Journal of Scientific Instruments Editor: Dr H R Lang Vol 28 and Supplement No 1, 1951 Pp xvi + 388 + iii + 80 (London: Institute of Physics, 1951) Bound, £3 12s; unbound, £3

/pdf/a-review-of-scientific-instruments-50cfd4j98s.pdf

A Review of Scientific Instruments

RF Linear Accelerators

ACLIP is a 3 GHz proton SCL linac designed as a booster for a 30 MeV commercial cyclotron. The final energy is 62 MeV well suitable for the therapy of ocular tumors or for further acceleration (up to 230 MeV) by a second linac in order to treat deep-seated tumours. The possibility of using magnetrons as the source of RF power, to reduce the overall cost of the machine, is one the more relevant features of this project and this investigation is carried out within the frame of a collaboration with e2v (Chelmsford, UK). ACLIP is formed by 5 modules coupled together. The first one (able to accelerate proton from 30 to 35 MeV) has been machined, completely brazed and in December 2008 full power RF tests were performed. In this paper we will review the main features of the linac and discuss the results of the RF measurements carried out on this prototype.

RF high power tests on the first module of the ACLIP LINAC

A module of a Side Coupled Linac (SCL) is formed by a cascade of two or more tanks, connected by a Bridge Coupler (BC) with an RF feeder, which realizes a well defined field configuration in all the coupled cavities. Usually the first step of the design consists in the use of 2D and 3D e-m CAD’s able to characterize the single cell parameters in terms of its geometrical quantities and to study the behaviour of many coupled cells, respectively. The usual procedure foresees a full characterization only of a tank ended by half cells shorted by p.e.c. flat plates, by using the 3D CAD output (mode frequencies) as an input for specific codes as Disper able to find out the lumped circuit parameters of such a structure. From these values one may only calculate the frequency values for a right termination of the tanks, but no codes are available to check the parameters for a full-cell ended tank. The new proposed procedure stems from a lumped circuit representation for resonant coupled structures where the equations were studied in any condition of termination. This gives the possibility of having a full characterization either of a half-cell or a full-cell ended structures. Furthermore this procedure foresees an absolutely innovative and more rational design of the BC using its lumped circuit modeling. Finally this rationale to design a module of an SCL allows to study ex ante the full coupled system in order to focus the crucial parameters for its optimum functioning.

A rationale to design side coupled linac (scl): a faster and more reliable tool

The behaviour of an SCL module is generally described resorting to an equation system borrowed from lumped circuit theories. This description holds for a narrow frequency band (mono-modal cavity behaviour). A milestone in this field is represented by the classical analysis made by Nagle & alii where they introduced an equation system allowing for the resonant frequencies of the cavities and the first and second order coupling constants. Eigenvalues and eigenvectors (resonant frequencies of the system and relevant current amplitudes) are also given. For the case of half-cell termination and non zero second order coupling constants, we show that the system, even if it is correct for on axis cavities, should not be taken unwisely. If not so, troubles will come from the first two and last two equations of the system. Due to the relevance of this formulation and of the case treated, we give an interpretation of the physical meaning of these equations and suggest the correct use of above mentioned system. We will suggest a measurement (numerical and/or experimental) procedure which may give accurate evaluation of the parameters of the lumped circuit representation. By doing so the use of the circuit representation will be put on firm basis. A thorough investigation was made on the accuracy of the parameters estimation due to measurement errors and fabrication tolerances.

/pdf/an-analysis-of-lumped-circuit-equation-for-side-coupled-30223zekeb.pdf

An analysis of lumped circuit equation for side coupled linac (scl)

In order to have efficient particle acceleration it is fundamental that the particles experience, in the accelerating gap, field amplitudes as uniform and as high as possible from gap to gap. Because of the unavoidable fabrication errors, an accelerating structure, when assembled, exhibits field values lower than the nominal ones and/or not uniform. All the usual procedures developed in order to adjust the parameter deviations responsible of the malfunctioning of these structures, are based on field amplitude measurements, by using the bead pull technique, which is a very invasive technique. In this paper the philosophy is reversed: it is assumed that all the information can be got by Sounding the Modes of the whole System (SMS) and correct the deviation of each frequency mode from its nominal value by means of an appropriate tuning of the cavities: resorting to a perturbative technique applied to a circuit model representing this kind of structures, it is possible to calculate the amount of tuning to give to the cavities. It will be shown that a very good equalization and maximization of the fields in the cavities can be achieved by using this technique.

A New Tuning Method for Resonant Coupling Structures

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

A. D'Elia

Author Tools

Chat about Author

Papers

A New Tuning Method for Resonant Coupling Structures