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Papers by Alessio Turchet

2007 IEEE Particle Accelerator Conference (PAC), 2007

The conventional line type modulators now in use for ELETTRA will have to be replaced for FERMI d... more The conventional line type modulators now in use for ELETTRA will have to be replaced for FERMI due to the increase in the pulse repetition frequency (PRF) from 10 to 50 Hz . The requirements for the FERMI modulator are as follows. The klystron which will be used is a Thales TH2132 with a microperviance of 1.9-2.1 uA/V 3/2 . The peak voltage from the modulator is 320 kV, and the current is 350 A. The pulse width is 4.5 us, with a PRF of 50 Hz. Flat top should be better than ±0.5 % of the peak voltage and pulse to pulse ripple better than ±0.1 % of the peak voltage. Prototypes for an upgraded line type modulator and a solid state induction type modulator are in fabrication. The solid state design uses eight induction cells, each cell driven by two parallel Insulated Gate Bipolar Transistors (IGBT). Each IGBT will power an amorphous core with up to 4.16 kV and 1.925 kA for up to 5 us. A single turn is passed through the aperture of each of the cells, inductively adding the pulse voltages. The output from the modulator is then fed to a conventional pulse transformer to reach the 320 kV requirement. This paper presents the system design of both modulator types. Details of the IGBT drivers, control electronics, IGBT and klystron protection and the charging supply for the solid state modulator are also presented.

Deep X-ray Lithography for interdisciplinary research

NESY Symposium 2016, 2016

Deep X-Ray Lithography for Aerospace Applications

Nanotech Italy 2014, 2014

Frontiers in Nanotechnology, 2022

X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process aroun... more X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process around 25 years ago. It is therefore a good time to make an analysis of the technique, with its pros and cons. In this perspective article, we describe X-ray lithography’s latest advancements. First, we report the improvement in the fabrication of the high aspect ratio and high-resolution micro/nanostructures. Then, we present the radiation-assisted synthesis and processing of novel materials for the next generation of functional devices. We finally draw our conclusion on the future prospects of the technique.

The ELETTRA storage ring, in operation since October 1993, was originally designed with all its v... more The ELETTRA storage ring, in operation since October 1993, was originally designed with all its vacuum chambers in AISI 316 LN stainless steel. New beamline projects have required the development of new kinds of insertion devices (ID) that can work in circular and vertical polarized modes besides the usual linear one. These new ID working modes however have undesirable heat load effects on the bending magnet vacuum chambers. For this reason new chambers have been developed in aluminum alloy, because of the higher value of thermal conductivity, with internal water-cooling channels close to the critical points of interaction with the photon beam. In this paper we describe some aspects of the aluminum chamber activities, focusing our attention on heat load problems.

The Design of a High Heat Load Shutter for a Superconducting Wiggler Front-End

A new superconducting wiggler will be installed in the ELETTRA storage ring; the maximum total po... more A new superconducting wiggler will be installed in the ELETTRA storage ring; the maximum total power and power density of this new insertion device are 18.34 kW and 5.88 kW/mrad 2 respectively, with a 2 GeV beam energy and eventual 400 mA of beam current. This intense X-Ray synchrotron radiation requires the installation of a new shutter in the beamline front-end. The high load absorber must be fitted in a pre-existing vacuum chamber and moving frame. In this paper the design of the absorber is described and in particular the cooling system optimization used to minimize temperatures on the front face and the cooling channel surface of the shutter. A definition of the absorber design parameters and the choice of material are presented along with several designs that were evaluated using Finite Element thermal analysis. Some improvements in the piping layout are also discussed in order to reduce the pressure losses.

Design and Fabrication of Microturbine Rotors for Small Power Generation

CANEUS 2004 Conference on Micro-Nano-Technologies, 2004

TASC/INFM, Sincrotrone Trieste (ELETTRA), and Mechatronic GmbH have started the design of a micro... more TASC/INFM, Sincrotrone Trieste (ELETTRA), and Mechatronic GmbH have started the design of a microturbine powered with compressed gas to be used as an electrical generator in a micro/nanosatellite. The research is funded by ESA for the realization of a liquid bipropellant micro-rocket engine that uses a micro-turbine and micro-pumps in order to pressurize the propellants. The turbine rotors have been fabricated with LIGA technology and die sinking Electro Discharge Machining. LIGA is well adapted to the production of high aspect ratio microstructures with very steep and well polished side walls and it does not limit the choice of material to silicon and derivative but offers the possibility to fabricate the turbine in metallic compounds. Moreover it has been found that LIGA, when coupled with EDM, is an optimum technique to obtain enbloc rotors with small diameter and high aspect ratio blades. The first step of the process is the fabrication of an X-ray mask containing a set of turbine rotors. The mask has been used on the ELETTRA deep X-ray lithography beamline to expose millimeter thick PMMA sheets glued on metallic substrates. After development the substrate is selectively electroplated with copper. The negative tone structures are then used as microelectrodes in a following EDM process. This further step allows obtaining turbines made of every conductive material. In particular we machined

Survey and alignment of ELETTRA storage ring

SPIE Proceedings, 2003

ELETTRA is an intermediate energy Synchrotron Light Source located in the outskirts of Trieste, I... more ELETTRA is an intermediate energy Synchrotron Light Source located in the outskirts of Trieste, Italy, open to researchers of basic and applied fields such as material and life sciences, physics, chemistry and geology. The synchrotron is operated 24 hours/day, 7 days/week with few periods of shutdown, mostly dedicated to maintenance. During one of these periods, in August 2001, ENEA Fusion

Heat load problems in deep X-ray lithography

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001

A 3D mathematical model of a complete Deep X-Ray Lithography scanning unit based on the Finite El... more A 3D mathematical model of a complete Deep X-Ray Lithography scanning unit based on the Finite Element Method (FEM) was developed to analyse the replication errors induced by the thermoelastic deformations occurring under irradiation. Different thermal and mechanical constraint conditions were considered in order to evaluate the maximum displacements of the irradiated mask area. The obtained results show that, to

Frontiers in nanotechnology, Feb 25, 2022

X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process aroun... more X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process around 25 years ago. It is therefore a good time to make an analysis of the technique, with its pros and cons. In this perspective article, we describe X-ray lithography's latest advancements. First, we report the improvement in the fabrication of the high aspect ratio and high-resolution micro/nanostructures. Then, we present the radiation-assisted synthesis and processing of novel materials for the next generation of functional devices. We finally draw our conclusion on the future prospects of the technique.

2007 IEEE Particle Accelerator Conference (PAC), 2007

The conventional line type modulators now in use for ELETTRA will have to be replaced for FERMI d... more The conventional line type modulators now in use for ELETTRA will have to be replaced for FERMI due to the increase in the pulse repetition frequency (PRF) from 10 to 50 Hz . The requirements for the FERMI modulator are as follows. The klystron which will be used is a Thales TH2132 with a microperviance of 1.9-2.1 uA/V 3/2 . The peak voltage from the modulator is 320 kV, and the current is 350 A. The pulse width is 4.5 us, with a PRF of 50 Hz. Flat top should be better than ±0.5 % of the peak voltage and pulse to pulse ripple better than ±0.1 % of the peak voltage. Prototypes for an upgraded line type modulator and a solid state induction type modulator are in fabrication. The solid state design uses eight induction cells, each cell driven by two parallel Insulated Gate Bipolar Transistors (IGBT). Each IGBT will power an amorphous core with up to 4.16 kV and 1.925 kA for up to 5 us. A single turn is passed through the aperture of each of the cells, inductively adding the pulse voltages. The output from the modulator is then fed to a conventional pulse transformer to reach the 320 kV requirement. This paper presents the system design of both modulator types. Details of the IGBT drivers, control electronics, IGBT and klystron protection and the charging supply for the solid state modulator are also presented.

Deep X-ray Lithography for interdisciplinary research

NESY Symposium 2016, 2016

Deep X-Ray Lithography for Aerospace Applications

Nanotech Italy 2014, 2014

Frontiers in Nanotechnology, 2022

X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process aroun... more X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process around 25 years ago. It is therefore a good time to make an analysis of the technique, with its pros and cons. In this perspective article, we describe X-ray lithography’s latest advancements. First, we report the improvement in the fabrication of the high aspect ratio and high-resolution micro/nanostructures. Then, we present the radiation-assisted synthesis and processing of novel materials for the next generation of functional devices. We finally draw our conclusion on the future prospects of the technique.

The ELETTRA storage ring, in operation since October 1993, was originally designed with all its v... more The ELETTRA storage ring, in operation since October 1993, was originally designed with all its vacuum chambers in AISI 316 LN stainless steel. New beamline projects have required the development of new kinds of insertion devices (ID) that can work in circular and vertical polarized modes besides the usual linear one. These new ID working modes however have undesirable heat load effects on the bending magnet vacuum chambers. For this reason new chambers have been developed in aluminum alloy, because of the higher value of thermal conductivity, with internal water-cooling channels close to the critical points of interaction with the photon beam. In this paper we describe some aspects of the aluminum chamber activities, focusing our attention on heat load problems.

The Design of a High Heat Load Shutter for a Superconducting Wiggler Front-End

A new superconducting wiggler will be installed in the ELETTRA storage ring; the maximum total po... more A new superconducting wiggler will be installed in the ELETTRA storage ring; the maximum total power and power density of this new insertion device are 18.34 kW and 5.88 kW/mrad 2 respectively, with a 2 GeV beam energy and eventual 400 mA of beam current. This intense X-Ray synchrotron radiation requires the installation of a new shutter in the beamline front-end. The high load absorber must be fitted in a pre-existing vacuum chamber and moving frame. In this paper the design of the absorber is described and in particular the cooling system optimization used to minimize temperatures on the front face and the cooling channel surface of the shutter. A definition of the absorber design parameters and the choice of material are presented along with several designs that were evaluated using Finite Element thermal analysis. Some improvements in the piping layout are also discussed in order to reduce the pressure losses.

Design and Fabrication of Microturbine Rotors for Small Power Generation

CANEUS 2004 Conference on Micro-Nano-Technologies, 2004

TASC/INFM, Sincrotrone Trieste (ELETTRA), and Mechatronic GmbH have started the design of a micro... more TASC/INFM, Sincrotrone Trieste (ELETTRA), and Mechatronic GmbH have started the design of a microturbine powered with compressed gas to be used as an electrical generator in a micro/nanosatellite. The research is funded by ESA for the realization of a liquid bipropellant micro-rocket engine that uses a micro-turbine and micro-pumps in order to pressurize the propellants. The turbine rotors have been fabricated with LIGA technology and die sinking Electro Discharge Machining. LIGA is well adapted to the production of high aspect ratio microstructures with very steep and well polished side walls and it does not limit the choice of material to silicon and derivative but offers the possibility to fabricate the turbine in metallic compounds. Moreover it has been found that LIGA, when coupled with EDM, is an optimum technique to obtain enbloc rotors with small diameter and high aspect ratio blades. The first step of the process is the fabrication of an X-ray mask containing a set of turbine rotors. The mask has been used on the ELETTRA deep X-ray lithography beamline to expose millimeter thick PMMA sheets glued on metallic substrates. After development the substrate is selectively electroplated with copper. The negative tone structures are then used as microelectrodes in a following EDM process. This further step allows obtaining turbines made of every conductive material. In particular we machined

Survey and alignment of ELETTRA storage ring

SPIE Proceedings, 2003

ELETTRA is an intermediate energy Synchrotron Light Source located in the outskirts of Trieste, I... more ELETTRA is an intermediate energy Synchrotron Light Source located in the outskirts of Trieste, Italy, open to researchers of basic and applied fields such as material and life sciences, physics, chemistry and geology. The synchrotron is operated 24 hours/day, 7 days/week with few periods of shutdown, mostly dedicated to maintenance. During one of these periods, in August 2001, ENEA Fusion

Heat load problems in deep X-ray lithography

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001

A 3D mathematical model of a complete Deep X-Ray Lithography scanning unit based on the Finite El... more A 3D mathematical model of a complete Deep X-Ray Lithography scanning unit based on the Finite Element Method (FEM) was developed to analyse the replication errors induced by the thermoelastic deformations occurring under irradiation. Different thermal and mechanical constraint conditions were considered in order to evaluate the maximum displacements of the irradiated mask area. The obtained results show that, to

Frontiers in nanotechnology, Feb 25, 2022

X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process aroun... more X-ray lithography has been first proposed almost 50 years ago, and the related LIGA process around 25 years ago. It is therefore a good time to make an analysis of the technique, with its pros and cons. In this perspective article, we describe X-ray lithography's latest advancements. First, we report the improvement in the fabrication of the high aspect ratio and high-resolution micro/nanostructures. Then, we present the radiation-assisted synthesis and processing of novel materials for the next generation of functional devices. We finally draw our conclusion on the future prospects of the technique.