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Proton Beam

Zs Podolyák, C M Shand, N Lalović, J Gerl, D Rudolph, T Alexander, P Boutachkov, M L Cortés, M Górska, I Kojouharov, N Kurz, C Louchart, E Merchán, C Michelagnoli, R M Pérez-Vidal, S Pietri, D Ralet, M Reese, H Schaffner, Ch Stahl, H Weick, F Ameil, G de Angelis, T Arici, R Carroll, Zs Dombrádi, A Gadea, P Golubev, M Lettmann, C Lizarazo, D Mahboub, H Pai, Z Patel, N Pietralla, P H Regan, L G Sarmiento, O Wieland, E Wilson, B Birkenbach, B Bruyneel, I Burrows, L Charles, E Clément, F C L Crespi, D M Cullen, P Désesquelles, J Eberth, V González, T Habermann, L Harkness-Brennan, H Hess, D S Judson, A Jungclaus, W Korten, M Labiche, A Maj, D Mengoni, D R Napoli, A Pullia, B Quintana, G Rainovski, P Reiter, M D Salsac, E Sanchis, J J Valiente Dóbon
The ^{54}Fe nucleus was populated from a ^{56}Fe beam impinging on a Be target with an energy of E/A=500  MeV. The internal decay via γ-ray emission of the 10^{+} metastable state was observed. As the structure of this isomeric state has to involve at least four unpaired nucleons, it cannot be populated in a simple two-neutron removal reaction from the ^{56}Fe ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of ^{54}Fe, suggesting that it was populated via the decay of the Δ^{0} resonance into a proton...
November 25, 2016: Physical Review Letters
Radhe Mohan, David Grosshans
In principle, proton therapy offers a substantial clinical advantage over the conventional photon therapy. This is because of the unique depth-dose characteristics of protons, which can be exploited to achieve significant reductions in normal tissue doses proximal and distal to the target volume. These may, in turn, allow escalation of tumor doses, greater sparing of normal tissues, thus potentially improving local control and survival while at the same time reducing toxicity and improving quality of life. Protons, accelerated to therapeutic energies ranging from 70 to 250MeV, typically with a cyclotron or a synchrotron, are transported to the treatment room where they enter the treatment head mounted on a rotating gantry...
December 2, 2016: Advanced Drug Delivery Reviews
Fan Liu, Li Jiang, Huei Ming Tan, Ashutosh Yadav, Preetika Biswas, Johan R C van der Maarel, Christian A Nijhuis, Jeroen A van Kan
Brownian ratchet based particle separation systems for application in lab on chip devices have drawn interest and are subject to ongoing theoretical and experimental investigations. We demonstrate a compact microfluidic particle separation chip, which implements an extended on-off Brownian ratchet scheme that actively separates and sorts particles using periodically switching magnetic fields, asymmetric sawtooth channel sidewalls, and Brownian motion. The microfluidic chip was made with Polydimethylsiloxane (PDMS) soft lithography of SU-8 molds, which in turn was fabricated using Proton Beam Writing...
November 2016: Biomicrofluidics
S Kaliki, C L Shields
Although it is a relatively rare disease, primarily found in the Caucasian population, uveal melanoma is the most common primary intraocular tumor in adults with a mean age-adjusted incidence of 5.1 cases per million per year. Tumors are located either in iris (4%), ciliary body (6%), or choroid (90%). The host susceptibility factors for uveal melanoma include fair skin, light eye color, inability to tan, ocular or oculodermal melanocytosis, cutaneous or iris or choroidal nevus, and BRCA1-associated protein 1 mutation...
December 2, 2016: Eye
Jerimy C Polf, Stephen Avery, Dennis S Mackin, Sam Beddar
A reply is provided to the points raised in the comment by Dr Sitek (2016 Phys. Med. Biol. 61 8941) on Polf et al (2015 Phys. Med. Biol. 60 7085).
December 21, 2016: Physics in Medicine and Biology
Arkadiusz Sitek
The origin ensemble (OE) algorithm is a new method used for image reconstruction from nuclear tomographic data. The main advantage of this algorithm is the ease of implementation for complex tomographic models and the sound statistical theory. In this comment, the author provides the basics of the statistical interpretation of OE and gives suggestions for the improvement of the algorithm in the application to prompt gamma imaging as described in Polf et al (2015 Phys. Med. Biol. 60 7085).
December 21, 2016: Physics in Medicine and Biology
S Yamamoto, K Ogawa, M Isobe, D S Darrow, S Kobayashi, K Nagasaki, H Okada, T Minami, S Kado, S Ohshima, G M Weir, Y Nakamura, S Konoshima, N Kemmochi, Y Ohtani, T Mizuuchi
A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7-42.5 keV (proton) and pitch angle of 90(∘)-140(∘), especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas...
November 2016: Review of Scientific Instruments
W J Capecchi, J K Anderson, P J Bonofiglo, J Kim, S Sears
The neutron emissivity profile in the Madison Symmetric Torus is being reconstructed through the use of a collimated neutron detector. A scintillator-photomultiplier tube (PMT) system is employed to detect the fusion neutrons with the plasma viewing volume defined by a 55 cm deep, 5 cm diameter aperture. Effective detection of neutrons from the viewing volume is achieved through neutron moderation using 1300 lbs of high density polyethylene shielding, which modeling predicts attenuates the penetrating flux by a factor of 10(4) or more...
November 2016: Review of Scientific Instruments
Xiao Ding Zhang, Guo Jun Yang, Yi Ding Li, Tao Wei, Xiaozhong He, Liang Chao Zhao, Zhuo Zhang, Chaofan Ma, Xiaoguo Jiang, Jinshui Shi
Lens focused proton radiograph on thin objects is demonstrated using an 11-MeV proton cyclotron at China Academy of Engineering Physics. The proton beam exiting from the tested objects is focused onto the image plane by a magnetic lens system mitigating image blur caused by multiple Coulomb scattering. Both simulations and experiments show that clear images can be obtained with a lens system for the objects with thickness up to 2.7 × 10(-2) g/cm(2) and the error for the areal density measurement is measured to be less than 2...
November 2016: Review of Scientific Instruments
R Clary, A Roquemore, J Douglass, D Jaramillo, S Korepanov, R Magee, S Medley, A Smirnov
C-2U is a high-confinement, advanced beam driven field-reversed configuration plasma experiment which sustains the configuration for >5 ms, in excess of typical MHD and fast particle instability times, as well as fast particle slowing down times. Fast particle dynamics are critical to C-2U performance and several diagnostics have been deployed to characterize the fast particle population, including neutron and proton detectors. To increase our understanding of fast particle behavior and supplement existing diagnostics, an E ∥ B neutral particle analyzer was installed, which simultaneously measures H(0) and D(0) flux with large dynamic range and high energy resolution...
November 2016: Review of Scientific Instruments
M C Thompson, H Gota, S Putvinski, M Tuszewski, M Binderbauer
The C-2U experiment at Tri Alpha Energy studies the evolution of field-reversed configuration (FRC) plasmas sustained by neutral beam injection. Data on the FRC plasma performance are provided by a comprehensive suite of diagnostics that includes magnetic sensors, interferometry, Thomson scattering, spectroscopy, bolometry, reflectometry, neutral particle analyzers, and fusion product detectors. While many of these diagnostic systems were inherited from the preceding experiment C-2, C-2U has a variety of new and upgraded diagnostic systems: multi-chord far-infrared polarimetry, multiple fast imaging cameras with selectable atomic line filters, proton detector arrays, and 100 channel bolometer units capable of observing multiple regions of the spectrum simultaneously...
November 2016: Review of Scientific Instruments
A Netepenko, W U Boeglin, D S Darrow, R Ellis, M J Sibilia
Detection of charged fusion products, such as protons and tritons resulting from D(d, p) t reactions, can be used to determine the position and time dependent fusion reaction rate profile in spherical tokamak plasmas with neutral beam heating. We have developed a prototype instrument consisting of 6 ion-implanted-silicon surface barrier detectors combined with collimators in such a way that each detector can accept 3 MeV protons and 1 MeV tritons and thus provides a curved view across the plasma cross section...
November 2016: Review of Scientific Instruments
M Gauthier, J B Kim, C B Curry, B Aurand, E J Gamboa, S Göde, C Goyon, A Hazi, S Kerr, A Pak, A Propp, B Ramakrishna, J Ruby, O Willi, G J Williams, C Rödel, S H Glenzer
We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams...
November 2016: Review of Scientific Instruments
A M Rasmus, A U Hazi, M J-E Manuel, C C Kuranz, S R Klein, P X Belancourt, J R Fein, M J MacDonald, R P Drake, B B Pollock, J Park, G J Williams, H Chen
Ultra-intense short pulse lasers incident on solid targets (e.g., thin Au foils) produce well collimated, broad-spectrum proton beams. These proton beams can be used to characterize magnetic fields, electric fields, and density gradients in high energy-density systems. The LLNL-Imaging Proton Spectrometer (L-IPS) was designed and built [H. Chen et al., Rev. Sci. Instrum. 81, 10D314 (2010)] for use with such laser produced proton beams. The L-IPS has an energy range of 50 keV-40 MeV with a resolving power (E/dE) of about 275 at 1 MeV and 21 at 20 MeV, as well as a single spatial imaging axis...
November 2016: Review of Scientific Instruments
Conrad B Falkson, Emily T Vella, Edward Yu, Medhat El-Mallah, Robert Mackenzie, Peter M Ellis, Yee C Ung
Patients with early-stage non-small-cell lung cancer (NSCLC) who are unable to undergo surgery can be offered radiation therapy (RT). Previously, conventional RT was offered; however, newer techniques such as stereotactic body RT (SBRT) have become available. The objective of the present systematic review was to investigate the effectiveness of RT with curative intent in patients with early-stage medically inoperable NSCLC. MEDLINE, EMBASE, and the Cochrane Library were searched for studies comparing stereotactic RT with curative intent compared with observation or other types of RT for early-stage, medically inoperable, NSCLC...
October 27, 2016: Clinical Lung Cancer
Tia E Plautz, V Bashkirov, V Giacometti, R F Hurley, R P Johnson, P Piersimoni, H F-W Sadrozinski, R W Schulte, A Zatserklyaniy
PURPOSE: To evaluate the spatial resolution of proton CT using both a prototype proton CT scanner and Monte Carlo simulations. METHODS: A custom cylindrical edge phantom containing twelve tissue-equivalent inserts with four different compositions at varying radial displacements from the axis of rotation was developed for measuring the modulation transfer function (MTF) of a prototype proton CT scanner. Two scans of the phantom, centered on the axis of rotation, were obtained with a 200 MeV, low-intensity proton beam: one scan with steps of 4°, and one scan with the phantom continuously rotating...
December 2016: Medical Physics
Jiajian Shen, Wei Liu, Joshua Stoker, Xiaoning Ding, Aman Anand, Yanle Hu, Michael G Herman, Martin Bues
PURPOSE: To find an efficient method to configure the proton fluence for a commercial proton pencil beam scanning (PBS) treatment planning system (TPS). METHODS: An in-water dose kernel was developed to mimic the dose kernel of the pencil beam convolution superposition algorithm, which is part of the commercial proton beam therapy planning software, eclipse™ (Varian Medical Systems, Palo Alto, CA). The field size factor (FSF) was calculated based on the spot profile reconstructed by the in-house dose kernel...
December 2016: Medical Physics
Paolo Farace, Roberto Righetto, Sylvain Deffet, Arturs Meijers, Francois Vander Stappen
PURPOSE: To introduce a fast ray-tracing algorithm in pencil proton radiography (PR) with a multilayer ionization chamber (MLIC) for in vivo range error mapping. METHODS: Pencil beam PR was obtained by delivering spots uniformly positioned in a square (45 × 45 mm(2) field-of-view) of 9 × 9 spots capable of crossing the phantoms (210 MeV). The exit beam was collected by a MLIC to sample the integral depth dose (IDDMLIC). PRs of an electron-density and of a head phantom were acquired by moving the couch to obtain multiple 45 × 45 mm(2) frames...
December 2016: Medical Physics
Shigeyuki Takamatsu, Kazutaka Yamamoto, Yoshikazu Maeda, Mariko Kawamura, Satoshi Shibata, Yoshitaka Sato, Kazuki Terashima, Yasuhiro Shimizu, Yuji Tameshige, Makoto Sasaki, Satoko Asahi, Tamaki Kondou, Satoshi Kobayashi, Osamu Matsui, Toshifumi Gabata
BACKGROUND: Proton beam therapy (PBT) achieves good local control for hepatocellular carcinoma (HCC), and toxicity tends to be lower than for photon radiotherapy. Focal liver parenchymal damage in radiotherapy is described as the focal liver reaction (FLR); the threshold doses (TDs) for FLR in the background liver have been analyzed in stereotactic ablative body radiotherapy and brachytherapy. To develop a safer approach for PBT, both TD and liver volume changes are considered clinically important in predicting the extent of damage before treatment, and subsequently in reducing background liver damage...
2016: PloS One
V Radchenko, C A L Meyer, J W Engle, C M Naranjo, G A Unc, T Mastren, M Brugh, E R Birnbaum, K D John, F M Nortier, M E Fassbender
Scandium-44g (half-life 3.97h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, (18)F, due to its favorable decay parameters. One source of (44g)Sc is the long-lived parent nuclide (44)Ti (half-life 60.0 a). A (44)Ti/(44g)Sc generator would have the ability to provide radionuclidically pure (44g)Sc on a daily basis. The production of (44)Ti via the (45)Sc(p,2n) reaction requires high proton beam currents and long irradiation times...
November 24, 2016: Journal of Chromatography. A
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