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| TUP270 | RF and Structural Analysis of the 72.75 MHz QWR for the ATLAS Upgrade | 1325 |
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Funding: This work was supported by Argonne National Lab under contract # 0F-32381 & 0F32422 An energy upgrade to the heavy-ion accelerator ATLAS at Argonne Lab is progressing*,**. The plans include replacing split-ring cavities with high performance quarter wave resonators. The new 72.75 MHz resonators are designed for optimum ion velocity β=.077 and a record high accelerating voltage of 2.5 MV by modifying the top geometry and reducing the peak surface fields. This new cavity has a longer center conductor than the 109 MHz cavities previously built by ANL with AES assistance, this and the other geometry changes add new engineering requirements to the design. This paper presents the engineering studies that were performed to resolve new issues. These studies include determining structural frequencies of the center conductor and stiffening methods, resonator frequency sensitivity to helium pressure fluctuations, and determining stress levels due to pressure and slow tuning. Evaluation of fast piezoelectric tuner frequency shift to tuner load was also performed and the local cavity shape was optimized based on these results. * P.N. Ostroumov, et.al, “A New Atlas Efficiency and Intensity Upgrade Project,” SRF2009, tuppo016 ** P.N. Ostroumov, et.al., “Efficiency and Intensity Upgrade of the Atlas Facility,” LINAC 2010, MOP045 |
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| TUP271 | CESR-type SRF Cavity - Meeting the ASME Pressure Vessel Criteria by Analysis | 1328 |
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Funding: This work is supported by BNL under contract #147322 Over a dozen CESR-B Type SRF cryomodules have been implemented in advanced accelerators around the world. The cryomodule incorporates a niobium cavity operating in liquid helium at approximately 1.2 bar and at 4.5 K, and therefore, is subjected to a differential pressure of 1.2 bar to the beam vacuum. Over the past few decades niobium RRR values have increased, as manufacturing processes have improved, resulting in higher purity niobium and improved thermal properties. Along with these increases may come a decrease of yield strength, therefore, prior designs such as CESR-B, must be evaluated at the newer strength levels when using the newer high purity niobium. In addition to this the DOE directive 10CFR851 requires all DOE laboratories to provide a level of safety equivalent to that of the ASME Boiler and Pressure Vessel codes. The goal of this work was to analyze the CESR-B Type cavity and compare the results to ASME pressure vessel criteria and where necessary modify the design to meet the code criteria. |
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| TUP272 | Analysis and Comparison to Test of AlMg3 Seals Near a SRF Cavity | 1331 |
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| The Energy Recovery Linac (ERL) presently under construction at Brookhaven National Laboratory is being developed as research and development towards eRHIC, an Electron-Heavy Ion Collider. The experimental 5-cell 703.75 MHz (ECX) cavity was recently evaluated at continuous field levels greater than 10 MV/m. These tests indicated stored energy limits of the cavity on the order of 75 joules. During design of the cavity the cold flange on one side was moved closer to the cavity to allow the cavity to fit into the available chemical processing chamber at Jefferson Laboratory. RF and thermal analysis of the AlMg3 seal region of the closer side indicate this to be the prime candidate limiting the fields. This work presents the analysis results and compares these results to test data. | ||
| TUP273 | RF Thermal and Structural Analysis of the 60.625 MHz RFQ for the ATLAS Upgrade | 1334 |
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Funding: This work was supported by Argonne National Lab under contract # 0F-32402 The upgrade for the ATLAS facility is designed to increase the efficiency and intensity of beams for the user facility*, **. This will be accomplished with a new CW normal conducting RFQ, which will increase both transverse and longitudinal acceptance of the LINAC. This RFQ must operate over a wide range of power levels to accelerate ion species from protons to uranium. The RFQ design is a split coaxial structure and is made of OFE copper. The geometry of the design must be stable during operation. Engineering studies of the design at different RF power levels were conducted to ensure that the geometry requirements were met. Frequency shift analysis was also completed to determine the effects of high power levels. Thermal stress analysis was completed to show that the structure frequency is repeatable. *P.N. Ostroumov, et.al, “A New Atlas Efficiency and Intensity Upgrade Project,” SRF2009, tuppo016 **P.N. Ostroumov, et.al., “Efficiency and Intensity Upgrade of the Atlas Facility,” LINAC 2010, MOP045 |
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| THP043 | High-performance Accelerators for Free-Electron Laser (FEL) and Security Applications | 2196 |
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We describe the status of two accelerators that Advanced Energy Systems has recently designed and built, and is presently commissioning. One system will drive the THz FEL at the Fritz Haber Institute of the Max Planck Society in Berlin, while the other will produce radiation for Homeland Security applications. A key aspect of the required FEL accelerator performance is low longitudinal emittance < 50 keV-psec at 200 pC bunch charge from a thermionic electron source. The other system is compact, robust and efficient since it must be transportable.
Consultants to AES |
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