| Paper |
Title |
Page |
| TUPP029 |
Diagnostics and Analysis Techniques for High Power X-Band Accelerating Structures |
490 |
| SUPG002 |
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- A. Degiovanni, S. Döbert, W. Farabolini, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
- J. Giner Navarro
IFIC, Valencia, Spain
- J. Tagg
National Instruments Switzerland, Ennetbaden, Switzerland
- B.J. Woolley
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
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The study of high gradient limitations due to RF breakdowns is extremely important for the CLIC project. A series of diagnostic tools and analysis techniques have been developed in order to monitor and characterize the behaviour of CLIC accelerating structures under high power operation in the first CERN X-band klystron-based test stand (Xbox1). The data collected during the last run on a TD26r05 structure are presented in this paper. From the analysis of the RF power and phases, the location of the breakdowns inside the structure could be determined. Other techniques based on the field emitted dark current signals collected by Faraday cups placed at the two extremities of the structure have also been investigated. The results of these analyses are reported and discussed.
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| TUPP033 |
Effect of Beam-Loading on the Breakdown Rate of High Gradient Accelerating Structures |
499 |
| TUPOL08 |
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- J.L. Navarro Quirante, R. Corsini, A. Degiovanni, S. Döbert, A. Grudiev, O. Kononenko, G. McMonagle, S.F. Rey, A. Solodko, I. Syratchev, F. Tecker, L. Timeo, B.J. Woolley, X.W. Wu, W. Wuensch
CERN, Geneva, Switzerland
- O. Kononenko
SLAC, Menlo Park, California, USA
- A. Solodko
JINR, Dubna, Moscow Region, Russia
- J. Tagg
National Instruments Switzerland, Ennetbaden, Switzerland
- B.J. Woolley
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
- X.W. Wu
TUB, Beijing, People's Republic of China
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The Compact Linear Collider (CLIC) is a study for a future room temperature electron-positron collider with a maximum center-of-mass energy of 3 TeV. To efficiently achieve such high energy, the project relies on a novel two beam acceleration concept and on high-gradient accelerating structures working at 100 MV/m. In order to meet the luminosity requirements, the break-down rate in these high-field structures has to be kept below 10 per billion. Such gradients and breakdown rates have been demonstrated by high-power RF testing several 12 GHz structures. However, the presence of beam-loading modifies the field distribution for the structure, such that a higher input power is needed in order to achieve the same accelerating gradient as the unloaded case. The potential impact on the break-down rate was never measured before. In this paper we present an experiment located at the CLIC Test Facility CTF3 recently proposed in order to quantify this effect, layout and hardware status, and discuss its first results.
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Slides TUPP033 [1.970 MB]
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Poster TUPP033 [2.355 MB]
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| THPP061 |
RF Design of a Novel S-Band Backward Traveling Wave Linac for Proton Therapy |
992 |
| THPOL03 |
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- S. Benedetti, U. Amaldi
TERA, Novara, Italy
- A. Degiovanni, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland
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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.
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Slides THPP061 [1.537 MB]
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| FRIOB02 |
Proton and Carbon Linacs for Hadron Therapy |
1207 |
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- A. Degiovanni, U. Amaldi
TERA, Novara, Italy
- A. Degiovanni
CERN, Geneva, Switzerland
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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.
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Slides FRIOB02 [14.013 MB]
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| FRIOB02 |
Proton and Carbon Linacs for Hadron Therapy |
1207 |
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- A. Degiovanni, U. Amaldi
TERA, Novara, Italy
- A. Degiovanni
CERN, Geneva, Switzerland
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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.
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Slides FRIOB02 [14.013 MB]
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