IPAC2019 - List of Authors (Marongiu, M.)

Paper	Title	Page
WEPGW022	A Numerical Analysis to Choose the Most Performing Optical Transition Radiation Screen	2518
	F. Cioeta, D. Alesini, A. Variola INFN/LNF, Frascati, Italy M. Ciambrella, A. Mostacci Sapienza University of Rome, Rome, Italy D. Cortis, M. Marongiu, V. Pettinacci INFN-Roma, Roma, Italy
	Optical Transition Radiation (OTR) screen represents the most appropriate instrument to measure and verify the characteristics of a beam spot size produced by a particle accelerator. In order to measure such beam properties, OTR screens have to sustain thermal and mechanical stresses due to the energy that several bunches deposit. Owing to these requirements, it is essential to identify the more suitable material to optimize the OTR dimensions and to get reliable measures from the diagnostic system. In this paper, we describe a numerical procedure to choose the most performing material taking into account the physical requirements of a multi-bunch high brightness. The procedure is based on a dedicated ANSYS script able to evaluate the fatigue life time of the material considering a high number of thermal cycles generated by several bunches. The main characteristic of this script is the capability to simulate the real thermal and mechanical effect on the target that the hitting particle beam produces. The numerical procedure has been applied to compare the performance of three relevant materials-Aluminium, Silicon and Graphite simulating a beam hitting with well-known parameters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW022
About •	paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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WEPRB105	Design of an X-Band Constant Impedance LINAC for Compact Light Project	3055
	J.M. Arnesano, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy M. Diomede, M. Marongiu INFN/LNF, Frascati, Italy L. Ficcadenti INFN-Roma, Roma, Italy
	Within the framework of Horizon 2020 project, Compact Light, in order to provide a high performance, high-gradient X-band technology, for the new generation of hard X-ray FEL, a travelling wave (TW) Linac, working on 2pi/3 mode at 11.9952 GHz, fed by two types of asymmetrically couplers, has been designed. The design was performed using CST Microwave Studio frequency domain solver. First, simulations have been conduct in order to obtain the best trade-off between single cell’s parameters, varying iris aperture. Then, the both couplers, with and without pumping port, has been tuned to avoid reflections at the input port. Finally, the entire structure, with 5 cells, was simulated. The main structure parameters will be present and we will also show and discuss the acceleranting gradient obtained vary with linac lenght and input power.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB105
About •	paper received ※ 15 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019
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WEPRB106	Simulation of the Transition Radiation Transport Through an Optic System	3059
SUSPFO036	use link to see paper's listing under its alternate paper code
	M. Marongiu, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy F.G. Bisesto, E. Chiadroni, G. Di Pirro, G. Franzini, A. Giribono, V. Shpakov, A. Stella, A. Variola INFN/LNF, Frascati, Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy A. Mostacci, L. Palumbo INFN-Roma, Roma, Italy
	Optical Transition Radiation (OTR) screens are widely used for beam profile measurements. The radiation is emitted when a charged particle beam crosses the boundary between two media with different optical properties. The main advantages of OTR are the instantaneous emission process allowing fast single shot measurements (i.e. bunch by bunch measurements in a multi bunch machine), and the good linearity with the beam charge (if coherent effects can be neglected). Furthermore, OTR angular distribution strongly depends on beam energy. Since OTR screens are typically placed in several positions along the Linac to monitor beam envelope, one may perform a distributed energy measurement along the machine: this will be useful, for instance, during the commissioning phase of a machine. This paper deals with the studies of an algorithm to optimize the generation and the transport of the transition radiation through an optic system using the simulation tool Zemax. The algorithm, in combination with a particle tracking code (i.e. Elegant), will allow to simulate the radiation generated by a beam and, so, to take into account beam divergence and energy spread or chromatic effects in the optic system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB106
About •	paper received ※ 08 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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THPTS065	Analysis on the Thermal Response to Beam Impedance Heating of the Post Ls2 Proton Synchrotron Beam Dump	4260
	L. Teofili, F. Giordano, I. Lamas, F.-X. Nuiry, G. Romagnoli, B. Salvant CERN, Meyrin, Switzerland M. Marongiu, M. Migliorati Sapienza University of Rome, Rome, Italy
	The High Luminosity Large Hadron Collider (HL-LHC) and the LIU (LHC-Injection Upgrade) projects at CERN are upgrading the whole CERN accelerators chain, increasing beam brightness and intensity. In this scenario, some critical machine components have to be redesigned and rebuilt. Due to the increase in beam intensity, minimizing the electromagnetic interaction between the beam and the device is a crucial design task. Indeed, these interactions could lead to beam instabilities and excessive thermo-mechanical loadings in the device. In this context, this paper presents an example of multi-physics study to investigate the impedance related thermal effects. The analysis is performed on the conceptual design of the new proton synchrotron (PS) internal dump.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS065
About •	paper received ※ 26 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Numerical Analysis to Choose the Most Performing Optical Transition Radiation Screen

2518

F. Cioeta, D. Alesini, A. Variola
INFN/LNF, Frascati, Italy
M. Ciambrella, A. Mostacci
Sapienza University of Rome, Rome, Italy
D. Cortis, M. Marongiu, V. Pettinacci
INFN-Roma, Roma, Italy

Optical Transition Radiation (OTR) screen represents the most appropriate instrument to measure and verify the characteristics of a beam spot size produced by a particle accelerator. In order to measure such beam properties, OTR screens have to sustain thermal and mechanical stresses due to the energy that several bunches deposit. Owing to these requirements, it is essential to identify the more suitable material to optimize the OTR dimensions and to get reliable measures from the diagnostic system. In this paper, we describe a numerical procedure to choose the most performing material taking into account the physical requirements of a multi-bunch high brightness. The procedure is based on a dedicated ANSYS script able to evaluate the fatigue life time of the material considering a high number of thermal cycles generated by several bunches. The main characteristic of this script is the capability to simulate the real thermal and mechanical effect on the target that the hitting particle beam produces. The numerical procedure has been applied to compare the performance of three relevant materials-Aluminium, Silicon and Graphite simulating a beam hitting with well-known parameters.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW022

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB105

Design of an X-Band Constant Impedance LINAC for Compact Light Project

3055

J.M. Arnesano, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
M. Diomede, M. Marongiu
INFN/LNF, Frascati, Italy
L. Ficcadenti
INFN-Roma, Roma, Italy

Within the framework of Horizon 2020 project, Compact Light, in order to provide a high performance, high-gradient X-band technology, for the new generation of hard X-ray FEL, a travelling wave (TW) Linac, working on 2pi/3 mode at 11.9952 GHz, fed by two types of asymmetrically couplers, has been designed. The design was performed using CST Microwave Studio frequency domain solver. First, simulations have been conduct in order to obtain the best trade-off between single cell’s parameters, varying iris aperture. Then, the both couplers, with and without pumping port, has been tuned to avoid reflections at the input port. Finally, the entire structure, with 5 cells, was simulated. The main structure parameters will be present and we will also show and discuss the acceleranting gradient obtained vary with linac lenght and input power.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB105

About •

paper received ※ 15 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB106

Simulation of the Transition Radiation Transport Through an Optic System

3059

SUSPFO036

use link to see paper's listing under its alternate paper code

M. Marongiu, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
F.G. Bisesto, E. Chiadroni, G. Di Pirro, G. Franzini, A. Giribono, V. Shpakov, A. Stella, A. Variola
INFN/LNF, Frascati, Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
A. Mostacci, L. Palumbo
INFN-Roma, Roma, Italy

Optical Transition Radiation (OTR) screens are widely used for beam profile measurements. The radiation is emitted when a charged particle beam crosses the boundary between two media with different optical properties. The main advantages of OTR are the instantaneous emission process allowing fast single shot measurements (i.e. bunch by bunch measurements in a multi bunch machine), and the good linearity with the beam charge (if coherent effects can be neglected). Furthermore, OTR angular distribution strongly depends on beam energy. Since OTR screens are typically placed in several positions along the Linac to monitor beam envelope, one may perform a distributed energy measurement along the machine: this will be useful, for instance, during the commissioning phase of a machine. This paper deals with the studies of an algorithm to optimize the generation and the transport of the transition radiation through an optic system using the simulation tool Zemax. The algorithm, in combination with a particle tracking code (i.e. Elegant), will allow to simulate the radiation generated by a beam and, so, to take into account beam divergence and energy spread or chromatic effects in the optic system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB106

About •

paper received ※ 08 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS065

Analysis on the Thermal Response to Beam Impedance Heating of the Post Ls2 Proton Synchrotron Beam Dump

4260

L. Teofili, F. Giordano, I. Lamas, F.-X. Nuiry, G. Romagnoli, B. Salvant
CERN, Meyrin, Switzerland
M. Marongiu, M. Migliorati
Sapienza University of Rome, Rome, Italy

The High Luminosity Large Hadron Collider (HL-LHC) and the LIU (LHC-Injection Upgrade) projects at CERN are upgrading the whole CERN accelerators chain, increasing beam brightness and intensity. In this scenario, some critical machine components have to be redesigned and rebuilt. Due to the increase in beam intensity, minimizing the electromagnetic interaction between the beam and the device is a crucial design task. Indeed, these interactions could lead to beam instabilities and excessive thermo-mechanical loadings in the device. In this context, this paper presents an example of multi-physics study to investigate the impedance related thermal effects. The analysis is performed on the conceptual design of the new proton synchrotron (PS) internal dump.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS065

About •

paper received ※ 26 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)