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The TOP-IMPLART (Intensity Modulated Proton Linear Accelerator for Radio Therapy) proton linac, is a RF pulsed linac, designed for protontherapy consisting of a low frequency (425 MHz) 7 MeV injector followed by a sequence of accelerating modules operating at 3 GHz under construction, assembly and test at the ENEA Frascati Research Center. The accelerator features also a vertical low energy (3-7 MeV) line for irradiation of samples in horizontal position. The segment currently completed includes 8 SCDTL modules up to 71 MeV grouped in two sections each one powered by a 10 MW klystron driven by a SCANDINOVA K100 modulator with a variable pulse length (1-5 us) at a repetition frequency of 25 Hz. The output current can be varied up to 30 uA. The beam is mainly used for radiobiology experiments and dosimetry systems tests, but the flexibility in beam characteristics makes it suitable also for applications different from protontherapy, as the irradiation of electronics components to verify their behavior in the space environment. In this work, the current status of the accelerator and beam characteristics measurements are presented with an overview of the experiments carried on it., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

In this work the design of a passive cavity beam intensity monitor to be used in the TOP-IMPLART medical proton linac for the on-line measurement of beam current is presented. It will be used to monitor the beam between modules and at the linac exit. TOP-IMPLART produces a pulsed proton beam with 3 us duration at 200 Hz repetition rate with a current between 0.1 uA and 50 uA. The current required for medical applications is less than 1 uA and has to be known with an accuracy better than 5%. Large dynamic range and space constraints make the use of usual non-interceptive beam diagnostics unfeasible. The proposed system consists of a resonant cavity working in the TM010 mode, generating an electromagnetic field when the beam enters the cavity; a magnetic pickup senses an RF pulse whose amplitude is proportional to the current. The RF pulse is amplified and subsequently detected with zero-biased Schottky diodes. The cavity operates in vacuum when used in the inter-module space. The work reports also the results of preliminary measurements done on an copper prototype in air at the exit of the TOP-IMPLART linac to test the sensitivity of the system on the actual 35 MeV proton beam., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

In the ENEA Frascati research center the APAM (Particle Accelerators and Medical Application) laboratory is devoted to the development of particle accelerators for medical applications. Two main facilities are operational. The TOP-IMPLART proton accelerator is a pulsed fully linear machine aimed at active intensity modulated proton therapy with a final energy of 150 MeV. The machine offers two beam extraction points: one at 3-7 MeV, on a vertical line, and the other one at 35 MeV, the maximum energy currently available, with a pulse current up to 35 μA, on the horizontal line. The REX (Removable target Electron X-ray) source consists of an electron standing wave LINAC generating a beam in the energy range of 3 to 5 MeV with a pulsed current of 0.2 A. This source can generate Bremsstrahlung X-ray beams using suitable converters (Pb, W, Ta). This paper describes the experimental results of satellite activities performed in these facilities in the fields of biology, dosimetry, electronics, PIXE spectroscopy and preservation of cultural heritage manufacts., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The TOP-IMPLART (Intensity Modulated Proton Linear Accelerator for RadioTherapy) is the demonstrator of a 150 MeV proton linear accelerator devoted to cancer treatment application under development at ENEA-Frascati. It is a full linear machine composed by a 425 MHz 7 MeV injector and a high frequency linac operating at 2997.92 MHz. The first accelerating section, installed and in operation, consists of 4 SCDTL structures and delivers a 35 MeV beam in 3 microseconds pulses at a maximum repetition frequency of 50 Hz. The principal advantage of a linear accelerator, in a therapeutic application, is the quick setting possibility (up to pulse-to-pulse, in principle) of the physical properties of the proton beam, offering larger flexibility (compared to traditional circular designs) and improved precision on dose delivery to the patient., The short and long range stability of the machine have been analyzed measuring on a pulse by pulse basis both the output beam characteristics and other machine parameters in order to identify those that mainly affect the beam stability. This work describes the methodology used in this study, the main results achieved and the future developments., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

A dedicated dose delivery monitor is under development for the TOP-IMPLART proton accelerator, the first LINAC for cancer therapy. It is expected to measure the intensity profile to precisely monitor the fully active 3+1D (x/y/z and intensity) dose delivery of each short pulses (few micro-s, 0.1-10 micro-A pulse current at ~100 Hz) of the therapeutic proton beam (up to 230 MeV). The monitor system consists of planar gas chambers operating in ionization regime with cathode plane made ofμpattern pads alternately connected by orthogonal strips*. The dedicated readout electronics features trans-impedance amplifier that dynamically adapts its integrating feedback capacitance to the incoming amount of charge, then opportunistically changing its gain. The measured absolute sensitivity is about 100 fC (better than 0.03 relative sensitivity), the dynamic range up to 10000 (2 gain settings) with time response at the level of few ns, and virtually no dead time. Small scale chamber prototype (0.875 mm pitch pads) and readout electronics have been tested and characterized under both electron (5 MeV) and proton (up to 27 MeV) beams., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

The results of a 27MeV proton LINAC commissioning are presented. The linac, operating at ENEA Frascati Research Center, consists of a 425MHz injector followed by a 3GHz booster. The injector is a commercial LINAC (ACCSYS-HITACHI PL7) composed by a duoplasmatron source with einzel lens, a 3MeV RFQ and a 7MeV DTL. Wide injection current range (0-1.5mA) is obtained varying extraction and lens potentials. The booster is a sequence of 3 SCDTL (Side Coupled DTL) modules with output energies of 11.6, 18 and 27MeV. Each module requires less than 2MW peak power in 4us length pulses. All modules are powered by a single klystron. The output beam has been characterized at 10Hz PRF. Fast AC transformers, Faraday cup and ionization chamber have been used for current/charge monitoring, while energy has been measured using a novel detector based on LiF crystals. Systematic measurements have been done to investigate the sensitivity of output beam to machine operating parameters (SCDTL temperatures, stability of injector and RF power) highlightning the existing correlations. The LINAC is part of a 150MeV protontherapy accelerator under development in the framework of the TOP-IMPLART Project., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

The TOP-IMPLART (Intensity Modulated Proton Therapy Linear Accelerator for Radiotherapy) linac is a 150 MeV pulsed proton linear accelerator for protontherapy applications under realization, installation and progressive commissioning at ENEA. It is the first linac running with 3GHz SCDTL (Side Coupled DTL) accelerating modules. These constitute the first two sections of the whole linac up to 71 MeV proton energy, while the accelerating structure of the following part of the accelerator is under definition. Each SCDTL section is powered by a 10 MW peak power klystron. The first section, consisting of 4 modules (7 to 35 MeV) has been completed and it is operational at low repetition rate (25 Hz). The second section, consisting of other 4 modules (up to 71 MeV), is currently under executive design. The output beam at each stage of the progressive commissioning is fully characterized. The beam is routinely employed in radiobiology experiments and detector evaluation. The paper presents the actual status of the machine, installation, beam characterization and an overview of the experimental activity results., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The purpose of the BIOxTREME project, launched by ENEA and funded by ASI (Italian Space Agency), is to formulate new biological drugs having a stimulant activity on the immune system finalizing the production for a ready to use resource in Bioregenerative Life Support Systems (BLSSs) for space missions with extended durations, in deep space, and with multiple crews. One of the project tasks is to study the effects of physical insults on plants, simulating cosmic environment on production platforms by static magnetic fields, microgravity and ionizing radiation. In order to examine the biological effects, to test plant radio-resistance and to build dose-response curves we carried out proton irradiations of a tomato cultivar Micro-Tom red hairy roots with the TOP-IMPLART accelerator at the ENEA Frascati Research center. The biological samples were placed in a holder specially made in a movable real-time monitoring chamber calibrated in dose. The fluence-homogeneity measurements over the sample and the calibration of the monitoring system were performed using GafChromic EBT3 films. The paper describes the experimental set-up and reports the preliminary results., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The medium-energy section of the proton linear accelerator for radiotherapy under realization in the framework of the TOP-IMPLART Project consists in a high frequency 7-35 MeV SCDTL (Side Coupled Drift Tube Linac) structure. The structure, made of 4 modules supplied by one klystron, has been completely designed. The first module up to 11.6 MeV has been built and is under commissioning at ENEA-Frascati and the second and third modules are under realization. The paper describes the system and presents the main results of the experimental activity on this part of the accelerator., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

In this work we present the latest update on the TOP-IMPLART LINAC. It is a 150 MeV proton linear accelerator for protontherapy application under realization at ENEA-Frascati in the framework of a project developed by ENEA, the Italian National Institute of Health (ISS) and Regina Elena National Cancer Institute-IFO-Rome. The accelerator consists of a 7 MeV injector operating at 425 MHz followed by a LINAC booster working at 2997.92 MHz at a maximum repetition frequency of 100 Hz. The medium energy section up to 35 MeV is a sequence of four SCDTL modules (Side Coupled Drift Tube LINAC) powered by a single 10 MW klystron: the first module bringing beam energy from 7MeV to 11.6MeV with an input power of 1.3 MW in a 4usec pulse has been successfully commissioned with a 10 uA per pulse beam accelerated at the design energy demonstrating the functionality of low energy proton acceleration at high RF frequency. The effects on beam dynamics, caused by the absence of any harmonic relation between the two operating frequencies of the LINAC has been simulated and experimentally verified during the commissioning activity. The second and third module installation and testing is undergoing., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The Italian TOP IMPLART project aims to develop the first proton linear accelerator for cancer radiotherapy. A 150MeV proton LINAC is under construction at the ENEA Frascati research center: currently the machine is composed by a 7MeV injector operating at 425MHz and four 3GHz SCDTL modules producing a proton beam of 35MeV. Operational procedures for irradiation of samples need careful measurements of average beam current, transverse distribution and pulse charge by different monitor types placed along the beam line. The injected current in the high frequency segment of the accelerator is measured by a Fast Current Transformer (FCT) at the entrance of the SCDTL modules and the pulsed current of the accelerated beam is measured by a second FCT, placed in air, at the exit. The output proton beam shape and intensity are measured by an integral ionization chamber, a double (XY) multistrip ionization chamber, a synthetic single crystal diamond detector and a Faraday cup. In this work, the results of these multiple diagnostic tools applied to different operating conditions of the machine are presented., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

A variable energy (3-7 MeV) and pulsed current (0.1 – 100 μA) proton beam has been made available for different applications (radiobiology experiments, detectors development, material studies) in an irradiation facility at ENEA-Frascati based on the 7 MeV injector of the protontherapy linac under realization in the framework of the TOP-IMPLART Project. It is a 425 MHz linear accelerator consisting in a 3 MeV RFQ followed by a DTL up to 7 MeV (PL-7 ACCSYS-HITACHI model) followed by an horizontal and a vertical beam transport line. The latter one is particularly suitable for radiobiology in vitro studies allowing to irradiate besides cell monolayes also cell growing in suspension culture. The paper describes the facility and the recent results of the experimental activity., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany