Micro-PIXE with 3.5 MeV protons for the study of low copper concentrations in atherosclerotic artery

The onset and progression of many degenerative diseases including atherosclerosis, have been shown to directly link to the presence/absence of certain metal ions. Consequently, the detection of these ions in tissues may improve the understanding of the driving pathophysiology. The Cu content during atherosclerosis development has not been studied due to its low concentration involved. In this work, the Cu level in atherosclerotic rabbit tissue is determined using PIXE with a 3.5 MeV proton beam. The arteries of three animal groups fed with different diets were studied: group 1, rabbits on normal standard diet, group 2, on High Fat Diet (HFD) and group 3, on HFD + Zinc diet. Zinc supplement has been proven to inhibit the beginning of atherosclerotic lesion. The result of this study shows that the Cu levels in all the atherosclerotic lesions were lower than that in the arterial walls of the samples in HFD groupThis work has been partially funded by a UAM-Banco de Santander Interuniversity Cooperation with Asia Grant (2017–2018) and by the Ministerio de Ciencia, Innovacióny Universidades (CTQ2017-84309-C2-2-R

Process design for the manufacturing of soft X-ray gratings in single-crystal diamond by high-energy heavy-ion irradiation

This paper describes in detail a novel manufacturing process for optical gratings suitable for use in the UV and soft X-ray regimes in a single-crystal diamond substrate based on highly focused swift heavy-ion irradiation. This type of grating is extensively used in light source facilities such as synchrotrons or free electron lasers, with ever-increasing demands in terms of thermal loads, depending on beamline operational parameters and architecture. The process proposed in this paper may be a future alternative to current manufacturing techniques, providing the advantage of being applicable to single-crystal diamond substrates, with their unique properties in terms of heat conductivity and radiation hardness. The paper summarizes the physical principle used for the grating patterns produced by swift heavy-ion irradiation and provides full details for the manufacturing process for a specific grating configuration, inspired in one of the beamlines at the ALBA synchrotron light source, while stressing the most challenging points for a potential implementation. Preliminary proof-of-concept experimental results are presented, showing the practical implementation of the methodology proposed herein

Process design for the manufacturing of soft X-ray gratings in single-crystal diamond by high-energy heavy-ion irradiation

Artículo con 9 figurasThis paper describes in detail a novel manufacturing process for optical gratings suitable for use in the UV and soft X-ray regimes in a single-crystal diamond substrate based on highly focused swift heavy-ion irradiation. This type of grating is extensively used in light source facilities such as synchrotrons or free electron lasers, with ever-increasing demands in terms of thermal loads, depending on beamline operational parameters and architecture. The process proposed in this paper may be a future alternative to current manufacturing techniques, providing the advantage of being applicable to single-crystal diamond substrates, with their unique properties in terms of heat conductivity and radiation hardness. The paper summarizes the physical principle used for the grating patterns produced by swift heavy-ion irradiation and provides full details for the manufacturing process for a specific grating configuration, inspired in one of the beamlines at the ALBA synchrotron light source, while stressing the most challenging points for a potential implementation. Preliminary proof-of-concept experimental results are presented, showing the practical implementation of the methodology proposed herein.The authors acknowledge funding support by the following projects: PID2020-112770RB-C22 from the Spanish Ministry of Science and Innovation, TechnoFusión (III)-CM (S2018/EMT-4437) from Comunidad de Madrid (cofinanced by ERDF and ESF), agreement between Community of Madrid and Universidad Autónoma de Madrid (item “Excellence of University Professorate”). M.L.C. acknowledges financial support from the research project “Captacion de Talento UAM” Ref: #541D300 supervised by the Vice-Chancellor of Research of Universidad Autónoma de Madrid (UAM). LOREA beamline at ALBA is a project co-funded by the European Regional Development Fund (ERDF) within the Framework of the Smart Growth Operative Programme 2014-2020. The authors acknowledge the support from The Centro de Microanálisis de Materiales (CMAM)—Universidad Autónoma de Madrid, for the beam time proposal (demonstration of a grating profile for soft X-rays in diamond via ion lithography) with code IuB-005/21, and its technical staff for their contribution to the operation of the accelerator. We also acknowledge P. Olivero for very useful comments on the manuscript draf

Elemental distributions in femoral bone of rat under osteoporosis preventive treatments

et al.One of the abnormalities of bone architecture is osteoporosis as occurring in post-menopausal women. Especially long bones, such as femur, become more fragile and more prone to fracture. The efficiency of several osteoporosis preventative treatments based on oestrogen and progestin in bone structure and mineral recovery was studied using ovariectomized Wistar rats as an osteoporosis experimental model. Diagonal cross-sections of the proximal epiphysis of femoral bones were analysed using nuclear microscopy techniques in order to map and determine the concentration profiles of P, Ca, S, Fe and Zn from the epiphysis to diaphysis and across the cortical and trabecular bone structures. In control animals (not ovariectomized), the S and Zn contents significantly characterized differences between cortical and trabecular bone structures, whereas P and Ca showed increased gradients from the epiphyseal region to the diaphysis. After ovariectomy the differences observed were differential according to the type of hormonal supplementation. A significant decrease in P and Ca contents and depletion of minor and trace minerals, such as S, Fe and Zn, were found for both cortical and trabecular bone structures after ovariectomy relative to controls. Bone mineral contents were reversed to control levels by synthetic oestrogen supplementation, and combined oestrogen and progesterone treatment. Recovery was more evident in the femoral epiphysis and neck than in the diaphysis. The use of oestrogen alone did not lead to bone recovery after ovariectomy. Alterations in bone mineral composition observed for animals receiving synthetic oestrogen and combined oestrogen and progesterone supplement might reflect beneficial structural changes in critical regions of long bones, mostly affected in post-menopausal osteoporosis.Peer reviewe

Micro-Raman spectroscopy of near-surface damage in diamond irradiated with 9-MeV boron ions

We have studied the near-surface damage in a diamond crystal caused by irradiation with swift boron ions and its healing after high-temperature annealing. A diamond crystal was irradiated with 9-MeV 11B3+ ions with fluence values between 1×10^15 and 4.42×10^16 ions/cm2 to generate various levels of lattice damage. The ions loose energy to the lattice and, according to simulations, stop at a depth of about 5 μm, where they form a thin buried implantation layer. For the near-surface layers damage is produced by the ions at high kinetic energy before they slow down. Only intrinsic defects can be produced, with no boron atoms. The lattice damage of the near-surface layers and its recovery after annealing for 1 h at 1000°C were studied by Raman and photoluminescence spectroscopies. Back-scattered light from a 514.5-nm laser beam was collected from the sample surface, probing a depth of a few micrometers. We observe some disordering of the lattice plus the formation of neutral vacancies, interstitial and other lattice defects. After annealing the Raman spectrum shows a significant recovery of the lattice order and the disappearance of isolated neutral vacancies. Residual damage is confirmed by the luminescence spectrum, that shows the appearance of new spectral features.This work was supported by the Ministerio de Economía y Competitividad (MINECO), Spain [ MAT2014-57547-R,MAT2014-54826-C2-1-R, andFIS2014-54498-R], the María de Maeztu Program for Units of Excellence in R&D [ MDM-2014-0377], and the Comunidad Autónoma de Madrid [ NANOFRONTMAG-CM (S2013/MIT-2850)]. Research by N. G. is supported by MINECO [JCI-2012-12652].Peer-reviewe

Study of the effects of focused high-energy boron ion implantation in diamond

Boron-doped diamond is a material with a great technological and industrial interest because of its exceptional chemical, physical and structural properties. At modest boron concentrations, insulating diamond becomes a p-type semiconductor and at higher concentrations a superconducting metal at low temperature. The most conventional preparation method used so far, has been the homogeneous incorporation of boron doping during the diamond synthesis carried out either with high-pressure sintering of crystals or by chemical vapour deposition (CVD) of films. With these methods, high boron concentration can be included without distorting significantly the diamond crystalline lattice. However, it is complicated to manufacture boron-doped microstructures. A promising alternative to produce such microstructures could be the implantation of focused high-energy boron ions, although boron fluences are limited by the damage produced in diamond. In this work, the effect of focused high-energy boron ion implantation in single crystals of diamond is studied under different irradiation fluences and conditions. Micro-Raman spectra of the sample were measured before and after annealing at 1000°C as a function of irradiation fluence, for both superficial and buried boron implantation, to assess the changes in the diamond lattice by the creation of vacancies and defects and their degree of recovery after annealing.The authors wish to thank the technical staff of CMAM for operating the tandem accelerator and the Ministerio de Economía y Competitividad (MINECO) for funding this work (Projects MAT2014-54826-C2-1-R, MAT2014-57547-R and FIS2014-54498-R). Research by NG is supported by the MINECO under the project JCI-2012-12652. MINECO/ICTI2013-2016/MAT2014-57547-R MINECO/ICTI2013-2016/FIS2014-54498-

PIXE and PIGE studies of gems in Torredonjimeno Treasure

[ES] El tesoro de Torredonjimeno (TDJ) es, junto al tesoro de Guarrazar uno de los pocos ejemplos de orfebrería de la época visigoda que se conservan actualmente; se encuentra distribuido en tres museos diferentes: Museo de Arqueología de Cataluña (MAC), Museo Arqueológico y Etnológico de Córdoba (MAECO) y Museo Arqueológico de Madrid (MAN). Está constituido por cruces, cadenas, fragmentos de diferentes objetos y gemas sueltas y montadas en cruces, fragmentos y letras colgantes. Con el fin de identificar las piedras preciosas utilizadas por los orfebres en la fabricación del tesoro de TDJ y de comparar los resultados obtenidos con los del tesoro de Guarrazar, se han analizado las gemas presentes en varias piezas utilizando técnicas con haces de iones, en concreto las técnicas PIXE (Particle Induced Xray Emission) y PIGE (Particle Induced g-ray Emission).[EN] The Torredonjimeno (TDJ) treasure is, with the Guarrazar treasure, one of the few examples of the Visigothic jewellery left today; it is shared between three different museums: Museo de Arqueología de Cataluña (MAC), Museo Arqueológico y Etnológico de Córdoba (MAECO) and Museo Arqueológico de Madrid (MAN). It is composed of crosses, chains, fragments of objects and gemstones isolated and mounted on crosses, fragments and pendant letters. In order to identify the precious stones employed by the jewellers of the TDJ treasure and to compare the results obtained with those of the Guarrazar treasure, we have analysed the gems set on several objects using ion beam techniques, in particular PIXE (Particle Induced X-ray Emission) and PIGE (Particle Induced g-ray Emission) methods.Peer reviewe

Lattice damage in 9-MeV-carbon irradiated diamond and its recovery after annealing

We have studied the radiation damage in diamond as a function of layer depth upon self-ion implantation with 9-MeV carbon ions and its recovery after annealing at 1000◦C. Raman and photoluminescence spectra show substantial damage of the lattice, namely, amorphization, neutral vacancies, and interstitial defects. Damage is maximum in the stopping layer at a depth of 4 μm. After annealing there is some recovery of the lattice, but the residual damage increases with fluence, up to about 2×10^16 ions/cm2. At this fluence the stopping layer becomes highly disordered and does not heal with annealing. Surprisingly, for higher fluence values, of about 5×10^16 ions/cm2, there is almost no residual damage. After full amorphization is reached, the layers appear to recrystallize by solid phase epitaxy (SPE), using the pristine diamond layers underneath as a template. These results prove that graphitization of diamond after annealing can be avoided in deeply buried layers, implanted at fluences much higher than expected. High fluences, in fact, can lead to high quality diamond layers. If SPE can be confirmed, it would have a great interest for diamond device applications, as it allows for higher doping levels.We thank the technical staff of CMAM for operating the tandem ion-beam accelerator. Funding: This work was supported by the Ministerio de Economía y Competitividad (MINECO), Spain [MAT2014-57547-R, MAT2014-54826-C2-1-R, FIS2014-54498-R, and CTQ-2014-53334-C2-2-R], the María de Maeztu Program for Units of Excellence in R&D [MDM-2014-0377], and the Comunidad Autónoma de Madrid [NANOFRONTMAG-CM (S2013/MIT-2850)].Peer reviewe

External microbeam set-up at the CNA (Sevilla) and its application to the study of Tartesic jewellery

6 pages.-- PACS nrs.: 81.70.Jb; 82.80.Ej; 82.80.Yc; 89.90.+n.-- et al.A new external microbeam system has been installed recently at the +45° beam line of the 3 MV Pelletron accelerator at the Centro Nacional de Aceleradores (Sevilla, Spain). The facility, based on the system from Oxford Microbeams (OM), includes two sets of slits, a doublet of magnetic quadrupole focusing lenses, a Faraday cup and an accurate positioning device. In addition, a beam profile monitor (BPM) and a quartz viewer have been installed in the line to facilitate the microbeam production. The first PIXE application of the new facility was made in the field of Archaeometry, on the study of Tartesic gold artefacts (700–500 BC, SW of Spain) from Ébora and other archaeological sites. The aim of the analysis was to perform an exhaustive and systematic study about the soldering procedures that were employed by the goldsmiths along the Valley of Guadalquivir River after the Phoenician colonisation.Peer reviewe

CNA: The first accelerator-based IBA facility in Spain

6 pages.-- PACS nrs.: 29.17.+w; 07.50.Qx; 07.30.Kf.The recently created Centro Nacional de Aceleradores (National Center for Accelerators, CNA) in Seville emerges as the first ion beam analysis facility in Spain. The laboratory is based on a 3 MV tandem accelerator model 9SDH-2 of NEC and it is primarily focused on material research and modification by means of IBA techniques: PIXE, RBS, NRA, PIGME and ERDA. The ions are delivered by two ion sources: Alphatross radio-frequency source and SNICS-II sputtering source. The ion beam handling system includes equipment for beam focusing, steering and diagnosis, a 90° analyzing magnet and a seven-port switcher magnet. A system based on magnetic steerers has been installed for high-precision beam energy scanning. In this paper the main elements of the laboratory will be described, focusing on the electronic equipment, detectors and the four beamlines planned for the moment: channeling line, microbeam line, multipurpose vacuum chamber and external microbeam. Moreover, the characteristics of the system as observed until now by means of performance tests, beam energy spread measurements and energy calibration experiments will be summarized.Peer reviewe