Search

The Superconducting Ion Gantry (SIG) project aims to design, construct, and test a curved superconducting dipole demonstrator magnet for an ion gantry (up to a rigidity of 6.6 Tm). The main demonstrator magnet parameters are a dipolar field of 4 T generated into a toroidal aperture with an 80 mm diameter, 1.65 m curvature radius, and 30° angular sector. The project is inserted in the framework of the EuroSIG collaboration among CNAO, CERN, INFN, and MedAustron. Within this collaboration, the main goal of SIG is to perform a feasibility study of winding and assembling cos-$\theta$ coils with a small curvature radius. In addition, a parallel program at CERN is dedicated to the study of the indirect cooling problem through the construction of a straight thermal demonstrator magnet sharing the SIG cross-section. The basic idea behind these programs is to check whether the vast experience of the community on superconducting accelerator magnets design can lead to a breakthrough in the gantry magnets domain. This article shows the main elements of the conceptual design of the SIG magnet and reports on the first winding trial performed at the LASA laboratory, in Milan, with a copper dummy cable. Moreover, possible solutions for the winding, curing, and impregnation of highly curved cos$\theta$ coils are discussed.

The use of Canted Cosine Theta (CCT) magnets for accelerator applications has gained popularity due to their ease of manufacturing and assembly. In the context of two EU-Horizon2020-funded projects, HITRIplus and IFAST, the development of two 80 mm free bore and 4 T central field CCT dipoles for use in ion therapy (hadron therapy) is underway. In IFAST, a straight dipole CCT features a superimposed quadrupole component (combined function winding), while in HITRIplus a curved CCT (bending radius of 1.65 m) is wound as pure dipole. Both projects are based on a Cu/Nb-Ti multistrand rope as conductor. The article presents advancements in the engineering design of the magnets. A number of validation tests have been made to validate the choices made during the conceptual design. Characterization tests of the low losses rope, winding tests, splice tests, and impregnation tests will be described. The explored alternatives for the fabrication of the curved formers and the support structure are also discussed.

As part of major European collaborations focused on the study of newly developed superconducting magnets for ion therapy, Istituto Nazionale di Fisica Nucleare (INFN) is directly involved through the Superconducting Ion Gantry (SIG) project. In ion therapy, rotating gantry systems are critical to better preserve healthy tissues during treatments, but they are typically huge and heavy structures: a superconducting version of them would lead to lighter and more viable solutions. SIG aims to design, in collaboration with Centro Nazionale di Adroterapia Oncologica (CNAO) and Conseil Européen pour la recherché Nucléaire (CERN), the main superconducting magnets for a 430 MeV/u carbon ion gantry. The main purpose of the project is to study the bending dipoles of this system: they are expected to have a curvature of 1.65 m, aperture of 80 mm, magnetic field of 4 T, ramp rates up to 0.4 T/s and Nb-Ti coils. Among the goal of SIG is the construction of a 30-degree demonstrator to prove the feasibility of these magnets. The plan is to design cos $\theta$ magnets, but we are currently working on an alternative strategy with cross section in block coil configuration. These parameters are very challenging and this solution could make it easier to achieve the required goals. In this work the optimized cross section and a novel winding technique for high curvature block coil magnets are presented.

The European project IFAST's WP8 Innovative Superconducting Magnets aims to develop the technology of Canted Cosine Theta (CCT) magnets wound with High-Temperature Superconductors (HTS). Superconducting magnets could lower the size and cost of synchrotrons and gantries for research and hadron therapy. HTS materials can lead to higher magnetic fields with smaller cryogenic systems than LTS. However, they pose challenges in cable production schemes, magnet design, and cost. The project's final goal is to design a straight CCT-layout magnet with a central dipole field of 4 T, and a ramp rate of 0.4 T/s, but a lower ramp rate of 0.15–0.2 T/s is acceptable for the first step. The paper presents a preliminary design, discussing in particular the protection scheme with the magnet protection solutions for the conductor: one with two and the other with four HTS tapes. Both options generate 4 T of dipole field without an Iron shell, with at least 10 K of margin at an operational temperature of 20 K. To meet the time and budget constraints of the project, a simple cable based on a co-winding of commercial REBCO tapes is proposed. Protection is the most challenging aspect of the design and an adiabatic quench analysis has been used to determine the required thickness of copper stabilizer tapes to mitigate the risk of damaging the magnet during a quench. Finally, the paper evaluates ac and radial current losses during the magnet cycles, discussing the heat distribution and possible solutions for heat extraction.

Purpose: This article summarizes the short lecture on gantries given at the “Hadrontherapy: status and perspectives. Development of a hadrontherapy facility: learning from the existing” event. Methods and materials: An introduction to gantries is given describing what a gantry is and which are the main difficulties and choices for an ion gantry. The gantry design activities ongoing at CNAO are shortly described. Results: The first part of the lecture and of the article describes some of the main choices to be made when designing a carbon ion gantry. The second part of the lecture reports shortly about the activities ongoing at CNAO within the HITRIplus and the EuroSIG projects. Conclusions: Carbon ion gantries are large, complicated and expensive objects and presently only three gantries for carbon are operational worldwide. The design of a gantry can be optimized in many ways and in many respects. In the paper, without the ambition of being exhaustive, some of the main choices are illustrated and the pros and cons of the possible options are discussed. Finally the gantry design activities ongoing in the EuroSIG collaboration and in the HITRIplus project are shortly reported.

The quest for advancing science and technology continues with the Future Circular Collider (FCC), which requires 16 T bending dipoles to be installed along its 100 km tunnel to achieve a center-of-mass energy of 100 TeV, in its hadron-hadron version. The promising Nb$_{3}$Sn technology for superconducting magnets presents a potential solution for large-scale production. In line with this, the European strategy for particle physics has urged for increased efforts in High Field Magnet R&D, specifically in constructing demonstrators for Nb$_{3}$Sn technology. To address this call, the Istituto Nazionale di Fisica Nucleare (INFN) and CERN entered into an agreement to build a 1.5 m long cos-theta dipole in Nb$_{3}$Sn, called Falcon Dipole (The Future Accelerator post-LHC Cos-theta Optimized Nb$_{3}$Sn Dipole). The project aims to consolidate the fabrication process for Nb$_{3}$Sn superconducting dipoles in the 12–14 T range, engaging industry partners in the initial stages of the R&D phase. This article provides a recall of the magnet design features and highlights the progress made in the development activities. Critical processes like the reaction treatment and the impregnation are discussed, with an emphasis on the test outcomes and the challenges faced. By taking these into account, plans for the production of the coils for the final configuration can be effectively formulated.

The Superconducting Ion Gantry (SIG) project is the contribution from INFN (the Italian National Institute for Nuclear Physics) to the international SIGRUM project with the aim of exploring new technological solutions for the critical elements of a 430 MeV/u carbon ion gantry. The project includes the design and construction of a cos$\theta$ 4 T superconducting dipole demonstrator magnet whose main scope is to prove the feasibility of winding and assembling an accelerator magnet type with a relatively small radius of curvature (1.65 m). In addition to the complexity due to the curvature, the target field ramp rate is 0.4 T/s and the cooling system must not adopt liquid helium. This paper discusses the design activities carried out in the last year on the electromagnetic and thermal domains and reports on the present concepts and infrastructure for the first winding trials.

As part of the research project called FCC-hh led by CERN, which aims to study the possibility of building a new 100 TeV center of mass energy particle collider along an 80-100 km circumference tunnel, there are many collaborations underway to test different designs for the main bending dipole of the collider. One of these collaborations involves INFN, the Italian Institute of Nuclear Physics, which has been working on the cos $\theta$ design until 2019 as part of the European EuroCirCol project. This study consisted of a conceptual design of a 16 T, double-aperture, four-layer dipole made of Nb$_{3}$ Sn. Considering the challenge that such a cutting-edge magnet represents, this conceptual design resulted in a 5-year agreement between INFN and CERN in order to study and build a 1.5 m long, single aperture, cos $\theta$, Nb$_{3}$ Sn dipole with a target magnetic field of 12 T. This project is called the Future Accelerator post-LHC Cos $\theta$ Optimized Nb$_{3}$ Sn Dipole (or FalconD for short). In this paper we present the mechanical analysis of this project after some major cross-sectional upgrades that have impacted the design by easing the assembly phase. One of the most challenging aspects of this design is its mechanical structure that must handle the intense magnetic forces generated by such a high magnetic field. The mechanical structure is based on the “bladder & key” (B&K) concept and it has never been adopted before in a cos$\theta$ dipole, so it needs to be validated. This contribution presents the 2D FEM of the FalconD, showing the mechanical behavior of the magnet during each construction step.

Canted Cosine Theta layout for accelerator magnets is a very attractive since such magnets can be manufactured and assembled without big tooling, and with a relatively modest number of parts and tools. In the frame of European Horizon2020 funds, two collaborations, HITRIplus and I.FAST, are developing a CCT design, of 80 mm free bore, 4 T central dipole field, and 0.4 T/s ramp-rate. This magnet is expected to be the bending element of a gantry, to control the beam delivery in therapy with ions (hadrontherapy). The paper illustrates first a comparison between CCT and more classical cosine theta layout, followed by the comparison between Nb-Ti, Nb3Sn, MgB2, and HTS tapes coils. Relevant requirement for the magnets of this study is to be operated at low current, to limit the heat generation, in sight of a liquid-free cooling system. The results of the comparison is then applied to the design of two magnet demonstrators. Both adopt a low-losses Nb-Ti rope, consistently with the need for keeping the heat generation as low as possible. The first is a straight combined function dipole-quadrupole, while the second is a curved CCT dipole. The paper concludes with the first manufacturing tests for the CCT formers, for which aluminium -bronze, stainless steel and charged PEEK polymer are being explored as basic material.

INFN has developed at the LASA lab (Milano, Italy) the High Order (HO) corrector magnets for the High Luminosity-LHC (HL-LHC) project, which will equip the new interaction regions. All the HO correctors, from skew quadrupole to dodecapole, are based on a novel superferric design, never used so far in high energy colliders, which allows a relatively simple, modular, and easy way to construct a magnet. After the completion of the production of the 54 series magnets in industry, the powering of all the produced magnets has been achieved. The delivery to CERN and the assembly of the first cold mass started. Each magnet has been powered individually and most of them have also been magnetically characterized, the aggregate results are presented and discussed. The lessons learned during the production and the testing of the magnets are reported. The quality assurance and the procedures developed in during development and production in industry proved to be key points of the successful experience of the HO correctors development, together with the solid design. We also report the lessons learned during the experience of the series production of the HO correctors.

Background: Chronic pancreatitis is a long-standing, inflammatory condition of the pancreas that leads to the progressive damage and loss of function of pancreatic parenchyma and to the development of possible locoregional and systemic medical complications.Materials and methods: In this review, we tried to summarize the current evidence on non-surgical treatment trying to suggest a practical approach to the management of chronic pancreatitis.Results: Besides the unclear pathophysiological mechanism and a poorly unknown epidemiology, chronic pancreatitis is a complex syndrome that displays different possible challenges for physicians. Despite being traditionally considered as a benign disease, chronic pancreatitis encompasses 10-year mortality rates which are superior to the ones reported for some of the most common cancers.Conclusions: Chronic pancreatitis encompasses the management of multiple and complex medical co-morbidities that needs to be understood and addressed in a multidisciplinary specialist context.

The main goal of this work is made a first approach to the study of formability of sandwich structures, composed by two aluminum sheets (skins), separated by an aluminum metal foam core, using bending tests. The bending tests performed on this work, can be described as a cylindrical punch, which apply a force at the middle span of the specimens, which were have three different lengths, 114 mm, 167.5 mm and 230 mm, in a specific die. The bending tests were used to evaluate the type of yielding of the global composite structure, by measuring the force / displacement values at a middle span. The type of yielding of the global structure has extremely importance in the study of formability of this type of composite, because it was composed by two different materials; each one presents a different mechanical behavior separately. The difference in mechanical behavior can be explained by the axisymmetric compressive stress states test and by the influence of the hydrostatic pressure in the yield stress of the porous material (aluminum foam) and has no influence on the yield stress of the homogeneous solid material (aluminum sheet). With this work, experimental information on the yielding of this composite structure was obtained, to be used in numerical models to study its formability.

The nickel complexes Ni(PPh3)2X2 (X = Cl, Br) have been found to be active for the selective oxidative coupling of aryl thiols with secondary amines and carbon monoxide to give thiocarbamates. With added oxygen, the reaction is catalytic, although competitive oxidation of the thiol is problematic.

A new route for the synthesis of thiocarbamates using a transition metal complex and CO as a replacement for phosgene has been discovered. The complex (PPh3)2PdCl2 reacts with N-benzylmethylamine, 4-chlorobenzenethiol, and CO to selectively generate a thiocarbamate. Kinetic studies and the isolation of several intermediates in this reaction allow for the proposal of a mechanistic scheme.

AbstractCytomegalovirus (CMV) infection is still a major cause of morbidity in high‐risk renal transplant recipients. In the present report, we have reviewed our records of renal transplant pediatric recipients (RTPR; mean age 14.1 ± 4.9 years) since 1991, when we started a policy of CMV prophylaxis constituting high‐dose oral acyclovir plus CMV hyperimmune immunoglobulins (Hlg) followed by early i.v. ganciclovir therapy in high‐risk patients (i.e., CMV donor +/ recipient ‐). Four patients received a kidney from a living relative (LR), 2 patients had one previous transplant, and 1 had a combined liver ‐kidney transplant. Thirty‐three patients who were negative for CMV antibodies (ab) before transplantation received a kidney from CMV ab positive donors. The immunosuppressive regimen included cyclosporin A and steroids, with the addition of azathioprine in the 4 patients who received an LR kidney. Serial assessments for CMV antigenemia (pp 65) were routinely performed for 6 months after transplantation to define CMV infection. Among the 33 CMV seronegative recipients (R ‐) who received the graft from a CMV seropositive donor (D +), 18 (54.5 %) experienced CMV infection, whereas among the 28 CMV R +, who received a graft from a CMV D +, 11 (39.3 %) experienced CMV infection. With regard to CMV ‐ related symptoms, only 2 patients suffered from a CMV syndrome (fever and leukopenia in 1 patient, fever and arthralgia in the other). In no case did the spectrum of CMV disease occur; only minor symptoms were present in 7 of the remaining CMV‐infected patients (fever in 6 and leukopenia in 1). Rejection episodes and renal function did not differ between CMV‐infected and non‐CMV‐infected patients. Our experiences support the use of prophylactic acyclovir plus CMV HIg followed by early therapy with i.v. ganciclovir to combat the risk of increased morbidity in high risk RTPR.

Abstract Cytomegalovirus (CMV) infection is still a major cause of morbidity in high-risk renal transplant recipients. In the present report, we have reviewed our records of renal transplant pediatric recipients (RTPR; mean age 14.1 ± 4.9 years) since 1991, when we started a policy of CMV prophylaxis constituting high-dose oral acyclovir plus CMV hyperimmune immunoglobulins (Hlg) followed by early i. v. ganciclovir therapy in high-risk patients (i. e., CMV donor + / recipient −). Four patients received a kidney from a living relative (LR), 2 patients had one previous transplant, and 1 had a combined liver – kidney transplant. Thirty-three patients who were negative for CMV antibodies (ab) before transplantation received a kidney from CMV ab positive donors. The immunosuppressive regimen included cyclosporine A and steroids, with the addition of azathioprine in the 4 patients who received an LR kidney. Serial assessments for CMV antigenemia (pp 65) were routinely performed for 6 months after transplantation to define CMV infection. Among the 33 CMV seronegative recipients (R −) who received the graft from a CMV seropositive donor (D +), 18 (54.5 %) experienced CMV infection, whereas among the 28 CMV R +, who received a graft from a CMV D +, 11 (39.3 %) experienced CMV infection. With regard to CMV − related symptoms, only 2 patients suffered from a CMV syndrome (fever and leukopenia in 1 patient, fever and arthralgia in the other). In no case did the spectrum of CMV disease occur; only minor symptoms were present in 7 of the remaining CMV-infected patients (fever in 6 and leukopenia in 1). Rejection episodes and renal function did not differ between CMV-infected and non-CMV-infected patients. Our experiences support the use of prophylactic acyclovir plus CMV HIg followed by early therapy with i. v. ganciclovir to combat the risk of increased morbidity in high risk RTPR.

An unusual case of bilateral aneurysms of the internal cervical carotid arteries in a 38 year old man with right hemiplegia and aphasia is described.