, impedance	992
	S. Benedetti, U. Amaldi TERA, Novara, Italy A. Degiovanni, A. Grudiev, W. Wuensch CERN, Geneva, Switzerland
	Proton therapy is a rapidly developing technique for tumour treatment, thanks to the physical and dosimetric advantages of charged particles in the dose distribution. Here the RF design of a novel high gradient accelerating structure for proton Linacs is discussed. The choice of a linear accelerator lies mainly in its advantage over cyclotron and synchrotron in terms of fast energy modulation of the beam, which allows the implementation of active spot scanning technique without need of passive absorbers. The design discussed hereafter represents a unicum thanks to the accelerating mode chosen, a 2.9985 GHz backward traveling wave mode with 150° phase advance, and to the RF design approach. The prototype has been designed to reach an accelerating gradient of 50 MV/m, which is more than twice that obtained before. This would allow a shorter Linac potentially reducing cost. The complete 3D RF design of the full structure for beta equal to 0.38 is presented. A prototype will be soon produced and tested at high power. This structure is part of the TULIP project, a proton therapy single-room facility based on high gradient linear accelerators.
	Slides THPP061 [1.537 MB]

THPP063	Beam Diagnostics Layout for the FAIR Proton Linac	linac, diagnostics, emittance, beam-diagnostic	998
	T. Sieber, M.H. Almalki, C. Dorn, J. Fils, P. Forck, R. Haseitl, W. Kaufmann, W. Vinzenz, M. Witthaus, B. Zwicker GSI, Darmstadt, Germany C.S. Simon CEA/DSM/IRFU, France
	The planned proton Linac for FAIR (Facility of Antiproton an Ion Research) will be - additionally to the existing GSI UNILAC - a second injector for the FAIR accelerator chain. It will inject a 70 MeV, (up to) 70 mA proton beam with a nominal pulse length of 30 us into the SIS18. The beam diagnostics system for the proton Linac comprises nine current transformers for pulse current determination and fourteen BPMs for position, mean beam energy and relative current measurement. SEM-Grids and stepping motor driven slits will be used for profile as well as for emittance measurements. A wire-based bunch shape monitor is foreseen, additionally a bending magnet for longitudinal emittance determination during commissioning. Presently, main efforts are conducted concerning the BPM system. Detailed signal simulations with the finite element code CST are performed. An electronics board using digital signal processing is evaluated by detailed lab-based characterization and beam-based measurements at the UNILAC. In this paper we present the general layout and the status of the diagnostics systems as well as key results from our measurements and simulations.

THPP071	Proposal of a 325 MHz Ladder-RFQ for the FAIR Proton-Linac	rfq, simulation, dipole, quadrupole	1016
	M. Schütt, U. Ratzinger IAP, Frankfurt am Main, Germany R. M. Brodhage GSI, Darmstadt, Germany
	Funding: BMBF 05P12RFRB9 For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The first rf accelerator element is a 325 MHz RFQ accelerating from 95 keV to 3.0 MeV. RFQ’s beyond 300 MHz were realized in 4-Vane-type geometry so far. At IAP there is a tradition in 4-Rod-type RFQ development. This type of RFQ is dominating at lower frequencies. Very promising results have been reached with a ladder type-RFQ, which has been investigated during 2013. In comparison with a traditional 4-Rod RFQ approach the geometry is more convenient at high frequencies. We will show most recent 3D simulations of the frequency tuning possibilities and of a whole cavity demonstrating the power of a ladder type RFQ. An RFQ layout for the new FAIR proton injector will be shown. (see also R. Brodhage, U. Ratzinger, A. Almomani, “Design Study of a High Frequency Proton Ladder RFQ” , Proc. of the 2013 IPAC Conference, Shanghai, China, p. 3788.)

THPP085	The Prototype of the Proton Injector for the European Spallation Source	plasma, extraction, emittance, simulation	1044
	L. Celona, L. Andò, G. Castro, S. Gammino, D. Mascali, L. Neri, G. Torrisi INFN/LNS, Catania, Italy
	The update of the design of the PS-ESS source and of its LEBT has been carried out in 2013 and the construction is now ongoing. The Ion Source will be able to provide a proton beam current larger than 70 mA to the 3.6 MeV RFQ. Several innovative solutions have been implemented in the redesign phase in order to cope with high-reliability/high-performance requirements of the ESS project. A flexible magnetic system will allow to investigate alternative configurations for future ion current upgrade of the machine based on the formation of a denser plasma. Innovative set-ups have been also explored for beam extraction, transport and chopping. Calculations have shown that space charge compensation up to 95 % is needed to preserve the low emittance in the low energy beam transfer line (LEBT). In order to obtain the optimal proton beam pulse rise and fall time – that should be 100 ns – we propose a LEBT chopping configuration that permits hundred nanosecond rise times despite the LEBT compensation needs few microseconds. The ongoing development of a 3D PIC code will be also described, that should allow predicting and tuning the beam pulse for different source/LEBT operative configurations.

THPP105	Beam Dynamics Simulation for the 1 GeV High Power Proton Linac	linac, focusing, rfq, simulation	1099
	S.M. Polozov, V.S. Dyubkov, T. Kulevoy, A.V. Samoshin MEPhI, Moscow, Russia G. Kropachev, T. Kulevoy ITEP, Moscow, Russia
	Funding: This work is supported in part by the Ministry of Science and Education of Russian Federation under contract No. 14.516.11.0084 The design of high energy and high power proton linacs for accelerating driven systems (ADS) is one of the accelerator technology frontiers. Such linacs are under developing in EU, Japan, PRC but not discussed in Russia previous fifteen years. The driver linac and the breeder conceptual designs were funded by the Ministry of Science and Education of Russian Federation in 2013. The 2 MeV RFQ linac was proposed as the first accelerating section. A number of RF focusing sections types (by RF crossed lenses, modified electrode profile RFQ, axi-symmetrical RF focusing) were discussed for medium energies. The conventional modular scheme linac based on spoke-cavities and 5-cell elliptical cavities was designed for higher energies. The results of beam dynamics simulation in this linac will present.

THPP122	Development of Superconducting Cavities and Related Infrastructure for High Intensity Proton Linac for Spallation Neutron Source	cavity, niobium, laser, linac	1140
	S.C. Joshi, J. Dwivedi, P.D. Gupta, P.R. Hannurkar, V. Jain, P. Khare, P.K. Kush, G. Mundra, A. Puntambekar, S. Raghvendra, S.B. Roy, P. Shrivastava RRCAT, Indore (M.P.), India
	Raja Ramanna Centre for Advanced Technology has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. The proton linac will require a large number of superconducting Radio Frequency cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. A dedicated facility is being set up for development of multi-cell superconducting cavities and their performance characterization. 1.3 GHz single-cell niobium cavities have been developed to establish the fabrication procedure. These cavities has exhibited high quality factor with an accelerating gradients up to 37 MV/m. A novel technique of laser welding of 1.3 GHz niobium cavity has been developed and demonstrated performance comparable to electron beam welded cavity. A dedicated facility for SCRF cavity forming, machining, electron beam welding, RF characterization, cavity tuning and cavity processing is being set up. To characterize a SCRF cavity at 2K, a vertical test stand has been developed and a horizontal test stand has been designed.

THPP132	Warming Rate Reduction of the SARAF RF Couplers by Application of a High Voltage Dc Bias	operation, experiment, cavity, linac	1168
	B. Kaizer, Y. Ben Aliz, I. Fishman, J. Rodnizki, L. Weissman Soreq NRC, Yavne, Israel
	Warming up of the coupler region of the SARAF Half Wave Resonator (HWR) cavities was one of the main limiting factors for long operation at high RF field values. The warming effect is, most likely, associated with multipacting in the coupler region. We have tried to suppress the multipacting discharge in the couplers by application a DC bias to their inner conductors. A bias-T, element that conducts up to 4 kW of 176 MHz RF power and provides DC insulation of the coupler inner conductor, was designed and built for this purpose. First on-line operation showed that the DC bias indeed reduces dramatically the warming rates of most of the cavities by an order of magnitude. Today, coupler warming is no longer the main factor hindering accelerator operation.

THPP137	Present Status of the 3 MeV Proton Linac at Tsinghua University	linac, rfq, status, target	1182
	Q.Z. Xing, C. Cheng, C.T. Du, L. Du, T. Du, X. Guan, C. Jiang, C.-X. Tang, X.W. Wang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China B.C. Wang NINT, Xi'an, People's Republic of China
	We present, in this paper, the present status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The ECR ion source produces 50 keV proton beam which is accelerated to 3 MeV by the downstream RFQ accelerator. The RFQ accelerator has been conditioned to 50 Hz/500 μs with the input power of 442 kW. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The status of the development of the Drift Tube Linac is also presented in this paper. The beam energy will be enhanced to 13 MeV after the DTL is ready in 2015.

FRIOA06	AWAKE: Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN	plasma, electron, laser, experiment	1196
	E. Gschwendtner CERN, Geneva, Switzerland
	Plasma wakefield acceleration is a promising alternative reaching accelerating fields a magnitude of up to 3 higher (GV/m) when compared to conventional RF acceleration. AWAKE, world’s first proton-driven plasma wakefield experiment, was launched at CERN to verify this concept. In this experiment proton bunches at 400 GeV/c will be extracted from the CERN SPS and sent to the plasma cell, where the proton beam drives the plasma wakefields and creates a large accelerating field. This large gradient of ~GV/m can be achieved by relying on the self-modulation instability (SMI) of the proton beam; when seeded by ionization through a short laser pulse, a train of micro-bunches with a period on the order of the plasma wavelength (~mm) develops, which can drive such a large amplitude wake from a long proton bunch (~12 cm). An electron beam will be injected into the plasma to probe the accelerating wakefield. The AWAKE experiment is being installed at CERN in the former CNGS facility, which must be modified to match the AWAKE requirements. First proton beam to the plasma cell is expected by end 2016.
	Slides FRIOA06 [7.276 MB]

FRIOB02	Proton and Carbon Linacs for Hadron Therapy	linac, hadron, ion, hadrontherapy	1207
	A. Degiovanni, U. Amaldi TERA, Novara, Italy A. Degiovanni CERN, Geneva, Switzerland
	Beams of 200 MeV protons and 400 MeV/u fully stripped carbon ions are used for the treatment of solid tumours seated at a maximum depth of 27 cm. More than 100’000 patients have been treated with proton beams and more than 10’000 with carbon ions. Very low proton currents - of the order of 1 nA - are enough to deliver the typical dose of 2 Gy/l in one minute. In the case of carbon ions the currents are of the order of 0.1-0.2 nA. For this reason 3 GHz linacs are well suited in spite of the small apertures and low duty cycle. The main advantage of linacs, pulsing at 200-400 Hz, is that the output energy can be continuously varied pulse-by-pulse and in 2-3 min a moving tumour target can be covered about 10 times by deposing the dose in many thousands of ‘spots’. High frequency hadron therapy linacs have been studied in the last 20 years and are now being built as hearts of proton therapy centres, while carbon ion linacs are still in the designing stage. At present the main challenges are the reduction of the footprint of compact ‘single-room’ proton machines and the power efficiency of dual proton and carbon ions ‘multi-room’ facilities.
	Slides FRIOB02 [14.013 MB]

FRIOB03	Prospects for Accelerator-Driven Thorium Systems	neutron, cyclotron, target, experiment	1213
	J.-P. Revol iThEC, Geneva, Switzerland
	To meet the tremendous world energy needs, systematic R&D has to be pursued to replace fossil fuels. Nuclear energy, which produces no green house gases and no air pollution, should be a leading candidate. How nuclear energy, based on thorium rather than uranium, could be an acceptable solution is discussed. Thorium can be used both to produce energy or to destroy nuclear waste. The thorium conference, organized by iThEC at CERN in October 2013, has shown that thorium is seriously considered by developing countries as a key element of their energy strategy. However, developed countries do not seem to move in that direction, while global cooperation is highly desirable in this domain. As thorium is not fissile, an elegant option is to use a proton accelerator to drive an “Accelerator Driven System (ADS)”, as suggested by Nobel Prize laureate Carlo Rubbia. Therefore, the accelerator community has an important challenge to meet: provide the required proton beam for ADS.
	Slides FRIOB03 [20.039 MB]

Paper

Title

Other Keywords

Page

MOPP001

First Experimental Results for the Superconducting Half-Wave Resonators for PXIE

cavity, niobium, cryomodule, accelerating-gradient

46

Z.A. Conway, A. Barcikowski, G.L. Cherry, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.W.T. MacDonald, R.C. Murphy, P.N. Ostroumov, T. Reid, K.W. Shepard
ANL, Argonne, Illinois, USA

Funding: This work was supported by the U.S. Department of energy, Offices of High-Energy Physics and Nuclear Physics, under Contract No. DE-AC02-76-CH03000 and DE-AC02-06CH11357.
The first pair of superconducting niobium half-wave resonators operating at 162.5 MHz for the FNAL PIP-II project are complete and this poster reports the cold test results. These cavities are optimized to accelerate protons/H⁻ from 2 to 10 MeV and build upon optimized electromagnetic designs and processing techniques developed at Argonne for the Intensity Upgrade of the ATLAS superconducting heavy ion accelerator.

MOPP015

High Energy Electron Radiography Experiment Research Based on Picosecond Pulse-width Bunch

experiment, electron, linac, quadrupole

76

Q.T. Zhao, S. Cao, R. Cheng, X.K. Shen, Z.M. Zhang, Y.T. Zhao
IMP, Lanzhou, People's Republic of China
Y.-C. Du
TUB, Beijing, People's Republic of China
W. Gai
ANL, Argonne, Illinois, USA

A new scheme is proposed that high energy electron beam as a probe is used for time resolved imaging measurement of high energy density materials, especially for high energy density matter and inertial confinement fusion. The first picosecond pulse-width electron radiography experiment was achieved by Institute of Modern Physics, Chinese Academy of Sciences and Tinghua University (THU), based on THU Linear electron accelerator (LINAC). It is used for principle test and certifying that this kind of LINAC with ultra-short pulse electron bunch can be used for electron radiography. The experiment results, such as magnifying factor and the imaging distortion, are consistent with the beam optical theory well. The 2.5 um RMS spatial resolution has been gotten with magnifying factor 46, with no optimization the imaging lens section. It is found that in the certain range of magnifying factor, the RMS spatial resolution will get better with bigger magnifying factor. The details of experiment set up, results, analysis and discussions are presented here.

Poster MOPP015 [2.866 MB]

MOPP026

Actively Cooled RF Power Coupler : Theoretical and Experimental Studies

cryomodule, cryogenics, cavity, linac

111

R. Bonomi, V. Parma
CERN, Geneva, Switzerland

In cryostats for Super-conducting Radio Frequency Cavities, the heat loads introduced by the high-power RF couplers represent an important fraction of the overall static thermal budget. Working at low operating temperature benefits from a reduced surface resistance (low dynamic losses) but is penalized by the high refrigeration cost. The external conductor of RF coaxial couplers provides a direct conduction path from ambient to cryogenic temperature plus is heated by resistive power deposition. Heat interception is therefore essential to contain heat in-leaks: a double-walled external conductor with a properly designed gas cooling effectively reduces heat loads to the cold bath by 1 order of magnitude. This paper presents the thermal design of the RF power coupler of the Superconducting Proton Linac (SPL) at CERN, featuring a helium vapour cooling between 4.5 K and ambient temperature. Numerical models, which can be used as design tools for other applications, have been developed to assess efficiency and thermal performance. A full-size mock-up cooled by nitrogen has been built for experimental validation. Comparison between calculations and measurements is presented and discussed.

MOPP038

Longitudinal Bunch Profile Monitoring at the ESS Linac

linac, simulation, neutron, target

143

I. Dolenc Kittelmann, B. Cheymol
ESS, Lund, Sweden

The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5MW, 2GeV proton linac. This high intensity linac will among other beam instrumentation require longitudinal bunch profile monitors. These shall be used during the commissioning phase and start-up periods for beam dynamics optimization and beam loss reduction. The paper focuses on the preliminary studies concerning the longitudinal bunch profile monitoring at the ESS linac.

MOPP059

Study and Design of the High Power RF Coupler for the CH-Cavity of the Fair pLINAC

coupling, cavity, linac, resonance

187

F. Maimone, G. Clemente, W. Vinzenz
GSI, Darmstadt, Germany

At GSI a proton Linac has been designed and developed in order to provide a 70 MeV proton beam for the FAIR facility. The pLINAC consists of an RFQ followed by six CH-DTL accelerating cavities and the electromagnetic field inside each cavity is generated by seven Klystrons providing up to 2.8 MW power at 325.224 MHz. The high power RF coupling between the Klystron and the accelerating CH-cavity has been studied and an inductive coupling loop has been designed. The coupler insertion inside the cavity and the rotation angle with respect to the magnetic field lines have been adjusted and the results of the analysis of the coupler positioning are presented. A prototype coupler is under construction and the measurement of RF coupling with the CH-cavity is scheduled within this year.

MOPP063

Development of a Pepper Pot Emittance Measurement Device for FRANZ

emittance, ion, ion-source, plasma

199

B. Klump, U. Ratzinger, W. Schweizer, K. Volk
IAP, Frankfurt am Main, Germany

Funding: This work is supported by HGS-HIRe
Within the FRANZ project [*] on the Institute of Applied Physics, University Frankfurt, a robust and simple pepper pot emittance measurement device for high beam power densities is developed. To use the device directly behind the ion source, a high robustness against HV breakdowns is necessary. This paper gives an overview on experimental setup, on the analysis method and on imaging properties of the screen. Furthermore, the implemented software-based evaluation method is shown. It concludes with a preliminary emittance measurement on the high current ion source for FRANZ.
[*] U. Ratzinger et al., “intense Pulsed Neutron Source FRANZ in the 1-500 keV Range“, Proc. ICANS-XVIII, Dongguan, April 2007, p.210

MOPP064

R&D of the 17 MeV MYRRHA Injector

emittance, cavity, rfq, linac

202

D. Mäder, M. Basten, D. Koser, H.C. Lenz, N.F. Petry, H. Podlech, A. Schempp, M. Schwarz, M. Vossberg
IAP, Frankfurt am Main, Germany
C. Zhang
GSI, Darmstadt, Germany

Funding: Project supported by the EU, FP7 MAX, Contract No. 269565
MYRRHA is designed as an accelerator driven system (ADS) for transmutation of long-lived radioactive waste. The challenge of the linac development is the very high reliability of the accelerator to limit the thermal stress inside the reactor. With the concept of parallel redundancy the injector will supply a cw proton beam with 4 mA and 17 MeV to the main linac. The new MYRRHA injector layout consists of a very robust beam dynamics design with low emittance growth rates. Sufficient drift space provides plenty room for diagnostic elements and increases the mountability. Behind a 4-Rod-RFQ and a pair of two-gap QWR rebunchers at 1.5 MeV the protons are matched into the CH cavity section. A focussing triplet between the rebunchers ensures an ideal transversal matching into the doublet lattice. Each of the 7 RT CH structures has a constant phase profile and does not exceed thermal losses of 29 kW/m. The transition to the 5 SC CH cavities with constant beta profile is at 5.9 MeV. For a safe operation of the niobium resonators the electric and magnetic peak fields are defined below 25 MV/m and 57 mT respectively.

Poster MOPP064 [4.024 MB]

MOPP065

Investigations of Space-Charge Compensation in Low-Energy Beam Transport (LEBT) Sections Using a Particle-in-Cell Code

electron, ion, simulation, space-charge

205

D. Noll, M. Droba, O. Meusel, U. Ratzinger, K. Schulte, C. Wiesner
IAP, Frankfurt am Main, Germany

Among the advantages of magnetostatic LEBT sections is the possibility for compensation of space charge by electrons in the case of positively charged ion beams. In the past, it has been shown that the distribution of these compensation electrons can lead to unwanted emittance growth. However, the distribution of electrons especially in the presence of the magnetic fields of the focussing lenses is difficult to predict. To improve the understanding of the influence on the beam, models for the relevant processes namely residual gas ionization using realistic cross sections as well as secondary electron production on surfaces have been implemented in a particle-in-cell code. In this contribution, we will present the code used as well as first results for two model systems as an example.

MOPP078

RF Power Systems for the FAIR Proton Linac

klystron, linac, electronics, cavity

236

J. Lesrel, C. Joly
IPN, Orsay, France
E. Plechov, A. Schnase, G. Schreiber, W. Vinzenz
GSI, Darmstadt, Germany

In the framework of collaboration between the FAIR project, GSI, and CNRS, the IPNO lab is in charge of providing the high power RF components for a cavity test stand and for the planned FAIR proton Linac. This Linac will be connected to the existing GSI synchrotron SIS18 for serving as an injector for the new FAIR facility. The 70 MeV FAIR proton Linac design contains a 3 MeV RFQ, and a DTL based on Cross-bar H-mode cavities (CH). It will operate with pulsed RF at 325.224 MHz with a width of 200 μs and a repetition rate of 4 Hz. The planned RF systems of the proton Linac will be presented as well as the description of the test stand. The first power test results are obtained with a Thales klystron developed jointly with CNRS. Three solid state amplifiers made by Sigmaphi Electronics for the bunchers will also be described in this paper.

MOPP080

Beam Dynamics Study for RAON Superconducting Linac

linac, ion, lattice, quadrupole

239

H. Jang, H.J. Kim
IBS, Daejeon, Republic of Korea
J.G. Hwang
KNU, Deagu, Republic of Korea
B.H. Oh
POSTECH, Pohang, Kyungbuk, Republic of Korea

Rare Isotope Science Project (RISP) in Korea is going to build an ion accelerator, RAON which can generate and accelerate various stable ions such as uranium, proton, xenon and rare isotopes such as tin, nickel. Linear accelerators of RAON adopted superconducting RF cavities and warm quadruple doublet structure. In RAON, there are two low energy linacs which can accelerate the Uranium beam from 0.5MeV/u to 17.5MeV/u, charge stripping sections and one high energy linac which can accelerate the Uranium beam up to 200MeV/u. Due to the diversity of planned ions and isotopes, their A/q range lies widely from 1 to 8. As a result, the research related with linac lattice design and beam dynamics is one of the important topics to build RAON. In this presentation the current status of RAON linac lattice design and the beam dynamics simulation results for acceleration of various ions will be described.

MOPP084

Nondestructive Diagnostics of Proton Beam Halo and Transverse Bunch Position by Cerenkov Slow Wave Structures

simulation, diagnostics, monitoring, electron

251

S.V. Kuzikov, M.B. Goykhman, A.V. Gromov, A.V. Palitsin, Yu.V. Rodin, A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia

An appearance of the halo around bunch of particles is very undesirable destructive phenomenon in high-intensity proton accelerators. We suggest using built-in short BWO section in form of the corrugated metallic waveguide, in order to control particle distribution in real time. In BWO low velocity proton bunch has synchronism with slow spatial harmonic of TM01 wave. Fields of slow harmonic sharply grow in direction from axis to walls and rf power, generated by flying bunch of the given charge, critically depends on transverse bunch size. Results of the simulation, carried out for 20 pC proton bunch of 10 ps duration, show that in 5 GHz BWO of 30 cm length the output rf pulse of several nanosecond duration is varied from mW- level (for 1 mm transverse bunch size) to several tens of mW (for bunch of 20 mm radius). This power level is high enough to control halo appearance in each single proton bunch. The producible rf power in a BWO is also dependent on bunch deflection from axis. This effect we plan to use, in order to provide transverse bunch position monitoring by means of two additional rectangular slow wave section which have corrugations on mutually perpendicular walls.

Poster MOPP084 [0.732 MB]

MOPP088

MUNES a Compact Neutron Source for BNCT and Radioactive Wastes Characterization

neutron, rfq, target, quadrupole

261

A. Pisent, P. Colautti, E. Fagotti
INFN/LNL, Legnaro (PD), Italy

At INFN LNL (Legnaro Italy) it has been built a high intensity Radio Frequency Quadrupole (RFQ) structure, able to produce a 5 MeV proton beam of 30 mA. Coupled with a Be target such a beam can generate a neutron flux of 10¹⁴ n/s, with a spectrum centered in the MeV region (that has been recently characterized in detail at LNL accelerators). This neutron flux can be moderated to generate a thermal or epithermal source for BNCT with very little contamination of energetic form energetic neutron and gamma. Since the approval of MUNES project (in 2012) the high technology issues related to a compact neutron source to be installed in an Hospital environment have been faced. In particular for the powering of the accelerating structure an innovative system, completely based on solid state amplifiers, has been developed and ordered to industry. An outline of MUNES design and the status of the project will be given in the paper.

MOPP099

Compact Proton Injector for Synchrotrons

rfq, linac, cavity, quadrupole

291

A.D. Kovalenko, A.V. Butenko
JINR, Dubna, Moscow Region, Russia
A. Kolomiets, A.S. Plastun
ITEP, Moscow, Russia

Compact linac comprising two sections of different RFQ structures was designed. The first section is conventional RFQ with output energy 3 MeV whereas the second one is RFQ with trapezoidal modulation of vanes. The linac output energy is 8 MeV. The both structures operate at frequency of 352 MHz. The total length of machine is less than 8 m. The output pulsed beam current is of 40 mA. The design is suitable for both as NICA injection complex and proton superconducting medical synchrotron.

MOPP124

Development of a 3 MeV Prototype RFQ Structure for High Intensity Proton Linac for ISNS

rfq, vacuum, ion, operation

345

S.C. Joshi, A. Chaturvedi, S.K. Chauhan, K.K. Das, G.V. Kane, S.V. Kokil, B. Oraon, S. Raghvendra, N.K. Sharma
RRCAT, Indore (M.P.), India

Raja Ramanna Centre for Advanced Technology (RRCAT) has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. A 3 MeV Radio Frequency Quadrupole (RFQ) will be used as front end of the pulsed proton linac. A full scale prototype RFQ structure has been designed and fabricated to validate the physics design and manufacturing procedures. The total of 3.46 meter has been divided in three segments for ease in machining. The fabricated RFQ structure has been assembled for low power RF characterization. The RFQ frequency and field tuning exercise is being carried out using 48 stub tuners. The paper will also present the engineering design aspects and fabrication issues for the full scale RFQ structure.

MOPP125

Comparison of Normal Conducting High Energy Accelerating Structures for a Moderate Operating Frequency

coupling, linac, Windows, impedance

348

V.V. Paramonov
RAS/INR, Moscow, Russia

The progress in the CERN Linac 4 project confirms the very attractive possibility for single frequency high intensity high energy normal conducting hadron linac. The important part of such linac is the accelerating structure for high energy part. Parameters of possible accelerating structures, referring to PIMS, at operating frequency 352 MHz are considered for proton energy up to 600 MeV. The set of parameters, such as dimensions, RF efficiency, field stability, cooling capability, vacuum conductivity, are considered and compared.

MOPP129

Status of the FETS Project

rfq, emittance, ion-source, ion

361

A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.M.H. Alsari, M. Aslaninejad, J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
J.J. Back
University of Warwick, Coventry, United Kingdom
G.E. Boorman, A. Bosco, S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
R.T.P. D'Arcy, S. Jolly
UCL, London, United Kingdom
M. Dudman, J.K. Pozimski
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
D.C. Plostinar
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) under construction at RAL is a demonstrator for front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, high energy physics proton drivers etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty factor, FETS consists of a high brightness ion source, magnetic low energy beam transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium energy beam transport (MEBT) containing a high speed beam chopper and non-destructive laser diagnostics. This paper describes the current status of the project and future plans.

MOPP134

Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening

cavity, simulation, linac, vacuum

373

J. Rodnizki, Y. Ben Aliz, A. Grin, Z. Horvitz, A. Perry, L. Weissman
Soreq NRC, Yavne, Israel
G.K. Davis
JLab, Newport News, Virginia, USA
J.R. Delayen
ODU, Norfolk, Virginia, USA

The SARAF Prototype Superconducting Module (PSM) houses six 176 MHz Half Wave Resonators(HWR). The PSM accelerates protons and deuterons from 1.5 MeV/u to 4 and 5.6 MeV. The HWRs are highly sensitive to the coolant liquid Helium pressure fluctuations which limit the available beam power to 2kW per cavity out of 4kW RF amplifier and coupler and so might limit the available beam current to 2mA depending on the output energy. The flat shape of the cavity along the beam line in the area of the high electric field generates the high sensitivity of the Eigen mode frequency to helium pressure. The evaluated cavity sensitivity is full consistent with the measured values. It was explored that the tuning system (the fog structure) has a significant contribution to the cavity sensitivity. By using ribs or by modifying the rigidity of the fog we may reduce the HWR sensitivity by a factor of 3. This analysis is applied to study the stresses on the cavity during cool down and warm up to avoid plastic deformation as the Niobium yield is an order of magnitude lower in room temperature.

MOPP137

Design Progress of the MYRRHA Low Energy Beam Line

rfq, emittance, solenoid, ion

381

R. Salemme, L. Medeiros Romão, D. Vandeplassche
Studiecentrum voor Kernenergie - Centre d'Étude de l'énergie Nucléaire (SCK•CEN), Mol, Belgium
M.A. Baylac, D. Bondoux, F. Bouly, J.-M. De Conto, E. Froidefond
LPSC, Grenoble Cedex, France
J.-L. Biarrotte
IPN, Orsay, France
D. Uriot
CEA/DSM/IRFU, France

The MYRRHA project, a flexible spectrum neutron irradiation facility, is designed according to the Accelerator Driven System (ADS) reactor concept. The MYRRHA driver consists of a high power superconducting proton LINAC. A prototype of the front end injector is being built up into a test platform conceived to experimentally address its design issues. Currently, the ECR proton source has been industrially procured. LPSC Grenoble designed the subsequent Low Energy Beam Transport (LEBT) section. Right before the RFQ, a short section hosts an electrostatic beam chopper producing carefully controlled beam interruptions. In this paper the status of the LEBT design with the associated beam instrumentation is reviewed. Future experimental plans including LEBT beam characterization and optimization of the beam transmission are presented.

TUIOB02

Beam Commissioning of the 100 MeV KOMAC Linac

DTL, linac, operation, klystron

413

Y.-S. Cho
KAERI, Daejon, Republic of Korea

Funding: This work was supported by the Ministry of Science, ICT & Future Planning of the Korean Government.
The operation of the 100MeV proton linear accelerator for multipurpose application started in July, 2013 at KOMAC (Korea Multipurpose Accelerator Complex), KAERI (Korea Atomic Energy Research Institute). Also, the operation of the two beam lines, one is for 20MeV beam and the other for 100MeV beam, started in order to supply proton beams to users. The accumulated operation time was 2,290 hours and the proton beam was supplied to 937 samples in 2013. In addition to the beam service, the effort to increase the beam power is continuing in 2014. Beam commissioning and operation status of the linac will be presented in this talk.

Slides TUIOB02 [7.200 MB]

TUPP039

Accuracy Determination of the ESS MEBT Emittance Measurements

emittance, scattering, quadrupole, linac

519

B. Cheymol, A. Ponton
ESS, Lund, Sweden

The European Spallation Source MEBT will be equipped with a full set of diagnostics in order to characterize the bean properties before the injection in the DTL. The 6D phase space of the beam shall be characterize during the commissioning of the normal conducting as well as on regular basis during retuning phase of the machine. In this paper we will discuss the accuracy of the transverse emittance measurement that will be performed with the slit-grid method. The slit geometric parameters have been determined in order to achieve the required resolution and sensitivity. Scattering effects at the slit have been considered to determine the emittance measurement accuracy.

TUPP045

Beam Physics Challenge in FRIB Driver Linac

linac, ion, focusing, acceleration

532

Y. Yamazaki, N.K. Bultman, A. Facco, Z.Q. He, M. Ikegami, M.J. Johnson, S.M. Lidia, F. Marti, G. Pozdeyev, K. Saito, J. Wei, X. Wu, Y. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA

Funding: *Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The Facility for Rare Isotope Beams driver linac provides CW beams of all the stable ions (from protons to uranium) with a beam power of 400 kW and a minimum beam energy of 200 MeV/u in order to produce a wide variety of rare isotopes, mainly for nuclear physics study. The low beam emittances, both transverse and longitudinal, are key performance requirements, together with beam stability. These are required for efficiently separating one isotope from another, the reason for choosing this linac configuration. Multi-charge states (five charge states for the uranium case) are accelerated for maximizing the beam current, while keeping the low emittances. The efficient acceleration of high beam currents from 0.5 MeV/u through the superconducting linac is, needless to say, one of the biggest challenges. The beam power is more than 200 times higher than existing similar SC heavy ion linac. In particular, the SC cavities are difficult to protect from heavy ion beam damage, which can be 30 times larger locally than a proton beam with the same beam power. Other challenges peculiar to the FRIB linac will be presented, together with the solutions.

TUPP055

Progress on Euclid SRF Conical Half-Wave Resonator Project

cavity, niobium, vacuum, SRF

547

E.N. Zaplatin
FZJ, Jülich, Germany
T.L. Grimm
Niowave, Inc., Lansing, Michigan, USA
A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: This Work is supported by the DOE SBIR Program, contract # DE-SC0006302.
Euclid conical Half-Wave Resonator (cHWR) project develops 162.5 MHz β=v/c=0.11 accelerator structure for the high-intensity proton accelerator complex proposed at Fermi National Accelerator Laboratory. The main idea of this project is to provide a self-compensation cavity design together with its helium vessel to minimize the resonant frequency dependence on external loads. A unique cavity side-tuning option is also under development. Niowave, Inc. proposed a complete cavity production procedure including preparation of technical drawings, processing steps and resonator high-gradient tests to demonstrate such possibility for the private company. Here we present the procedure of the cavity and helium vessel fabrication, cavity preparation and initial experimental results.

TUPP056

High Current Proton Beam Operation at GSI UNILAC

ion, linac, operation, ion-source

550

W.A. Barth, A. Adonin, P. Gerhard, M. Heilmann, R. Hollinger, W. Vinzenz, H. Vormann
GSI, Darmstadt, Germany

A significant part of the experimental program at FAIR is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR Proton LINAC will deliver a pulsed proton beam of up to 35 mA of 36 μs duration at a repetition rate of 4 Hz. The current GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not dedicated for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown, that the UNILAC is able to provide for sufficient high intensities of CH3-beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach results in up to 2 mA of proton intensity at a maximum beam energy of 20 MeV, 100 μs pulse duration and a rep. rate of 4 Hz. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 17% of the FAIR requirements.

TUPP063

Improvements of the LORASR Code and their Impact on Current Beam Dynamics Designs

linac, DTL, focusing, quadrupole

569

R. Tiede, D. Mäder, N.F. Petry, H. Podlech, U. Ratzinger, C. Zhang
IAP, Frankfurt am Main, Germany

LORASR is a multi-particle tracking code optimized for the beam dynamics design of ‘Combined Zero Degree Structure (KONUS)’ lattices, which can benefit from an adapted input file structure and code architecture. Recent code developments focused on the implementation of tools for machine error studies and loss profile investigations, including also steering correction strategies. These tools are a stringent necessity for the design of high intensity linacs. Thus, the abilities of the present LORASR release allow performing a manifold of checks and optimizations before finalizing the layouts of KONUS-based or conventional linacs. Two representative examples are the MAX-MYRRHA Injector and the GSI FAIR Facility Proton Linac, both under development with strong participation of IAP, Frankfurt University. This paper presents the status of the LORASR code development with focus on the new features and illustrates the impact on current designs by examples taken from the above-mentioned projects.

TUPP073

Study of the ACS Cavity Without a Bridge Cavity

cavity, linac, coupling, alignment

596

F. Naito, K. Takata
KEK, Ibaraki, Japan
H. Ao, K. Hasegawa, K. Hirano, T. Morishita, N. Ouchi
JAEA/J-PARC, Tokai-mura, Japan

J-PARC has installed the Annular-ring Coupled Structure (ACS) linac to increase the beam energy up to 400 MeV. One ACS module is composed of two accelerating tanks which are coupled by the bridge cavity. The bridge cavity simplifies the handling of the multi-tank system. While it is possible to feed the RF power into the each tanks directly with the power divider and the phase shifter instead of the bridge cavity. The rf properties of the ACS linac with the direct rf-power supply system has been measured by using the low power model made of aluminum. The measured results are described in the paper.

Slides TUPP073 [5.042 MB]

TUPP097

100-MeV Proton Beam Phase Measurement by Using Stripline BPM

linac, DTL, simulation, coupling

656

H.S. Kim, Y.-S. Cho, H.-J. Kwon
KAERI, Daejon, Republic of Korea

Funding: This work is supported by Ministry of Science, ICT & Future Planning of the Korean Government.
In Korea Multipurpose Accelerator Complex (KOMAC), a 100-MeV proton linac, which is composed of a proton injector based on the microwave ion source, 3-MeV RFQ with a four-vane type and 100-MeV DTL with electromagnetic quadrupoles has been developed and currently provides the proton beam to users for various applications. To increase the beam power up to the design value, several improvements are required including the fine adjustment of the RF set-point during the operation. A stripline BPM is used for the beam phase measurement, where the pickup signals from four electrodes are combined by using the RF combiner, then mixed with 300 MHz LO reference signal resulting in 50 MHz IF signal which is processed by digital IQ demodulation method. In this paper, the details of the beam phase measurement setup and results will be presented.

TUPP103

The Beam Envelope Control in SC Linac for the Proton Radiotherapy

linac, controls, cavity, simulation

665

A.V. Samoshin, I.A. Ashanin, S.M. Polozov
MEPhI, Moscow, Russia

Proton cancer therapy is conventionally based on normal conducting synchrotrons and cyclotrons. The high electrical power consumption and especial devices necessary to energy variation are main problems of such facilities. Superconducting linacs based on short identical independently phased cavities have a seriously progress and it's development allow to propose their using for medical application. High accelerating gradient and small capacity losses nearly 10^-4 Vt/m are main advantages in advance of normal conducting facilities, the energy variation can be realized by means of RF field amplitude and phase variation in a number of cavities. Besides linac structures are lack of unwieldy magnetic system, simplicity of input and output of particles and high current densities. The parameters choose and the optimization for SC linac structure with energy up to 240 MeV and envelope control will discuss in this paper. The simulation was done using BEAMDULAC-SCL code*. The study of beam dynamics will direct to realize the energy variation in range 150-240 MeV with beam quality preservation.
* A.V. Samoshin. Proc. of LINAC2012, Tel-Aviv, Israel, TUPB069, p. 630 - 632

TUPP109

Cryogenic Testing of High-Velocity Spoke Cavities

cavity, cryogenics, acceleration, linac

677

C.S. Hopper, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
J.R. Delayen, H. Park
JLab, Newport News, Virginia, USA

Spoke-loaded cavities are being investigated for the high-velocity regime. The relative compactness at low-frequency makes them attractive for applications requiring, or benefiting from, 4 K operation. Additionally, the large velocity acceptance makes them good candidates for the acceleration of high-velocity protons and ions. Here we present the results of cryogenic testing of a 325 MHz, β0 = 0.82 single-spoke cavity and a 500 MHz, β0 = 1 double-spoke cavity.

WEIOB01

Chopping High-Intensity Ion Beams at FRANZ

ion, rfq, ion-source, solenoid

765

C. Wiesner, M. Droba, O. Meusel, D. Noll, O. Payir, U. Ratzinger, P.P. Schneider
IAP, Frankfurt am Main, Germany

The accelerator-driven Frankfurt Neutron Source FRANZ is under construction at the science campus of Frankfurt University. Its Low-Energy Beam Transport (LEBT) line also serves as test stand for transport and chopping experiments with high-intensity ion beams. The high-current proton source was tested successfully with dc currents above 200 mA . The LEBT section consisting of four solenoids and a 250 kHz, 120 ns chopper was successfully commissioned using a helium test beam at low beam currents. Transport simulations including space-charge compensation and measurements are discussed. Simulations and experimental results of the novel LEBT chopper using a Wien-filter type field array and pulsed electrode voltages of up to ±6kV will be presented.

Slides WEIOB01 [7.925 MB]

WEIOB02

SARAF Phase-I Proton / Deuteron Linac Beam Operation Status

operation, target, rfq, neutron

770

A. Kreisel, A. Arenshtam, Y. Ben Aliz, D. Berkovits, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I.G. Gertz, A. Grin, S. Halfon, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, J. Luner, I. Mor, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, D. Vartsky, L. Weissman, E. Zemach
Soreq NRC, Yavne, Israel

SARAF Phase-I linac is the first accelerator to demonstrate acceleration of variable energy 2 mA CW proton beam. Such intense beam is used in SARAF Phase-I to irradiate a liquid lithium jet target for nuclear astrophysics studies. Several improvements were necessary to allow beam operation with such high current. The improvements include a DC bias that was introduced on the cavity RF coupler to reduce coupler heating. A new slow chopper was commissioned to enable increase the current by increasing the duty cycle with fewer changes in the beam optics. A beam dump was developed to allow beam studies of a 2 mA CW proton beam. The beam dump is based on tungsten pins which distributes, by radiation, the high beam power over a large area which is then easily water cooled. While most of beam tuning is done using a low intensity pilot beam, some nondestructive methods were studied to monitor the high intensity beam. These include a current transformer and a residual gas monitor (RGM) to monitor beam transverse distribution. Additional valuable information about the beam current and energy is gained from measurements of the nuclear reaction products of the proton on lithium targets.

Slides WEIOB02 [3.027 MB]

THPP015

Status of the FAIR Proton Source and LEBT

linac, ion, diagnostics, ion-source

863

N. Chauvin, O. Delferrière, Y. Gauthier, P. Girardot, J.L. Jannin, A. Lotode, N. Misiara, J. Neyret, F. Senée, C.S. Simon, O. Tuske
CEA/IRFU, Gif-sur-Yvette, France
R. Berezov, J. Fils, P. Forck, R. Hollinger, V. Ivanova, C. Ullmann, W. Vinzenz
GSI, Darmstadt, Germany
A. Maugueret
CEA/DSM/IRFU, France

The unique Facility for Antiproton and Ion Research – FAIR will deliver stable and rare isotope beams covering a huge range of intensities and beam energies. A significant part of the experimental program at FAIR is dedicated to antiproton physics that requires an ultimate number 7x10¹⁰ cooled pbar/h. The high-intensity proton beam that is necessary for antiproton production will be deliver by a dedicated 75 mA/70 MeV proton linac. The injector section of this accelerator is composed by an ECR source, delivering a pulsed 100 mA H⁺ beam (4 Hz) at 95 keV and a low energy beam transport (LEBT) line required to match the beam for the RFQ injection. The proposed design for the LEBT is based on a dual solenoids focusing scheme. A dedicated chamber containing several diagnostics (Alisson scanner, Wien filter, SEM grid, Iris, Faraday Cup) will be located between the two solenoids. At the end of the beam line, an electrostatic chopper system is foreseen to inject up to 50μseconds long beam pulses into the RFQ. The status of LEBT simulations, design and fabrication of the FAIR proton injector will be presented.

THPP040

A Compact High-Frequency RFQ for Medical Applications

rfq, linac, cavity, quadrupole

935

M. Vretenar, A. Dallocchio, V.A. Dimov, M. Garlaschè, A. Grudiev, A.M. Lombardi, S.J. Mathot, E. Montesinos, M.A. Timmins
CERN, Geneva, Switzerland

In the frame of a new program for medical applications, CERN has designed and is presently constructing a compact 750 MHz Radio Frequency Quadrupole to be used as injector for hadron therapy linacs. The RFQ reaches an energy of 5 MeV in only 2 meters; it is divided into four standardized modules of 500 mm, each equipped with 12 tuner ports and one RF input. The inner quadrant radius is 46 mm and the RFQ has an outer diameter of 134 mm; its total weight is only 220 kg. The beam dynamics and RF design have been optimized for reduced length and minimum RF power consumption; construction techniques have been adapted for future industrial production. The multiple RF ports are foreseen for using either 4 solid-state units or 4 IOT’s as RF power sources. Although hadron therapy requires only a low duty cycle, the RFQ has been designed for 5% duty cycle in view of other uses. This extremely compact and economical RFQ design opens several new perspectives for medical applications, in particular for PET isotopes production in hospitals with two coupled high-frequency RFQs reaching 10 MeV and for Technetium production for SPECT tomography with two RFQs followed by a DTL.

THPP044

ESS Normal Conducting Linac Status and Plans

linac, rfq, DTL, vacuum

948

A. Ponton, B. Cheymol, R. De Prisco, M. Eshraqi, R. Miyamoto, E. Sargsyan
ESS, Lund, Sweden
G. Bourdelle, M. Desmons, A. France, O. Piquet, B. Pottin
CEA/DSM/IRFU, France
I. Bustinduy, P.J. González, J.L. Muñoz, I. Rueda, F. Sordo
ESS Bilbao, Bilbao, Spain
L. Celona, S. Gammino, L. Neri
INFN/LNS, Catania, Italy
M. Comunian, F. Grespan, A. Pisent, C. R. Roncolato
INFN/LNL, Legnaro (PD), Italy
P. Mereu
INFN-Torino, Torino, Italy

The ESS Normal Conducting (NC) linac is composed of an ion source, a Low Energy Beam Transport line, a Radio Frequency Quarupole (RFQ), a Medium Energy Beam Transport Line (MEBT) and a Drift Tube Linac (DTL). It creates, bunches and accelerates the proton beam up to 90 MeV before injecting into the superconducting linac which will deliver a 5 MW beam onto the neutron production target. The construction of the NC linac is part of a broad collaboration involving experts of various Labs in Europe. The technical chalenges and the collaboration strategy for the NC linac will be presented.

THPP061

RF Design of a Novel S-Band Backward Traveling Wave Linac for Proton Therapy

coupling, linac, accelerating-gradient, impedance

992

S. Benedetti, U. Amaldi
TERA, Novara, Italy
A. Degiovanni, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland

Proton therapy is a rapidly developing technique for tumour treatment, thanks to the physical and dosimetric advantages of charged particles in the dose distribution. Here the RF design of a novel high gradient accelerating structure for proton Linacs is discussed. The choice of a linear accelerator lies mainly in its advantage over cyclotron and synchrotron in terms of fast energy modulation of the beam, which allows the implementation of active spot scanning technique without need of passive absorbers. The design discussed hereafter represents a unicum thanks to the accelerating mode chosen, a 2.9985 GHz backward traveling wave mode with 150° phase advance, and to the RF design approach. The prototype has been designed to reach an accelerating gradient of 50 MV/m, which is more than twice that obtained before. This would allow a shorter Linac potentially reducing cost. The complete 3D RF design of the full structure for beta equal to 0.38 is presented. A prototype will be soon produced and tested at high power. This structure is part of the TULIP project, a proton therapy single-room facility based on high gradient linear accelerators.

Slides THPP061 [1.537 MB]

THPP063

Beam Diagnostics Layout for the FAIR Proton Linac

linac, diagnostics, emittance, beam-diagnostic

998

T. Sieber, M.H. Almalki, C. Dorn, J. Fils, P. Forck, R. Haseitl, W. Kaufmann, W. Vinzenz, M. Witthaus, B. Zwicker
GSI, Darmstadt, Germany
C.S. Simon
CEA/DSM/IRFU, France

The planned proton Linac for FAIR (Facility of Antiproton an Ion Research) will be - additionally to the existing GSI UNILAC - a second injector for the FAIR accelerator chain. It will inject a 70 MeV, (up to) 70 mA proton beam with a nominal pulse length of 30 us into the SIS18. The beam diagnostics system for the proton Linac comprises nine current transformers for pulse current determination and fourteen BPMs for position, mean beam energy and relative current measurement. SEM-Grids and stepping motor driven slits will be used for profile as well as for emittance measurements. A wire-based bunch shape monitor is foreseen, additionally a bending magnet for longitudinal emittance determination during commissioning. Presently, main efforts are conducted concerning the BPM system. Detailed signal simulations with the finite element code CST are performed. An electronics board using digital signal processing is evaluated by detailed lab-based characterization and beam-based measurements at the UNILAC. In this paper we present the general layout and the status of the diagnostics systems as well as key results from our measurements and simulations.

THPP071

Proposal of a 325 MHz Ladder-RFQ for the FAIR Proton-Linac

rfq, simulation, dipole, quadrupole

1016

M. Schütt, U. Ratzinger
IAP, Frankfurt am Main, Germany
R. M. Brodhage
GSI, Darmstadt, Germany

Funding: BMBF 05P12RFRB9
For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The first rf accelerator element is a 325 MHz RFQ accelerating from 95 keV to 3.0 MeV. RFQ’s beyond 300 MHz were realized in 4-Vane-type geometry so far. At IAP there is a tradition in 4-Rod-type RFQ development. This type of RFQ is dominating at lower frequencies. Very promising results have been reached with a ladder type-RFQ, which has been investigated during 2013. In comparison with a traditional 4-Rod RFQ approach the geometry is more convenient at high frequencies. We will show most recent 3D simulations of the frequency tuning possibilities and of a whole cavity demonstrating the power of a ladder type RFQ. An RFQ layout for the new FAIR proton injector will be shown. (see also R. Brodhage, U. Ratzinger, A. Almomani, “Design Study of a High Frequency Proton Ladder RFQ” , Proc. of the 2013 IPAC Conference, Shanghai, China, p. 3788.)

THPP085

The Prototype of the Proton Injector for the European Spallation Source

plasma, extraction, emittance, simulation

1044

L. Celona, L. Andò, G. Castro, S. Gammino, D. Mascali, L. Neri, G. Torrisi
INFN/LNS, Catania, Italy

The update of the design of the PS-ESS source and of its LEBT has been carried out in 2013 and the construction is now ongoing. The Ion Source will be able to provide a proton beam current larger than 70 mA to the 3.6 MeV RFQ. Several innovative solutions have been implemented in the redesign phase in order to cope with high-reliability/high-performance requirements of the ESS project. A flexible magnetic system will allow to investigate alternative configurations for future ion current upgrade of the machine based on the formation of a denser plasma. Innovative set-ups have been also explored for beam extraction, transport and chopping. Calculations have shown that space charge compensation up to 95 % is needed to preserve the low emittance in the low energy beam transfer line (LEBT). In order to obtain the optimal proton beam pulse rise and fall time – that should be 100 ns – we propose a LEBT chopping configuration that permits hundred nanosecond rise times despite the LEBT compensation needs few microseconds. The ongoing development of a 3D PIC code will be also described, that should allow predicting and tuning the beam pulse for different source/LEBT operative configurations.

THPP105

Beam Dynamics Simulation for the 1 GeV High Power Proton Linac

linac, focusing, rfq, simulation

1099

S.M. Polozov, V.S. Dyubkov, T. Kulevoy, A.V. Samoshin
MEPhI, Moscow, Russia
G. Kropachev, T. Kulevoy
ITEP, Moscow, Russia

Funding: This work is supported in part by the Ministry of Science and Education of Russian Federation under contract No. 14.516.11.0084
The design of high energy and high power proton linacs for accelerating driven systems (ADS) is one of the accelerator technology frontiers. Such linacs are under developing in EU, Japan, PRC but not discussed in Russia previous fifteen years. The driver linac and the breeder conceptual designs were funded by the Ministry of Science and Education of Russian Federation in 2013. The 2 MeV RFQ linac was proposed as the first accelerating section. A number of RF focusing sections types (by RF crossed lenses, modified electrode profile RFQ, axi-symmetrical RF focusing) were discussed for medium energies. The conventional modular scheme linac based on spoke-cavities and 5-cell elliptical cavities was designed for higher energies. The results of beam dynamics simulation in this linac will present.

THPP122

Development of Superconducting Cavities and Related Infrastructure for High Intensity Proton Linac for Spallation Neutron Source

cavity, niobium, laser, linac

1140

S.C. Joshi, J. Dwivedi, P.D. Gupta, P.R. Hannurkar, V. Jain, P. Khare, P.K. Kush, G. Mundra, A. Puntambekar, S. Raghvendra, S.B. Roy, P. Shrivastava
RRCAT, Indore (M.P.), India

Raja Ramanna Centre for Advanced Technology has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. The proton linac will require a large number of superconducting Radio Frequency cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. A dedicated facility is being set up for development of multi-cell superconducting cavities and their performance characterization. 1.3 GHz single-cell niobium cavities have been developed to establish the fabrication procedure. These cavities has exhibited high quality factor with an accelerating gradients up to 37 MV/m. A novel technique of laser welding of 1.3 GHz niobium cavity has been developed and demonstrated performance comparable to electron beam welded cavity. A dedicated facility for SCRF cavity forming, machining, electron beam welding, RF characterization, cavity tuning and cavity processing is being set up. To characterize a SCRF cavity at 2K, a vertical test stand has been developed and a horizontal test stand has been designed.

THPP132

Warming Rate Reduction of the SARAF RF Couplers by Application of a High Voltage Dc Bias

operation, experiment, cavity, linac

1168

B. Kaizer, Y. Ben Aliz, I. Fishman, J. Rodnizki, L. Weissman
Soreq NRC, Yavne, Israel

Warming up of the coupler region of the SARAF Half Wave Resonator (HWR) cavities was one of the main limiting factors for long operation at high RF field values. The warming effect is, most likely, associated with multipacting in the coupler region. We have tried to suppress the multipacting discharge in the couplers by application a DC bias to their inner conductors. A bias-T, element that conducts up to 4 kW of 176 MHz RF power and provides DC insulation of the coupler inner conductor, was designed and built for this purpose. First on-line operation showed that the DC bias indeed reduces dramatically the warming rates of most of the cavities by an order of magnitude. Today, coupler warming is no longer the main factor hindering accelerator operation.

THPP137

Present Status of the 3 MeV Proton Linac at Tsinghua University

linac, rfq, status, target

1182

Q.Z. Xing, C. Cheng, C.T. Du, L. Du, T. Du, X. Guan, C. Jiang, C.-X. Tang, X.W. Wang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
B.C. Wang
NINT, Xi'an, People's Republic of China

We present, in this paper, the present status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The ECR ion source produces 50 keV proton beam which is accelerated to 3 MeV by the downstream RFQ accelerator. The RFQ accelerator has been conditioned to 50 Hz/500 μs with the input power of 442 kW. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The status of the development of the Drift Tube Linac is also presented in this paper. The beam energy will be enhanced to 13 MeV after the DTL is ready in 2015.

FRIOA06

AWAKE: Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

plasma, electron, laser, experiment

1196

E. Gschwendtner
CERN, Geneva, Switzerland

Plasma wakefield acceleration is a promising alternative reaching accelerating fields a magnitude of up to 3 higher (GV/m) when compared to conventional RF acceleration. AWAKE, world’s first proton-driven plasma wakefield experiment, was launched at CERN to verify this concept. In this experiment proton bunches at 400 GeV/c will be extracted from the CERN SPS and sent to the plasma cell, where the proton beam drives the plasma wakefields and creates a large accelerating field. This large gradient of ~GV/m can be achieved by relying on the self-modulation instability (SMI) of the proton beam; when seeded by ionization through a short laser pulse, a train of micro-bunches with a period on the order of the plasma wavelength (~mm) develops, which can drive such a large amplitude wake from a long proton bunch (~12 cm). An electron beam will be injected into the plasma to probe the accelerating wakefield. The AWAKE experiment is being installed at CERN in the former CNGS facility, which must be modified to match the AWAKE requirements. First proton beam to the plasma cell is expected by end 2016.

Slides FRIOA06 [7.276 MB]

FRIOB02

Proton and Carbon Linacs for Hadron Therapy

linac, hadron, ion, hadrontherapy

1207

A. Degiovanni, U. Amaldi
TERA, Novara, Italy
A. Degiovanni
CERN, Geneva, Switzerland

Beams of 200 MeV protons and 400 MeV/u fully stripped carbon ions are used for the treatment of solid tumours seated at a maximum depth of 27 cm. More than 100’000 patients have been treated with proton beams and more than 10’000 with carbon ions. Very low proton currents - of the order of 1 nA - are enough to deliver the typical dose of 2 Gy/l in one minute. In the case of carbon ions the currents are of the order of 0.1-0.2 nA. For this reason 3 GHz linacs are well suited in spite of the small apertures and low duty cycle. The main advantage of linacs, pulsing at 200-400 Hz, is that the output energy can be continuously varied pulse-by-pulse and in 2-3 min a moving tumour target can be covered about 10 times by deposing the dose in many thousands of ‘spots’. High frequency hadron therapy linacs have been studied in the last 20 years and are now being built as hearts of proton therapy centres, while carbon ion linacs are still in the designing stage. At present the main challenges are the reduction of the footprint of compact ‘single-room’ proton machines and the power efficiency of dual proton and carbon ions ‘multi-room’ facilities.

Slides FRIOB02 [14.013 MB]

FRIOB03

Prospects for Accelerator-Driven Thorium Systems

neutron, cyclotron, target, experiment

1213

J.-P. Revol
iThEC, Geneva, Switzerland

To meet the tremendous world energy needs, systematic R&D has to be pursued to replace fossil fuels. Nuclear energy, which produces no green house gases and no air pollution, should be a leading candidate. How nuclear energy, based on thorium rather than uranium, could be an acceptable solution is discussed. Thorium can be used both to produce energy or to destroy nuclear waste. The thorium conference, organized by iThEC at CERN in October 2013, has shown that thorium is seriously considered by developing countries as a key element of their energy strategy. However, developed countries do not seem to move in that direction, while global cooperation is highly desirable in this domain. As thorium is not fissile, an elegant option is to use a proton accelerator to drive an “Accelerator Driven System (ADS)”, as suggested by Nobel Prize laureate Carlo Rubbia. Therefore, the accelerator community has an important challenge to meet: provide the required proton beam for ADS.

Slides FRIOB03 [20.039 MB]