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Poster communications

Electron beam charge measurement on PHIL photo-injector using a microcontroller based system

Abstract : PHIL [1] is an electron beam accelerator at LAL. It produces low energy (E<5 MeV) and high current (maximum 2nC/bunch, 10 ps duration) electron bunch at a repetition frequency of 5Hz. The beam charge measurements are performed by two Faraday Cups (FC) at both ends of the beam line and also with two Integrating Current Transformer (ICT), installed immediately after the RF gun and at the end of the straight beam line (see figure 1). Extracted signals from the ICT and FC, are processed by electronic circuits, displayed on an oscilloscope, and used to calculate the beam charge manually using the oscilloscope features. This operation is not accurate, does't permit to follow and save the temporal evolution of the charge and cannot be integrated in the control command system. To overcome this problem, a new approach was adopted, based on two systems: An electronic back-end to integrate the signal from coming the charge measurement systems (20ns large pulse), and outputs a large duration signal (around 400 mu s) whose amplitude is proportional to the beam charge. A microcontroller is used to acquire the integrated signal with a repetition rate of 5Hz, make the analog-digital conversion, and calculate the mean beam charge. The output signal can be sent to the control command system for displaying and to automate other process, especially the measurements of the beam charge versus RF/Laser phase. This system offers good accuracy, with a resolution of around 1pC, and can be easily integrated in the control command system.
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Contributor : Sabine Starita <>
Submitted on : Thursday, February 27, 2014 - 11:18:31 AM
Last modification on : Wednesday, September 16, 2020 - 4:24:39 PM





N. El Kamchi, V. Chaumat, P. Lepercq, H. Monard, A. Variola. Electron beam charge measurement on PHIL photo-injector using a microcontroller based system. International Conference on Instrumentation for Colliding Beam Physics (INSTR14), Feb 2014, Novosibirsk, Russia. IOP, 9, pp.C08027, 2014, Journal of Instrumentation. ⟨10.1088/1748-0221/9/08/C08027⟩. ⟨in2p3-00952628⟩



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