| Paper | Title | Page |
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| MOPAS006 | Design and Fabrication of a Multi-element Corrector Magnet for the Fermilab Booster Synchrotron | 452 |
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Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000. To better control the beam position, tune, and chromaticity in the Fermilab Booster synchrotron, a new package of six corrector elements has been designed, incorporating both normal and skew orientations of dipole, quadrupole, and sextupole magnets. The devices are under construction and installation at 48 locations is planned. The density of elements and the rapid slew rate have posed special challenges. The magnet construction is presented along with DC measurements of the magnetic field. |
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| WEPMN105 | Fast Thermometry for Superconducting RF Cavity Testing | 2280 |
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Funding: Work supported by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy. Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several RTDs were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of this fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity. |
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| WEPMN107 | RF and Data Acquisition Systems for Fermilab's ILC SRF Cavity Vertical Test Stand | 2286 |
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Funding: Operated by Universities Research Association, Inc. for the U. S. Department of Energy under contract DE-AC02-76CH03000 Fermilab is developing a facility for vertical testing of SRF cavities as part of a program to improve cavity performance reproducibility for the ILC. The RF system for this facility, using the classic combination of oscillator, phase detector/mixer, and loop amplifier to detect the resonant cavity frequency and lock onto the cavity, is based on the proven production cavity test systems used at Jefferson Lab for CEBAF and SNS cavity testing. The design approach is modular in nature, using commercial-off-the-shelf (COTS) components. This yields a system that can be easily debugged and modified, and with ready availability of spares. Data acquisition and control is provided by a PXI-based hardware platform in conjunction with software developed in the LabView programming environment. This software provides for amplitude and phase adjustment of incident RF power, and measures all relevant cavity power levels, cavity thermal environment parameters, as well as field emission-produced radiation. It also calculates the various cavity performance parameters and their associated errors. Performance during system commissioning and initial cavity tests will be presented. |
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| WEPMN108 | A Technique for Monitoring Fast Tuner Piezoactuator Preload Forces for Superconducting RF Cavities | 2289 |
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Funding: Work supported by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.
The technology for mechanically compensating Lorentz Force detuning in superconducting RF cavities has already been developed at DESY. One technique is based on commercial piezoelectric actuators and was successfully demonstrated on TESLA cavities*. Piezo actuators for fast tuners can operate in a frequency range up to several kHz; however, it is very important to maintain a constant preload force on the piezo stack in the range of 10 to 50% of its specified blocking force. Determining the preload force during cooldown, warm-up, or re-tuning of the cavity is difficult without instrumentation, and exceeding the specified range can permanently damage the piezo stack. A technique based on strain gauge technology for superconducting magnets has been applied to fast tuners for monitoring the preload on the piezoelectric assembly. This paper will address the design and testing of piezo actuator preload sensor technology. Results from measurements of preload sensors installed on the tuner of the DESY Capture Cavity II tested at Fermilab will be presented. These results include measurements during cooldown, warm-up, and cavity tuning along with dynamic Lorentz force compensation.
* M. Liepe et al," Dynamic Lorentz Force Compensation with a Fast Piezoelectric Tuner" PAC2001 |