DIPAC2011 - List of Authors (Ferianis, M.)

Paper

Title

Page

The Fermi@Elettra Cavity BPM System: Description and Commissioning Results

26

M. Ferianis, A.O. Borga, P. Craievich, R. De Monte, G. Gaio, M. Predonzani
ELETTRA, Basovizza, Italy
M. Dal Forno
DIEIT, Trieste, Italy

The Fermi@elettra cavity BPM (C-BPM) system is based on an original implementation of the C-BPM scheme as the pick-up, operating at 6.5GHz, is coupled to a dedicated, self-calibrating electronics based on a novel concept. The system has been developed in-house; both the E-M and the mechanical design of the pick-up have been carried out, including an original frequency tuning scheme. The detector electronics directly obtains the envelope of the sum and difference signals by means of an RF 180° hybrid; no mixer for the RF signal down conversion is used. The detector is based on 3 blocks: an RF front-end, a baseband analogue transmission module and a digital back-end unit, based on a micro-TCA platform. The digital back-end is equipped with a powerful Virtex 5 FPGA and several real-time tasks have been implemented on it, including intra-pulse calibration. Ten C-BPM stations have been installed so far, fully integrated in the FERMI control System, enabling a real-time control of this key FEL diagnostics. Results on performances with beam are also presented; the scale factor of C-BPMs is obtained with beam, as two-axis micrometer translation stages have been installed.

Slides MOOC03 [2.733 MB]

MOPD37

Simulations of the Coherent Gap Radiation for the Bunch Length Monitor of FERMI@Elettra

134

R. Appio, P. Craievich, M. Ferianis, M. Veronese
ELETTRA, Basovizza, Italy

Non-destructive bunch length measurements after the magnetic compression is performed in Fermi@Elettra via the so-called Bunch Length Monitor (BLM) diagnostics. The BLM system is based on the diffraction radiation from a ceramic gap, captured by three millimeter-waves diodes, and the edge radiation from the last bending magnet of the bunch compressors, captured by a pyrodetector. In this paper we report on the study of the coherent radiation from a gap which we performed both applying the analytical theory and by means of simulations of the radiated electromagnetic field (CST Particle Studio). The study started from a simple gap in vacuum; time and frequency domain results were then investigated and compared with analytical theory. Finally in order to study a more realistic system, we investigated the effect of the dielectric and metallic holed shield used to assure the electric continuity.

TUPD14

Commissioning of the Cavity BPM for the FERMI@Elettra FEL Project

329

P. Craievich, T. Borden, A.O. Borga, R. De Monte, M. Ferianis, M. Predonzani
ELETTRA, Basovizza, Italy
M. Dal Forno, R. Vescovo
DIEIT, Trieste, Italy

The cavity Beam Position Monitor (BPM) is a fundamental beam diagnostic device that allows the measurements of the electron beam trajectory in a non-destructively way and with sub-micron resolution. Ten cavity BPM systems have been installed along the undulators chain in the FERMI@Elettra FEL1 project. In this paper we discuss the installation, commissioning and performance of these cavity BPM systems. We have carried out preliminary operations during a pre-beam period, such as the alignment and fine tuning of the RF cavities under vacuum. During the commissioning each BPM has been calibrated by mechanically moving the support on which the BPM is mounted. We have estimated the single shot resolution in presence of beam jitter by reading the beam position synchronously over many electron bunches from three or more BPMs. The algorithms have been subsequently improved, and the results are described.

Poster TUPD14 [0.460 MB]

Paper	Title	Page
MOOC03	The Fermi@Elettra Cavity BPM System: Description and Commissioning Results	26
	M. Ferianis, A.O. Borga, P. Craievich, R. De Monte, G. Gaio, M. Predonzani ELETTRA, Basovizza, Italy M. Dal Forno DIEIT, Trieste, Italy
	The Fermi@elettra cavity BPM (C-BPM) system is based on an original implementation of the C-BPM scheme as the pick-up, operating at 6.5GHz, is coupled to a dedicated, self-calibrating electronics based on a novel concept. The system has been developed in-house; both the E-M and the mechanical design of the pick-up have been carried out, including an original frequency tuning scheme. The detector electronics directly obtains the envelope of the sum and difference signals by means of an RF 180° hybrid; no mixer for the RF signal down conversion is used. The detector is based on 3 blocks: an RF front-end, a baseband analogue transmission module and a digital back-end unit, based on a micro-TCA platform. The digital back-end is equipped with a powerful Virtex 5 FPGA and several real-time tasks have been implemented on it, including intra-pulse calibration. Ten C-BPM stations have been installed so far, fully integrated in the FERMI control System, enabling a real-time control of this key FEL diagnostics. Results on performances with beam are also presented; the scale factor of C-BPMs is obtained with beam, as two-axis micrometer translation stages have been installed.
	Slides MOOC03 [2.733 MB]

MOPD37	Simulations of the Coherent Gap Radiation for the Bunch Length Monitor of FERMI@Elettra	134
	R. Appio, P. Craievich, M. Ferianis, M. Veronese ELETTRA, Basovizza, Italy
	Non-destructive bunch length measurements after the magnetic compression is performed in Fermi@Elettra via the so-called Bunch Length Monitor (BLM) diagnostics. The BLM system is based on the diffraction radiation from a ceramic gap, captured by three millimeter-waves diodes, and the edge radiation from the last bending magnet of the bunch compressors, captured by a pyrodetector. In this paper we report on the study of the coherent radiation from a gap which we performed both applying the analytical theory and by means of simulations of the radiated electromagnetic field (CST Particle Studio). The study started from a simple gap in vacuum; time and frequency domain results were then investigated and compared with analytical theory. Finally in order to study a more realistic system, we investigated the effect of the dielectric and metallic holed shield used to assure the electric continuity.

TUPD14	Commissioning of the Cavity BPM for the FERMI@Elettra FEL Project	329
	P. Craievich, T. Borden, A.O. Borga, R. De Monte, M. Ferianis, M. Predonzani ELETTRA, Basovizza, Italy M. Dal Forno, R. Vescovo DIEIT, Trieste, Italy
	The cavity Beam Position Monitor (BPM) is a fundamental beam diagnostic device that allows the measurements of the electron beam trajectory in a non-destructively way and with sub-micron resolution. Ten cavity BPM systems have been installed along the undulators chain in the FERMI@Elettra FEL1 project. In this paper we discuss the installation, commissioning and performance of these cavity BPM systems. We have carried out preliminary operations during a pre-beam period, such as the alignment and fine tuning of the RF cavities under vacuum. During the commissioning each BPM has been calibrated by mechanically moving the support on which the BPM is mounted. We have estimated the single shot resolution in presence of beam jitter by reading the beam position synchronously over many electron bunches from three or more BPMs. The algorithms have been subsequently improved, and the results are described.
	Poster TUPD14 [0.460 MB]