28 research outputs found

    Innovative Analytical Method for X-ray Imaging and Space-Resolved Spectroscopy of ECR Plasmas

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    At the Italian National Institute for Nuclear Physics-Southern National Laboratory (INFN-LNS), and in collaboration with the ATOMKI laboratories, an innovative multi-diagnostic system with advanced analytical methods has been designed and implemented. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF systems, interfero-polarimetry, X-ray detectors), and here we focus on high-resolution, spatially resolved X-ray spectroscopy, performed by means of a X-ray pin-hole camera setup operating in the 0.5–20 keV energy domain. The diagnostic system was installed at a 14 GHz Electron Cyclotron Resonance (ECR) ion source (ATOMKI, Debrecen), enabling high-precision, X-ray, spectrally resolved imaging of ECR plasmas heated by hundreds of Watts. The achieved spatial and energy resolutions were 0.5 mm and 300 eV at 8 keV, respectively. Here, we present the innovative analysis algorithm that we properly developed to obtain Single Photon-Counted (SPhC) images providing the local plasma-emitted spectrum in a High-Dynamic-Range (HDR) mode, by distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar). This method allows for a quantitative characterization of warm electrons population in the plasma (and its 2D distribution), which are the most important for ionization, and to estimate local plasma density and spectral temperatures. The developed post-processing analysis is also able to remove the readout noise that is often observable at very low exposure times (msec). The setup is now being updated, including fast shutters and trigger systems to allow simultaneous space and time-resolved plasma spectroscopy during transients, stable and turbulent regimes

    High Resolution He-like Argon And Sulfur Spectra From The PSI ECRIT

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    We present new results on the X-ray spectroscopy of multicharged argon, sulfur and chlorine obtained with the Electron Cyclotron Resonance Ion Trap (ECRIT) in operation at the Paul Scherrer Institut (Villigen, Switzerland). We used a Johann-type Bragg spectrometer with a spherically-bent crystal, with an energy resolution of about 0.4 eV. The ECRIT itself is of a hybrid type, with a superconducting split coil magnet, special iron inserts which provides the mirror field, and a permanent magnetic hexapole. The high frequency was provided by a 6.4 GHz microwave emitter. We obtained high intensity X-ray spectra of multicharged F-like to He-like argon, sulfur and chlorine with one 1s hole. In particular, we observed the 1s2s^{3}S_1 \to 1s^2^{1}S_0 M1 and 1s2p^{3}P_2 \to 1s^2^{1}S_0 M2 transitions in He-like argon, sulfur and chlorine with unprecedented statistics and resolution. The energies of the observed lines are being determined with good accuracy using the He-like M1 line as a reference

    Fullerenes in electron cyclotron resonance ion sources

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    Fullerene plasmas and beams have been produced in our electron cyclotron resonance ion sources (ECRIS) originally designed for other purposes. The ATOMKI-ECRIS is a traditional ion source with solenoid mirror coils to generate highly charged ions. The variable frequencies NIRS-KEI-1 and NIRS-KEI-2 are ECR ion sources built from permanent magnets and specialized for the production of carbon beams. The paper summarizes the experiments and results obtained by these facilities with fullerenes. Continuous effort has been made to get the highest C-60 beam intensities. Surprisingly, the best result was obtained by moving the C-60 oven deep inside the plasma chamber, very close to the resonance zone. Record intensity singly and doubly charged fullerene beams were obtained (600 and 1600 nA, respectively) at lower C-60 material consumption. Fullerene derivatives were also produced. We mixed fullerenes with other plasmas (N, Fe) with the aim of making new materials. Nitrogen encapsulated fullerenes (mass: 720+14=734) were successfully produced. In the case of iron, two methods (ferrocene, oven) were tested. Molecules with mass of 720+56=776 were detected in the extracted beam spectra

    Elevated Levels of Asymmetric Dimethylarginine (ADMA) in the Pericardial Fluid of Cardiac Patients Correlate with Cardiac Hypertrophy.

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    Pericardial fluid (PF) contains several biologically active substances, which may provide information regarding the cardiac conditions. Nitric oxide (NO) has been implicated in cardiac remodeling. We hypothesized that L-arginine (L-Arg) precursor of NO-synthase (NOS) and asymmetric dimethylarginine (ADMA), an inhibitor of NOS, are present in PF of cardiac patients and their altered levels may contribute to altered cardiac morphology.L-Arg and ADMA concentrations in plasma and PF, and echocardiographic parameters of patients undergoing coronary artery bypass graft (CABG, n = 28) or valve replacement (VR, n = 25) were determined.We have found LV hypertrophy in 35.7% of CABG, and 80% of VR patients. In all groups, plasma and PF L-Arg levels were higher than that of ADMA. Plasma L-Arg level was higher in CABG than VR (75.7 ± 4.6 μmol/L vs. 58.1 ± 4.9 μmol/L, p = 0.011), whereas PF ADMA level was higher in VR than CABG (0.9 ± 0.0 μmol/L vs. 0.7 ± 0.0 μmol/L, p = 0.009). L-Arg/ADMA ratio was lower in the VR than CABG (VRplasma: 76.1 ± 6.6 vs. CABGplasma: 125.4 ± 10.7, p = 0.004; VRPF: 81.7 ± 4.8 vs. CABGPF: 110.4 ± 7.2, p = 0.009). There was a positive correlation between plasma L-Arg and ADMA in CABG (r = 0.539, p = 0.015); and plasma and PF L-Arg in CABG (r = 0.357, p = 0.031); and plasma and PF ADMA in VR (r = 0.529, p = 0.003); and PF L-Arg and ADMA in both CABG and VR (CABG: r = 0.468, p = 0.006; VR: r = 0.371, p = 0.034). The following echocardiographic parameters were higher in VR compared to CABG: interventricular septum (14.7 ± 0.5 mm vs. 11.9 ± 0.4 mm, p = 0.000); posterior wall thickness (12.6 ± 0.3 mm vs. 11.5 ± 0.2 mm, p = 0.000); left ventricular (LV) mass (318.6 ± 23.5 g vs. 234.6 ± 12.3 g, p = 0.007); right ventricular (RV) (33.9 ± 0.9 cm2 vs. 29.7 ± 0.7 cm2, p = 0.004); right atrial (18.6 ± 1.0 cm2 vs. 15.4 ± 0.6 cm2, p = 0.020); left atrial (19.8 ± 1.0 cm2 vs. 16.9 ± 0.6 cm2, p = 0.033) areas. There was a positive correlation between plasma ADMA and RV area (r = 0.453, p = 0.011); PF ADMA and end-diastolic (r = 0.434, p = 0.015) and systolic diameter of LV (r = 0.487, p = 0.007); and negative correlation between PF ADMA and LV ejection fraction (r = -0.445, p = 0.013) in VR.We suggest that elevated levels of ADMA in the PF of patients indicate upregulated RAS and reduced bioavailability of NO, which can contribute to the development of cardiac hypertrophy and remodeling

    Multiply charged carbon-ion production for medical application

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    Over 3000 cancer patients have already been treated by the heavy-ion medical accelerator in Chiba at the National Institute of Radiological Sciences since 1994. The clinical results have clearly verified the effectiveness and safety of heavy-ion radiotherapy. The most important result has been to establish that the carbon ion is one of the most effective radiations for radiotherapy. The ion source is required to realize a stable beam with the same conditions for daily operation. However, the deposition of carbon ions on the wall of the plasma chamber is normally unavoidable. This causes an "anti-wall-coating effect," i.e., a decreasing of the beam, especially for the higher charge-state ions due to the surface material of the wall. The ion source must be required to produce a sufficiently intense beam under the bad condition. Other problems were solved by improvements and maintenance, and thus we obtained enough reproducibility and stability along with decreased failures. We summarize our over 13 years of experience, and show the scope for further developments

    Review on heavy ion radiotherapy facilities and related ion sources

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    Heavy ion radiotherapy awakens worldwide interest recently. The clinical results obtained by the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan have clearly demonstrated the advantages of carbon ion radiotherapy. Presently, there are four facilities for heavy ion radiotherapy in operation, and several new facilities are under construction or being planned. The most common requests for ion sources are a long lifetime and good stability and reproducibility. Sufficient intensity has been achieved by electron cyclotron resonance ion sources at the present facilities

    Correlations between the levels of asymmetric dimethylarginine (ADMA) and echocardiographic parameters of patients undergoing valve replacement (VR) surgery.

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    <p>(A) plasma ADMA vs. area of right ventricle (<i>y</i> = 10.438<i>x</i> + 25.49, <i>r</i> = 0.453, <i>p</i> = 0.011); (B) PF ADMA vs. left ventricular (LV) end-systolic diameter (<i>y</i> = 23.689<i>x</i> + 13.53, <i>r</i> = 0.487, <i>p</i> = 0.007); (C) PF ADMA vs. LV end-diastolic diameter (<i>y</i> = 20.531<i>x</i> + 34.72, r = 0.434, p = 0.015); D: PF ADMA vs. LV ejection fraction (<i>y</i> = -16.779<i>x</i> + 73.55, r = -0.445, p = 0.013).</p

    Types of surgery operation.

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    <p>CABG: coronary artery bypass graft (the number indicates the vessels involved); VR: valve replacement; AMI: acute myocardial infarction.</p><p>Types of surgery operation.</p
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