Theory of electric field breakdown nucleation due to mobile dislocations

Engelberg, Eliyahu Zvi; Yashar, Ayelet Badichi; Ashkenazy, Yinon; Assaf, Michael; Popov, Inna

doi:10.1103/physrevaccelbeams.22.083501

Cited by 16 publications

(1 citation statement)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Overall the radiation at a given field level decreases with conditioning time. This is consistent with other experiments [43] and an explanation is given in [44].…”

Section: Dark Current Studiessupporting

confidence: 93%

High-gradient testing of an S -band, normal-conducting low phase velocity accelerating structure

Vnuchenko

Martinez

Benedetti

et al. 2020

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

A novel high-gradient accelerating structure with low phase velocity, v=c ¼ 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 × 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.

show abstract

“…Overall the radiation at a given field level decreases with conditioning time. This is consistent with other experiments [43] and an explanation is given in [44].…”

Section: Dark Current Studiessupporting

confidence: 93%