Design, construction and tuning of S-band coupler for electron linear accelerator of institute for research in fundamental sciences (IPM E-linac)

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Due to Iran's growing need for accelerators in various applications, IPM's electron Linac project has been defined. This accelerator is a 15 MeV energy S-band traveling-wave accelerator which is being designed and constructed based on the klystron that has been built in Iran. Based on the design, operating mode is π/2 and the accelerating chamber consists of two 60cm long tubes with constant impedance and a 30cm long buncher. Amongst all construction methods, shrinking method is selected for construction of IPM's electron Linac tube because it has a simple procedure and there is no need for large vacuum or hydrogen furnaces. In this paper, different aspects of this method are investigated. According to the calculations, linear ratio of frequency alteration to radius change is 787.8 MHz/cm, and the maximum deformation at the tube wall where disks and the tube make contact is 2.7µm. Applying shrinking method for construction of 8-and 24-cavity tubes results in satisfactory frequency and quality factor. Average deviations of cavities frequency of 8-and 24-cavity tubes to the design values are 0.68 MHz and 1.8 MHz respectively before tune and 0.2 MHz and 0.4 MHz after tune. Accelerating tubes, buncher, and high power couplers of IPM's electron linac are constructed using shrinking method.

Section: Construction Of Testing Traveling-wave Tube Using Shrinking ...mentioning

confidence: 99%

Investigation of using shrinking method in construction of Institute for Research in Fundamental Sciences Electron Linear Accelerator TW-tube (IPM TW-Linac tube)

Ghasemi

Davani

2015

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“…Nuclear Science and Technology Research Institute (NSTRI) has begun extensive research in this area [1,2]. After constructing traveling wave linac (IPM e-linac) [3][4][5], the production of smaller and sealed accelerators is a priority for the above mentioned applications. Iran needs to increase the number of medical accelerators to not less than three times (currently 80) as well as to increase the number of accelerators capable of cargo inspections.…”

Section: Introductionmentioning

confidence: 99%

Multiphysics analysis of side-coupled RF cavity

Kejani¹,

Ghasemi²,

Davani³

et al. 2019

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A: By changing the resonant frequency of the cavity due to the power dissipation in its wall, the impedance matching will impair and the power will reflect. The acceptable frequency shift range which is based on the cooling system in the cavity design depends on the ability of the automatic frequency controller system and the bandwidth of the RF amplifier output frequency. This paper describes how to couple electromagnetic, thermal and mechanical analysis and calculates the cavity frequency shift during operation. Multiphysics analysis investigations had done for an S-band side-coupled cavity. By using the Superfish code, the power loss ratio at different surfaces of the cavity could be accurately calculated and Steady-State Thermal (SST) analysis could be performed correctly. In this paper, the report on the simultaneous use of multiphysics analysis with the modules of the Ansys software is presented and the results of both simulations are compared. The temperature distribution of the cavity was obtained by using the Fluent software and its results were compared with the temperature distribution gained from applying the convection coefficient to the SST. Three cooling systems were investigated for different powers with different cross-sections. In this section of the investigation, after thermal analysis, deformed geometry was obtained due to thermal stresses. By electromagnetic analyzing of deformed geometry, its frequency shift was obtained for all different cases. In order to evaluate the simulations, after the construction of a single-cavity, frequency variations are measured in terms of temperature variation and the results are compared with each other. After constructing a single-cavity, frequency shifts based on temperature variations are measured and the results are compared with each other. K: Acceleration cavities and magnets superconducting (high-temperature superconductor; radiation hardened magnets; normal-conducting; permanent magnet devices; wigglers and undulators); Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics);

“…Design and construction of electron linear accelerators (e-Linacs) began in earnest in the mid-1940s and presently different types of these accelerators with different energies were commercialized to use in various applications such as industrial, medical (radiotherapy), cargo inspection, food irradiation and sterilization of medical equipment [1]. Electron linear accelerators are divided into two types: the traveling wave, and the standing wave e-Linac with related advantages and disadvantages [2,3].…”

Section: Introductionmentioning

confidence: 99%

“…The first project was the design and construction of a 15 MeV traveling wave linear accelerator. This project was carried out by the Iranian Institute for Research in Fundamental Sciences and was the first attempt in Iran to construct an electron linear accelerator [1,4,5]. Based on Iran's needs for medical accelerators, the design and construction of a 6 MeV e-Linac was considered for the treatment of many kinds of cancers [2].…”

Section: Introductionmentioning

confidence: 99%

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Design of a side coupled standing wave accelerating tube for NSTRI e-Linac

Zarei¹,

Davani

Rachti³

et al. 2017

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The design and construction of a 6 MeV electron linear accelerator (e-Linac) was defined in the Institute of Nuclear Science and Technology (NSTRI) for cargo inspection and medical applications. For this accelerator, a side coupled standing wave tube resonant at a frequency of 2998.5 MHZ in π/2 mode was selected. In this article, the authors provide a step-by-step explanation of the process of the design for this tube.The design and simulation of the accelerating and coupling cavities were carried out in five steps; (1) separate design of the accelerating and coupling cavities, (2) design of the coupling aperture between the cavities, (3) design of the entire structure for resonance at the nominal frequency, (4) design of the buncher, and (5) design of the power coupling port. At all design stages, in addition to finding the dimensions of the cavity, the impact of construction tolerances and simulation errors on the electromagnetic parameters were investigated. The values obtained for the coupling coefficient, coupling constant, quality factor and capture efficiency are 2.11, 0.011, 16203 and 36%, respectively.The results of beam dynamics study of the simulated tube in ASTRA have yielded a value of 5.14 π-mm-mrad for the horizontal emittance, 5.06 π-mm-mrad for the vertical emittance, 1.17 mm for the horizontal beam size, 1.16 mm for the vertical beam size and 1090 keV for the energy spread of the output beam.