| Records |
| Author |
Vnuchenko, A.; Esperante Pereira, D.; Gimeno, B.; Benedetti, S.; Catalan Lasheras, N.; Garlasch, M.; Grudiev, A.; McMonagle, G.; Pitman, S.; Syratchev, I.; Timmins, M.; Wegner, R.; Woolley, B.; Wuensch, W.; Faus-Golfe, A. |
| Title |
High-gradient testing of an S-band, normal-conducting low phase velocity accelerating structure |
Type |
Journal Article |
| Year |
2020 |
Publication |
Physical Review Accelerators and Beams |
Abbreviated Journal |
Phys. Rev. Accel. Beams |
| Volume |
23 |
Issue |
8 |
Pages |
084801 - 13pp |
| Keywords |
|
Abstract  |
A novel high-gradient accelerating structure with low phase velocity, v/c = 0.38, has been designed, manufactured and high-power tested. The structure was designed and built using the methodology and technology developed for CLIC 100 MV/m high-gradient accelerating structures, which have speed of light phase velocity, but adapts them to a structure for nonrelativistic particles. The parameters of the structure were optimized for the compact proton therapy linac project, and specifically to 76 MeV energy protons, but the type of structure opens more generally the possibility of compact low phase velocity linacs. The structure operates in S-band, is backward traveling wave (BTW) with a phase advance of 150 degrees and has an active length of 19 cm. The main objective for designing and testing this structure was to demonstrate that low velocity particles, in particular protons, can be accelerated with high gradients. In addition, the performance of this structure compared to other type of structures provides insights into the factors that limit high gradient operation. The structure was conditioned successfully to high gradient using the same protocol as for CLIC X-band structures. However, after the high power test, data analysis realized that the structure had been installed backwards, that is, the input power had been fed into what is nominally the output end of the structure. This resulted in higher peak fields at the power feed end and a steeply decreasing field profile along the structure, rather than the intended near constant field and gradient profile. A local accelerating gradient of 81 MV/m near the input end was achieved at a pulse length of 1.2 μs and with a breakdown rate (BDR) of 7.2 x 10(-7) 1 /pulse/m. The reverse configuration was accidental but the operating with this field condition gave very important insights into high-gradient behaviour and a comprehensive analysis has been carried out. A particular attention was paid to the characterization of the distribution of BD positions along the structure and within a cell. |
| Address |
[Vnuchenko, A.; Esperante Pereira, D.; Gimeno Martinez, B.] Inst Fsica Corpuscular IFIC, Valencia 46980, Spain, Email: anna.vnuchenko@cern.ch |
| Corporate Author |
|
Thesis |
|
| Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9888 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000582958800002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4584 |
| Permanent link to this record |
| |
|
| |
| Author |
Coves, A.; Maestre, H.; Archiles, R.; Andres, M.V.; Gimeno, B. |
| Title |
Surface-Impedance Formulation for Hollow-Core Waveguides Based on Subwavelength Gratings |
Type |
Journal Article |
| Year |
2022 |
Publication |
IEEE Access |
Abbreviated Journal |
IEEE Access |
| Volume |
10 |
Issue |
|
Pages |
18843-18854 |
| Keywords |
Electromagnetic waveguides; Optical waveguides; Planar waveguides; Gratings; Surface waves; Surface impedance; Optical surface waves; Surface impedance; hollow-core waveguide; surface-relief grating |
| Abstract |
A rigorous Surface Impedance (SI) formulation for planar waveguides is presented. This modal technique splits the modal analysis of the waveguide in two steps. First, we obtain the modes characteristic equations as a function of the SI and, second, we need to obtain the surface impedance values using either analytical or numerical methods. We validate the technique by comparison with well-known analytical cases: the parallel-plate waveguide with losses and the dielectric slab waveguide. Then, we analyze an optical hollow-core waveguide defined by two high-contrast subwavelength gratings validating our results by comparison with reported values. Finally, we show the potential of our formulation with the analysis of a THz hollow-core waveguide defined by two surface-relief subwavelength gratings, including material losses in our formulation. |
| Address |
[Coves, Angela; Maestre, Haroldo] Univ Miguel Hernandez Elche, Dept Commun Engn I3E, Elche 03202, Spain, Email: angela.coves@umh.es |
| Corporate Author |
|
Thesis |
|
| Publisher |
Ieee-Inst Electrical Electronics Engineers Inc |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2169-3536 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000760714900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5139 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhang, X.; Chang, C.; Gimeno, B. |
| Title |
Multipactor Analysis in Circular Waveguides Excited by TM01 Mode |
Type |
Journal Article |
| Year |
2019 |
Publication |
IEEE Transactions on Electron Devices |
Abbreviated Journal |
IEEE Trans. Electron Devices |
| Volume |
66 |
Issue |
11 |
Pages |
4943-4951 |
| Keywords |
Circular waveguide; multipactor; ponderomotive force; TM01 mode |
| Abstract |
A series of detailed numerical simulations are used to investigate the properties ofmultipactor breakdown in circularwaveguidespropagating the TM01 mode. AMonte Carlo model is constructed to track the motion of the electrons, study the multipactor scenarios, and predict the multipactor thresholds. The theoretical and numerical analyses indicate that the product of the frequency and the gap (f . D) affects both the intensity of the ponderomotive force and its spatial distribution, which results from the nonuniformity of the radio frequency (RF) field and significantly influences the electrons' trajectoriesandmultipactor trends. The decrease in f . D results in a remarkable enhancement in the magnitude of the ponderomotive force, while the maximal intensity gradually moves toward the half radius R/2 area. Low values of f . D correspond to high ponderomotive potential, which sustains the short-range electrons and triggers the single-sidedmultipactor. In contrast, high values of f . D correspond to low ponderomotive potential, contributing to long-range electrons and exciting the double-sided multipactor. Fitting to the susceptibility diagram produces the border line and a modified f . D threshold of (f . D) th approximate to 338.4 GHz mm, which separates the susceptibility diagram into single-sided, double-sided, andmixed-sided zones. The initial electron energy influences their trajectories at high f . D and low RF power. This effect tends to dominate the multipactor behavior in the mixed-sided region. |
| Address |
[Zhang, Xue] Xiangtan Univ, Coll Informat Engn, Xiangtan 411105, Hunan, Peoples R China, Email: zhangxue.iecas@yahoo.com; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Ieee-Inst Electrical Electronics Engineers Inc |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0018-9383 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000494419900066 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4191 |
| Permanent link to this record |
| |
|
| |
| Author |
D'Auria, G. et al; Gonzalez-Iglesias, D.; Gimeno, B.; Pereira, D.E. |
| Title |
The CompactLight Design Study |
Type |
Journal Article |
| Year |
2024 |
Publication |
European Physical Journal-Special Topics |
Abbreviated Journal |
Eur. Phys. J.-Spec. Top. |
| Volume |
|
Issue |
|
Pages |
1-208 |
| Keywords |
|
| Abstract |
CompactLight is a Design Study funded by the European Union under the Horizon 2020 research and innovation funding programme, with Grant Agreement No. 777431. CompactLight was conducted by an International Collaboration of 23 international laboratories and academic institutions, three private companies, and five third parties. The project, which started in January 2018 with a duration of 48 months, aimed to design an innovative, compact, and cost-effective hard X-ray FEL facility complemented by a soft X-ray source to pave the road for future compact accelerator-based facilities. The result is an accelerator that can be operated at up to 1 kHz pulse repetition rate, beyond today's state of the art, using the latest concepts for high brightness electron photoinjectors, very high gradient accelerating structures in X-band, and novel short-period undulators. In this report, we summarize the main deliverable of the project: the CompactLight Conceptual Design Report, which overviews the current status of the design and addresses the main technological challenges. |
| Address |
[D'Auria, G.; Danailov, M.; Mitri, S. Di; Ferianis, M.; Gioppo, R.; Rochow, R.; Tabacco, C.; Zangrando, M.] Elettra Sincrotrone Trieste SCpA, AREA Sci Pk, I-34149 Trieste, Italy, Email: gerardo.dauria@elettra.eu |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer Heidelberg |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1951-6355 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:001198683900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6122 |
| Permanent link to this record |
| |
|
| |
| Author |
Martinez-Reviriego, P.; Esperante, D.; Grudiev, A.; Gimeno, B.; Blanch, C.; Gonzalez-Iglesias, D.; Fuster-Martinez, N.; Martin-Luna, P.; Martinez, E.; Menendez, A.; Fuster, J. |
| Title |
Dielectric assist accelerating structures for compact linear accelerators of low energy particles in hadrontherapy treatments |
Type |
Journal Article |
| Year |
2024 |
Publication |
Frontiers in Physics |
Abbreviated Journal |
Front. Physics |
| Volume |
12 |
Issue |
|
Pages |
1345237 - 12pp |
| Keywords |
dielectric assist accelerating (DAA) structures; radio frequency (RF); LINAC; hadrontherapy; standing wave |
| Abstract |
Dielectric Assist Accelerating (DAA) structures based on ultralow-loss ceramic are being studied as an alternative to conventional disk-loaded copper cavities. This accelerating structure consists of dielectric disks with irises arranged periodically in metallic structures working under the TM02-pi mode. In this paper, the numerical design of an S-band DAA structure for low beta particles, such as protons or carbon ions used for Hadrontherapy treatments, is shown. Four dielectric materials with different permittivity and loss tangent are studied as well as different particle velocities. Through optimization, a design that concentrates most of the RF power in the vacuum space near the beam axis is obtained, leading to a significant reduction of power loss on the metallic walls. This allows to fabricate cavities with an extremely high quality factor, over 100,000, and shunt impedance over 300 M omega/m at room temperature. During the numerical study, the design optimization has been improved by adjusting some of the cell parameters in order to both increase the shunt impedance and reduce the peak electric field in certain locations of the cavity, which can lead to instabilities in its normal functioning. |
| Address |
[Martinez-Reviriego, Pablo; Esperante, Daniel; Gimeno, Benito; Blanch, Cesar; Gonzalez-Iglesias, Daniel; Fuster-Martinez, Nuria; Martin-Luna, Pablo; Martinez, Eduardo; Menendez, Abraham; Fuster, Juan] CSIC Univ Valencia, Inst Fis Corpuscular IFIC, Paterna, Spain, Email: pablo.martinez.reviriego@ific.uv.es |
| Corporate Author |
|
Thesis |
|
| Publisher |
Frontiers Media Sa |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2296-424x |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:001162373700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5953 |
| Permanent link to this record |
