IPAC2015 - List of Authors (Grudiev, A.)

Paper	Title	Page
TUPTY054	RF Design of the CLIC Structure Prototype Optimized for Manufacturing from Two Halves	2147
	H. Zha, A. Grudiev CERN, Geneva, Switzerland V.A. Dolgashev SLAC, Menlo Park, California, USA
	We present the RF design of a 12GHz Compact Linear Collider (CLIC) main linac accelerating structure prototype. The structure is made from two longitudinally symmetric halves. The main manufacturing process of each half is precision milling. The structure uses the same iris dimensions as the CLIC-G structure but the cell shape is optimized for milling. The geometry is optimized to reduce the surface electric and magnetic fields and the modified Poynting vector. This design can potentially reduce fabrication cost.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY054
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TUPTY055	Optimization of the RF Design of the CLIC Main Linac Accelerating Structure	2150
	H. Zha, A. Grudiev CERN, Geneva, Switzerland
	We present a new optimized design of the accelerating structure for the main linac of CLIC (Compact Linear Collider). The new structure has lower surface magnetic fields and a significantly smaller transverse size compared to the baseline design described in the CLIC Concept Design Report (CDR). This new design should reach higher accelerating gradients and have a reduced manufacturing cost. The details of the RF design procedure and the obtained results are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY055
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TUPTY056	Beam-Based Measurements of Long Range Transverse Wakefields in CLIC Main Linac Accelerating Structure	2153
	H. Zha, A. Grudiev, A. Latina, D. Schulte, A. Solodko, W. Wuensch CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway G. De Michele EPFL, Lausanne, Switzerland G. De Michele PSI, Villigen PSI, Switzerland N. Lipkowitz, G. Yocky SLAC, Menlo Park, California, USA
	The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures in the main linac. Every accelerating structure cell has four waveguides, terminated with individual RF loads, to damp the unwanted long-range transverse wakefields, in order to maintain beam stability in multi-bunch operation. In order to experimentally verify the calculated suppression of the wakefields, a prototype structure has been built and installed in FACET test facility at SLAC. The results of the measurements of the wakefields in the prototype structure by means of positron and electron bunches are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY056
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WEYB2	Beam Dynamics in a High Frequency RFQ	2408
	A.M. Lombardi, V.A. Dimov, M. Garlaschè, A. Grudiev, S.J. Mathot, E. Montesinos, S. Myers, M.A. Timmins, M. Vretenar CERN, Geneva, Switzerland
	CERN is constructing a 750 MHz Radio Frequency Quadrupole (RFQ) which can accelerate a proton beam to 5 MeV in a length of 2 m. The beam dynamics strategic parameters have been chosen to make this RFQ a good candidate for the injector of a medical facility operating at frequency of 3 GHz. Minimising beam losses above 1 MeV, containing the RF power losses and opening the road to industrialisation have been the guidelines for an unconventional RFQ design. In this paper, the optimisation efforts, the structure design and the expected beam qualities will be detailed. The status of the construction as well as the potential for further developments will be presented.
	Slides WEYB2 [2.166 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEYB2
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WEPHA025	Design of a Variable X-band RF Power Splitter	3167
	H. Zha, A. Grudiev, D. Gudkov, I. Syratchev CERN, Geneva, Switzerland
	The design of a two output ports, high power X-Band RF splitter with arbitrary split ratio is presented. This ratio is adjusted by mechanical changing the position a special RF short circuit piston. The piston is mounted on a step-motor providing the precise movement. Special measures were taken in the design to decrease the maximum electrical field on the cooper surface, as well as to maximise the bandwidth of the device. This splitter will be tested in the high power X-band test stand at CERN.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA025
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WEPHA057	High Gradient Testing of an X-band Crab Cavity at XBox2	3242
	B.J. Woolley, P.K. Ambattu, R. Apsimon, G. Burt, A.C. Dexter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A. Grudiev, I. Syratchev, R. Wegner, B.J. Woolley, W. Wuensch CERN, Geneva, Switzerland
	CERN’s Compact linear collider (CLIC) will require crab cavities to align the bunches to provide effective head-on collisions. An X-band quasi-TM11 deflecting cavity has been designed and manufactured for testing at CERN’s Xbox-2 high power standalone test stand. The cavity is currently under test and has reached an input power level in excess of 40MW, with a measured breakdown rate of better than 10^-5 breakdowns per pulse. This paper also describes surface field quantities which are important in assessing the expected BDR when designing high gradient structures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA057
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THPF101	Design of a Proton Travelling Wave Linac with a Novel Tracking Code	3945
	S. Benedetti EPFL, Lausanne, Switzerland U. Amaldi TERA, Novara, Italy A. Grudiev, A. Latina CERN, Geneva, Switzerland
	A non-relativistic proton linac based on high gradient backward travelling wave accelerating structures was designed using a novel dedicated 3D particle tracking code. Together with the specific RF design approach adopted, the choice of a 2.9985 GHz backward travelling wave (BTW) structure with 150° RF phase advance per cell was driven by the goal of reaching an accelerating gradient of 50 MV/m, which is more than twice that achieved so far. This choice dictated the need to develop a new code for tracking charged particles through travelling wave structures which were never used before in proton linacs. Nevertheless, the new code has the capability of tracking particles through any kind of accelerating structure, given its real and imaginary electromagnetic field map. This project opens a completely new field in the design of compact linacs for proton therapy, possibly leading to cost-effective and widespread single room facilities for cancer treatment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF101
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Paper

Title

Page

RF Design of the CLIC Structure Prototype Optimized for Manufacturing from Two Halves

2147

H. Zha, A. Grudiev
CERN, Geneva, Switzerland
V.A. Dolgashev
SLAC, Menlo Park, California, USA

We present the RF design of a 12GHz Compact Linear Collider (CLIC) main linac accelerating structure prototype. The structure is made from two longitudinally symmetric halves. The main manufacturing process of each half is precision milling. The structure uses the same iris dimensions as the CLIC-G structure but the cell shape is optimized for milling. The geometry is optimized to reduce the surface electric and magnetic fields and the modified Poynting vector. This design can potentially reduce fabrication cost.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY054

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTY055

Optimization of the RF Design of the CLIC Main Linac Accelerating Structure

2150

H. Zha, A. Grudiev
CERN, Geneva, Switzerland

We present a new optimized design of the accelerating structure for the main linac of CLIC (Compact Linear Collider). The new structure has lower surface magnetic fields and a significantly smaller transverse size compared to the baseline design described in the CLIC Concept Design Report (CDR). This new design should reach higher accelerating gradients and have a reduced manufacturing cost. The details of the RF design procedure and the obtained results are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY055

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTY056

Beam-Based Measurements of Long Range Transverse Wakefields in CLIC Main Linac Accelerating Structure

2153

H. Zha, A. Grudiev, A. Latina, D. Schulte, A. Solodko, W. Wuensch
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway
G. De Michele
EPFL, Lausanne, Switzerland
G. De Michele
PSI, Villigen PSI, Switzerland
N. Lipkowitz, G. Yocky
SLAC, Menlo Park, California, USA

The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures in the main linac. Every accelerating structure cell has four waveguides, terminated with individual RF loads, to damp the unwanted long-range transverse wakefields, in order to maintain beam stability in multi-bunch operation. In order to experimentally verify the calculated suppression of the wakefields, a prototype structure has been built and installed in FACET test facility at SLAC. The results of the measurements of the wakefields in the prototype structure by means of positron and electron bunches are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY056

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYB2

Beam Dynamics in a High Frequency RFQ

2408

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

CERN is constructing a 750 MHz Radio Frequency Quadrupole (RFQ) which can accelerate a proton beam to 5 MeV in a length of 2 m. The beam dynamics strategic parameters have been chosen to make this RFQ a good candidate for the injector of a medical facility operating at frequency of 3 GHz. Minimising beam losses above 1 MeV, containing the RF power losses and opening the road to industrialisation have been the guidelines for an unconventional RFQ design. In this paper, the optimisation efforts, the structure design and the expected beam qualities will be detailed. The status of the construction as well as the potential for further developments will be presented.

Slides WEYB2 [2.166 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEYB2

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA025

Design of a Variable X-band RF Power Splitter

3167

H. Zha, A. Grudiev, D. Gudkov, I. Syratchev
CERN, Geneva, Switzerland

The design of a two output ports, high power X-Band RF splitter with arbitrary split ratio is presented. This ratio is adjusted by mechanical changing the position a special RF short circuit piston. The piston is mounted on a step-motor providing the precise movement. Special measures were taken in the design to decrease the maximum electrical field on the cooper surface, as well as to maximise the bandwidth of the device. This splitter will be tested in the high power X-band test stand at CERN.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA025

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA057

High Gradient Testing of an X-band Crab Cavity at XBox2

3242

B.J. Woolley, P.K. Ambattu, R. Apsimon, G. Burt, A.C. Dexter
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A. Grudiev, I. Syratchev, R. Wegner, B.J. Woolley, W. Wuensch
CERN, Geneva, Switzerland

CERN’s Compact linear collider (CLIC) will require crab cavities to align the bunches to provide effective head-on collisions. An X-band quasi-TM11 deflecting cavity has been designed and manufactured for testing at CERN’s Xbox-2 high power standalone test stand. The cavity is currently under test and has reached an input power level in excess of 40MW, with a measured breakdown rate of better than 10^-5 breakdowns per pulse. This paper also describes surface field quantities which are important in assessing the expected BDR when designing high gradient structures.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA057

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF101

Design of a Proton Travelling Wave Linac with a Novel Tracking Code

3945

S. Benedetti
EPFL, Lausanne, Switzerland
U. Amaldi
TERA, Novara, Italy
A. Grudiev, A. Latina
CERN, Geneva, Switzerland

A non-relativistic proton linac based on high gradient backward travelling wave accelerating structures was designed using a novel dedicated 3D particle tracking code. Together with the specific RF design approach adopted, the choice of a 2.9985 GHz backward travelling wave (BTW) structure with 150° RF phase advance per cell was driven by the goal of reaching an accelerating gradient of 50 MV/m, which is more than twice that achieved so far. This choice dictated the need to develop a new code for tracking charged particles through travelling wave structures which were never used before in proton linacs. Nevertheless, the new code has the capability of tracking particles through any kind of accelerating structure, given its real and imaginary electromagnetic field map. This project opens a completely new field in the design of compact linacs for proton therapy, possibly leading to cost-effective and widespread single room facilities for cancer treatment.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF101

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)