Si-PM based Beam Phase Measurement Technique for Cyclotron

2017

This paper propose a method to measure the proton beam energy of the CS-30 cyclotron by using two fast current transformer (FCT) and accurately estimate THE TIME OF FLIGHT (TOF) using windowed crosscorrelation method. Currently available techniques use pulse width or edge delay measurement to get the TOF. However, the accuracy of these methods are limited by sampling rate, signal level, noise, and distortion. By using Cross-Correlation and interpolation, we can get a fractional delay measurement, and the system works with low level signals (low beam current) and it is robust in the presence of noise and distortion.

Journal of Synchrotron Radiation, 2015

The stability of the photon beam position on synchrotron beamlines is critical for most if not all synchrotron radiation experiments. The position of the beam at the experiment or optical element location is set by the position and angle of the electron beam source as it traverses the magnetic field of the bend-magnet or insertion device. Thus an ideal photon beam monitor would be able to simultaneously measure the photon beam's position and angle, and thus infer the electron beam's position in phase space. X-ray diffraction is commonly used to prepare monochromatic beams on X-ray beamlines usually in the form of a double-crystal monochromator. Diffraction couples the photon wavelength or energy to the incident angle on the lattice planes within the crystal. The beam from such a monochromator will contain a spread of energies due to the vertical divergence of the photon beam from the source. This range of energies can easily cover the absorption edge of a filter element such as iodine at 33.17 keV. A vertical profile measurement of the photon beam footprint with and without the filter can be used to determine the vertical centroid position and angle of the photon beam. In the measurements described here an imaging detector is used to measure these vertical profiles with an iodine filter that horizontally covers part of the monochromatic beam. The goal was to investigate the use of a combined monochromator, filter and detector as a phase-space beam position monitor. The system was tested for sensitivity to position and angle under a number of synchrotron operating conditions, such as normal operations and special operating modes where the photon beam is intentionally altered in position and angle at the source point. The results are comparable with other methods of beam position measurement and indicate that such a system is feasible in situations where part of the synchrotron beam can be used for the phase-space measurement. research papers J. Synchrotron Rad. (2015). 22, 946-955 Nazanin Samadi et al. Phase-space beam position monitor 947

Applied Radiation and Isotopes, 2011

This work recommends a new and simple-to-perform method for measuring the beam energy of an accelerator. The proposed method requires the irradiation of two monitor foils interspaced by an energy degrader. The primary advantage of the proposed method, which makes this method unique from previous energy evaluation strategies that employ the use of monitor foils, is that this method is independent of the detector efficiency calibration. This method was evaluated by performing proton activation of nat Cu foils using both a cyclotron and a tandem Van de Graaff accelerator. The monitor foil activities were read using a dose calibrator set to an arbitrary calibration setting. Excellent agreement was noted between the nominal and measured proton energies.

2017

The magnetic field of the CS-30 Cyclotron at King Faisal Specialist Hospital and Research Centre (KFSHRC) has been measured using Hall probe-based mapping system. Although the CS-30 Cyclotron was under full operation for 3 decades, yet, it was crucial to evaluate the stability of beam orbits and also to study the low extraction efficiency, particularly after stripping the cyclotron coils and its three sectors. The rational for stripping magnetic component was to replace the pole tip seal underneath the frame. The Hall probe was mounted on a high precision X Y stage, which was driven by three stepping motors, two motors for Y axis and a motor for X axis. The 3MH5 digital Tesla-meter is a high performance magnetic field measuring instrument, based on the Hall Effect magnetic field to voltage transducer. It has digital data correction to provide 0.01% accuracy and it provides the possibility of automatic data acquisition via USB port of our computer. In this paper, a Hall probe mapping...

VEC Centre Kolkata has constructed a K500 superconducting cyclotron (SCC). Several beam diagnostic components have been designed, fabricated and installed in SCC. In the low energy beam line, uncooled slits, faraday cup, beam viewers, and collimators are used. The inflector is also operated in a faraday cup mode to measure the beam inside SCC. The radial probe and viewer probe are respectively used to measure beam current and to observe the beam size and shape inside SCC. The magnetic channels, electro-static deflectors and M9 slit are also used to measure beam current at the extraction radius. Water cooled faraday cup and beam viewers are used in the external beam line. The radius of curvature of the radial probe track was reduced to align the internal and external track during its assembly. It was observed that the probe did not functioning properly during beam trials. Different modifications were incorporated. But, problem with the probe persisted. The paper describes the beam diagnostic components used in the cyclotron, discusses the problems faced in operating the radial probe, modifications tried and outlines the future steps planned to operate the beam diagnostic components.

2017

The aim of the AMIT cyclotron is to deliver an 8.5 MeV, 10 μA CW proton beam to a target to produce radioisotopes for PET diagnostics. Such a small cyclotron poses some challenges to the diagnostics design for commissioning and normal operation due to its small size, so miniaturized devices should be built in order to fit in the available space. Two sets of diagnostics have been designed, each one aiming at a different phase of the machine lifecycle. During normal operation the stripping foil and the target will be used to measure the current, a dual transverse profile monitor based on a scintillating screen will be used for interceptive measurements and a Fluorescence Profile Monitor will measure the beam position and the horizontal profile without intercepting the beam. During first stages of commissioning the dual transverse profile monitor and the target will be substituted by an emittance monitor based on a pepperpot to characterize the beam at the cyclotron exit. Also a movabl...

Journal of Physics: Conference Series

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Review of Scientific Instruments, 2016

A cheap and efficient diagnostic system for beam monitoring has been recently developed at INFN-LNS in Catania. It consists of a high sensitivity CCD camera detecting the light produced by an ion beam hitting the surface of a scintillating screen and a frame grabber for image acquisition. A scintillating screen, developed at INFN-LNS and consisting of a 2 μm BaF2 layer evaporated on an aluminium plate, has been tested by using 20Ne and 40Ar beams in the keV energy range. The CAESAR ECR ion source has been used for investigating the influence of the frequency and magnetic field tuning effects, the impact of the microwave injected power, and of the focusing solenoids along the low energy beam transport on the beam shape and current. These tests will allow to better understand the interplay between the plasma and beam dynamics and, moreover, to improve the transport efficiency along the low energy beam line and the matching with the superconducting cyclotron, particularly relevant in v...

Proceedings of the 1997 Particle Accelerator Conference (Cat. No.97CH36167)

The system for the single-turn injection of 5 MeV/u heavy ions into the Nuclotron is described. The system comprises a superconducting septum-magnet, kick electric plates, beam diagnostic apparatus and magnet correctors. The septum magnet has an iron yoke. The coil and septum made of a hollow superconductor, are cooled with a two-phase helium flow. The magnetic field is 1T. The electric field and its fall time in the fast kicker are 7 kV/cm and about 100 nsec, respectively. The beam diagnostics are composed of the Faraday cups and multi-wire collector chambers for current and profile measurements over a wide range of intensities. The magnetic correctors in the beam line and the Nuclotron ring are used for injection adjustment. The system has operated since 1992. The experimental results are presented.

2014

Non–invasive, highly accurate and reliable beam monitors are a desired aim of any beam diagnostics design. Knowledge of beam parameters is essential in fundamental research, industrial or medical applications with varying demands. It’s also extremely critical in the optimization of ion beams used for cancer treatment. Ocular tumour treatment at the Clatterbridge Cancer Centre (CCC) uses a 60 MeV proton beam. Disturbances introduced to a beam by intercepting devices risk affecting its energy and deteriorating the energy spread, thereby limiting the effectiveness of the treatment. The advantageous semi-circular structure of the LHCb Vertex Locator (VELO) detector has been investigated in the QUASAR Group as an interesting option for a noninvasive online beam monitor. The method relies on beam ‘halo’ measurements without disturbing the part of the beam used for treatment. This contribution discusses the measurement method, setup design and integration within the CCC treatment beam line...