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| MOPP022 | Transatlantic Transport of Fermilab 3.9 GHZ Cryomodule for TTF/FLASH to DESY | alignment, acceleration, laser, vacuum | 592 | ||
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In an exchange of technology agreement, Fermilab built and will deliver a 3.9 GHz (3rd harmonic) cryomodule to DESY to be installed in the TTF/FLASH beamline. This cryomodule delivery will involve a combination of flatbed air ride truck and commercial aircraft transport to Hamburg Germany. A description of the isolation and damping systems that maintain alignment during transport and protect fragile components is provided. Initially, transport and corresponding alignment stability studies were performed in order to assess the risk associated with transatlantic travel of a fully assembled cryomodule. Shock loads were applied to the cryomodule by using a coldmass mockup to prevent subjecting actual critical components (such as the cavities and input couplers) to excessive forces. Accumulative and peak shock loads were applied through over-the-road testing and using a pendulum hammer apparatus, respectively. Finite Element Analysis (FEA) studies were implemented to define location of instrumentation for transport studies and provide modal frequencies and shapes. Shock and vibration measurement results of transport studies and stabilization techniques are discussed.
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| MOPP044 | Cavity Diagnostic System for the Vertical Test of the STF Baseline 9-cell Cavity at KEK | monitoring, electron, controls, diagnostics | 643 | ||
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Four 9-cell cavities, which are TESLA-type 9-cell cavities, were developed and tested in KEK for the future ILC project. A simple cavity diagnostic system was introduced to search the heating spot and to detect the x-ray emission. It is composed of the carbon resistors and the PIN photo diodes. They were attached on the equator of the cell, around the HOM couplers and on the end flanges. They were very effective to search the heating spot and to detect the x-ray emission during the vertical tests. All cavities eventually had the heating spot around the equator in the final state of the vertical test. It is conceivable that the quality of the electron beam welding was somewhat poor, when the dumbbells were connected. On this February, a new vertical test facility will be completed in STF (Superconducting RF Test Facility). Six 9-cell cavities will be tested by using the new system for S0 plan, which goal is the higher accelerating gradient for ILC. The new temperature and x-ray mapping system and new DAQ system will be introduced. This paper reports the recent status in the new vertical test facility in KEK-STF.
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| MOPP161 | Plasma Etching Rates and Surface Composition of Bulk Nb Treated in Ar/Cl2 Microwave Discharge | plasma, electron, ion, monitoring | 928 | ||
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To achieve theoretically predicted values of the accelerating fields in superconducting radiofrequency (SRF) cavities, their inside surface should be fairly smooth and free of impurities. Thus, surface preparation is the critical step in production of SRF cavities. Plasma etching process is a dry chemistry technique that can be used to achieve these requirements. It is based on interaction between reactive halogen species produced in the glow discharge and the surface. During this process, volatile Nb halides are evaporated from the surface of Nb, removing the mechanically damaged and contaminated layer. We present treatment of bulk Nb samples in the Ar/Cl2 microwave discharge. We achieved etching rates comparable to the rates obtained with the electropolishing method without introducing impurities in Nb. The rate dependence on various discharge parameters and reactive gas composition is presented. Surface composition and topology measurements were carried out before and after plasma treatment to determine level of impurities. Optimal experimental conditions determined on samples will applied be on single cell cavities, pursuing improvement of their RF performance.
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| TUPC117 | Beam Based Alignment of Quadrupole Triplets by Use of MATLAB Based Modeling | quadrupole, storage-ring, alignment, optics | 1341 | ||
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A new beam based method is introduced to measure the transversal shifts of quadrupole magnets in relation to each other within triplet structures. The displacements of the quadrupole magnets can be calculated by quadrupole strength variation in combination with a simulation of the orbit distortions utilizing a MATLAB based model for beam optics. A local smoothing of the quadrupole alignment can be achieved with accuracy better than those of geodetic surveys. Results are presented and compared with data from geodetic surveys.
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| TUPC118 | First Data from the Linear Collider Alignment and Survey Project (LiCAS) | laser, alignment, linear-collider, collider | 1344 | ||
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The LiCAS project has developed a prototype robotic survey system for rapid and highly accurate surveying of long linear accelerator tunnel networks. It is aimed at the survey of the reference network for the International Linear Collider (ILC). This Rapid Tunnel Reference Surveyor (RTRS) is designed to be an R\&D instrument for evaluating the potential performance of the RTRS concept and its survey technology. The prototype has been commissioned in a test tunnel at DESY with initial calibrations and measurements ongoing. We will report on the results obtained so far and present conclusions for the design of an RTRS suitable for the ILC.
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| TUPD020 | Remote Alignment of Low Beta Quadrupoles with Micrometric Resolution | radiation, alignment, quadrupole, controls | 1470 | ||
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Considering their location in a high radiation environment and the alignment tolerances requested, the Low Beta quadrupoles of LHC will be positioned remotely (controlling 5 degrees of freedom), with a displacement resolution of few microns in horizontal and vertical. Stepping motor gearbox assemblies are plugged into the jacks which support the cryomagnets in order to move them to the desired position regarding the quality of the beam collisions in the detectors. This displacement will be monitored in real time by the sensors located on the magnets. This paper describes the positioning strategy implemented as well as the software tools used to manage it.
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| TUPP011 | The ESRF Temperature Monitoring System from an Operational Point of View | monitoring, vacuum, radiation, controls | 1547 | ||
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The vacuum control system of the ESRF electron Storage Ring (SR) is in operation since more than ten years now. Apart from difficulties to have appropriate support for the old system, we start facing problems of aging and obsolescence. We have been reviewing our philosophy of data acquisition and remote control in order to upgrade our systems with state of the art technology by taking into account our operational experience. We have installed shielded "intelligent" devices inside the SR and took advantage of the latest developments linked to new communication technologies and standards, such as TCP/IP MODbus protocol and WEB server based instrument control. This presentation outlines our present work dedicated to the ESRF temperature acquisition system based on Programmable Logic Controllers (PLC), and new developments regarding the user interface in the control room. Several examples show the importance of surveying the temperatures in order to identify various mechanical or operational problems which allow us to anticipate later failures and provide us with an additional machine diagnostic tool.
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| TUPP012 | Presentation of the New ESRF Vacuum Control Applications from an Operational Point of View | vacuum, controls, diagnostics, ion | 1550 | ||
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The ESRF is in operation since more than ten years. Due to the aging vacuum system, we are faced to different kinds of failures such as air or water leaks, overheating of RF-liners or poor chamber alignment. In order to anticipate these failures and therefore reduce down times, we started to develop new diagnostic tools which allow us to detect much faster and with more precision any possible failures or malfunctioning of our vacuum system. Also driven by the increase of machine performances and the continuous vacuum installations, we search for new tools to safely commission such upgrades. This paper outlines our work on the development of a new vacuum user interface, which not simply reflects the actual status of our vacuum system, but which also provides us with a dynamic survey of computed vacuum signals highlighting unusual vacuum behaviours.
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| TUPP133 | Assembly of the Carbon Beam Gantry at the Heidelberg Ion Therapy (HIT) Accelerator | ion, quadrupole, alignment, proton | 1839 | ||
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The HIT facility comprises the only carbon ion gantry worldwide. This gantry is especially unique in offering fully flexible beam transport to the patient up to a magnetic rigidity of 6.6 Tm, equivalent to an energy of C-ions of 430 MeV/u. It includes a full 3D-beam scanning system and full medical treatment environment. The gantry can be rotated by 360 degree so that the beam may be aimed at the patient from arbitrary directions. Commissioning of the gantry with beam was started in January 2008, when the first beams were transported into the treatment room. The design and assembly of this gantry with a rotating mass on the order of 600 tons was a real challenge to the project partners involved, in particular the supplier MT Mechatronics. Given the tight tolerances for the position of the beam line components the survey and alignment procedure was difficult, since also the elastic deformation for the different rotation angles had to be taken into account. This presentation will report on the experiences and results of the assembly and alignment phases. Furthermore, the final performance reached for precision and reproducibility of the beam line components will be presented.
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| WEPC029 | Assessment of the Impact of External Stimuli on the Floor Stability of Diamond | storage-ring, damping, site, monitoring | 2049 | ||
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Continuous vibration monitoring is carried out and the stability of the Diamond floor slab has been assessed with regard to how it has responded to various external stimuli. Data has been collected on weather conditions and comparison made at extremes with floor vibration. The impact of a high level walkway bridge on the hall floor has also been assessed and there was a unique opportunity for an operational facility to measure the vibration response during a complete power black-out. The impact of local construction work is also presented.
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| WEPP009 | Collimator Integration and Installation Example of One Object to be Installed in the LHC | vacuum, insertion, collimation, alignment | 2542 | ||
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The collimation system is a vital part of the LHC project, protecting the accelerator against unavoidable regular and irregular beam loss. About 80 collimators will be installed in the machine before the first run. Two insertion regions are dedicated to collimation and these regions will be among the most radioactive in the LHC. The space available in the collimation regions is very restricted. It was therefore important to ensure that the 3-D integration of these areas of the LHC tunnel would allow straightforward installation of collimators and also exchange of collimators under the remote handling constraints imposed by high radiation levels. The paper describes the 3-D integration studies and verifications of the collimation regions combining the restricted space available, the dimensions of the different types of collimators and the space needed for transport and handling. The paper explains how installation has been planned and carried out taking into account the handling system and component availability.
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| THPC030 | Simulation Studies of Correlated Misalignments in the ILC Main Linac and the Influence of Ground Motion | emittance, alignment, simulation, linac | 3044 | ||
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Component misalignments are an important source of emittance dilution in the main linac of the International Linear Collider (ILC). The impact of static uncorrelated alignment errors has been widely studied with various simulation codes and several beam based alignment algorithms. For a realistic scenario one has to take into account that the survey and alignment process will introduce correlations between the component errors. In the present paper we study the performance of the Dispersion Matched Steering (DMS) technique for the case of such correlated misalignments. Different models for the correlations are investigated including a proposed alignment strategy for the ILC main linac* which has been implemented into the Merlin C++ library**. In addition to the initial static errors, dynamic errors due to ground motion will produce an emittance growth with time. For this case we have also investigated the stability of DMS tuning over time.
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* Kiyoshi Kubo, private communication |
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