MAPS development for the ALICE ITS upgrade

NASA Astrophysics Data System (ADS)

Yang, P.; Aglieri, G.; Cavicchioli, C.; Chalmet, P. L.; Chanlek, N.; Collu, A.; Gao, C.; Hillemanns, H.; Junique, A.; Kofarago, M.; Keil, M.; Kugathasan, T.; Kim, D.; Kim, J.; Lattuca, A.; Marin Tobon, C. A.; Marras, D.; Mager, M.; Martinengo, P.; Mazza, G.; Mugnier, H.; Musa, L.; Puggioni, C.; Rousset, J.; Reidt, F.; Riedler, P.; Snoeys, W.; Siddhanta, S.; Usai, G.; van Hoorne, J. W.; Yi, J.

2015-03-01

Monolithic Active Pixel Sensors (MAPS) offer the possibility to build pixel detectors and tracking layers with high spatial resolution and low material budget in commercial CMOS processes. Significant progress has been made in the field of MAPS in recent years, and they are now considered for the upgrades of the LHC experiments. This contribution will focus on MAPS detectors developed for the ALICE Inner Tracking System (ITS) upgrade and manufactured in the TowerJazz 180 nm CMOS imaging sensor process on wafers with a high resistivity epitaxial layer. Several sensor chip prototypes have been developed and produced to optimise both charge collection and readout circuitry. The chips have been characterised using electrical measurements, radioactive sources and particle beams. The tests indicate that the sensors satisfy the ALICE requirements and first prototypes with the final size of 1.5 × 3 cm2 have been produced in the first half of 2014. This contribution summarises the characterisation measurements and presents first results from the full-scale chips.

Recent results on reactions with radioactive beams at RIBRAS (Radioactive Ion Beams in Brazil)

NASA Astrophysics Data System (ADS)

Lépine-Szily, A.; Lichtenthäler, R.; Guimarães, V.; Arazi, A.; Barioni, A.; Benjamim, E. A.; de Faria, P. N.; Descouvemont, P.; Gasques, L. R.; E; Leistenschneider; Mendes, D. R., Jr.; Morais, M. C.; Morcelle, V.; Moro, A. M.; Pampa Condori, R.; Pires, K. C. C.; Rodriguez-Gallardo, M.; Scarduelli, V.; Shorto, J. M. B.; Zamora, J. C.

2015-04-01

We present a quick description of RIBRAS (Radioactive Ion beams in Brazil), which is a superconducting double solenoid system, installed at the Pelletron Laboratory of the University of São Paulo and extends the capabilities of the original Pelletron Tandem Accelerator of 8MV terminal voltage (8UD) by producing secondary beams of unstable nuclei. The experimental program of the RIBRAS covers the study of elastic and inelastic scattering with the objective to study the interaction potential and the reaction mechanisms between weakly bound (RIB) and halo (6He and 8B) projectiles on light, medium and heavy mass targets. With highly purified beams, the study of resonant elastic scattering and resonant transfer reactions, using inverse kinematics and thick targets, have also been included in our recent experimental program.

Exotic Nuclei in South America

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtenthaeler, R.; Lepine-Szily, A.; Guimaraes, V.

The Radioactive Ion Beams in Brasil(RIBRAS) is described. Experiments using radioactive secondary beams of light rare isotopes such as {sup 6}He, {sup 7}Be, {sup 8}Li on several targets have been performed and the results are presented.

Resonant scattering experiments with radioactive nuclear beams - Recent results and future plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teranishi, T.; Sakaguchi, S.; Uesaka, T.

2013-04-19

Resonant scattering with low-energy radioactive nuclear beams of E < 5 MeV/u have been studied at CRIB of CNS and at RIPS of RIKEN. As an extension to the present experimental technique, we will install an advanced polarized proton target for resonant scattering experiments. A Monte-Carlo simulation was performed to study the feasibility of future experiments with the polarized target. In the Monte-Carlo simulation, excitation functions and analyzing powers were calculated using a newly developed R-matrix calculation code. A project of a small-scale radioactive beam facility at Kyushu University is also briefly described.

BEARS: Radioactive ion beams at LBNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, J.; Guo, F.Q.; Haustein, P.E.

1998-07-01

BEARS (Berkeley Experiments with Accelerated Radioactive Species) is an initiative to develop a radioactive ion-beam capability at Lawrence Berkeley National Laboratory. The aim is to produce isotopes at an existing medical cyclotron and to accelerate them at the 88 inch Cyclotron. To overcome the 300-meter physical separation of these two accelerators, a carrier-gas transport system will be used. At the terminus of the capillary, the carrier gas will be separated and the isotopes will be injected into the 88 inch Cyclotron`s Electron Cyclotron Resonance (ECR) ion source. The first radioactive beams to be developed will include 20-min {sup 11}C andmore » 70-sec {sup 14}O, produced by (p,n) and (p,{alpha}) reactions on low-Z targets. A test program is currently being conducted at the 88 inch Cyclotron to develop the parts of the BEARS system. Preliminary results of these tests lead to projections of initial {sup 11}C beams of up to 2.5 {times} 10{sup 7} ions/sec and {sup 14}O beams of 3 {times} 10{sup 5} ions/sec.« less

Charge breeding simulations for radioactive ion beam production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Variale, V.; Raino, A. C.; Clauser, T.

2012-02-15

The charge breeding technique is used for radioactive ion beam (RIB) production in order of optimizing the re-acceleration of the radioactive element ions produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In order to get high intensity RIB, experiments with charge breeding of very high efficiency could be required. To reach this goal, the charge breeding simulation could help to optimize the high charge state production efficiency by finding more proper parameters for the radioactive 1+more » ions. In this paper a device based on an electron beam ion source (EBIS) is considered. In order to study that problem, a code already developed for studying the ion selective containment in an EBIS with RF quadrupoles, BRICTEST, has been modified to simulate the ion charge state breeding rate for different 1+ ion injection conditions. Particularly, the charge breeding simulations for an EBIS with a hollow electron beam have been studied.« less

Nuclear Structure Studies with Radioactive Ion Beams in the Mass A = 80 Region

NASA Astrophysics Data System (ADS)

Galindo-Uribarri, A.; Padilla-Rodal, E.; Batchelder, J. C.; Beene, J. R.; Lagergren, K. B.; Mueller, P. E.; Radford, D. C.; Stracener, D. W.; Urrego-Blanco, J. P.; Varner, R. L.; Yu, C.-H.

2009-03-01

An experimental program to measure spectroscopic properties of neutron-rich nuclei in the A = 80 region is underway at the Holifield Radioactive Ion Beam Facility. Our approach has been to get a comprehensive picture of the shell structure in this region by studying a series of properties of low lying states (E(2+), B(E2), g-factors and quadrupole moments). The beams, instrumentation and techniques developed specifically for this purpose have allowed us to systematically study the behavior of these observables along isotopic and isotonic chains using both stable and radioactive nuclei under almost identical experimental conditions. We have developed many techniques and detectors for in-beam gamma spectroscopy with radioactive ion beams. Most of the detectors can be used individually or in combination. Generally these detector systems have very large efficiencies. We give examples of their use from three recent experiments; namely, Coulomb excitation of n-rich nuclei along the N = 50 shell closure, the static quadrupole moment of the first 2+ in 78Ge and g-factor measurements of n-rich isotopes near N = 50.

Obstacle evasion in free-space optical communications utilizing Airy beams

NASA Astrophysics Data System (ADS)

Zhu, Guoxuan; Wen, Yuanhui; Wu, Xiong; Chen, Yujie; Liu, Jie; Yu, Siyuan

2018-03-01

A high speed free-space optical communication system capable of self-bending signal transmission around line-of-sight obstacles is proposed and demonstrated. Airy beams are generated and controlled to achieve different propagating trajectories, and the signal transmission characteristics of these beams around the obstacle are investigated. Our results confirm that, by optimising their ballistic trajectories, Airy beams are able to bypass obstacles with more signal energy and thus improve the communication performance compared with normal Gaussian beams.

Thermal-electric numerical simulation of a surface ion source for the production of radioactive ion beams

NASA Astrophysics Data System (ADS)

Manzolaro, Mattia; Meneghetti, Giovanni; Andrighetto, Alberto

2010-11-01

In a facility for the production of radioactive ion beams (RIBs), the target system and the ion source are the most critical objects. In the context of the Selective Production of Exotic Species (SPES) project, a proton beam directly impinges a Uranium Carbide production target, generating approximately 10 13 fissions per second. The radioactive isotopes produced by the 238U fissions are then directed to the ion source to acquire a charge state. After that, the radioactive ions obtained are transported electrostatically to the subsequent areas of the facility. In this work the surface ion source at present adopted for the SPES project is studied by means of both analytical and numerical thermal-electric models. The theoretical results are compared with temperature and electric potential difference measurements.

A combined thermal dissociation and electron impact ionization source for radioactive ion beam generation{sup a}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alton, G.D.; Williams, C.

1996-04-01

The probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecular feed materials with conventional, hot-cathode, electron-impact ion sources is low and consequently, the ion beams from these sources often appear as mixtures of several molecular sideband beams. This fragmentation process leads to dilution of the intensity of the species of interest for radioactive ion beam (RIB) applications where beam intensity is at a premium. We have conceived an ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high ionization efficiency characteristics of an electron impact ionization source that will, inmore » principle, overcome this handicap. The source concept will be evaluated as a potential candidate for use for RIB generation at the Holifield Radioactive Ion Beam Facility, now under construction at the Oak Ridge National Laboratory. The design features and principles of operation of the source are described in this article. {copyright} {ital 1996 American Institute of Physics.}« less

A combined thermal dissociation and electron impact ionization source for radioactive ion beam generation (abstract){sup a}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alton, G.D.; Williams, C.

1996-03-01

The probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecular feed materials with conventional, hot-cathode, electron-impact ion sources is low and consequently, the ion beams from these sources often appear as mixtures of several molecular sideband beams. This fragmentation process leads to dilution of the intensity of the species of interest for radioactive ion beam (RIB) applications where beam intensity is at a premium. We have conceived an ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high ionization efficiency characteristics of an electron impact ionization source that will, inmore » principle, overcome this handicap. The source concept will be evaluated as a potential candidate for use for RIB generation at the Holifield Radioactive Ion Beam Facility, now under construction at the Oak Ridge National Laboratory. The design features and principles of operation of the source are described in this article. {copyright} {ital 1996 American Institute of Physics.}« less

Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Levand, A.; Pardo, R.

2012-02-15

The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi {sup 252}Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci {sup 252}Cf source to produce radioactive beamsmore » with intensities up to 10{sup 6} ions/s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for {sup 23}Na{sup 8+}, 15.6% for {sup 84}Kr{sup 17+}, and 13.7% for {sup 85}Rb{sup 19+} with typical breeding times of 10 ms/charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for {sup 143}Cs{sup 27+} and 14.7% for {sup 143}Ba{sup 27+}. The project has been commissioned with a radioactive beam of {sup 143}Ba{sup 27+} accelerated to 6.1 MeV/u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.« less

A UHV compatible source for a highly polarized thermal atomic beam of radioactive 8Li

NASA Astrophysics Data System (ADS)

Jänsch, H. J.; Kirchner, G.; Kühlert, O.; Lisowski, M.; Paggel, J. J.; Platzer, R.; Schillinger, R.; Tilsner, H.; Weindel, C.; Winnefeld, H.; Fick, D.

2000-12-01

A beam of the radioactive isotope 8Li is prepared at thermal velocities. The nuclei are highly spin polarized by transverse optical pumping of the thermal beam. The installation is ultra-high vacuum (UHV) compatible in a non-UHV accelerator environment. Since the atomic beam is used in a surface science experiment, where contamination must be avoided, special emphasis is given to the vacuum coupling of the accelerator/ 8Li production/surface experimental areas. The atomic beam is produced by stopping the nuclear reaction products and evaporating them again from high-temperature graphite. To enhance the atomic beam, a novel tubular thermalizer is applied. The thermal polarized atomic beam intensity is approximately 5×10 8 atoms/s sr.

The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia.

PubMed

Mohamed Johar, S; Embong, Z

2015-11-01

The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h(-1). As the background radiation is correlated to the amount of parent nuclides, (238)U and (232)Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 × 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of (238)U and (232)Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Y., E-mail: yjma@ciae.ac.cn; Cui, B.; Ma, R.

The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org , p. 267]. For low intensity ion beam [30–300 keV/1 pA–10 μA], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 μA], the beam profile scanner will bemore » installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.« less

Gold and isotopically enriched platinium targets for the production of radioactive beams of francium

NASA Astrophysics Data System (ADS)

Lipski, A. R.; Orozco, L. A.; Pearson, M. R.; Simsarian, J. E.; Sprouse, G. D.; Zhao, W. Z.

1999-12-01

Au and isotopically enriched Pt targets are discussed for the production of radioactive Fr beams. Target foils, serving also as ionizers, have to be heated in order to enhance the diffusion of atoms to the surface for further extraction and injection into the electrostatic transport system.

Isomer beam elastic scattering: 26mAl(p, p) for astrophysics

NASA Astrophysics Data System (ADS)

Kahl, D.; Shimizu, H.; Yamaguchi, H.; Abe, K.; Beliuskina, O.; Cha, S. M.; Chae, K. Y.; Chen, A. A.; Ge, Z.; Hayakawa, S.; Imai, N.; Iwasa, N.; Kim, A.; Kim, D. H.; Kim, M. J.; Kubono, S.; Kwag, M. S.; Liang, J.; Moon, J. Y.; Nishimura, S.; Oka, S.; Park, S. Y.; Psaltis, A.; Teranishi, T.; Ueno, Y.; Yang, L.

2018-01-01

The advent of radioactive ground-state beams some three decades ago ultimately sparked a revolution in our understanding of nuclear physics. However, studies with radioactive isomer beams are sparse and have often required sophisticated apparatuses coupled with the technologies of ground-state beams due to typical mass differences on the order of hundreds of keV and vastly different lifetimes for isomers. We present an application of a isomeric beam of 26mAl to one of the most famous observables in nuclear astrophysics: galactic 26Al. The characteristic decay of 26Al in the Galaxy was the first such specific radioactivity to be observed originating from outside the Earth some four decades ago. We present a newly-developed, novel technique to probe the structure of low-spin states in 27Si. Using the Center for Nuclear Study low-energy radioisotope beam separator (CRIB), we report on the measurement of 26mAl proton resonant elastic scattering conducted with a thick target in inverse kinematics. The preliminary results of this on-going study are presented.

Direct Reaction Measurements Using GODDESS

DOE PAGES

Pain, S. D.; Ratkiewicz, A.; Baugher, T.; ...

2017-10-26

GODDESS is a coupling of the charged-particle detection system ORRUBA to the gamma-ray detector array Gammasphere. This coupling has been developed in order to facilitate the high-resolution measurement of direct reactions in normal and inverse kinematics with stable and radioactive beams. GODDESS has been commissioned using a beam of 134Xe at 10 MeV/A, in a campaign of stable beam measurements. The measurement demonstrates the capabilities of GODDESS under radioactive beam conditions, and provides the first data on the single-neutron states in 135Xe, including previously unobserved states based on the orbitals above the N=82 shell closure.

On the optimisation of the use of 3He in radiation portal monitors

NASA Astrophysics Data System (ADS)

Tomanin, Alice; Peerani, Paolo; Janssens-Maenhout, Greet

2013-02-01

Radiation Portal Monitors (RPMs) are used to detect illicit trafficking of nuclear or other radioactive material concealed in vehicles, cargo containers or people at strategic check points, such as borders, seaports and airports. Most of them include neutron detectors for the interception of potential plutonium smuggling. The most common technology used for neutron detection in RPMs is based on 3He proportional counters. The recent severe shortage of this rare and expensive gas has created a problem of capacity for manufacturers to provide enough detectors to satisfy the market demand. In this paper we analyse the design of typical commercial RPMs and try to optimise the detector parameters in order either to maximise the efficiency using the same amount of 3He or minimise the amount of gas needed to reach the same detection performance: by reducing the volume or gas pressure in an optimised design.

Potential hazard due to induced radioactivity secondary to radiotherapy: the report of task group 136 of the American Association of Physicists in Medicine.

PubMed

Thomadsen, Bruce; Nath, Ravinder; Bateman, Fred B; Farr, Jonathan; Glisson, Cal; Islam, Mohammad K; LaFrance, Terry; Moore, Mary E; George Xu, X; Yudelev, Mark

2014-11-01

External-beam radiation therapy mostly uses high-energy photons (x-rays) produced by medical accelerators, but many facilities now use proton beams, and a few use fast-neutron beams. High-energy photons offer several advantages over lower-energy photons in terms of better dose distributions for deep-seated tumors, lower skin dose, less sensitivity to tissue heterogeneities, etc. However, for beams operating at or above 10 MV, some of the materials in the accelerator room and the radiotherapy patient become radioactive due primarily to photonuclear reactions and neutron capture, exposing therapy staff and patients to unwanted radiation dose. Some recent advances in radiotherapy technology require treatments using a higher number of monitor units and monitor-unit rates for the same delivered dose, and compared to the conventional treatment techniques and fractionation schemes, the activation dose to personnel can be substantially higher. Radiotherapy treatments with proton and neutron beams all result in activated materials in the treatment room. In this report, the authors review critically the published literature on radiation exposures from induced radioactivity in radiotherapy. They conclude that the additional exposure to the patient due to induced radioactivity is negligible compared to the overall radiation exposure as a part of the treatment. The additional exposure to the staff due to induced activity from photon beams is small at an estimated level of about 1 to 2 mSv y. This is well below the allowed occupational exposure limits. Therefore, the potential hazard to staff from induced radioactivity in the use of high-energy x-rays is considered to be low, and no specific actions are considered necessary or mandatory. However, in the spirit of the "As Low as Reasonably Achievable (ALARA)" program, some reasonable steps are recommended that can be taken to reduce this small exposure to an even lower level. The dose reduction strategies suggested should be followed only if these actions are considered reasonable and practical in the individual clinics. Therapists working with proton beam and neutron beam units handle treatment devices that do become radioactive, and they should wear extremity monitors and make handling apertures and boluses their last task upon entering the room following treatment. Personnel doses from neutron-beam units can approach regulatory limits depending on the number of patients and beams, and strategies to reduce doses should be followed.

An ion source module for the Beijing Radioactive Ion-beam Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, B., E-mail: cui@ciae.ac.cn; Huang, Q.; Tang, B.

2014-02-15

An ion source module is developed for Beijing Radioactive Ion-beam Facility. The ion source module is designed to meet the requirements of remote handling. The connection and disconnection of the electricity, cooling and vacuum between the module and peripheral units can be executed without on-site manual work. The primary test of the target ion source has been carried out and a Li{sup +} beam has been extracted. Details of the ion source module and its primary test results are described.

Speckle-based at-wavelength metrology of X-ray mirrors with super accuracy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashyap, Yogesh; Wang, Hongchang; Sawhney, Kawal, E-mail: kawal.sawhney@diamond.ac.uk

2016-05-15

X-ray active mirrors, such as bimorph and mechanically bendable mirrors, are increasingly being used on beamlines at modern synchrotron source facilities to generate either focused or “tophat” beams. As well as optical tests in the metrology lab, it is becoming increasingly important to optimise and characterise active optics under actual beamline operating conditions. Recently developed X-ray speckle-based at-wavelength metrology technique has shown great potential. The technique has been established and further developed at the Diamond Light Source and is increasingly being used to optimise active mirrors. Details of the X-ray speckle-based at-wavelength metrology technique and an example of its applicabilitymore » in characterising and optimising a micro-focusing bimorph X-ray mirror are presented. Importantly, an unprecedented angular sensitivity in the range of two nanoradians for measuring the slope error of an optical surface has been demonstrated. Such a super precision metrology technique will be beneficial to the manufacturers of polished mirrors and also in optimization of beam shaping during experiments.« less

Radiological protection from radioactive waste management in existing exposure situations resulting from a nuclear accident.

PubMed

Sugiyama, Daisuke; Hattori, Takatoshi

2013-01-01

In environmental remediation after nuclear accidents, radioactive wastes have to be appropriately managed in existing exposure situations with contamination resulting from the emission of radionuclides by such accidents. In this paper, a framework of radiation protection from radioactive waste management in existing exposure situations for application to the practical and reasonable waste management in contaminated areas, referring to related ICRP recommendations was proposed. In the proposed concept, intermediate reference levels for waste management are adopted gradually according to the progress of the reduction in the existing ambient dose in the environment on the basis of the principles of justification and optimisation by taking into account the practicability of the management of radioactive waste and environmental remediation. It is essential to include the participation of relevant stakeholders living in existing exposure situations in the selection of reference levels for the existing ambient dose and waste management.

Radiological protection from radioactive waste management in existing exposure situations resulting from a nuclear accident

PubMed Central

Sugiyama, Daisuke; Hattori, Takatoshi

2013-01-01

In environmental remediation after nuclear accidents, radioactive wastes have to be appropriately managed in existing exposure situations with contamination resulting from the emission of radionuclides by such accidents. In this paper, a framework of radiation protection from radioactive waste management in existing exposure situations for application to the practical and reasonable waste management in contaminated areas, referring to related ICRP recommendations was proposed. In the proposed concept, intermediate reference levels for waste management are adopted gradually according to the progress of the reduction in the existing ambient dose in the environment on the basis of the principles of justification and optimisation by taking into account the practicability of the management of radioactive waste and environmental remediation. It is essential to include the participation of relevant stakeholders living in existing exposure situations in the selection of reference levels for the existing ambient dose and waste management. PMID:22719047

Scintillator-based transverse proton beam profiler for laser-plasma ion sources.

PubMed

Dover, N P; Nishiuchi, M; Sakaki, H; Alkhimova, M A; Faenov, A Ya; Fukuda, Y; Kiriyama, H; Kon, A; Kondo, K; Nishitani, K; Ogura, K; Pikuz, T A; Pirozhkov, A S; Sagisaka, A; Kando, M; Kondo, K

2017-07-01

A high repetition rate scintillator-based transverse beam profile diagnostic for laser-plasma accelerated proton beams has been designed and commissioned. The proton beam profiler uses differential filtering to provide coarse energy resolution and a flexible design to allow optimisation for expected beam energy range and trade-off between spatial and energy resolution depending on the application. A plastic scintillator detector, imaged with a standard 12-bit scientific camera, allows data to be taken at a high repetition rate. An algorithm encompassing the scintillator non-linearity is described to estimate the proton spectrum at different spatial locations.

Astrophysics at the future Rare Isotope Accelerator

NASA Astrophysics Data System (ADS)

Smith, Michael; Schatz, Hendrik; Timmes, Frank X.; Wiescher, Michael; Greife, Uwe

PoS(NIC-IX)179 Significant progress in studies of core collapse supernovae, thermonuclear supernovae, X-ray bursts, novae, and other astrophysical phenomena require intense beams of a wide range of unsta- ble nuclei. While some such beams are currently available and being used for important studies in nuclear astrophysics, the beams are often insufficient in intensity, purity, or available isotopes. It is anticipated that a next-generation radioactive beam facility will be built in the U.S. in the next decade to address these shortcomings, and a Working Group has been established to develop and promote nuclear astrophysics research at this new facility. Many of the topics addressed by the Working Group are relevant for the RIKEN RI Beam Factory, the planned GSI-Fair facility, and other advanced radioactive beam facilities around the world.

Coulomb excitation with radioactive nuclear beam of 64Cu

NASA Astrophysics Data System (ADS)

Guo, Gang; Xu, Jincheng; Chen, Quan; He, Ming; Qin, Jiuchang; Shen, Dongjun; Wu, Shaoyong; Jiang, Yongliang; Cheng, Yehao

2003-09-01

The radioactive nuclear beam of 64Cu was obtained utilizing a two-stage method at the HI-13 tandem accelerator of China Institute of Atomic Energy. The B(E2) value of the first excitation state of 64Cu has been directly measured for the first time by Coulomb excitation method, using the radioactive nuclear beam of 64Cu. An upper limit of the B(E2;2 1+→1 gs+) value from the first excitation state to the ground state of 64Cu is determined to be 49 W.u., which is significantly smaller than 250±170 W.u., the value adopted by Nuclear Data Sheets. The reliability of the experimental method was verified by simultaneously performing the Coulomb excitation experiment of 181Ta.

BEARS: Radioactive Ion Beams at Berkeley

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, J.; Joosten, R.; Donahue, C.A.

2000-03-14

A light-isotope radioactive ion beam capability has been added to the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory by coupling to the production cyclotron of the Berkeley Isotope Facility. The connection required the development and construction of a 350 m gas transport system between the two accelerators as well as automated cryogenic separation of the produced activity. The first beam developed, {sup 11}C, has been successfully accelerated with an on-target intensity of 1 x 10{sup 8} ions/sec at energies of around 10 MeV/u.

Charge breeding of radioactive isotopes at the CARIBU facility with an electron beam ion source

NASA Astrophysics Data System (ADS)

Vondrasek, R. C.; Dickerson, C. A.; Hendricks, M.; Ostroumov, P.; Pardo, R.; Savard, G.; Scott, R.; Zinkann, G.

2018-05-01

An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed at Argonne National Laboratory as part of the californium rare ion breeder upgrade. For the past year, the EBIS-CB has been undergoing commissioning as part of the ATLAS accelerator complex. It has delivered both stable and radioactive beams with A/Q < 6, breeding times <30 ms, low background contamination, and charge breeding efficiencies >18% into a single charge state. The operation of this device, challenges during the commissioning phase, and future improvements will be discussed.

Study of Collectivity in n-rich A=80 Nuclei using Radioactive Ion Beams

NASA Astrophysics Data System (ADS)

Padilla, E.; Galindo-Uribarri, A.; Baktash, C.; Fuentes, B.; Gross, C.; Mueller, P.; Radford, D. C.; Stracener, D.; Yu, C.-H.; Bijker, R.; Castanos, O.; Batchelder, J.; Hartley, D. J.

2002-04-01

We report on recent experiments performed at the HRIBF of Oak Ridge National Laboratory (ORNL) aimed to study neutron-rich nuclei in the A 80 mass region. First time use of Radioactive Ion Beams (RIBs) (78,80)Ge complemented with stable beam information allowed a systematic study of B(E2)-values that characterize the n-rich even-even Ge and Se isotopes. A comparison of the experimental results with IBA2 calculations will be presented. *Supported by US-DOE under the contract DE-AC05-00AOR22725.

The rare isotope beams production at the Texas A and M university Cyclotron Institute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tabacaru, G.; May, D. P.; Chubarian, G.

2013-04-19

The Cyclotron Institute at Texas A and M initiated an upgrade project for the production of radioactive-ion beams that incorporates a light-ion guide (LIG) and a heavy-ion guide coupled (HIG) with an Electron Cyclotron Resonance Ion Source (ECRIS) constructed for charge-boosting (CB-ECRIS). This scheme is intended to produce radioactive beams suitable for injection into the K500 superconducting cyclotron. The current status of the project and details on the ion sources and devices used in the project is presented.

A shrinking hypersphere PSO for engineering optimisation problems

NASA Astrophysics Data System (ADS)

Yadav, Anupam; Deep, Kusum

2016-03-01

Many real-world and engineering design problems can be formulated as constrained optimisation problems (COPs). Swarm intelligence techniques are a good approach to solve COPs. In this paper an efficient shrinking hypersphere-based particle swarm optimisation (SHPSO) algorithm is proposed for constrained optimisation. The proposed SHPSO is designed in such a way that the movement of the particle is set to move under the influence of shrinking hyperspheres. A parameter-free approach is used to handle the constraints. The performance of the SHPSO is compared against the state-of-the-art algorithms for a set of 24 benchmark problems. An exhaustive comparison of the results is provided statistically as well as graphically. Moreover three engineering design problems namely welded beam design, compressed string design and pressure vessel design problems are solved using SHPSO and the results are compared with the state-of-the-art algorithms.

Measurement of the 21Na(p,{gamma})22Mg Reaction with the Dragon Facility at TRIUMF-ISAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, A.A.; Bishop, S.; D'Auria, J.M.

2003-08-26

The DRAGON recoil separator facility, designed to measure the rates of radiative proton and alpha capture reactions important for nuclear astrophysics, is now operational at the TRIUMF-ISAC radioactive beam facility in Vancouver, Canada. We report on first measurements of the 21Na(p,{gamma})22Mg reaction rate with radioactive beams of 21Na.

Radiation protection considerations along a radioactive ion beam transport line

NASA Astrophysics Data System (ADS)

Sarchiapone, Lucia; Zafiropoulos, Demetre

2016-09-01

The goal of the SPES project is to produce accelerated radioactive ion beams for Physics studies at “Laboratori Nazionali di Legnaro” (INFN, Italy). This accelerator complex is scheduled to be built by 2016 for an effective operation in 2017. Radioactive species are produced in a uranium carbide target, by the interaction of 200 μA of protons at 40 MeV. All of the ionized species in the 1+ state come out of the target (ISOL method), and pass through a Wien filter for a first selection and an HMRS (high mass resolution spectrometer). Then they are transported by an electrostatic beam line toward a charge state breeder (where the 1+ to n+ multi-ionization takes place) before selection and reacceleration at the already existing superconducting linac. The work concerning dose evaluations, activation calculation, and radiation protection constraints related to the transport of the radioactive ion beam (RIB) from the target to the mass separator will be described in this paper. The FLUKA code has been used as tool for those calculations needing Monte Carlo simulations, in particular for the evaluation of the dose rate due to the presence of the radioactive beam in the selection/interaction points. The time evolution of a radionuclide inventory can be computed online with FLUKA for arbitrary irradiation profiles and decay times. The activity evolution is analytically evaluated through the implementation of the Bateman equations. Furthermore, the generation and transport of decay radiation (limited to gamma, beta- and beta+ emissions) is possible, referring to a dedicated database of decay emissions using mostly information obtained from NNDC, sometimes supplemented with other data and checked for consistency. When the use of Monte Carlo simulations was not feasible, the Bateman equations, or possible simplifications, have been used directly.

The TRIUMF nuclear structure program and TIGRESS

NASA Astrophysics Data System (ADS)

Garrett, P. E.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Chakrawarthy, R. S.; Churchman, R.; Cline, D.; Cooper, R. J.; Cross, D.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T.; Finlay, P.; Gagnon, K.; Gallant, A. T.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Hackman, G.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Kulp, W. D.; Leach, K. G.; Lee, G.; Leslie, J. R.; Maharaj, R.; Martin, J.-P.; Mattoon, C.; Mills, W. J.; Morton, A. C.; Nelson, L.; Newman, O.; Nolan, P. J.; Padilla-Rodal, E.; Pearson, C. J.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Ruiz, C.; Sarazin, F.; Schumaker, M. A.; Scraggs, D. P.; Strange, M. D.; Subramanian, M.; Svensson, C. E.; Waddington, J. C.; Wan, J.; Whitbeck, A.; Williams, S. J.; Wood, J. L.; Wong, J. C.; Wu, C. Y.; Zganjar, E. F.

2007-08-01

The isotope separator and accelerator (ISAC) facility located at the TRIUMF laboratory in Vancouver, Canada, is one of the world's most advanced isotope separator on-line-type radioactive ion beam facilities. An extensive γ-ray spectroscopy programme at ISAC is centred around two major research facilities: (i) the 8π γ-ray spectrometer for β-delayed γ-ray spectroscopy experiments with the low-energy beams from ISAC-I, and (ii) the next generation TRIUMF-ISAC gamma-ray escape suppressed spectrometer (TIGRESS) for in-beam experiments with the accelerated radioactive-ion beams. An overview of these facilities and recent results from the diverse programme of nuclear structure and fundamental interaction studies they support is presented.

Reprint of: Reaction measurements with the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target

NASA Astrophysics Data System (ADS)

Chipps, K. A.

2018-01-01

Explosive stellar environments are sometimes driven by nuclear reactions on short-lived, radioactive nuclei. These reactions often drive the stellar explosion, alter the observable light curves produced, and dictate the final abundances of the isotopes created. Unfortunately, many reaction rates at stellar temperatures cannot be directly measured in the laboratory, due to the physical limitations of ultra-low cross sections and high background rates. An additional complication arises because many of the important reactions involve radioactive nuclei which have lifetimes too short to be made into a target. As such, direct reactions require very intense and pure beams of exotic nuclei. Indirect approaches with both stable and radioactive beams can, however, provide crucial information on the nuclei involved in these astrophysical reactions. A major development toward both direct and indirect studies of nuclear reactions rates is the commissioning of the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) supersonic gas jet target. The JENSA system provides a pure, homogeneous, highly localized, dense, and robust gaseous target for radioactive ion beam studies. Charged-particle reactions measurements made with gas jet targets can be cleaner and display better resolution than with traditional targets. With the availability of pure and localized gas jet targets in combination with developments in exotic radioactive ion beams and next-generation detector systems, the range of reaction studies that are experimentally possible is vastly expanded. Various representative cases will be discussed.

Induced radioactivity of a GSO scintillator by secondary fragments in carbon ion therapy and its effects on in-beam OpenPET imaging.

PubMed

Hirano, Yoshiyuki; Nitta, Munetaka; Nishikido, Fumihiko; Yoshida, Eiji; Inadama, Naoko; Yamaya, Taiga

2016-07-07

The accumulation of induced radioactivity within in-beam PET scanner scintillators is of concern for its long-term clinical usage in particle therapy. To estimate the effects on OpenPET which we are developing for in-beam PET based on GSOZ (Zi doped Gd2SiO5), we measured the induced radioactivity of GSO activated by secondary fragments in a water phantom irradiation by a (12)C beam with an energy of 290 MeV u(-1). Radioisotopes of Na, Ce, Eu, Gd, Nd, Pm and Tb including positron emitters were observed in the gamma ray spectra of the activated GSO with a high purity Ge detector and their absolute radioactivities were calculated. We used the Monte Carlo simulation platform, Geant4 in which the observed radioactivity was assigned to the scintillators of a precisely reproduced OpenPET and the single and coincidence rates immediately after one treatment and after one-year usage were estimated for the most severe conditions. Comparing the highest coincidence rate originating from the activated scintillators (background) and the expected coincidence rate from an imaging object (signal), we determined the expected signal-to-noise ratio to be more than 7 within 3 min and more than 10 within 1 min from the scan start time. We concluded the effects of scintillator activation and their accumulation on the OpenPET imaging were small and clinical long-term usage of the OpenPET was feasible.

Induced radioactivity of a GSO scintillator by secondary fragments in carbon ion therapy and its effects on in-beam OpenPET imaging

NASA Astrophysics Data System (ADS)

Hirano, Yoshiyuki; Nitta, Munetaka; Nishikido, Fumihiko; Yoshida, Eiji; Inadama, Naoko; Yamaya, Taiga

2016-07-01

The accumulation of induced radioactivity within in-beam PET scanner scintillators is of concern for its long-term clinical usage in particle therapy. To estimate the effects on OpenPET which we are developing for in-beam PET based on GSOZ (Zi doped Gd2SiO5), we measured the induced radioactivity of GSO activated by secondary fragments in a water phantom irradiation by a 12C beam with an energy of 290 MeV u-1. Radioisotopes of Na, Ce, Eu, Gd, Nd, Pm and Tb including positron emitters were observed in the gamma ray spectra of the activated GSO with a high purity Ge detector and their absolute radioactivities were calculated. We used the Monte Carlo simulation platform, Geant4 in which the observed radioactivity was assigned to the scintillators of a precisely reproduced OpenPET and the single and coincidence rates immediately after one treatment and after one-year usage were estimated for the most severe conditions. Comparing the highest coincidence rate originating from the activated scintillators (background) and the expected coincidence rate from an imaging object (signal), we determined the expected signal-to-noise ratio to be more than 7 within 3 min and more than 10 within 1 min from the scan start time. We concluded the effects of scintillator activation and their accumulation on the OpenPET imaging were small and clinical long-term usage of the OpenPET was feasible.

Cobalt-60 Machines and Medical Linear Accelerators: Competing Technologies for External Beam Radiotherapy.

PubMed

Healy, B J; van der Merwe, D; Christaki, K E; Meghzifene, A

2017-02-01

Medical linear accelerators (linacs) and cobalt-60 machines are both mature technologies for external beam radiotherapy. A comparison is made between these two technologies in terms of infrastructure and maintenance, dosimetry, shielding requirements, staffing, costs, security, patient throughput and clinical use. Infrastructure and maintenance are more demanding for linacs due to the complex electric componentry. In dosimetry, a higher beam energy, modulated dose rate and smaller focal spot size mean that it is easier to create an optimised treatment with a linac for conformal dose coverage of the tumour while sparing healthy organs at risk. In shielding, the requirements for a concrete bunker are similar for cobalt-60 machines and linacs but extra shielding and protection from neutrons are required for linacs. Staffing levels can be higher for linacs and more staff training is required for linacs. Life cycle costs are higher for linacs, especially multi-energy linacs. Security is more complex for cobalt-60 machines because of the high activity radioactive source. Patient throughput can be affected by source decay for cobalt-60 machines but poor maintenance and breakdowns can severely affect patient throughput for linacs. In clinical use, more complex treatment techniques are easier to achieve with linacs, and the availability of electron beams on high-energy linacs can be useful for certain treatments. In summary, there is no simple answer to the question of the choice of either cobalt-60 machines or linacs for radiotherapy in low- and middle-income countries. In fact a radiotherapy department with a combination of technologies, including orthovoltage X-ray units, may be an option. Local needs, conditions and resources will have to be factored into any decision on technology taking into account the characteristics of both forms of teletherapy, with the primary goal being the sustainability of the radiotherapy service over the useful lifetime of the equipment. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Coulomb excitation of a radioactive beam of rubidium-78

NASA Astrophysics Data System (ADS)

Schwartz, Jazmin

2000-11-01

Much attention has been focused on the structure of nuclei far from stability and on the technologies necessary to study them. The increased interest in these nuclei is due to their importance in generalizing nuclear structure, and to the crucial roles many of them play in astrophysical processes. One approach being investigated to reach the driplines is the construction of radioactive beam facilities for nuclear physics research at the drip- lines. One of the more promising tools for research into the structure of these exotic nuclei is the use of Coulomb excitation reactions. This process has the advantage of having relatively large excitation cross sections (in the order of barns) which are directly calculable, as they involve only the matrix elements of the electro-magnetic interaction. Thus, experimental observables can be directly related to nuclear matrix elements. Coulomb excitation is normally inferred by measuring the gamma-rays emitted during the subsequent de-excitation of states. When radioactive beams are used, a background of gamma-rays arising from β+ decay of the beam is present, which can be intense. The presently available radioactive beams are usually not intense (<10 5) pps, so the gamma-rays of interest are never strong and it is difficult to suppress gamma-rays from background processes. Nevertheless, by exploiting the characteristics of prompt excitation, photons emitted through the Coulomb excitation mechanism can be separated from backgrounds by measuring gamma-rays emitted with appropriate time and intensity correlations with respect to the scattered ions. This thesis reports on a ``proof-of-principle'' experiment involving the Coulomb excitation of a low energy (E/A < 1.5 MeV/u), low intensity (~104 particles per second) beam of radioactive nuclei. We have produced a secondary radioactive beam of 78Rb and Coulomb re- excited it. The beam was produced in the fusion evaporation reaction 24Mg(58Ni,3pn)78Rb using beams delivered by the Argonne National Laboratory ATLAS accelerator, at a beam energy of 260 MeV and an intensity of 20 pnA. A gamma-ray spectrum has been extracted consisting of transitions associated with re-excitation of A = 78 isobars. We see the excitation of stable 78Kr which is well known and serves as a reference. Gamma-rays associated with excitation of 78Rbgs, R78b4+ , R78b4- , and 78Sr were also observed. There are also indications of the excitation of the A = 75 impurities of the beam. Calculation of the relative yields indicate that 78Rbgs and R78b4+,4- are all very deformed (β2 ~ 0.4), and that the isomers have partial alignment of quasi-particles with J = 4 and K = 3 at their bandheads. This incomplete alignment is consistent with calculations coupling g/ particles to a highly deformed core.

Production of spin-polarized radioactive ion beams via projectile fragmentation reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kameda, D.; Ueno, H.; Yoshimi, A.

2008-02-06

Spin-polarized radioactive ion beams are produced in the projectile fragmentation reaction induced by intermediate-energy heavy ion beams. The degree of spin polarization shows characteristic dependence on the outgoing momentum of the projectile fragment in the magnitude around 1{approx}10%. The qualitative behavior is well described by the kinematical model of the fragmentation process. Recently, we have successfully produced spin-polarized beams of aluminum isotopes in the mass A{approx}30 region via the fragmentation of 95 MeV/u {sup 40}Ar projectiles. The magnetic moments of {sup 30}Al and {sup 32}Al and the electric quadrupole moments of {sup 31}Al and {sup 32}Al have been measured usingmore » the {beta}-NMR technique with the polarized RI beams of the Al isotopes.« less

The National Superconducting Cyclotron Laboratory

NASA Astrophysics Data System (ADS)

Gelbke, C. Korad; Morrissey, D. J.; York, R. C.

1996-10-01

The National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University has constructed and operates two superconducting cyclotrons for research in nuclear science, accelerator and instrumental physics. The K500, the world's first superconducting cyclotron, was commissioned in 1982 and the K1200, the world's most powerful cyclotron, was commissioned in 1988. Heavy-ion beams across the entire periodic table produced in a pair of ECR ion sources and accelerated to energies on the order of 100 MeV/A are delivered to a modern and versatile complement of experimental apparatus, including the new S800 high-resolution superconducting magnetic spectrograph now undergoing initial testing. The diverse variety of beams are used for studies of the quantum-statistical properties of hot nuclei, the liquid-gas phase transition in nuclear matter, and for nuclear structure research, particularly with radioactive ion beams from the A1200 fragment separator. The NSCL provides radioactive nuclear beams out to the limits of stability on both the neutron-rich and the proton-rich sides of the valley of stability. The laboratory is also used for multi-disciplinary research in astrophysics, condensed matter physics, geophysics, medicine, and biology. The NSCL has recently proposed a major upgrade of its facility based on coupled operation of the two cyclotrons. The upgrade will provide large increases in beam intensities for radioactive beam production and increased energies of the heaviest beams.

The optimisation, design and verification of feed horn structures for future Cosmic Microwave Background missions

NASA Astrophysics Data System (ADS)

McCarthy, Darragh; Trappe, Neil; Murphy, J. Anthony; O'Sullivan, Créidhe; Gradziel, Marcin; Doherty, Stephen; Huggard, Peter G.; Polegro, Arturo; van der Vorst, Maarten

2016-05-01

In order to investigate the origins of the Universe, it is necessary to carry out full sky surveys of the temperature and polarisation of the Cosmic Microwave Background (CMB) radiation, the remnant of the Big Bang. Missions such as COBE and Planck have previously mapped the CMB temperature, however in order to further constrain evolutionary and inflationary models, it is necessary to measure the polarisation of the CMB with greater accuracy and sensitivity than before. Missions undertaking such observations require large arrays of feed horn antennas to feed the detector arrays. Corrugated horns provide the best performance, however owing to the large number required (circa 5000 in the case of the proposed COrE+ mission), such horns are prohibitive in terms of thermal, mechanical and cost limitations. In this paper we consider the optimisation of an alternative smooth-walled piecewise conical profiled horn, using the mode-matching technique alongside a genetic algorithm. The technique is optimised to return a suitable design using efficient modelling software and standard desktop computing power. A design is presented showing a directional beam pattern and low levels of return loss, cross-polar power and sidelobes, as required by future CMB missions. This design is manufactured and the measured results compared with simulation, showing excellent agreement and meeting the required performance criteria. The optimisation process described here is robust and can be applied to many other applications where specific performance characteristics are required, with the user simply defining the beam requirements.

Astrophysics experiments with radioactive beams at ATLAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Back, B. B.; Clark, J. A.; Pardo, R. C.

Reactions involving short-lived nuclei play an important role in nuclear astrophysics, especially in explosive scenarios which occur in novae, supernovae or X-ray bursts. This article describes the nuclear astrophysics program with radioactive ion beams at the ATLAS accelerator at Argonne National Laboratory. The CARIBU facility as well as recent improvements for the in-flight technique are discussed. New detectors which are important for studies of the rapid proton or the rapid neutron-capture processes are described. At the end we briefly mention plans for future upgrades to enhance the intensity, purity and the range of in-flight and CARIBU beams.

Gamma-Ray Spectroscopy at TRIUMF-ISAC: the New Frontier of Radioactive Ion Beam Research

NASA Astrophysics Data System (ADS)

Ball, G. C.; Andreoiu, C.; Austin, R. A. E.; Bandyopadhyay, D.; Becker, J. A.; Bricault, P.; Brown, N.; Chan, S.; Churchman, R.; Colosimo, S.; Coombes, H.; Cross, D.; Demand, G.; Drake, T. E.; Dombsky, M.; Ettenauer, S.; Finlay, P.; Furse, D.; Garnsworthy, A.; Garrett, P. E.; Green, K. L.; Grinyer, G. F.; Hyland, B.; Hackman, G.; Kanungo, R.; Kulp, W. D.; Lassen, J.; Leach, K. G.; Leslie, J. R.; Mattoon, C.; Melconian, D.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Rand, E.; Sarazin, F.; Svensson, C. E.; Sumithrarachchi, S.; Schumaker, M. A.; Triambak, S.; Waddington, J. C.; Walker, P. M.; Williams, S. J.; Wood, J. L.; Wong, J.; Zganjar, E. F.

2009-03-01

High-resolution gamma-ray spectroscopy is essential to fully exploit the unique scientific opportunities at the next generation radioactive ion beam facilities such as the TRIUMF Isotope Separator and Accelerator (ISAC). At ISAC the 8π spectrometer and its associated auxiliary detectors is optimize for β-decay studies while TIGRESS an array of segmented clover HPGe detectors has been designed for studies with accelerated beams. This paper gives a brief overview of these facilities and also presents recent examples of the diverse experimental program carried out at the 8π spectrometer.

Possibilities of production of transfermium nuclei in complete fusion reactions with radioactive beams

NASA Astrophysics Data System (ADS)

Hong, Juhee; Adamian, G. G.; Antonenko, N. V.

2017-07-01

The possibilities of direct production of new isotopes of transfermium nuclei 261,263,264No, 264Lr263, 263,264,266,268Rf, 265Db264, and 267,268,270,272Sg are studied in various asymmetric hot fusion-evaporation reactions with radioactive beams. The optimal reaction partners and conditions for the synthesis of new isotopes are suggested. The products of the suggested reactions can fill a gap of unknown isotopes between the isotopes of heaviest nuclei obtained in the x n evaporation channels of the cold and hot complete fusion reactions with the stable beams.

Off-line commissioning of EBIS and plans for its integration into ATLAS and CARIBU.

PubMed

Ostroumov, P N; Barcikowski, A; Dickerson, C A; Mustapha, B; Perry, A; Sharamentov, S I; Vondrasek, R C; Zinkann, G

2016-02-01

An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed at Argonne to breed radioactive beams from the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne Tandem Linac Accelerator System (ATLAS). The EBIS-CB will replace the existing ECR charge breeder to increase the intensity and significantly improve the purity of reaccelerated radioactive ion beams. The CARIBU EBIS-CB has been successfully commissioned offline with an external singly charged cesium ion source. The performance of the EBIS fully meets the specifications to breed rare isotope beams delivered from CARIBU. The EBIS is being relocated and integrated into ATLAS and CARIBU. A long electrostatic beam transport system including two 180° bends in the vertical plane has been designed. The commissioning of the EBIS and the beam transport system in their permanent location will start at the end of this year.

Off-line commissioning of EBIS and plans for its integration into ATLAS and CARIBU

NASA Astrophysics Data System (ADS)

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Mustapha, B.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G.

2016-02-01

An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed at Argonne to breed radioactive beams from the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne Tandem Linac Accelerator System (ATLAS). The EBIS-CB will replace the existing ECR charge breeder to increase the intensity and significantly improve the purity of reaccelerated radioactive ion beams. The CARIBU EBIS-CB has been successfully commissioned offline with an external singly charged cesium ion source. The performance of the EBIS fully meets the specifications to breed rare isotope beams delivered from CARIBU. The EBIS is being relocated and integrated into ATLAS and CARIBU. A long electrostatic beam transport system including two 180° bends in the vertical plane has been designed. The commissioning of the EBIS and the beam transport system in their permanent location will start at the end of this year.

Development of target ion source systems for radioactive beams at GANIL

NASA Astrophysics Data System (ADS)

Bajeat, O.; Delahaye, P.; Couratin, C.; Dubois, M.; Franberg-Delahaye, H.; Henares, J. L.; Huguet, Y.; Jardin, P.; Lecesne, N.; Lecomte, P.; Leroy, R.; Maunoury, L.; Osmond, B.; Sjodin, M.

2013-12-01

The GANIL facility (Caen, France) is dedicated to the acceleration of heavy ion beams including radioactive beams produced by the Isotope Separation On-Line (ISOL) method at the SPIRAL1 facility. To extend the range of radioactive ion beams available at GANIL, using the ISOL method two projects are underway: SPIRAL1 upgrade and the construction of SPIRAL2. For SPIRAL1, a new target ion source system (TISS) using the VADIS FEBIAD ion source coupled to the SPIRAL1 carbon target will be tested on-line by the end of 2013 and installed in the cave of SPIRAL1 for operation in 2015. The SPIRAL2 project is under construction and is being design for using different production methods as fission, fusion or spallation reactions to cover a large area of the chart of nuclei. It will produce among others neutron rich beams obtained by the fission of uranium induced by fast neutrons. The production target made from uranium carbide and heated at 2000 °C will be associated with several types of ion sources. Developments currently in progress at GANIL for each of these projects are presented.

A TPS kernel for calculating survival vs. depth: distributions in a carbon radiotherapy beam, based on Katz's cellular Track Structure Theory.

PubMed

Waligórski, M P R; Grzanka, L; Korcyl, M; Olko, P

2015-09-01

An algorithm was developed of a treatment planning system (TPS) kernel for carbon radiotherapy in which Katz's Track Structure Theory of cellular survival (TST) is applied as its radiobiology component. The physical beam model is based on available tabularised data, prepared by Monte Carlo simulations of a set of pristine carbon beams of different input energies. An optimisation tool developed for this purpose is used to find the composition of pristine carbon beams of input energies and fluences which delivers a pre-selected depth-dose distribution profile over the spread-out Bragg peak (SOBP) region. Using an extrapolation algorithm, energy-fluence spectra of the primary carbon ions and of all their secondary fragments are obtained over regular steps of beam depths. To obtain survival vs. depth distributions, the TST calculation is applied to the energy-fluence spectra of the mixed field of primary ions and of their secondary products at the given beam depths. Katz's TST offers a unique analytical and quantitative prediction of cell survival in such mixed ion fields. By optimising the pristine beam composition to a published depth-dose profile over the SOBP region of a carbon beam and using TST model parameters representing the survival of CHO (Chinese Hamster Ovary) cells in vitro, it was possible to satisfactorily reproduce a published data set of CHO cell survival vs. depth measurements after carbon ion irradiation. The authors also show by a TST calculation that 'biological dose' is neither linear nor additive. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Predicting induced radioactivity for the accelerator operations at the Taiwan Photon Source.

PubMed

Sheu, R J; Jiang, S H

2010-12-01

This study investigates the characteristics of induced radioactivity due to the operations of a 3-GeV electron accelerator at the Taiwan Photon Source (TPS). According to the beam loss analysis, the authors set two representative irradiation conditions for the activation analysis. The FLUKA Monte Carlo code has been used to predict the isotope inventories, residual activities, and remanent dose rates as a function of time. The calculation model itself is simple but conservative for the evaluation of induced radioactivity in a light source facility. This study highlights the importance of beam loss scenarios and demonstrates the great advantage of using FLUKA in comparing the predicted radioactivity with corresponding regulatory limits. The calculated results lead to the conclusion that, due to fairly low electron consumption, the radioactivity induced in the accelerator components and surrounding concrete walls of the TPS is rather moderate and manageable, while the possible activation of air and cooling water in the tunnel and their environmental releases are negligible.

Sub-barrier radioactive ion beam investigations using a new methodology and analysis for the stacked target technique

NASA Astrophysics Data System (ADS)

Fisichella, M.; Shotter, A. C.; Di Pietro, A.; Figuera, P.; Lattuada, M.; Marchetta, C.; Privitera, V.; Romano, L.; Ruiz, C.; Zadro, M.

2015-12-01

For low energy reaction studies involving radioactive ion beams, the experimental reaction yields are generally small due to the low intensity of the beams. For this reason, the stacked target technique has been often used to measure excitation functions. This technique offers considerable advantages since the reaction cross-section at several energies can be simultaneously measured. In a further effort to increase yields, thick targets are also employed. The main disadvantage of the method is the degradation of the beam quality as it passes through the stack due to the statistical nature of energy loss processes and any nonuniformity of the stacked targets. This degradation can lead to ambiguities of associating effective beam energies to reaction product yields for the targets within the stack and, as a consequence, to an error in the determination of the excitation function for the reaction under study. A thorough investigation of these ambiguities is reported, and a best practice procedure of analyzing data obtained using the stacked target technique with radioactive ion beams is recommended. Using this procedure a re-evaluation is reported of some previously published sub-barrier fusion data in order to demonstrate the possibility of misinterpretations of derived excitation functions. In addition, this best practice procedure has been used to evaluate, from a new data set, the sub-barrier fusion excitation function for the reaction 6Li+120Sn .

The Radioactive Ion Beams in Brazil (RIBRAS) facility. Description, program, main results, future plans

NASA Astrophysics Data System (ADS)

Lépine-Szily, A.; Lichtenthäler, R.; Guimarães, V.

2014-08-01

RIBRAS (Radioactive Ion Beams in Brazil) is a facility installed at the Institute of Physics of the University of São Paulo (IFUSP), Brazil. The RIBRAS system consists of two superconducting solenoids and uses the "in-flight method" to produce radioactive ion beams using the primary beam provided by the 8UD Pelletron Tandem of IFUSP. The ion beams produced so far by RIBRAS are 6He, 8Li, 7Be, 10Be, 8B, 12B with intensities that can vary from 104 to 106 pps. Initially the experimental program covered the study of elastic and inelastic scattering with the objective to study the interaction potential and the reaction mechanisms between weakly bound (RIB) and halo (6He and 8B projectiles on light, medium and heavy mass targets. With highly purified beams, the study of resonant elastic scattering and resonant transfer reactions, using inverse kinematics and thick targets, has also been included in our experimental program. Also, transfer reactions of astrophysical interest and fusion reactions induced by halo nuclei are part of the near-future research program. Our recent results on elastic scattering, alpha-particle production and total reaction cross sections, as well as the resonant elastic and transfer reactions, are presented. Our plans for the near future are related to the installation of a new beam line and a cave for gamma-ray detection. We intend to place in operation a large area neutron detector available in our laboratory. The long-range plans could be the move of the RIBRAS system to the more energetic beam line of the LINAC post-accelerator (10MeV/nucleon primary beams) still in construction in our laboratory.

First radioactive beams at ACCULINNA-2 facility and first proposed experiment

NASA Astrophysics Data System (ADS)

Bezbakh, A. A.; Beekman, W.; Chudoba, V.; Fomichev, A. S.; Golovkov, M. S.; Gorshkov, A. V.; Grigorenko, L. V.; Kaminski, G.; Krupko, S. A.; Mentel, M.; Nikolskii, E. Yu.; Parfenova, Yu. L.; Plucinski, P.; Sidorchuk, S. I.; Slepnev, R. S.; Sharov, P. G.; Ter-Akopian, G. M.; Zalewski, B.

2018-04-01

New fragment separator ACCULINNA-2 was installed at the primary beam line of the U-400M cyclotron in 2016. Recently, first radioactive ion beams were obtained. The design parameters of new facility were experimentally confirmed. Intensity, purity and transverse profile of several secondary beams at the final focal plane were studied. The intensities obtained for the secondary beams of 14B, 12Be, 9;11Li, 6;8He in the fragmentation reaction 15N (49.7 AMeV) + Be (2 mm) are in average 15 times higher in comparison to the ones produced at its forerunner ACCULINNA separator. The ACCULINNA-2 separator will become a backbone facility at the FLNR for the research in the field of light exotic nuclei in the vicinity of the nuclear drip lines. The planned first experiment, aimed for the observation of the 7H nucleus at ACCULINNA-2, is outlined.

Status of the ion sources developments for the Spiral2 project at GANILa)

NASA Astrophysics Data System (ADS)

Lehérissier, P.; Bajeat, O.; Barué, C.; Canet, C.; Dubois, M.; Dupuis, M.; Flambard, J. L.; Frigot, R.; Jardin, P.; Leboucher, C.; Lemagnen, F.; Maunoury, L.; Osmond, B.; Pacquet, J. Y.; Pichard, A.; Thuillier, T.; Peaucelle, C.

2012-02-01

The SPIRAL 2 facility is now under construction and will deliver either stable or radioactive ion beams. First tests of nickel beam production have been performed at GANIL with a new version of the large capacity oven, and a calcium beam has been produced on the heavy ion low energy beam transport line of SPIRAL 2, installed at LPSC Grenoble. For the production of radioactive beams, several target/ion-source systems (TISSs) are under development at GANIL as the 2.45 GHz electron cyclotron resonance ion source, the surface ionization source, and the oven prototype for heating the uranium carbide target up to 2000 °C. The existing test bench has been upgraded for these developments and a new one, dedicated for the validation of the TISS before mounting in the production module, is under design. Results and current status of these activities are presented.

Use of cone beam CT in children and young people in three United Kingdom dental hospitals.

PubMed

Hidalgo-Rivas, Jose Alejandro; Theodorakou, Chrysoula; Carmichael, Fiona; Murray, Brenda; Payne, Martin; Horner, Keith

2014-09-01

There is limited evidence about the use of cone-beam computed tomography (CBCT) in paediatric dentistry. Appropriate use of CBCT is particularly important because of greater radiation risks in this age group. To survey the use of CBCT in children and young people in three Dental Hospitals in the United Kingdom (UK), with special attention paid to aspects of justification and optimisation. Retrospective analysis of patient records over a 24-month period, looking at CBCT examinations performed on subjects under 18 years of age. Clinical indications, region of interest, scan field of view (FoV), incidental findings and exposure factors used were recorded. There were 294 CBCT examinations performed in this age group, representing 13.7% of all scanned patients. CBCT was used more frequently in the >13 year age group. The most common use was for localisation of unerupted teeth in the anterior maxilla and the detection of root resorption. Optimisation of X-ray exposures did not appear to be consistent. When planning a CBCT service for children and young people, a limited FoV machine would be the appropriate choice for the majority of clinical requirements. It would facilitate clinical evaluation of scans, would limit the number of incidental findings and contribute to optimisation of radiation doses.

Measurement of the beryllium-7 plus proton fusion cross section

NASA Astrophysics Data System (ADS)

Fitzgerald, Ryan P.

2005-11-01

The fusion of protons with radioactive nuclei plays an important role in a wide variety of astrophysical scenarios ranging from high-temperature environments like novae and X-ray bursts to the production of neutrinos in the sun. For example, the 8 B neutrino flux measured in neutrino detectors on earth is directly proportional to the cross section for the fusion of protons with radioactive 7 Be. An experimental program has been established to study proton-fusion experiments in inverse kinematics at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL) using a windowless gas target and the Daresbury Recoil Separator (DRS). The performance of the target and separator have been well characterized using a variety of experiments with stable beams including 12 C, 19 F, and 24 Mg. For instance, the areal density of hydrogen in the target was determined to 3% accuracy. This well-characterized system was used to measure accurate stopping powers for many elements in hydrogen gas for the first time. The first measurement of a proton-fusion cross section with a radioactive ion beam at ORNL, the fusion of protons with 7 Be, was performed using the hydrogen gas target and the DRS. The 7 Be was produced at the Triangle Universities Nuclear Laboratory (TUNL) and chemically isolated at ORNL. An average 7 Be beam current of 2.5 ppA bombarded the windowless gas target for a period of 3 days. Recoiling B-8 nuclei were efficiently collected using the DRS and were clearly identified in a gas-filled ion detector. The cross section at a center-of-mass energy of 1.502 MeV was determined to be 1.12 mb with 24% uncertainty. The zero-energy S-factor was determined to be 26.8 eV-b with 25% uncertainty. The technique has been clearly demonstrated, and a precise measurement of the fusion cross section will be possible with the development of a somewhat more intense 7 Be radioactive ion beam.

Laser photodetachment of radioactive 128 I -

DOE PAGES

Rothe, Sebastian; Sundberg, Julia; Welander, Jakob; ...

2017-08-31

The first experimental investigation of the electron affinity (EA) of a radioactive isotope has been conducted at the CERN-ISOLDE radioactive ion beam facility. The EA of the radioactive iodine isotope 128I ($t$ 1/2 = 25 min) was determined to be 3.059 052(38) eV. The experiment was conducted using the newly developed Gothenburg ANion Detector for Affinity measurements by Laser PHotodetachment (GANDALPH) apparatus, connected to a CERN-ISOLDE experimental beamline. 128I was produced in fission induced by 1.4 GeV protons striking a thorium/tantalum foil target and then extracted as singly charged negative ions at a beam energy of 20 keV. Laser photodetachmentmore » of the fast ion beam was performed in a collinear geometry inside the GANDALPH chamber. Neutral atoms produced in the photodetachment process were detected by allowing them to impinge on a glass surface, creating secondary electrons which were then detected using a channel electron multiplier. The photon energy of the laser was tuned across the threshold of the photodetachment process and the detachment threshold data were fitted to a Wigner law function in order to extract the EA. In conclusion, this first successful demonstration of photodetachment at an isotope separator on line facility opens up the opportunity for future studies of the fundamental properties of negatively charged radioactive isotopes such as the EA of astatine and polonium.« less

First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE)

NASA Astrophysics Data System (ADS)

Serianni, G.; De Muri, M.; Muraro, A.; Veltri, P.; Bonomo, F.; Chitarin, G.; Pasqualotto, R.; Pavei, M.; Rizzolo, A.; Valente, M.; Franzen, P.; Ruf, B.; Schiesko, L.

2014-02-01

The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions.

First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serianni, G., E-mail: gianluigi.serianni@igi.cnr.it; De Muri, M.; Veltri, P.

2014-02-15

The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some resultsmore » concerning the BATMAN beam under varying operating conditions.« less

European organization for nuclear research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoenbacher, H.; Tavlet, M.

1987-09-10

The CERN Intersecting Storage Rings (ISR) operated from 1971 to 1984. During that time high-energy physics experiments were carried out with 30 GeV colliding proton beams. At the end of this period the machine was decommissioned and dismantled. This involved the movement of about 1000 machine elements, e.g., magnets, vacuum pumps, rf cavities, etc., 2500 racks, 7000 shielding blocks, 3500 km of cables and 7 km of beam piping. All these items were considered to be radioactive until the contrary was proven. They were then sorted, either for storage and reuse or for radioactive or non-radioactive waste. The paper describesmore » the radiation protection surveillance of this project which lasted for five months. It includes the radiation protection standards, the control of personnel and materials, typical radioactivity levels and isotopes, as well as final cleaning and decommissioning of an originally restricted radiation area to a free accessible area.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garrett, J.D.

These proceedings report the deliberations of a 3 1/2 day workshop on the Production and Use of Intense Radioactive Ion Beams at the Isospin Laboratory, which was held at the Joint Institute for Heavy Ion Research in Oak Ridge, Tennessee, October 1992. The purpose of this workshop was not to duplicate the programs of other recent radioactive ion beam workshops or international conferences that have focused on the scientific concepts which radioactive beams can, and in fact already are, addressing. Instead, the intent was to address the technical problems associated with the construction of the next generation ISOL facility andmore » to initiate a discussion of the type of experimental equipment that should be developed for such a facility. We have tried to bring together in Oak Ridge the world`s experts in radioactive targets/ion sources, light and heavy-ion accelerators, and detection systems. After 1 1/2 days of overview presentations, the participants divided into three discussion groups (Experiments with Radioactive Beams, Target Ion Sources and Mass Separation, and Accelerators-Primary and Secondary) for 1 1/2 days of detailed discussions of the most pertinent issues. The final session was devoted to reports from each of the discussion groups and a general discussion of where to go from here. An outgrowth of these discussions was the establishment of working groups to coordinate future technical developments associated with the pertinent issues. The proceedings include the text of all the overview presentations, reports from each discussion group, as well as contributions from those participants who chose to provide the text of their presentations in the discussion groups and the Concluding Remarks. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.« less

Optimisation of 12 MeV electron beam simulation using variance reduction technique

NASA Astrophysics Data System (ADS)

Jayamani, J.; Termizi, N. A. S. Mohd; Kamarulzaman, F. N. Mohd; Aziz, M. Z. Abdul

2017-05-01

Monte Carlo (MC) simulation for electron beam radiotherapy consumes a long computation time. An algorithm called variance reduction technique (VRT) in MC was implemented to speed up this duration. This work focused on optimisation of VRT parameter which refers to electron range rejection and particle history. EGSnrc MC source code was used to simulate (BEAMnrc code) and validate (DOSXYZnrc code) the Siemens Primus linear accelerator model with the non-VRT parameter. The validated MC model simulation was repeated by applying VRT parameter (electron range rejection) that controlled by global electron cut-off energy 1,2 and 5 MeV using 20 × 107 particle history. 5 MeV range rejection generated the fastest MC simulation with 50% reduction in computation time compared to non-VRT simulation. Thus, 5 MeV electron range rejection utilized in particle history analysis ranged from 7.5 × 107 to 20 × 107. In this study, 5 MeV electron cut-off with 10 × 107 particle history, the simulation was four times faster than non-VRT calculation with 1% deviation. Proper understanding and use of VRT can significantly reduce MC electron beam calculation duration at the same time preserving its accuracy.

The ISOLDE facility and the HIE-HISOLDE project: Recent highlights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borge, M. J. G.

2014-07-23

The ISOLDE facility at CERN has as objective the production, study and research of nuclei far from stability. The facility provides low energy radioactive beams and post-accelerated beams. In the last 45 years the ISOLDE facility has gathered unique expertise in research with radioactive beams. Over 700 isotopes of more than 70 elements have been used in a wide range of research domains, including cutting edge studies in nuclear structure, atomic physics, nuclear astrophysics, and fundamental interactions. These nuclear probes are also used to do frontier research in solid state and life sciences. There is an on-going upgrade of themore » facility, the HIE-ISOLDE project, which aims to improve the ISOLDE capabilities in a wide front, from an energy increase of the post-accelerated beam to improvements in beam quality and beam purity. The first phase of HIE-ISOLDE will start for physics in the autumn of 2015 with an upgrade of energy for all post-accelerated ISOLDE beams up to 5.5 MeV/u. In this contribution the most recent highlights of the facility are presented.« less

Cyclotron production for the radiometal Zirconium-89 with an IBA cyclone 18/9 and COSTIS solid target system (STS)

NASA Astrophysics Data System (ADS)

Dabkowski, A. M.; Probst, K.; Marshall, C.

2012-12-01

The development of biological targeting agents such as proteins, peptides, antibodies and nanoparticles with a range of biological half-lives demands the production of new radionuclides with half-lives (physical) complementary to these biological properties. Zirconium-89 (89Zr) is a promising radionuclide for development of new immuno-PET agents due to its convenient half-life of 78.4 h, β+ emission rate of 23%, low maximum energy of 0.9 MeV resulting in good spatial resolution, stable daughter isotope of Yttrium-89 (89Y) and favorable imaging characteristics, with only one significant γ-line of 909 keV emitted during decay alongside the 511 keV positron photons. Our aim was to prove that isotopically pure 89Zr could be produced in an IBA Cyclone 18/9 cyclotron equipped with a COSTIS STS using the 89Y(p,n)89Zr reaction and optimise the yield by reducing the beam degrader thickness without producing either 88Zr or 88Y. The degradation of the beam energy with 400 and 500 μm thick Niobium foils were achieved without overheating problems with 2-3 hours long irradiation times. From repeated measurements of activity, it was clear that there is a bi-exponential decay of radioactivity due to the short lived 89mZr and 89Zr. The measured half-life of the longer lived radionulide was consistent with value for 89Zr. The energy spectrum from 89Zr had energy peaks at 511 keV and 909 keV and was consistent with 89Zr. Production of 89Zr with 500 μm thick Niobium beam degrader (Ep = 9.8MeV) was achieved, without producing either 88Zr or 88Y. It was necessary to wait at least 4 hours before measuring the activity and decay correct in order to calculate the 89gZr activity at the end of cyclotron production. Degrading the proton beam to 10 MeV produces radionuclidically pure 89Zr with yields from 8 to 9 MBq/μAh. Whilst this is enough for pre-clinical use, the yield is not enough for either clinical use or commercial supply. Using thinner beam degraders to increase the proton beam energy increases the radionuclidic yield but it is not yet possible to exclude the presence of radionuclidic impurities.

Computer simulation of electron flow in linear-beam microwave tubes

NASA Astrophysics Data System (ADS)

Kumar, Lalit

1990-12-01

The computer simulation of electron flow in linear-beam microwave tubes, such as a travelling-wave tube (TWT) and klystron, is used for designing and optimising the electron gun and collector and for analysing the large-signal beam-wave interaction phenomenon. Major aspects of simulation of electron flow in static and rf fields present in such tubes are discussed. Some advancements made in this respect and results obtained from computer programs developed by the research group at CEERI for a gridded electron gun, depressed collector, and large-signal analysis of TWT and klystron are presented.

Argonne National Laboratory |

Science.gov Websites

for next-gen lithium batteries. Spotlight New ion source dramatically improves radioactive beams for Argonne's CARIBU facility A new Electron Beam Ion Source Charge Breeder operated with Argonne's CARIBU and

Measurement of pattern recognition efficiency of tracks generated by ionizing radiation in a Medipix2 device

NASA Astrophysics Data System (ADS)

Bouchami, J.; Gutiérrez, A.; Holy, T.; Houdayer, A.; Jakůbek, J.; Lebel, C.; Leroy, C.; Macana, J.; Martin, J.-P.; Pospíšil, S.; Prak, S.; Sabella, P.; Teyssier, C.; CERN Medipix Collaboration

2011-05-01

Several experiments were performed to establish the Medipix2 device capabilities for track recognition and its efficiency at measuring fluxes. A Medipix2 device was exposed to 241Am, 106Ru and 137Cs radioactive sources, separately and simultaneously. It was also exposed to heavy particle beams (protons and alpha-particles), recoiled on a gold foil to reduce the incoming flux and allow the study of the detector response struck by incoming particles at different incidence angles. For three proton beams (400 keV, 4 and 10 MeV), the device was exposed to the radioactive sources on top of beam, giving a mixed radiation field. To test the reliability of track recognition with this device, the activities of the radioactive sources were extracted from the experimental data and compared to the expected activities. Rotation of the Medipix2 device allowed the test of the heavy tracks recognition at different incidence angles.

Thin and thick targets for radioactive ion beam production at SPIRAL1 facility

NASA Astrophysics Data System (ADS)

Jardin, P.; Bajeat, O.; Delahaye, P.; Dubois, M.; Kuchi, V.; Maunoury, L.

2018-05-01

The upgrade of the Système de Production d'Ions Radioactifs Accélérés en Ligne (SPIRAL1) facility will deliver its new Radioactive Ion Beams (RIB) by summer 2017. The goal of the upgrade is an improvement of the performances of the installation in terms of isotopes species and ion charge states [1]. Ion beams are produced using the Isotope Separator On Line Method, consisting in an association of a primary beam of stable ions, a hot target and an ion source. The primary beam impinges on the material of the target. Radioactive isotopes are produced by nuclear reactions and propagate up to the source, where they are ionized and accelerated to create a RIB. One advantage of SPIRAL1 driver is the variety of its available primary beams, from carbon to uranium with energies up to 95 MeV/A. Within the SPIRAL1 upgrade, they will be combined with targets made of a large choice of materials, extending in this way the number of possible nuclear reactions (fusion-evaporation, transfer, fragmentation) for producing a wider range of isotopes, up to regions of the nuclide chart still scarcely explored. Depending on the reaction process, on the collision energy and on the primary beam power, thin and thick targets are used. As their functions can be different, their design must cope with specific constraints which will be described. After a presentation of the goals of present and future SPIRAL1 Target Ion Source System, the main target features, studies and designs under progress are presented.

Planned development of a radioactive beam capability at the LBNL 88-inch cyclotron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.; Moltz, D.M.; Norman, E.B.

1997-12-31

Planned development of low-Z, proton-rich, radioactive beams ({sup 11}C, {sup 13}N, {sup 14}, {sup 15}O, and {sup 18}F) at the 88 inch Cyclotron of the Lawrence Berkeley National Lab is described. Based on the {open_quotes}coupled cyclotron method{close_quotes}, isotopes produced by (p,n) and (p,a) reactions at a high-current (30 mA), low-energy (10 MeV) medical cyclotron will be transferred {approximately}300 meters by high-speed gas-jet transport to the ECR ion-source at the 88 inch Cyclotron. Important features of this approach are its low cost, use of simple and well tested technology, applicability to nearly all elements, and avoidance of lengthy (chemical or physical)more » isotopic release delays at the production target. Developmental progress is reported for various operational components. Based on conservative estimates, e.g. 1% ECR ion-yield, extracted radioactive ion beams are projected to exceed 10{sup 6} ions/sec. Experiments which will use these beams include studies of the scattering of mirror nuclei, single and mutual excitation in inelastic scattering and single nucleon transfer reactions.« less

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Kutsaev, Sergey; Delahaye, P.

2012-11-15

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficienciesmore » of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.« less

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Delahaye, P.; Kutsaev, Sergey

2012-11-01

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a 252Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies ofmore » both gaseous and solid species including 14.7% for the radioactive species 143Ba27+. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for 23Na7+ and 17.9% for 39K10+ were obtained injecting stable Na+ and K+ beams from a surface ionization source.« less

Study of the radioactivity induced in air by a 15-MeV proton beam.

PubMed

Braccini, S; Ereditato, A; Nesteruk, K P; Scampoli, P; Zihlmann, K

2015-02-01

Radioactivity induced by a 15-MeV proton beam extracted into air was studied at the beam transport line of the 18-MeV cyclotron at the Bern University Hospital (Inselspital). The produced radioactivity was calculated and measured by means of proportional counters located at the main exhaust of the laboratory. These devices were designed for precise assessment of air contamination for radiation protection purposes. The main produced isotopes were (11)C, (13)N and (14)O. Both measurements and calculations correspond to two different irradiation conditions. In the former, protons were allowed to travel for their full range in air. In the latter, they were stopped at the distance of 1.5 m by a beam dump. Radioactivity was measured continuously in the exhausted air starting from 2 min after the end of irradiation. For this reason, the short-lived (14)O isotope gave a negligible contribution to the measured activity. Good agreement was found between the measurements and the calculations within the estimated uncertainties. Currents in the range of 120-370 nA were extracted in air for 10-30 s producing activities of 9-22 MBq of (11)C and (13)N. The total activities for (11)C and (13)N per beam current and irradiation time for the former and the latter irradiation conditions were measured to be (3.60 ± 0.48) × 10(-3) MBq (nA s)(-1) and (2.89 ± 0.37) × 10(-3) MBq (nA s)(-1), respectively. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Beam production of 18Ne with in-flight method for alpha scattering at CRIB

NASA Astrophysics Data System (ADS)

Duy, N. N.; Chae, K. Y.; Cha, S. M.; Yamaguchi, H.; Abe, K.; Bae, S. H.; Binh, D. N.; Choi, S. H.; Hahn, K. I.; Hayakawa, S.; Hong, B.; Iwasa, N.; Kahl, D.; Khiem, L. H.; Kim, A.; Kim, D. H.; Kim, E. J.; Kim, G. W.; Kim, M. J.; Kwak, K.; Kwag, M. S.; Lee, E. J.; Lim, S. I.; Moon, B.; Moon, J. Y.; Park, S. Y.; Phong, V. H.; Shimizu, H.; Yang, L.; Ge, Z.; Hao, T. V. Nhan

2018-07-01

We conducted a measurement of 18Ne + α scattering in inverse kinematics, in order to search for experimental evidence of α-cluster structure in 22Mg above the alpha threshold (Ethr = 8 . 14 MeV) and determine the astrophysical rates of the 18Ne(α, p)21Na reaction under the conditions of break-out from the Hot-CNO cycle. A high intensity 18Ne beam at 2.54 AMeV was successfully produced at CRIB (CNS Radioactive Ion Beam separator) of the Center for Nuclear Study, the University of Tokyo. This paper presents the in-flight production of the radioactive 18Ne beam by using the production reaction 3He(16O, 18Ne)n with a windowed cryogenic gas target, which was employed in the mentioned resonant α-scattering experiment.

Deformation and Heat Transfer on Three Sides Protected Beams under Fire Accident

NASA Astrophysics Data System (ADS)

Imran, M.; Liew, M. S.; Garcia, E. M.; Nasif, M. S.; Yassin, A. Y. M.; Niazi, U. M.

2018-04-01

Fire accidents are common in oil and gas industry. The application of passive fire protection (PFP) is a costly solution. The PFP is applied only on critical structural members to optimise project cost. In some cases, beams cannot be protected from the top flange in order to accommodate for the placement of pipe supports and grating. It is important to understand the thermal and mechanical response of beam under such condition. This paper discusses the response of steel beam under ISO 834 fire protected, unprotected and three sides protected beams. The model validated against an experimental study. The experimental study has shown good agreement with FE model. The study revealed that the beams protected from three sides heat-up faster compare to fully protected beam showing different temperature gradient. However, the affects load carrying capacity are insignificant under ISO 834 fire.

The REX-ISOLDE charge breeder as an operational machine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wenander, F.; Delahaye, P.; Scrivens, R.

2006-03-15

The charge breeding system of radioactive beam experiment at ISOLDE (REX-ISOLDE), consisting of a large Penning trap in combination with an electron-beam ion source (EBIS), is now a mature concept after having delivered radioactive beams for postacceleration to a number of experiments for three years. The system, preparing ions prior to injection into a compact linear accelerator, has shown to be versatile in terms of the ion species and energies that can be delivered. During the experimental periods 2004 and 2005 a significant part of the ISOLDE beam time was dedicated to REX-ISOLDE experiments. Ion masses in the range betweenmore » A=7 and 153 have been handled with record efficiencies. High-intensity as well as very-short-lived isotope beams were proven to be feasible. Continuous injection into the EBIS has also been successfully tested. Two means of suppressing unwanted beam contaminations were tested and are now in use. In addition, the experience gained from the trap-EBIS concept from a machine operational point of view will be discussed and the limitations described.« less

Physical and engineering aspect of carbon beam therapy

NASA Astrophysics Data System (ADS)

Kanai, Tatsuaki; Kanematsu, Nobuyuki; Minohara, Shinichi; Yusa, Ken; Urakabe, Eriko; Mizuno, Hideyuki; Iseki, Yasushi; Kanazawa, Mitsutaka; Kitagawa, Atsushi; Tomitani, Takehiro

2003-08-01

Conformal irradiation system of HIMAC has been up-graded for a clinical trial using a technique of a layer-stacking method. The system has been developed for localizing irradiation dose to target volume more effectively than the present irradiation dose. With dynamic control of the beam modifying devices, a pair of wobbler magnets, and multileaf collimator and range shifter, during the irradiation, more conformal radiotherapy can be achieved. The system, which has to be adequately safe for patient irradiations, was constructed and tested from a viewpoint of safety and the quality of the dose localization realized. A secondary beam line has been constructed for use of radioactive beam in heavy-ion radiotherapy. Spot scanning method has been adapted for the beam delivery system of the radioactive beam. Dose distributions of the spot beam were measured and analyzed taking into account of aberration of the beam optics. Distributions of the stopped positron-emitter beam can be observed by PET. Pencil beam of the positron-emitter, about 1 mm size, can also be used for measurements ranges of the test beam in patients using positron camera. The positron camera, consisting of a pair of Anger-type scintillation detectors, has been developed for this verification before treatment. Wash-out effect of the positron-emitter was examined using the positron camera installed. In this report, present status of the HIMAC irradiation system is described in detail.

Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams

NASA Astrophysics Data System (ADS)

Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.

2016-03-01

The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The transfer line enables the unstable isotopes generated by the 238U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

Selective Isobar Suppression for Accelerator Mass Spectrometry and Radioactive Ion Beam Science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galindo-Uribarri, Alfredo; Havener, Charles C; Lewis, Thomas L.

2010-01-01

Several applications of AMS will benefit from pushing further the detection limits of AMS isotopes. A new method of selective isobar suppression by photodetachment in a radio-frequency quadrupole ion cooler is being developed at HRIBF with a two-fold purpose: (1) increasing the AMS sensitivity for certain isotopes of interest and (2) purifying radioactive ion beams for nuclear science. The potential of suppressing the 36S contaminants in a 36Cl beam using this method has been explored with stable S- and Cl- ions and a Nd:YLF laser. In the study, the laser beam was directed along the experiment's beam line and throughmore » a RF quadrupole ion cooler. Negative 32S and 35Cl ions produced by a Cs sputter ion source were focused into the ion cooler where they were slowed by collisions with He buffer gas; this increased the interaction time between the negative ion beam and the laser beam. As a result, suppression of S- by a factor of 3000 was obtained with about 2.5 W average laser power in the cooler while no reduction in Cl- current was observed.« less

The NUSTAR project at FAIR

NASA Astrophysics Data System (ADS)

Nilsson, Thomas; the NUSTAR Collaboration

2015-11-01

The FAIR facility, under construction at the GSI site in Darmstadt, will be addressing a wealth of outstanding questions within the realm of subatomic, atomic, plasma, bio-physics and applications through a combination of novel accelerators, storage rings and innovative experimental set-ups. One of the key installations is the fragment separator Super-FRS that will be able to deliver an unprecedented range of radioactive ion beams in the energy range of 0-1.5 GeV u-1. These beams will be distributed to three branches, each with its unique domain with respect to beam energies and properties. The high-energy branch will permit reactions with radioactive beams at relativistic energies, whereas the low-energy branch will supply decelerated beams for high-resolution spectroscopy, traps and laser spectroscopy. Finally, the ring branch will uniquely permit stored and cooled exotic beams for a range of methods only possible in a storage ring. Thus, by developing experimental set-ups tailored for these beams, there are several complementary possibilities to gain information on key nuclei and reaction, to further our understanding on contemporary questions within nuclear structure and nuclear astrophysics. This ambitious programme is to be exploited within the nuclear structure, astrophysics and reactions collaboration.

Reference dosimetry study for 3 MEV electron beam accelerator in malaysia

NASA Astrophysics Data System (ADS)

Ali, Noriah Mod; Sunaga, Hiromi; Tanaka, Ryuichi

1995-09-01

An effective quality assurance programme is initiated for the use of the electron beam with energies up to 3 MeV. The key element of the programme is the establishment of a relationship between the standardised beam to the routine technique which is employed to verify the beam parameter. A total absorbing calorimeter was adopted as a suitable reference system and when used in combination with the electron current densitymeter (ECD) will enable to determine the mean energy for electron with energies between 1 to 3 MeV. An appropriate method of transfering the standard parameter is studied and the work that is expected to optimise the accuracy attainable with routine check-up of the irradiation parameter are presented.

A comparative study on laser induced shock cleaning of radioactive contaminants in air and water

NASA Astrophysics Data System (ADS)

Kumar, Aniruddha; Prasad, Manisha; Bhatt, R. B.; Behere, P. G.; Biswas, D. J.

2018-03-01

Efficient removal of Uranium-di-oxide (UO2) particulates from stainless steel surface was effected by Nd-YAG laser induced plasma shock waves in air as well as in water environment. The propagation velocity of the generated shock wave was measured by employing the photo-acoustic probe deflection method. Monitoring of the alpha activity of the sample with a ZnS (Ag) scintillation detector before and after the laser exposure allowed the estimation of decontamination efficiency defined as the percentage removal of the initial activity. Experiments were carried out to study the effect of laser pulse energy, number of laser exposures, orientation of the sample, the separation between the substrate surface and the onset point of the shock wave on the de-contamination efficiency. The most optimised cleaning was found to occur when the laser beam impinged normally on the sample that was immersed in water and placed at a distance of ∼0.7 mm from the laser focal spot. Analysis of the cleaned surface by optical microscopes established that laser induced shock cleaning in no way altered the surface property. The shock force generated in both air and water has been estimated theoretically and has been found to exceed the Van der Waal's binding force for spherical contaminant particulate.

Nuclear reactions with carbon-11 and oxygen-14 radioactive ion beams

NASA Astrophysics Data System (ADS)

Guo, Fanqing

Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2 x 10 8 pps intensity on target and an 14O beam of up to 3 x 104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn) 208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of alpha decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p) 14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z = 8 proton magic number for odd Z, Tz = -3/2 nuclei. It is expected that future work on proton-rich nuclides will rely heavily on RIBs and/or mass separators. Currently, radioactive ion beam intensities are sufficient for the study of a reasonable number of very proton-rich nuclides.

Testing atomic mass models with radioactive beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.

1989-01-01

Significantly increased yields of new or poorly characterized exotic isotopes that lie far from beta-decay stability can be expected when radioactive beams are used to produce these nuclides. Measurements of the masses of these new species are very important. Such measurements are motivated by the general tendency of mass models to diverge from one another upon excursions from the line of beta-stability. Therefore in these regions (where atomic mass data are presently nonexistent or sparse) the models can be tested rigorously to highlight the features that affect the quality of their short-range and long-range extrapolation properties. Selection of systems tomore » study can be guided, in part, by a desire to probe those mass regions where distinctions among mass models are most apparent and where yields of exotic isotopes, produced via radioactive beams, can be optimized. Identification of models in such regions that have good predictive properties will aid materially in guiding the selection of additional experiments which ultimately will provide expansion of the atomic mass database for further refinement of the mass models. 6 refs., 5 figs.« less

Dosimetric accuracy of a treatment planning system for actively scanned proton beams and small target volumes: Monte Carlo and experimental validation

NASA Astrophysics Data System (ADS)

Magro, G.; Molinelli, S.; Mairani, A.; Mirandola, A.; Panizza, D.; Russo, S.; Ferrari, A.; Valvo, F.; Fossati, P.; Ciocca, M.

2015-09-01

This study was performed to evaluate the accuracy of a commercial treatment planning system (TPS), in optimising proton pencil beam dose distributions for small targets of different sizes (5-30 mm side) located at increasing depths in water. The TPS analytical algorithm was benchmarked against experimental data and the FLUKA Monte Carlo (MC) code, previously validated for the selected beam-line. We tested the Siemens syngo® TPS plan optimisation module for water cubes fixing the configurable parameters at clinical standards, with homogeneous target coverage to a 2 Gy (RBE) dose prescription as unique goal. Plans were delivered and the dose at each volume centre was measured in water with a calibrated PTW Advanced Markus® chamber. An EBT3® film was also positioned at the phantom entrance window for the acquisition of 2D dose maps. Discrepancies between TPS calculated and MC simulated values were mainly due to the different lateral spread modeling and resulted in being related to the field-to-spot size ratio. The accuracy of the TPS was proved to be clinically acceptable in all cases but very small and shallow volumes. In this contest, the use of MC to validate TPS results proved to be a reliable procedure for pre-treatment plan verification.

Dosimetric accuracy of a treatment planning system for actively scanned proton beams and small target volumes: Monte Carlo and experimental validation.

PubMed

Magro, G; Molinelli, S; Mairani, A; Mirandola, A; Panizza, D; Russo, S; Ferrari, A; Valvo, F; Fossati, P; Ciocca, M

2015-09-07

This study was performed to evaluate the accuracy of a commercial treatment planning system (TPS), in optimising proton pencil beam dose distributions for small targets of different sizes (5-30 mm side) located at increasing depths in water. The TPS analytical algorithm was benchmarked against experimental data and the FLUKA Monte Carlo (MC) code, previously validated for the selected beam-line. We tested the Siemens syngo(®) TPS plan optimisation module for water cubes fixing the configurable parameters at clinical standards, with homogeneous target coverage to a 2 Gy (RBE) dose prescription as unique goal. Plans were delivered and the dose at each volume centre was measured in water with a calibrated PTW Advanced Markus(®) chamber. An EBT3(®) film was also positioned at the phantom entrance window for the acquisition of 2D dose maps. Discrepancies between TPS calculated and MC simulated values were mainly due to the different lateral spread modeling and resulted in being related to the field-to-spot size ratio. The accuracy of the TPS was proved to be clinically acceptable in all cases but very small and shallow volumes. In this contest, the use of MC to validate TPS results proved to be a reliable procedure for pre-treatment plan verification.

Impact of field number and beam angle on functional image-guided lung cancer radiotherapy planning

NASA Astrophysics Data System (ADS)

Tahir, Bilal A.; Bragg, Chris M.; Wild, Jim M.; Swinscoe, James A.; Lawless, Sarah E.; Hart, Kerry A.; Hatton, Matthew Q.; Ireland, Rob H.

2017-09-01

To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 magnetic resonance imaging (3He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment 3He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving  ⩾20 Gy (V20) were compared with plans that minimised 3He MRI defined functional lung receiving  ⩾20 Gy (fV20). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV20 and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV90). Incorporation of 3He MRI led to median reductions in fV20 of 1.3% (range: 0.2-9.3% p  =  0.04) and 0.2% (range: 0 to 4.1%; p  =  0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised 3He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.

A low cost ion beam profile monitor

NASA Astrophysics Data System (ADS)

Godfrey, L.; Hoyes, G. G.; Pairsuwan, W.

1990-09-01

An intercepting multiwire ion beam profile monitor, of thickness 0.9 cm and active area 5 × 5 cm, has been developed for use with the low-intensity deuteron beamline at the Fast Neutron Research Facility (FNRF), Chiang Mai University. It has been used to optimise the transport of a continuous ion beam of current up to 200 μA and kinetic energy up to 140 keV. The monitor enables the determination of the two-dimensional beam profile using closely-spaced samples at 1.5 mm, and the measurement of relative beam current. The design incorporates low material and labour costs, elimination of the need for commercial vacuum feedthroughs, a minimal amount of devoted electronics with no need for preamplifiers, and permits quick insertion of the monitors, wherever needed along the beamline, with minimum disruption to neighbouring elements.

Structure effects on reaction mechanisms in collisions induced by radioactive ion beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pietro, A. Di, E-mail: dipietro@lns.infn.it; Figuera, P.; Scuderi, V.

2006-08-15

The present paper concerns the study of reactions induced by radioactive beams of halo and weakly bound nuclei at energies around and above the Coulomb barrier. The results obtained for the reaction induced by the halo nucleus {sup 6}He on {sup 64}Zn have been compared with the results for the reaction induced by {sup 4}He on the same target. The results of the reaction induced by the weakly bound unstable {sup 13}N on the weakly bound {sup 9}Be have been compared with those for the reaction {sup 10}B + {sup 12}C.

Particle beam generator using a radioactive source

DOEpatents

Underwood, D.G.

1993-03-30

The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

Probing the fusion of neutron-rich nuclei with re-accelerated radioactive beams

NASA Astrophysics Data System (ADS)

Vadas, J.; Singh, Varinderjit; Wiggins, B. B.; Huston, J.; Hudan, S.; deSouza, R. T.; Lin, Z.; Horowitz, C. J.; Chbihi, A.; Ackermann, D.; Famiano, M.; Brown, K. W.

2018-03-01

We report the first measurement of the fusion excitation functions for K,4739+28Si at near-barrier energies. Evaporation residues resulting from the fusion process were identified by direct measurement of their energy and time of flight with high geometric efficiency. At the lowest incident energy, the cross section measured for the neutron-rich 47K-induced reaction is ≈6 times larger than that of the β -stable system. This experimental approach, both in measurement and in analysis, demonstrates how to efficiently measure fusion with low-intensity re-accelerated radioactive beams, establishing the framework for future studies.

Particle beam generator using a radioactive source

DOEpatents

Underwood, David G.

1993-01-01

The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

The RIB facility EXOTIC and its experimental program at INFN-LNL

NASA Astrophysics Data System (ADS)

Parascandolo, Concetta

2018-05-01

In this contribution, I will present a review about the EXOTIC facility and the research field accessible by using its Radioactive Ion Beams. The EXOTIC facility, installed at the INFN-Laboratori Nazionali di Legnaro, is devoted to the in-flight production of light Radioactive Ion Beams in the energy range between 3-5 MeV/nucleon. The scientific activity performed at EXOTIC concerns different aspects of nuclear physics and nuclear astrophysics, such as, the investigation of reaction mechanisms and nuclear structure, resonant scattering experiments and measurements of nuclear reaction cross sections of astrophysical interest.

Kinetics analysis and quantitative calculations for the successive radioactive decay process

NASA Astrophysics Data System (ADS)

Zhou, Zhiping; Yan, Deyue; Zhao, Yuliang; Chai, Zhifang

2015-01-01

The general radioactive decay kinetics equations with branching were developed and the analytical solutions were derived by Laplace transform method. The time dependence of all the nuclide concentrations can be easily obtained by applying the equations to any known radioactive decay series. Taking the example of thorium radioactive decay series, the concentration evolution over time of various nuclide members in the family has been given by the quantitative numerical calculations with a computer. The method can be applied to the quantitative prediction and analysis for the daughter nuclides in the successive decay with branching of the complicated radioactive processes, such as the natural radioactive decay series, nuclear reactor, nuclear waste disposal, nuclear spallation, synthesis and identification of superheavy nuclides, radioactive ion beam physics and chemistry, etc.

Accelerating Radioactive Ion Beams With REX-ISOLDE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ames, F.; Emhofer, S.; Habs, D.

2003-08-26

The post accelerator REX-ISOLDE is installed at the ISOLDE facility at CERN, where a broad variety of radioactive ions can be addressed. Since the end of 2001 beams at the final energy of 2.2 MeV/u are available. REX-ISOLDE uses a unique system of beam bunching and charge breeding. First a Penning trap accumulates and bunches the ions, which are delivered as a quasi-continuous beam from the ISOLDE target-ion-source, and then an electron beam ion source (EBIS) charge-breeds them to a mass-to-charge ratio below 4.5. This enables a very compact design for the following LINAC, consisting of a 4 rod RFQ,more » an IH structure and three 7-gap-resonators. The later ones allow a variation of the final energy between 0.8 and 2.2 MeV/u. Although the machine is still in the commissioning phase, first physics experiments have been done with neutron rich Na and Mg isotopes and 9Li. A total efficiency of several percent has already been obtained.« less

Progress towards an intense beam of positrons created by a Van de Graaff accelerator

NASA Astrophysics Data System (ADS)

Lund, K. R.; Weber, M. H.; Lynn, K. G.; Jennings, J.; Minnal, C.; Narimannezhad, A.; Rao, R.; Monster, K. A. W.

2017-12-01

A 4MV Van de Graaff accelerator was used to induce the nuclear reaction 12C(d,n)13N in order to produce an intense beam of positrons. The graphite target was heated so the radioactive 13N would desorb from the bulk into the vacuum. This radioactive gas is frozen onto a cryogenic freezer where it decays to produce an antiparticle beam of positrons. This high current beam is then guided into a superconducting magnet with field strength up to 7 Tesla where the positrons will be stored in a newly designed Micro-Penning-Malmberg trap. Several source geometries have been experimented on and found a maximum antimatter beam with a positron flux of greater than 0.55 ± 0.03 × 106 e+s-1 was achieved. This beam was produced using a solid rare gas moderator composed of krypton (Kr) at a temperature of 25 ± 5 K. Due to geometric restrictions on this set up and other loss mechanisms, 107-108 e+s-1 of the total number of positrons are lost. Simulations and preliminary experiments suggest a new geometry, currently under testing, will produce a beam of 107 e+s-1 or more. The setup and preliminary results for the new geometry will be discussed as well.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rozhdestvensky, Yu V

The possibility is studied for obtaining intense cold atomic beams by using the Renyi entropy to optimise the laser cooling process. It is shown in the case of a Gaussian velocity distribution of atoms, the Renyi entropy coincides with the density of particles in the phase space. The optimisation procedure for cooling atoms by resonance optical radiation is described, which is based on the thermodynamic law of increasing the Renyi entropy in time. Our method is compared with the known methods for increasing the laser cooling efficiency such as the tuning of a laser frequency in time and a changemore » of the atomic transition frequency in an inhomogeneous transverse field of a magnetic solenoid. (laser cooling)« less

Optimisation of X-ray emission from a laser plasma source for the realisation of microbeam in sub-keV region.

PubMed

Di Paolo Emilio, M; Festuccia, R; Palladino, L

2015-09-01

In this work, the X-ray emission generated from a plasma produced by focusing Nd-YAG laser beam on the Mylar and Yttrium targets will be characterised. The goal is to reach the best condition that optimises the X-ray conversion efficiency at 500 eV (pre-edge of the Oxigen K-shell), strongly absorbed by carbon-based structures. The characteristics of the microbeam optical system, the software/hardware control and the preliminary measurements of the X-ray fluence will be presented. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Nuclear Structure Studies in the 132Sn Region: Safe Coulex with Carbon Targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allmond, James M; Stuchbery, Andrew E; Galindo-Uribarri, Alfredo

2015-01-01

The collective and single-particle structure of nuclei in the 132Sn region was recently studied by Coulomb excitation and heavy-ion induced transfer reactions using carbon, beryllium, and titanium targets. In particular, Coulomb excitation was used determine a complete set of electromagnetic moments for the first 2 + states and one-neutron transfer was used to probe the purity and evolution of single-neutron states. These recent experiments were conducted at the Holifield Radioactive Ion Beam Facility at ORNL using a CsI-HPGe detector array (BareBall- CLARION) to detect scattered particles and emitted gamma rays from the in-beam reactions. A Bragg-curve detector was used tomore » measure the energy loss of the various beams through the targets and to measure the radioactive beam compositions. A sample of the Coulomb excitation results is presented here with an emphasis placed on 116Sn. In particular, the safe Coulex criterion for carbon targets will be analyzed and discussed.« less

Physics with Heavy Neutron Rich Ribs at the Hribf

NASA Astrophysics Data System (ADS)

Radford, David

2002-10-01

The Holifield Radioactive Ion Beam Facility at the Oak Ridge National Laboratory has recently produced the world's first post-accelerated beams of heavy neutron-rich nuclei. B(E2;0^+ arrow 2^+) values for neutron-rich ^126,128Sn and ^132,134,136Te isotopes have been measured by Coulomb excitation of radioactive ion beams in inverse kinematics. The results for ^132Te and ^134Te (N=80,82) show excellent agreement with systematics of lighter Te isotopes, but the B(E2) value for ^136Te (N=84) is unexpectedly small. Single-neutron transfer reactions leading to ^135Te were identified using a ^134Te beam on ^natBe and ^13C targets at energies just above the Coulomb barrier. The use of the Be target provided an unambiguous signature for neutron transfer through the detection of two correlated α particles, arising from the breakup of unstable ^8Be. The results of these experiments will be discussed, togther with plans for future experiments with these heavy n-rich RIBs.

Factors affecting weld root morphology in laser keyhole welding

NASA Astrophysics Data System (ADS)

Frostevarg, Jan

2018-02-01

Welding production efficiency is usually optimised if full penetration can be achieved in a single pass. Techniques such as electron and laser beam welding offer deep high speed keyhole welding, especially since multi-kilowatt lasers became available. However, there are limitations for these techniques when considering weld imperfections such as weld cap undercuts, interior porosity or humps at the root. The thickness of sheets during full penetration welding is practically limited by these root humps. The mechanisms behind root morphology formation are not yet satisfactory understood. In this paper root humping is studied by reviewing previous studies and findings and also by sample examination and process observation by high speed imaging. Different process regimes governing root quality are presented, categorized and explained. Even though this study mainly covers laser beam and laser arc hybrid welding, the presented findings can generally be applied full penetration welding in medium to thick sheets, especially the discussion of surface tension effects. As a final result of this analysis, a map of methods to optimise weld root topology is presented.

Experimental electron beam irradiation of food and the induction of radioactivity.

PubMed

Findlay, D J; Parsons, T V; Sene, M R

1992-05-01

Samples of chicken, prawns, cheeses and spices were irradiated on the Harwell electron linear accelerator HELIOS at 20 MeV to assess mechanisms for the induction of radioactivity. The induced radioactivity was measured using a lead shielded Ge(Li) gamma-ray spectrometer, and the results were compared with activities calculated on the basis of photoneutron and photoproton reactions induced by real and virtual photons. In general, there was good agreement. Bounds were also placed on the induction of radioactivity by capture of neutrons produced in the food samples themselves. Further, the data were used to assess the effects of a gross malfunction of an electron beam irradiation facility; after 1 day, the specific activity of food samples irradiated to 10 kGy at 20 MeV was approximately 0.01 Bq g-1. In addition, food samples were also irradiated at 10 MeV, and irradiated and control samples were analysed for microbiological burden. Reductions in the microbiological burden of the food samples by factors consistent with those found in previous measurements were found.

Gamma-ray Transition Matrix Elements in ^21Na: First TIGRESS Radioactive Beam Experiment

NASA Astrophysics Data System (ADS)

Hackman, Greg

2007-04-01

Modern shell model calculations should be expected to reliably reproduce the properties of the deformed five-particle nucleus ^21Na. However the lowest-lying B(E2) value deduced from lifetime and mixing ratio measurements disagrees with models by an unacceptably large factor of two. To measure the B(E2) values directly, a beam of ^21Na at 1.7 MeV/u from the TRIUMF ISAC facility was directed upon a 0.5 mg/cm^2 ^natTi target. Gamma-ray yield in coincidence with inelastically scattered heavy ions was measured with two TIGRESS high energy- and position-resolution germanium detector units and the BAMBINO highly segmented silicon detector system. The result resolves the discrepancy between the shell model and prior measurements. This represents the first radioactive in-beam experiment with TIGRESS.

Magneto-optical trapping of potassium isotopes

NASA Astrophysics Data System (ADS)

Williamson, Robert Sylvester, III

1997-12-01

We have demonstrated a magneto-optical trap (scMOT) suitable for capturing radioactive potassium produced on- line with the UW-Madison 12MeV tandem electrostatic accelerator. To do this, we made and characterized the first scMOT for potassium, measured the potassium ultracold collision rate, and developed a numerical trap- loading rate model that makes useful quantitative predictions. We have created a cold beam of collimated potassium atoms using a pyramidal magneto-optical funnel and used it to load a long-lifetime scMOT operating at ultrahigh vacuum. We have also built a target that produces a beam of radioactive 37K and 38K and coupled it to the magneto-optical funnel and trap. Once a trap of radioactive 38K has been demonstrated, the primary goal of this project is to measure the beta-asymmetry parameter in the decay of 38K, performing a sensitive test of the Standard Model of weak interactions.

Radioactive iodine-125 implantation for cancer of the prostate.

PubMed

Nag, S

1985-01-01

Localized cancer of the prostate can be treated by radical prostatectomy, external beam irradiation, or radioactive implantation with similar survival results. Radical prostatectomy, however, almost universally results in impotency, although a new, nerve-sparing procedure may preserve potency in B1 patients. External beam irradiation radiates a large volume of tissue with significant rectal and bladder morbidity, 23-47% risk of impotency, and requires prolonged treatment (6-8 weeks). Radioactive implantation may be done suprapubically or transperineally using iodine-125, gold-198, or radon-222 permanent implantation techniques and iridium-192 or radium-226 removable implantation techniques. Interstitial iodine-125 implantation is frequently employed since it is a short procedure and limits the morbidity to a 7% incidence of impotency, 20% urinary complications, and 5% rectal complications. The overall 5-year survival of patients with iodine-125 is 79%, the survival rate decreasing with increasing T or N stage or increasing grade of tumor.

First Results with TIGRESS and Accelerated Radioactive Ion Beams from ISAC: Coulomb Excitation of 20,21,29Na

NASA Astrophysics Data System (ADS)

Schumaker, M. A.; Hurst, A. M.; Svensson, C. E.; Wu, C. Y.; Becker, J. A.; Cline, D.; Hackman, G.; Pearson, C. J.; Stoyer, M. A.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Barton, C. J.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Colosimo, S. J.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Djongolov, M.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Gray-Jones, C.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Leach, K. G.; Kulp, W. D.; Lisetskiy, A. F.; Lee, G.; Lloyd, S.; Maharaj, R.; Martin, J.-P.; Millar, B. A.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Oxley, D. C.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Rigby, S. V.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Sumithrarachchi, C. S.; Triambak, S.; Waddington, J. C.; Walker, P. M.; Wan, J.; Whitbeck, A.; Williams, S. J.; Wong, J.; Wood, J. L.

2009-03-01

The TRIUMF-ISAC Gamma-Ray Escape Suppressed Spectrometer (TIGRESS) is a state-of-the-art γ-ray spectrometer being constructed at the ISAC-II radioactive ion beam facility at TRIUMF. TIGRESS will be comprised of twelve 32-fold segmented high-purity germanium (HPGe) clover-type γ-ray detectors, with BGO/CsI(Tl) Compton-suppression shields, and is currently operational at ISAC-II in an early-implementation configuration of six detectors. Results have been obtained for the first experiments performed using TIGRESS, which examined the A = 20, 21, and 29 isotopes of Na by Coulomb excitation.

Probing the fusion of neutron-rich nuclei with re-accelerated radioactive beams

DOE PAGES

Vadas, J.; Singh, Varinderjit; Wiggins, B. B.; ...

2018-03-27

Here, we report the first measurement of the fusion excitation functions for 39,47K + 28Si at near-barrier energies. Evaporation residues resulting from the fusion process were identified by direct measurement of their energy and time-of-flight with high geometric efficiency. At the lowest incident energy, the cross section measured for the neutron-rich 47K-induced reaction is ≈6 times larger than that of the β-stable system. This experimental approach, both in measurement and in analysis, demonstrates how to efficiently measure fusion with low-intensity re-accelerated radioactive beams, establishing the framework for future studies.

Probing the fusion of neutron-rich nuclei with re-accelerated radioactive beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vadas, J.; Singh, Varinderjit; Wiggins, B. B.

Here, we report the first measurement of the fusion excitation functions for 39,47K + 28Si at near-barrier energies. Evaporation residues resulting from the fusion process were identified by direct measurement of their energy and time-of-flight with high geometric efficiency. At the lowest incident energy, the cross section measured for the neutron-rich 47K-induced reaction is ≈6 times larger than that of the β-stable system. This experimental approach, both in measurement and in analysis, demonstrates how to efficiently measure fusion with low-intensity re-accelerated radioactive beams, establishing the framework for future studies.

Nuclear reactions with 11C and 14O radioactive ion beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Fanqing

2004-01-01

Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x10 8 pps intensity onmore » target and an 14O beam of up to 3x10 4 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au( 11C,xn) 208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p( 14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p( 14N,p) 14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z = 8 proton magic number for odd Z, T z=-3/2 nuclei. It is expected that future work on proton-rich nuclides will rely heavily on RIBs and/or mass separators. Currently, radioactive ion beam intensities are sufficient for the study of a reasonable number of very proton-rich nuclides.« less

A Novel In-Beam Delayed Neutron Counting Technique for Characterization of Special Nuclear Materials

NASA Astrophysics Data System (ADS)

Bentoumi, G.; Rogge, R. B.; Andrews, M. T.; Corcoran, E. C.; Dimayuga, I.; Kelly, D. G.; Li, L.; Sur, B.

2016-12-01

A delayed neutron counting (DNC) system, where the sample to be analyzed remains stationary in a thermal neutron beam outside of the reactor, has been developed at the National Research Universal (NRU) reactor of the Canadian Nuclear Laboratories (CNL) at Chalk River. The new in-beam DNC is a novel approach for non-destructive characterization of special nuclear materials (SNM) that could enable identification and quantification of fissile isotopes within a large and shielded sample. Despite the orders of magnitude reduction in neutron flux, the in-beam DNC method can be as informative as the conventional in-core DNC for most cases while offering practical advantages and mitigated risk when dealing with large radioactive samples of unknown origin. This paper addresses (1) the qualification of in-beam DNC using a monochromatic thermal neutron beam in conjunction with a proven counting apparatus designed originally for in-core DNC, and (2) application of in-beam DNC to an examination of large sealed capsules containing unknown radioactive materials. Initial results showed that the in-beam DNC setup permits non-destructive analysis of bulky and gamma shielded samples. The method does not lend itself to trace analysis, and at best could only reveal the presence of a few milligrams of 235U via the assay of in-beam DNC total counts. Through analysis of DNC count rates, the technique could be used in combination with other neutron or gamma techniques to quantify isotopes present within samples.

Development of a radio-frequency quadrupole cooler for high beam currents

NASA Astrophysics Data System (ADS)

Boussaid, Ramzi; Ban, G.; Quéméner, G.; Merrer, Y.; Lorry, J.

2017-12-01

The SHIRaC prototype is a recently developed radio-frequency quadrupole (RFQ) beam cooler with an improved optics design to deliver the required beam quality to a high resolution separator (HRS). For an isobaric separation of isotopes, the HRS demands beams with emittance not exceeding 3 π mm mrad and longitudinal energy spread ˜1 eV . Simulation studies showed a significant contribution of the buffer gas diffusion, space charge effect and mainly the rf fringe field to degrade the achieved beam quality at the RFQ exit. A miniature rf quadrupole (μ RFQ ) has been implemented at that exit to remove the degrading effects and provide beams with 1 eV of energy spread and around 1.75 π mm mrad of emittance for 4 Pa gas pressure. This solution enables also to transmit more than 60% of the incoming ions for currents up to 1 μ A . Detailed studies of this development are presented and discussed in this paper. Transport of beams from SHIRaC towards the HRS has been done with an electrostatic quadrupole triplet. Simulations and first experimental tests showed that more than 95% of ions can reach the HRS. Because SPIRAL-2 beams are of high current and very radioactive, the buffer gas will be highly contaminated. Safe maintenance of the SHIRaC beam line needs exceptional treatment of radioactive contaminants. For that, special vinyl sleep should be mounted on elements to be maintained. A detailed maintenance process will be presented.

Experimental Studies of Light-Ion Nuclear Reactions Using Low-Energy RI Beams

NASA Astrophysics Data System (ADS)

Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Sakaguchi, Y.; Abe, K.; Shimuzu, H.; Wakabayashi, Y.; Hashimoto, T.; Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; La Cognata, M.; Lamia, L.; Romano, S.; Kubono, S.; Iwasa, N.; Teranishi, T.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.; Kato, S.; Komatsubara, T.; Coc, A.; de Sereville, N.; Hammache, F.; Kiss, G.; Bishop, S.

CRIB (CNS Radio-Isotope Beam separator) is a low-energy RI beam separator of Center for Nuclear Study (CNS), the University of Tokyo. Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the RI beams at CRIB, forming international collaborations. A striking method to study astrophyiscal reactions involving radioactive nuclei is the thick-target method in inverse kinematics. Several astrophysical alpha-induced reactions have been be studied with that method at CRIB. A recent example is on the α resonant scattering with a radioactive 7Be beam. This study is related to the astrophysical 7Be(α , γ ) reactions, important at hot p-p chain and ν p-process in supernovae. There have been measurements based on several indirect methods, such as the asymptotic normalization coefficient (ANC) and Trojan horse method (THM). The first THM measurement using an RI beam has been performed at CRIB, to study the 18F(p, α )15O reaction at astrophysical energies via the three body reaction 2H(18F, α 15O)n. The 18F(p, α )15O reaction rate is crucial to understand the 511-keV γ -ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.

Spes: An intense source of Neutron-Rich Radioactive Beams at Legnaro

NASA Astrophysics Data System (ADS)

Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Ballan, M.; Borgna, F.; D'Agostini, F.; Gramegna, F.; Prete, G.; Meneghetti, G.; Ferrari, M.; Zenoni, A.

2018-02-01

The Isotope Separation On-Line (ISOL) method for the production of Radioactive Ion Beams (RIB) is attracting significant interest in the worldwide nuclear physics community. Within this context the SPES (Selective Production of Exotic Species) RIB facility is now under construction at INFN LNL (Istituto Nazionale di Fisica Nucleare Laboratori Nazionali di Legnaro). This technique is established as one of the main techniques for high intensity and high quality beams production. The SPES facility will produce n-rich isotopes by means of a 40 MeV proton beam, emitted by a cyclotron, impinging on a uranium carbide multi-foil fission target. The aim of this work is to describe the most important results obtained by the study of the on-line behavior of the SPES production target assembly. This target system will produce RIBs at a rate of about 1013 fissions per second, it will be able to dissipate a total power of up to 10 kW, and it is planned to work continuously for 2 week-runs of irradiation. ISOL beams of 24 different elements will be produced, therefore a target and ion source development is ongoing to ensure a great variety of produced isotopes and to improve the beam intensity and purity.

Scintillator Detector Development at Central Michigan University

NASA Astrophysics Data System (ADS)

McClain, David; Estrade, Alfredo; Neupane, Shree

2017-09-01

Experimental nuclear physics relies both on the accuracy and precision of the instruments for radiation detection used in experimental setups. At Central Michigan University we have setup a lab to work with scintillator detectors for radioactive ion beam experiments, using a Picosecond Laser and radioactive sources for testing. We have tested the resolution for prototypes of large area scintillators that could be used for fast timing measurements in the focal plane of spectrometers, such as the future High Rigidity Spectrometer at the Facility for Rare Isotope Beams (FRIB). We measured the resolution as a function of the length of the detector, and also the position of the beam along the scintillator. We have also designed a scintillating detector to veto light ion background in beta-decay experiments with the Advanced Implantation Detector Array (AIDA) at RIKEN in Japan. We tested different configurations of Silicon Photomultipliers and scintillating fiber optics to find the best detection efficiency.

Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams

NASA Astrophysics Data System (ADS)

Strugalska-Gola, Elzbieta; Bielewicz, Marcin; Kilim, Stanislaw; Szuta, Marcin; Tyutyunnikov, Sergey

2017-03-01

This work was performed within the international project "Energy plus Transmutation of Radioactive Wastes" (E&T - RAW) for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89) samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this.

Coulomb excitation of radioactive 20, 21Na

NASA Astrophysics Data System (ADS)

Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.

2009-12-01

The low-energy structures of the radioactive nuclei 20, 21Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ˜ 5×106 ions/s were accelerated to 1.7MeV/A and Coulomb excited in a 0.5mg/cm^2 natTi target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for γ -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For 21Na , Coulomb excitation from the 3/2+ ground state to the first excited 5/2+ state was observed, while for 20Na , Coulomb excitation was observed from the 2+ ground state to the first excited 3+ and 4+ states. For both beams, B ( λ L) values were determined using the 2+ rightarrow 0+ de-excitation in 48Ti as a reference. The resulting B( E2) ↓ value for 21Na is 137±9 e^2fm^4, while the resulting B( λ L) ↓ values for 20Na are 55±6 e^2fm^4 for the 3+ rightarrow 2+ , 35.7±5.7 e^2 fm^4 for the 4+ rightarrow 2+ , and 0.154±0.030 μ_ N^2 for the 4+ rightarrow 3+ transitions. This analysis significantly improves the measurement of the 21Na B( E2) value, and provides the first experimental determination of B( λ L) values for the proton dripline nucleus 20Na .-1

Update on developments at SNIF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zacks, J., E-mail: jamie.zacks@ccfe.ac.uk; Turner, I.; Day, I.

The Small Negative Ion Facility (SNIF) at CCFE has been undergoing continuous development and enhancement to both improve operational reliability and increase diagnostic capability. SNIF uses a CW 13.56MHz, 5kW RF driven volume source with a 30kV triode accelerator. Improvement and characterisation work includes: Installation of a new “L” type RF matching unit, used to calculate the load on the RF generator. Use of the electron suppressing biased insert as a Langmuir probe under different beam extraction conditions. Measurement of the hydrogen Fulcher molecular spectrum, used to calculate gas temperature in the source. Beam optimisation through parameter scans, using coppermore » target plate and visible cameras, with results compared with AXCEL-INP to provide beam current estimate. Modelling of the beam power density profile on the target plate using ANSYS to estimate beam power and provide another estimate of beam current. This work is described, and has allowed an estimation of the extracted beam current of approximately 6mA (4mA/cm2) at 3.5kW RF power and a source pressure of 0.6Pa.« less

Evaluating activation of the shielding walls of a treatment room using the Monte Carlo method

NASA Astrophysics Data System (ADS)

Lee, D.-Y.; Kim, J.-H.

2018-05-01

This study investigates the radiation activation process in a medical linear accelerator, which creates a photon beam with the energy acquired from accelerated electrons. The concrete shielding walls used in conjunction with a medical linear accelerator occupy the largest portion of facility decommissioning costs. Therefore, to evaluate the activation of the shielding wall, this study simulated the operation of a linear accelerator with high-energy photon beams (10, 15, and 20 MV). The results of the simulations showed that the high-energy photon beams produced a large number of neutrons in the areas around the linear accelerator head. Several radionuclides were identified, and their half-lives and radioactivity levels were calculated. Half-lives ranged from 2.62 hours to 3.68E+06 years, and the radioactivity levels of most of the radionuclides were found to satisfy their respective clearance requirements. These results indicate that photon beams of 15 MV or lower satisfy the clearance requirements for decommissioning a linear accelerator facility, whereas those of 20 MV or higher lie partially above the regulatory clearance levels.

A beam radiation monitor based on CVD diamonds for SuperB

NASA Astrophysics Data System (ADS)

Cardarelli, R.; Di Ciaccio, A.

2013-08-01

Chemical Vapor Deposition (CVD) diamond particle detectors are in use in the CERN experiments at LHC and at particle accelerator laboratories in Europe, USA and Japan mainly as beam monitors. Nowadays it is considered a proven technology with a very fast signal read-out and a very high radiation tolerance suitable for measurements in high radiation environment zones i.e. near the accelerators beam pipes. The specific properties of CVD diamonds make them a prime candidate for measuring single particles as well as high-intensity particle cascades, for timing measurements on the sub-nanosecond scale and for beam protection systems in hostile environments. A single-crystalline CVD (scCVD) diamond sensor, read out with a new generation of fast and high transition frequency SiGe bipolar transistor amplifiers, has been tested for an application as radiation monitor to safeguard the silicon vertex tracker in the SuperB detector from excessive radiation damage, cumulative dose and instantaneous dose rates. Test results with 5.5 MeV alpha particles from a 241Am radioactive source and from electrons from a 90Sr radioactive source are presented in this paper.

Non-perturbative measurement of low-intensity charged particle beams

NASA Astrophysics Data System (ADS)

Fernandes, M.; Geithner, R.; Golm, J.; Neubert, R.; Schwickert, M.; Stöhlker, T.; Tan, J.; Welsch, C. P.

2017-01-01

Non-perturbative measurements of low-intensity charged particle beams are particularly challenging to beam diagnostics due to the low amplitude of the induced electromagnetic fields. In the low-energy antiproton decelerator (AD) and the future extra low energy antiproton rings at CERN, an absolute measurement of the beam intensity is essential to monitor the operation efficiency. Superconducting quantum interference device (SQUID) based cryogenic current comparators (CCC) have been used for measuring slow charged beams in the nA range, showing a very good current resolution. But these were unable to measure fast bunched beams, due to the slew-rate limitation of SQUID devices and presented a strong susceptibility to external perturbations. Here, we present a CCC system developed for the AD machine, which was optimised in terms of its current resolution, system stability, ability to cope with short bunched beams, and immunity to mechanical vibrations. This paper presents the monitor design and the first results from measurements with a low energy antiproton beam obtained in the AD in 2015. These are the first CCC beam current measurements ever performed in a synchrotron machine with both coasting and short bunched beams. It is shown that the system is able to stably measure the AD beam throughout the entire cycle, with a current resolution of 30 {nA}.

The use of aluminum nitride to improve Aluminum-26 Accelerator Mass Spectrometry measurements and production of Radioactive Ion Beams

NASA Astrophysics Data System (ADS)

Janzen, Meghan S.; Galindo-Uribarri, Alfredo; Liu, Yuan; Mills, Gerald D.; Romero-Romero, Elisa; Stracener, Daniel W.

2015-10-01

We present results and discuss the use of aluminum nitride as a promising source material for Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beams (RIBs) science applications of 26Al isotopes. The measurement of 26Al in geological samples by AMS is typically conducted on Al2O3 targets. However, Al2O3 is not an ideal source material because it does not form a prolific beam of Al- required for measuring low-levels of 26Al. Multiple samples of aluminum oxide (Al2O3), aluminum nitride (AlN), mixed Al2O3-AlN as well as aluminum fluoride (AlF3) were tested and compared using the ion source test facility and the stable ion beam (SIB) injector platform at the 25-MV tandem electrostatic accelerator at Oak Ridge National Laboratory. Negative ion currents of atomic and molecular aluminum were examined for each source material. It was found that pure AlN targets produced substantially higher beam currents than the other materials and that there was some dependence on the exposure of AlN to air. The applicability of using AlN as a source material for geological samples was explored by preparing quartz samples as Al2O3 and converting them to AlN using a carbothermal reduction technique, which involved reducing the Al2O3 with graphite powder at 1600 °C within a nitrogen atmosphere. The quartz material was successfully converted to AlN. Thus far, AlN proves to be a promising source material and could lead towards increasing the sensitivity of low-level 26Al AMS measurements. The potential of using AlN as a source material for nuclear physics is also very promising by placing 26AlN directly into a source to produce more intense radioactive beams of 26Al.

The use of aluminum nitride to improve Aluminum-26 Accelerator Mass Spectrometry measurements and production of Radioactive Ion Beams

DOE PAGES

Janzen, Meghan S.; Galindo-Uribarri, Alfredo; Liu, Yuan; ...

2015-06-29

In this paper, we present results and discuss the use of aluminum nitride as a promising source material for Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beams (RIBs) science applications of 26Al isotopes. The measurement of 26Al in geological samples by AMS is typically conducted on Al 2O 3 targets. However, Al 2O 3 is not an ideal source material because it does not form a prolific beam of Al - required for measuring low-levels of 26Al. Multiple samples of aluminum oxide (Al 2O 3), aluminum nitride (AlN), mixed Al 2O 3–AlN as well as aluminum fluoride (AlF 3) weremore » tested and compared using the ion source test facility and the stable ion beam (SIB) injector platform at the 25-MV tandem electrostatic accelerator at Oak Ridge National Laboratory. Negative ion currents of atomic and molecular aluminum were examined for each source material. It was found that pure AlN targets produced substantially higher beam currents than the other materials and that there was some dependence on the exposure of AlN to air. The applicability of using AlN as a source material for geological samples was explored by preparing quartz samples as Al 2O 3 and converting them to AlN using a carbothermal reduction technique, which involved reducing the Al 2O 3 with graphite powder at 1600°C within a nitrogen atmosphere. The quartz material was successfully converted to AlN. Thus far, AlN proves to be a promising source material and could lead towards increasing the sensitivity of low-level 26Al AMS measurements. In conclusion, the potential of using AlN as a source material for nuclear physics is also very promising by placing 26AlN directly into a source to produce more intense radioactive beams of 26Al.« less

Atomic mass measurements with radioactive beams and/or targets: Where to start

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.

1989-01-01

Radioactive beams or radioactive targets (or both) can significantly increase the yields of exotic isotopes, allowing studies to be performed in regions which are currently inaccessible. An important goal to pursue with these exotic species is a broad program of nuclidic mass measurements. This is motivated by the observation that mass model predictions generally diverge from one another in regions far from beta-decay stability where well measured masses are sparse or nonexistent. Stringent tests of mass models are therefore possible and these can highlight important features in the mass models that affect the quality of their short-range and long-range extrapolationmore » properties. Selection of systems to study can be guided, in part, by a desire to probe those regions where distinctions among mass models are most apparent and where exotic isotope yields will be optimal. Several examples will be presented to highlight future opportunities in this area. 10 refs., 5 figs.« less

Updating irradiated graphite disposal: Project 'GRAPA' and the international decommissioning network.

PubMed

Wickham, Anthony; Steinmetz, Hans-Jürgen; O'Sullivan, Patrick; Ojovan, Michael I

2017-05-01

Demonstrating competence in planning and executing the disposal of radioactive wastes is a key factor in the public perception of the nuclear power industry and must be demonstrated when making the case for new nuclear build. This work addresses the particular waste stream of irradiated graphite, mostly derived from reactor moderators and amounting to more than 250,000 tonnes world-wide. Use may be made of its unique chemical and physical properties to consider possible processing and disposal options outside the normal simple classifications and repository options for mixed low or intermediate-level wastes. The IAEA has an obvious involvement in radioactive waste disposal and has established a new project 'GRAPA' - Irradiated Graphite Processing Approaches - to encourage an international debate and collaborative work aimed at optimising and facilitating the treatment of irradiated graphite. Copyright © 2017 Elsevier Ltd. All rights reserved.

Status of nanofabrication at King's College, London

NASA Astrophysics Data System (ADS)

Charalambous, P.

2003-03-01

Since the last X-ray microscopy conference (Berkeley, 1999) we have made considerable progress in all aspects of nanofabrication and more specifically on further optimisation of various aspects of Zone Plate construction and quality control. Here we report on some of these areas of improvement, as well as some of the more interesting ZPs fabricated recently and deployed at various beam lines world wide.

Fusion cross sections measurements with MUSIC

NASA Astrophysics Data System (ADS)

Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

2014-09-01

The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

Improving the efficiency of optical coherence tomography by using the non-ideal behaviour of a polarising beam splitter.

PubMed

Lippok, Norman; Nielsen, Poul; Vanholsbeeck, Frédérique

2011-04-11

We present a new way of improving the efficiency of optical coherence tomography by using the polarisation crosstalk of a polarising beam splitter to direct most of the available source optical power to the sample. The use of a quarter wave plate in both the reference and the sample arms allows most of the sample power to be directed to the detector while adjusting the reference arm to ensure noise optimised operation. As a result, the sensitivity of such a system can be improved by 6 dB, or alternatively the acquisition time can be improved by a factor of 4 for shot noise limited performance,compared to a traditional OCT configuration using a 50/50 beam splitter. © 2011 Optical Society of America

The Neutrons for Science Facility at SPIRAL-2

NASA Astrophysics Data System (ADS)

Ledoux, X.; Aïche, M.; Avrigeanu, M.; Avrigeanu, V.; Audouin, L.; Balanzat, E.; Ban-détat, B.; Ban, G.; Barreau, G.; Bauge, E.; Bélier, G.; Bem, P.; Blideanu, V.; Borcea, C.; Bouffard, S.; Caillaud, T.; Chatillon, A.; Czajkowski, S.; Dessagne, P.; Doré, D.; Fallot, M.; Farget, F.; Fischer, U.; Giot, L.; Granier, T.; Guillous, S.; Gunsing, F.; Gustavsson, C.; Jacquot, B.; Jansson, K.; Jurado, B.; Kerveno, M.; Klix, A.; Landoas, O.; Lecolley, F. R.; Lecouey, J. L.; Majerle, M.; Marie, N.; Materna, T.; Mrazek, J.; Negoita, F.; Novak, J.; Oberstedt, S.; Oberstedt, A.; Panebianco, S.; Perrot, L.; Plompen, A. J. M.; Pomp, S.; Ramillon, J. M.; Ridikas, D.; Rossé, B.; Rudolf, G.; Serot, O.; Simakov, S. P.; Simeckova, E.; Smith, A. G.; Sublet, J. C.; Taieb, J.; Tassan-Got, L.; Tarrio, D.; Takibayev, A.; Thfoin, I.; Tsekhanovich, I.; Varignon, C.

2014-05-01

The Neutrons For Science (NFS) facility is a component of SPIRAL-2 laboratory under construction at Caen (France). SPIRAL-2 is dedicated to the production of high intensity Radioactive Ions Beams (RIB). It is based on a high-power linear accelerator (LINAG) to accelerate deuterons beams in order to produce neutrons by breakup reactions on a C converter. These neutrons will induce fission in 238U for production of radioactive isotopes. Additionally to the RIB production, the proton and deuteron beams delivered by the accelerator will be used in the NFS facility. NFS is composed of a pulsed neutron beam and irradiation stations for cross-section measurements and material studies. The beams delivered by the LINAG will allow producing intense neutron beams in the 100 keV-40 MeV energy range with either a continuous or quasi-mono-energetic spectrum. At NFS available average fluxes will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV - 40 MeV range. NFS will be a very powerful tool for fundamental physics and application related research in support of the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. The facility and its characteristics are described, and several examples of the first potential experiments are presented.

First results of Trojan horse method using radioactive ion beams: {sup 18}F(p,α) at astrophysical energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherubini, S.; Spitaleri, C.; Puglia, S.

2014-05-02

The abundance of {sup 18}F in Nova explosions is considered to be an important piece of information for the understanding of this astrophysical phenomenon. It is then necessary to study the nuclear processess that both produce and destroy this isotope in Novae. Among these latter reactions, the {sup 18}F(p,α){sup 15}O is one of the most important {sup 18}F destruction channels. Here we report on an experiment performed using the CRIB apparatus of the Center for Nuclear Study of the University of Tokyo. This was the first experiment that used the Trojan Horse method applied to a Radioactive Ion Beam inducedmore » reaction.« less

The Research Program at RIBRAS (Radioactive Ion Beams in Brasil)-III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtenthaeler, R.; Lepine-Szily, A.; Guimaraes, V.

A part of the research program developed in the RIBRAS facility over the last four years is presented. Experiments using radioactive secondary beams of light exotic nuclei such as {sup 6}He, {sup 7}Be, {sup 8}Li on several targets have been performed. Elastic angular distributions have been analysed by the Optical Model and four body Continuous Discretized Coupled Channels Calculations (4b-CDCC) and the total reaction cross sections have been obtained. A comparison between the reaction cross sections of {sup 6}He and other stable projectiles with medium-heavy targets was performed. Measurements of the proton transfer reaction {sup 12}C({sup 8}Li,{sup 9}Be){sup 11}B aremore » also presented.« less

A singly charged ion source for radioactive {sup 11}C ion acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katagiri, K.; Noda, A.; Nagatsu, K.

2016-02-15

A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive {sup 11}C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source wasmore » found to have favorable performance as a singly charged ion source.« less

Future carbon beams at SPIRAL1 facility: Which method is the most efficient?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maunoury, L., E-mail: maunoury@ganil.fr; Delahaye, P.; Dubois, M.

2014-02-15

Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P.more » Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO{sub 2}), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.« less

Future carbon beams at SPIRAL1 facility: Which method is the most efficient?

NASA Astrophysics Data System (ADS)

Maunoury, L.; Delahaye, P.; Angot, J.; Dubois, M.; Dupuis, M.; Frigot, R.; Grinyer, J.; Jardin, P.; Leboucher, C.; Lamy, T.

2014-02-01

Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P. Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO2), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.

Future carbon beams at SPIRAL1 facility: which method is the most efficient?

PubMed

Maunoury, L; Delahaye, P; Angot, J; Dubois, M; Dupuis, M; Frigot, R; Grinyer, J; Jardin, P; Leboucher, C; Lamy, T

2014-02-01

Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P. Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO2), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.

Intermediate quality control tests in the development of a superconducting RF cryomodule for CW operation

NASA Astrophysics Data System (ADS)

Pattalwar, Shrikant; Jones, Thomas; Strachan, John; Bate, Robert; Davies, Phil; McIntosh, Peter

2012-06-01

Through an international cryomodule collaboration, ASTeC at Daresbury Laboratory has taken the primary responsibility in leading the development of an optimised Superconducting RF (SRF) cryomodule, operating in CW mode for energy recovery facilities and other high duty cycle accelerators. For high beam current operation, Higher Order Mode (HOM) absorbers are critical components of the SRF Cryomodule, ensuring excessive heating of the accelerating structures and beam instabilities are effectively managed. This paper describes some of the cold tests conducted on the HOM absorbers and other critical components during the construction phase, to ensure that the quality and reliable cryomodule performance is maintained.

Optimising the Active Muon Shield for the SHiP Experiment at CERN

NASA Astrophysics Data System (ADS)

Baranov, A.; Burnaev, E.; Derkach, D.; Filatov, A.; Klyuchnikov, N.; Lantwin, O.; Ratnikov, F.; Ustyuzhanin, A.; Zaitsev, A.

2017-12-01

The SHiP experiment is designed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. The critical challenge for this experiment is to keep the Standard Model background level negligible. In the beam dump, around 1011 muons will be produced per second. The muon rate in the spectrometer has to be reduced by at least four orders of magnitude to avoid muoninduced backgrounds. It is demonstrated that new improved active muon shield may be used to magnetically deflect the muons out of the acceptance of the spectrometer.

Understanding Release from Actinide Targets -- Recent Results from RIB Development

NASA Astrophysics Data System (ADS)

Kronenberg, Andreas; Carter, H. K.; Spejewski, E. H.; Stracener, D. W.

2006-10-01

Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. The Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory uses the ISOL (Isotope Separation Online) technique to provide radioactive ion beams. So far, uranium carbide has been used as a target to produce neutron-rich fission fragments. Thermodynamic calculations indicate the possibility of in-situ chemical side band formations of volatile species of refractory metals, such as V and Re. These elements release out of oxide targets after production in a nuclear reaction, and can occur only through in-situ formation of their volatile oxide. These have been confirmed experimentally. The results from recent, more detailed investigations of ThO2, UB4 and other actinide targets as well as conclusions from systematic studies will be presented. This research was sponsored by the NNSA under Stewardship Science Academic Alliance program through DOE Cooperative Agreement # DE-FC03-3NA00143.

The drift chamber array at the external target facility in HIRFL-CSR

NASA Astrophysics Data System (ADS)

Sun, Y. Z.; Sun, Z. Y.; Wang, S. T.; Duan, L. M.; Sun, Y.; Yan, D.; Tang, S. W.; Yang, H. R.; Lu, C. G.; Ma, P.; Yu, Y. H.; Zhang, X. H.; Yue, K.; Fang, F.; Su, H.

2018-06-01

A drift chamber array at the External Target Facility in HIRFL-CSR has been constructed for three-dimensional particle tracking in high-energy radioactive ion beam experiments. The design, readout, track reconstruction program and calibration procedures for the detector are described. The drift chamber array was tested in a 311 AMeV 40Ar beam experiment. The detector performance based on the measurements of the beam test is presented. A spatial resolution of 230 μm is achieved.

Recent Results from ISOLDE and HIE-ISOLDE

NASA Astrophysics Data System (ADS)

Borge, María J. G.

2018-02-01

ISOLDE is the CERN facility dedicated to the production of rare ion beams for many different experiments in the fields of nuclear and atomic physics, materials science and life sciences. The HIE-ISOLDE, Higher Intensity and Energy upgrade has finished its stage 1 dedicated to upgrade the energy up to 5.5 MeV/u, producing the first radioactive beams with this energy in September 9th 2016. Recent results from the low energy and post-accelerated beams are given in this contribution.

Recent optimization of the beam-optical characteristics of the 6 MV van de Graaff accelerator for high brightness beams at the iThemba LABS NMP facility

NASA Astrophysics Data System (ADS)

Conradie, J. L.; Eisa, M. E. M.; Celliers, P. J.; Delsink, J. L. G.; Fourie, D. T.; de Villiers, J. G.; Maine, P. M.; Springhorn, K. A.; Pineda-Vargas, C. A.

2005-04-01

With the aim of improving the reliability and stability of the beams delivered to the nuclear microprobe at iThemba LABS, as well as optimization of the beam characteristics along the van de Graaff accelerator beamlines in general, relevant modifications were implemented since the beginning of 2003. The design and layout of the beamlines were revised. The beam-optical characteristics through the accelerator, from the ion source up to the analysing magnet directly after the accelerator, were calculated and the design optimised, using the computer codes TRANSPORT, IGUN and TOSCA. The ion source characteristics and optimal operating conditions were determined on an ion source test bench. The measured optimal emittance for 90% of the beam intensity was about 50π mm mrad for an extraction voltage of 6 kV. These changes allow operation of the Nuclear Microprobe at proton energies in the range 1 MeV-4 MeV with beam intensities of tenths of a pA at the target surface. The capabilities of the nuclear microprobe facility were evaluated in the improved beamline, with particular emphasis to bio-medical samples.

Induced Radioactivity in Lead Shielding at the National Synchrotron Light Source

DOE PAGES

Ghosh, Vinita J.; Schaefer, Charles; Kahnhauser, Henry

2017-06-30

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was shut down in September 2014. Lead bricks used as radiological shadow shielding within the accelerator were exposed to stray radiation fields during normal operations. The FLUKA code, a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter, was used to estimate induced radioactivity in this shielding and stainless steel beam pipe from known beam losses. The FLUKA output was processed using MICROSHIELD® to estimate on-contact exposure rates with individually exposed bricks to help design and optimize the radiological survey process. Thismore » entire process can be modeled using FLUKA, but use of MICROSHIELD® as a secondary method was chosen because of the project’s resource constraints. Due to the compressed schedule and lack of shielding configuration data, simple FLUKA models were developed in this paper. FLUKA activity estimates for stainless steel were compared with sampling data to validate results, which show that simple FLUKA models and irradiation geometries can be used to predict radioactivity inventories accurately in exposed materials. During decommissioning 0.1% of the lead bricks were found to have measurable levels of induced radioactivity. Finally, post-processing with MICROSHIELD® provides an acceptable secondary method of estimating residual exposure rates.« less

Induced Radioactivity in Lead Shielding at the National Synchrotron Light Source.

PubMed

Ghosh, Vinita J; Schaefer, Charles; Kahnhauser, Henry

2017-06-01

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was shut down in September 2014. Lead bricks used as radiological shadow shielding within the accelerator were exposed to stray radiation fields during normal operations. The FLUKA code, a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter, was used to estimate induced radioactivity in this shielding and stainless steel beam pipe from known beam losses. The FLUKA output was processed using MICROSHIELD® to estimate on-contact exposure rates with individually exposed bricks to help design and optimize the radiological survey process. This entire process can be modeled using FLUKA, but use of MICROSHIELD® as a secondary method was chosen because of the project's resource constraints. Due to the compressed schedule and lack of shielding configuration data, simple FLUKA models were developed. FLUKA activity estimates for stainless steel were compared with sampling data to validate results, which show that simple FLUKA models and irradiation geometries can be used to predict radioactivity inventories accurately in exposed materials. During decommissioning 0.1% of the lead bricks were found to have measurable levels of induced radioactivity. Post-processing with MICROSHIELD® provides an acceptable secondary method of estimating residual exposure rates.

Recent Direct Reaction Experimental Studies with Radioactive Tin Beams

DOE PAGES

Jones, K. L.; Ahn, S.; Allmond, J. M.; ...

2015-01-01

Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine (ISOL) method. Some of the most interesting regions to study with direct reactions are close to the magic numbers where changes in shell structure can be tracked. These changes can impact the final abundances of explosive nucleosynthesis. The structure of the chain of tin isotopes is strongly influenced by the Z = 50 proton shell closure, as well as the neutron shell closures lying in the neutron-rich, Nmore » = 82, and neutron-deficient, N = 50, regions. Here, we present two examples of direct reactions on exotic tin isotopes. The first uses a one-neutron transfer reaction and a low-energy reaccelerated ISOL beam to study states in Sn-131 from across the N = 82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient Sn- 106,108Sn. In conclusion, In both cases, measurements of γ rays in coincidence with charged particles proved to be invaluable.« less

DOSE AND GAMMA-RAY SPECTRA FROM NEUTRON-INDUCED RADIOACTIVITY IN MEDICAL LINEAR ACCELERATORS FOLLOWING HIGH-ENERGY TOTAL BODY IRRADIATION.

PubMed

Keehan, S; Taylor, M L; Smith, R L; Dunn, L; Kron, T; Franich, R D

2016-12-01

Production of radioisotopes in medical linear accelerators (linacs) is of concern when the beam energy exceeds the threshold for the photonuclear interaction. Staff and patients may receive a radiation dose as a result of the induced radioactivity in the linac. Gamma-ray spectroscopy was used to identify the isotopes produced following the delivery of 18 MV photon beams from a Varian 21EX and an Elekta Synergy. The prominent radioisotopes produced include 187 W, 63 Zn, 56 Mn, 24 Na and 28 Al in both linac models. The dose rate was measured at the beam exit window (12.6 µSv in the first 10 min) following 18 MV total body irradiation (TBI) beams. For a throughput of 24 TBI patients per year, staff members are estimated to receive an annual dose of up to 750 μSv at the patient location. This can be further reduced to 65 μSv by closing the jaws before re-entering the treatment bunker. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Direct nuclear reaction experiments for stellar nucleosynthesis

NASA Astrophysics Data System (ADS)

Cherubini, S.

2017-09-01

During the last two decades indirect methods where proposed and used in many experiments in order to measure nuclear cross sections between charged particles at stellar energies. These are among the lowest to be measured in nuclear physics. One of these methods, the Trojan Horse method, is based on the Quasi-Free reaction mechanism and has proved to be particularly flexible and reliable. It allowed for the measurement of the cross sections of various reactions of astrophysical interest using stable beams. The use and reliability of indirect methods become even more important when reactions induced by Radioactive Ion Beams are considered, given the much lower intensity generally available for these beams. The first Trojan Horse measurement of a process involving the use of a Radioactive Ion Beam dealt with the ^{18} F(p, α ^{15} O process in Nova conditions. To obtain pieces of information on this process, in particular about its cross section at Nova energies, the Trojan Horse method was applied to the ^{18} F(d, α ^{15} O)n three body reaction. In order to establish the reliability of the Trojan Horse method approach, the Treiman-Yang criterion is an important test and it will be addressed briefly in this paper.

Measurements and PHITS Monte Carlo Estimations of Residual Activities Induced by the 181 MeV Proton Beam in the Injection Area at J-PARC RCS Ring

NASA Astrophysics Data System (ADS)

Yamakawa, Emi; Yoshimoto, Masahiro; Kinsho, Michikazu

At the injection area of the RCS ring in the J-PARC, residual gamma dose at the rectangular ceramic ducts, especially immediately downstream of the charge-exchanged foil, has increased with the output beam power. In order to investigate the cause of high residual activities, residual gamma dose and radioactive sources produced at the exterior surface of the ducts have been measured by a GM survey meter and a handy type of Germanium (Ge) semiconductor detector in the case of 181 MeV injected proton beam energy. With these measurements, it is revealed that the radioactive sources produced by nuclear reactions cause the high activities at the injection area. For a better understanding of phenomena in the injection area, various simulations have been done with the PHITS Monte Carlo code. The distribution of radioactive sources and residual gamma dose rate obtained by the calculations are consistent with the measurement results. With this consistency, secondary neutrons and protons derived from nuclear reactions at the charge-exchanged foil are the dominant cause to high residual gamma dose at the ceramic ducts in the injection area. These measurements and calculations are unique approaches to reveal the cause of high residual dose around the foil. This study is essential for the future of high-intensity proton accelerators using a stripping foil.

Electron-beam-driven RI separator for SCRIT (ERIS) at RIKEN RI beam factory

NASA Astrophysics Data System (ADS)

Ohnishi, T.; Ichikawa, S.; Koizumi, K.; Kurita, K.; Miyashita, Y.; Ogawara, R.; Tamaki, S.; Togasaki, M.; Wakasugi, M.

2013-12-01

We constructed a radioactive isotope (RI) separator named ERIS (electron-beam-driven RI separator for SCRIT) for the SCRIT (Self-Confinement RI Target) electron scattering facility at RIKEN RI Beam Factory (RIBF). In ERIS, production rate of fission products in the photofission of uranium is estimated to be 2.2 ×1011 fissions/s with 30 g of uranium and a 1-kW electron beam. During the commissioning of ERIS, the mass resolution and overall efficiency, including ionization, extraction, and transmission, were found to be 1660 and 21%, respectively, using natural xenon gas. The preparation of uranium carbide (UC2) RI production targets is described from which a 132Sn beam was successfully separated in our first attempt at RI production.

Accelerated radiation damage test facility using a 5 MV tandem ion accelerator

NASA Astrophysics Data System (ADS)

Wady, P. T.; Draude, A.; Shubeita, S. M.; Smith, A. D.; Mason, N.; Pimblott, S. M.; Jimenez-Melero, E.

2016-01-01

We have developed a new irradiation facility that allows to perform accelerated damage tests of nuclear reactor materials at temperatures up to 400 °C using the intense proton (<100 μA) and heavy ion (≈10 μA) beams produced by a 5 MV tandem ion accelerator. The dedicated beam line for radiation damage studies comprises: (1) beam diagnosis and focusing optical components, (2) a scanning and slit system that allows uniform irradiation of a sample area of 0.5-6 cm2, and (3) a sample stage designed to be able to monitor in-situ the sample temperature, current deposited on the sample, and the gamma spectrum of potential radio-active nuclides produced during the sample irradiation. The beam line capabilities have been tested by irradiating a 20Cr-25Ni-Nb stabilised stainless steel with a 3 MeV proton beam to a dose level of 3 dpa. The irradiation temperature was 356 °C, with a maximum range in temperature values of ±6 °C within the first 24 h of continuous irradiation. The sample stage is connected to ground through an electrometer to measure accurately the charge deposited on the sample. The charge can be integrated in hardware during irradiation, and this methodology removes uncertainties due to fluctuations in beam current. The measured gamma spectrum allowed the identification of the main radioactive nuclides produced during the proton bombardment from the lifetimes and gamma emissions. This dedicated radiation damage beam line is hosted by the Dalton Cumbrian Facility of the University of Manchester.

The SPES surface ionization source

NASA Astrophysics Data System (ADS)

Manzolaro, M.; D'Agostini, F.; Monetti, A.; Andrighetto, A.

2017-09-01

Ion sources and target systems play a crucial role in isotope separation on line facilities, determining the main characteristics of the radioactive ion beams available for experiments. In the context of the selective production of exotic species (SPES) facility, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The radioactive isotopes produced by the 238U fissions are delivered to the 1+ ion source by means of a tubular transfer line. Here they can be ionized and subsequently accelerated toward the experimental areas. In this work, the characterization of the surface ionization source currently adopted for the SPES facility is presented, taking as a reference ionization efficiency and transversal emittance measurements. The effects of long term operation at high temperature are also illustrated and discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Ashutosh, E-mail: asingh.rs.ece@iitbhu.ac.in; Center of Research in Microwave Tubes, Department of Electronics Engineering, Indian Institute of Technology; Jain, P. K.

In this paper, the effects of electron beam parameters and velocity spread on the RF behavior of a metallic photonic band gap (PBG) cavity gyrotron operating at 35 GHz with TE{sub 041}–like mode have been theoretically demonstrated. PBG cavity is used here to achieve a single mode operation of the overmoded cavity. The nonlinear time-dependent multimode analysis has been used to observe the beam-wave interaction behavior of the PBG cavity gyrotron, and a commercially available PIC code “CST Particle Studio” has been reconfigured to obtain 3D simulation results in order to validate the analytical values. The output power for this typicalmore » PBG gyrotron has been obtained ∼108 kW with ∼15.5% efficiency in a well confined TE{sub 041}–like mode, while all other competing modes have significantly low values of power output. The output power and efficiency of a gyrotron depend highly on the electron beam parameters and velocity spread. The influence of several electron beam parameters, e.g., beam voltage, beam current, beam velocity pitch factor, and DC magnetic field, on the PBG gyrotron operations has been investigated. This study would be helpful in optimising the electron beam parameters and estimating accurate RF output power of the high frequency PBG cavity based gyrotron oscillators.« less

Application of snakes and dynamic programming optimisation technique in modeling of buildings in informal settlement areas

NASA Astrophysics Data System (ADS)

Rüther, Heinz; Martine, Hagai M.; Mtalo, E. G.

This paper presents a novel approach to semiautomatic building extraction in informal settlement areas from aerial photographs. The proposed approach uses a strategy of delineating buildings by optimising their approximate building contour position. Approximate building contours are derived automatically by locating elevation blobs in digital surface models. Building extraction is then effected by means of the snakes algorithm and the dynamic programming optimisation technique. With dynamic programming, the building contour optimisation problem is realized through a discrete multistage process and solved by the "time-delayed" algorithm, as developed in this work. The proposed building extraction approach is a semiautomatic process, with user-controlled operations linking fully automated subprocesses. Inputs into the proposed building extraction system are ortho-images and digital surface models, the latter being generated through image matching techniques. Buildings are modeled as "lumps" or elevation blobs in digital surface models, which are derived by altimetric thresholding of digital surface models. Initial windows for building extraction are provided by projecting the elevation blobs centre points onto an ortho-image. In the next step, approximate building contours are extracted from the ortho-image by region growing constrained by edges. Approximate building contours thus derived are inputs into the dynamic programming optimisation process in which final building contours are established. The proposed system is tested on two study areas: Marconi Beam in Cape Town, South Africa, and Manzese in Dar es Salaam, Tanzania. Sixty percent of buildings in the study areas have been extracted and verified and it is concluded that the proposed approach contributes meaningfully to the extraction of buildings in moderately complex and crowded informal settlement areas.

Sampling design optimisation for rainfall prediction using a non-stationary geostatistical model

NASA Astrophysics Data System (ADS)

Wadoux, Alexandre M. J.-C.; Brus, Dick J.; Rico-Ramirez, Miguel A.; Heuvelink, Gerard B. M.

2017-09-01

The accuracy of spatial predictions of rainfall by merging rain-gauge and radar data is partly determined by the sampling design of the rain-gauge network. Optimising the locations of the rain-gauges may increase the accuracy of the predictions. Existing spatial sampling design optimisation methods are based on minimisation of the spatially averaged prediction error variance under the assumption of intrinsic stationarity. Over the past years, substantial progress has been made to deal with non-stationary spatial processes in kriging. Various well-documented geostatistical models relax the assumption of stationarity in the mean, while recent studies show the importance of considering non-stationarity in the variance for environmental processes occurring in complex landscapes. We optimised the sampling locations of rain-gauges using an extension of the Kriging with External Drift (KED) model for prediction of rainfall fields. The model incorporates both non-stationarity in the mean and in the variance, which are modelled as functions of external covariates such as radar imagery, distance to radar station and radar beam blockage. Spatial predictions are made repeatedly over time, each time recalibrating the model. The space-time averaged KED variance was minimised by Spatial Simulated Annealing (SSA). The methodology was tested using a case study predicting daily rainfall in the north of England for a one-year period. Results show that (i) the proposed non-stationary variance model outperforms the stationary variance model, and (ii) a small but significant decrease of the rainfall prediction error variance is obtained with the optimised rain-gauge network. In particular, it pays off to place rain-gauges at locations where the radar imagery is inaccurate, while keeping the distribution over the study area sufficiently uniform.

Influence of heat input in electron beam process on microstructure and properties of duplex stainless steel welded interface

NASA Astrophysics Data System (ADS)

Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Zhao, Lei; Lv, Xiaoqing; Zhang, Jianyang

2018-03-01

The influence of heat input in electron beam (EB) process on microstructure, mechanical properties, and pitting corrosion resistance of duplex stainless steel (DSS) welded interface was investigated. The rapid cooling in EB welding resulted in insufficient austenite formation. The austenite mainly consisted of grain boundary austenite and intragranular austenite, and there was abundant Cr2N precipitation in the ferrite. The Ni, Mo, and Si segregation indicated that the dendritic solidification was primarily ferrite in the weld. The weld exhibited higher hardness, lower toughness, and poorer pitting corrosion resistance than the base metal. The impact fractures of the welds were dominated by the transgranular cleavage failure of the ferrite. The ferrite was selectively attacked because of its lower pitting resistance equivalent number than that of austenite. The Cr2N precipitation accelerated the pitting corrosion. In summary, the optimised heat input slightly increased the austenite content, reduced the segregation degree and ferrite texture intensity, decreased the hardness, and improved the toughness and pitting corrosion resistance. However, the effects were limited. Furthermore, optimising the heat input could not suppress the Cr2N precipitation. Taking into full consideration the microstructure and properties, a heat input of 0.46 kJ/mm is recommended for the EB welding of DSS.

Development of an Optimised Application Protocol For Sonophoretic Transdermal Delivery of a Model Hydrophilic Drug

PubMed Central

Sarheed, Omar; Abdul Rasool, Bazigha K

2011-01-01

It has now been known for over a decade that low frequency ultrasound can be used to effectively enhance transdermal drug penetration - an approach termed sonophoresis. Mechanistically, acoustic cavitation results in the creation of defects in the stratum corneum that allow accelerated absorption of topically applied molecules. The aim of this study was to develop an optimised sonophoresis protocol for studying transdermal drug delivery in vitro. To this end, caffeine was selected as a model hydrophilic drug while porcine skin was used as a model barrier. Following acoustic validation, 20kHz ultrasound was applied for different durations (range: 5 s to 10 min) using three different modes (10%, 33% or 100% duty cycles) and two distinct sonication procedures (either before or concurrent with drug deposition). Each ultrasonic protocol was assessed in terms of its heating and caffeine flux-enhancing effects. It was found that the best regimen was a concurrent 5 min, pulsed (10% duty cycle) beam of SATA intensity 0.37 W/cm2. A key insight was that in the case of pulsed beams of 10% duty cycle, sonication concurrent with drug deposition was superior to sonication prior to drug deposition and potential mechanisms for this are discussed. PMID:21629673

A high repetition rate transverse beam profile diagnostic for laser-plasma proton sources

NASA Astrophysics Data System (ADS)

Dover, Nicholas; Nishiuchi, Mamiko; Sakaki, Hironao; Kando, Masaki; Nishitani, Keita

2016-10-01

The recently upgraded J-KAREN-P laser can provide PW peak power and intensities approaching 1022 Wcm-2 at 0.1 Hz. Scaling of sheath acceleration to such high intensities predicts generation of protons to near 100 MeV, but changes in electron heating mechanisms may affect the emitted proton beam properties, such as divergence and pointing. High repetition rate simultaneous measurement of the transverse proton distribution and energy spectrum are therefore key to understanding and optimising the source. Recently plastic scintillators have been used to measure online proton beam transverse profiles, removing the need for time consuming post-processing. We are therefore developing a scintillator based transverse proton beam profile diagnostic for use in ion acceleration experiments using the J-KAREN-P laser. Differential filtering provides a coarse energy spectrum measurement, and time-gating allows differentiation of protons from other radiation. We will discuss the design and implementation of the diagnostic, as well as proof-of-principle results from initial experiments on the J-KAREN-P system demonstrating the measurement of sheath accelerated proton beams up to 20 MeV.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira Santos, F. de; Collaboration: E521S Collaboration

The properties of the low lying states of {sup 15}F were studied by measuring the resonant elastic scattering of an {sup 14}O radioactive beam on protons. This experiment was performed at GANIL with a post-accelerated beam produced by the SPIRAL1 facility. We confirm the existence of a second excited state in {sup 15}F with a narrow width, which may seem particularly surprising for a state located above the Coulomb barrier.

Validation of Analytical Damping Ratio by Fatigue Stress Limit

NASA Astrophysics Data System (ADS)

Foong, Faruq Muhammad; Chung Ket, Thein; Beng Lee, Ooi; Aziz, Abdul Rashid Abdul

2018-03-01

The optimisation process of a vibration energy harvester is usually restricted to experimental approaches due to the lack of an analytical equation to describe the damping of a system. This study derives an analytical equation, which describes the first mode damping ratio of a clamp-free cantilever beam under harmonic base excitation by combining the transverse equation of motion of the beam with the damping-stress equation. This equation, as opposed to other common damping determination methods, is independent of experimental inputs or finite element simulations and can be solved using a simple iterative convergence method. The derived equation was determined to be correct for cases when the maximum bending stress in the beam is below the fatigue limit stress of the beam. However, an increasing trend in the error between the experiment and the analytical results were observed at high stress levels. Hence, the fatigue limit stress was used as a parameter to define the validity of the analytical equation.

Rotational degree-of-freedom synthesis: An optimised finite difference method for non-exact data

NASA Astrophysics Data System (ADS)

Gibbons, T. J.; Öztürk, E.; Sims, N. D.

2018-01-01

Measuring the rotational dynamic behaviour of a structure is important for many areas of dynamics such as passive vibration control, acoustics, and model updating. Specialist and dedicated equipment is often needed, unless the rotational degree-of-freedom is synthesised based upon translational data. However, this involves numerically differentiating the translational mode shapes to approximate the rotational modes, for example using a finite difference algorithm. A key challenge with this approach is choosing the measurement spacing between the data points, an issue which has often been overlooked in the published literature. The present contribution will for the first time prove that the use of a finite difference approach can be unstable when using non-exact measured data and a small measurement spacing, for beam-like structures. Then, a generalised analytical error analysis is used to propose an optimised measurement spacing, which balances the numerical error of the finite difference equation with the propagation error from the perturbed data. The approach is demonstrated using both numerical and experimental investigations. It is shown that by obtaining a small number of test measurements it is possible to optimise the measurement accuracy, without any further assumptions on the boundary conditions of the structure.

Methods of increasing the performance of radionuclide generators used in nuclear medicine: daughter nuclide build-up optimisation, elution-purification-concentration integration, and effective control of radionuclidic purity.

PubMed

Le, Van So; Do, Zoe Phuc-Hien; Le, Minh Khoi; Le, Vicki; Le, Natalie Nha-Truc

2014-06-10

Methods of increasing the performance of radionuclide generators used in nuclear medicine radiotherapy and SPECT/PET imaging were developed and detailed for 99Mo/99mTc and 68Ge/68Ga radionuclide generators as the cases. Optimisation methods of the daughter nuclide build-up versus stand-by time and/or specific activity using mean progress functions were developed for increasing the performance of radionuclide generators. As a result of this optimisation, the separation of the daughter nuclide from its parent one should be performed at a defined optimal time to avoid the deterioration in specific activity of the daughter nuclide and wasting stand-by time of the generator, while the daughter nuclide yield is maintained to a reasonably high extent. A new characteristic parameter of the formation-decay kinetics of parent/daughter nuclide system was found and effectively used in the practice of the generator production and utilisation. A method of "early elution schedule" was also developed for increasing the daughter nuclide production yield and specific radioactivity, thus saving the cost of the generator and improving the quality of the daughter radionuclide solution. These newly developed optimisation methods in combination with an integrated elution-purification-concentration system of radionuclide generators recently developed is the most suitable way to operate the generator effectively on the basis of economic use and improvement of purposely suitable quality and specific activity of the produced daughter radionuclides. All these features benefit the economic use of the generator, the improved quality of labelling/scan, and the lowered cost of nuclear medicine procedure. Besides, a new method of quality control protocol set-up for post-delivery test of radionuclidic purity has been developed based on the relationship between gamma ray spectrometric detection limit, required limit of impure radionuclide activity and its measurement certainty with respect to optimising decay/measurement time and product sample activity used for QC quality control. The optimisation ensures a certainty of measurement of the specific impure radionuclide and avoids wasting the useful amount of valuable purified/concentrated daughter nuclide product. This process is important for the spectrometric measurement of very low activity of impure radionuclide contamination in the radioisotope products of much higher activity used in medical imaging and targeted radiotherapy.

First charge breeding results at CARIBU EBIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondrashev, S., E-mail: kondrashev@anl.gov; Barcikowski, A., E-mail: kondrashev@anl.gov; Dickerson, C., E-mail: kondrashev@anl.gov

The Electron Beam Ion Source (EBIS) developed to breed CARIBU radioactive beams at ATLAS is currently in the off-line commissioning stage. The beam commissioning is being performed using a low emittance surface ionization source producing singly-charged cesium ions. The primary goal of the off-line commissioning is the demonstration of high-efficiency charge breeding in the pulsed injection mode. An overview of the final design of the CARIBU EBIS charge breeder, the off-line commissioning installation and the first results on charge breeding of stable cesium ions are presented and discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habs, D.; Guenther, M. M.; Jentschel, M.

With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here wemore » describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.« less

Ethical issues related to professional exposure of pregnant women in the medical field: monitoring and limiting effective dose.

PubMed

Santos, J A M; Nunes, R

2011-03-01

The International Commission on Radiological Protection recommendations for occupational exposed pregnant women do not imply necessarily the complete avoidance of work with radiation or radioactive materials. Instead, a careful review of the exposure conditions, once the pregnancy is declared, as part of the exercise of the ICRP optimisation principle (based in a teleological ethics point of view) is suggested. The dose limitation (following a deontological ethics point of view) of the fetus/embryo is, however, not clearly well established as happens in the case of workers or members of the public. Also, the justification of practices (to continue to work or not with radiation or radioactive materials) is not clearly addressed in most national or international recommendations. An analysis of this justification (bearing in mind both teleological and deontological ethics) is examined in this work having in mind the best interest of the child-to-be as well as other existing social and economical factors.

Test measurement of 7Be(p,γ)8B with the recoil mass separator ERNA

NASA Astrophysics Data System (ADS)

Buompane, R.; De Cesare, N.; Di Leva, A.; D'Onofrio, A.; Gialanella, L.; Romano, M.; De Cesare, M.; Duarte, J. G.; Fülöp, Zs.; Morales-Gallegos, L.; Gyürky, Gy.; Gasques, L. R.; Marzaioli, F.; Palumbo, G.; Porzio, G.; Rapagnani, D.; Roca, V.; Rogalla, D.; Romoli, M.; Sabbarese, C.; Schürmann, D.; Terrasi, F.

2018-06-01

7Be(p,γ)8B has an important role in nuclear astrophysics, having a direct impact on both the high energy component of solar neutrinos and the 7Li abundance after the Big Bang Nucleosynthesis. All direct measurements providing useful information on this reaction so far used the same approach, i.e. a proton beam on a radioactive 7Be target. The overall precision and accuracy of the estimate of the astrophysical rate of this reaction are limited by the discrepancy between the results of existing measurements, possibly due to the complicated stoichiometry and beam induced deterioration of the radioactive targets. The ERNA (European Recoil separator for Nuclear Astrophysics) collaboration planned a new experiment in inverse kinematics exploiting the intense 7Be beam available at CIRCE (Center for Isotopic Research on Cultural and Environmental heritage), Caserta, Italy. The 8B recoils are produced in a windowless hydrogen gas target and detected after the efficient mass separation provided by ERNA. Here we present the commissioning of the experimental setup and a first cross section measurement at E_{cm}≈ 812 keV.

Investigations of Nuclear Structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarantites, Demetrios; Reviol, W.

The proposal addresses studies of nuclear structure at low-energies and development of instrumentation for that purpose. The structure studies deal with features of neutron-rich nuclei with unexplored shapes (football- or pear-shaped nuclei). The regions of interest are: neutron rich nuclei like 132-138Sn, or 48-54Ca, and the Zr, Mo, and Ru isotopes. The tools used can be grouped as follows: either Gammasphere or Gretina multi-gamma detector arrays and auxiliary detectors (Microball, Neutron Shell, and the newly completed Phoswich Wall).The neutron-rich nuclei are accessed by radioactive-beam binary reactions or by 252Cf spontaneous fission. The experiments with heavy radioactive beams aim at excitingmore » the beam nuclei by pick-up or transfer a neutron or a proton from a light target like 13C, 9Be, 11B or 14N .For these binary-reaction studies the Phoswich Wall detector system is essential. It is based on four multi-anode photomultiplier tubes on which CsI and thin fast-timing plastic scintillators are attached. Their signals are digitized with a high density microchip system.« less

The Active Target Time Projection Chamber at NSCL

NASA Astrophysics Data System (ADS)

Bazin, D.; Bradt, J.; Ayyad, Y.; Mittig, W.; Ahn, T.; Beceiro-Novo, S.; Carpenter, L.; Cortesi, M.; Fritsch, A.; Kolata, J. J.; Lynch, W.; Watwood, N.

2017-11-01

Reactions in inverse kinematics close to the Coulomb barrier offer unique opportunities to study exotic nuclei, but they are plagued by the difficulty to efficiently and precisely measure the characteristics of the emerging particles. The Active Target Time Projection Chamber (AT-TPC) offers an elegant solution to this dilemma. In this device, the detector gas of the time projection chamber is at the same time the target in which nuclear reactions take place. The use of this new paradigm offers several advantages over conventional inert target methods, the most significant being the ability to increase the luminosity of experiments without loss of resolution. The AT-TPC and some results obtained on resonant α scattering to explore the clustering properties of neutron-rich nuclei are presented, as well as fusion cross section results using a 10Be radioactive beam. In addition, the first re-accelerated radioactive beam experiment using the fully commissioned ReA3 linac was conducted recently at the NSCL with the AT-TPC, where proton resonant scattering of a 4.6 MeV/u 46Ar beam was used to measure the neutron single-particle strength in 47Ar.

Spallation reaction study for fission products in nuclear waste: Cross section measurements for 137Cs and 90Sr on proton and deuteron

NASA Astrophysics Data System (ADS)

Wang, H.; Otsu, H.; Sakurai, H.; Ahn, D. S.; Aikawa, M.; Doornenbal, P.; Fukuda, N.; Isobe, T.; Kawakami, S.; Koyama, S.; Kubo, T.; Kubono, S.; Lorusso, G.; Maeda, Y.; Makinaga, A.; Momiyama, S.; Nakano, K.; Niikura, M.; Shiga, Y.; Söderström, P.-A.; Suzuki, H.; Takeda, H.; Takeuchi, S.; Taniuchi, R.; Watanabe, Ya.; Watanabe, Yu.; Yamasaki, H.; Yoshida, K.

2016-03-01

We have studied spallation reactions for the fission products 137Cs and 90Sr for the purpose of nuclear waste transmutation. The spallation cross sections on the proton and deuteron were obtained in inverse kinematics for the first time using secondary beams of 137Cs and 90Sr at 185 MeV/nucleon at the RIKEN Radioactive Isotope Beam Factory. The target dependence has been investigated systematically, and the cross-section differences between the proton and deuteron are found to be larger for lighter spallation products. The experimental data are compared with the PHITS calculation, which includes cascade and evaporation processes. Our results suggest that both proton- and deuteron-induced spallation reactions are promising mechanisms for the transmutation of radioactive fission products.

Design of robust microlinacs for wide replacement of radioisotope sources

NASA Astrophysics Data System (ADS)

Smirnov, A. V.; Agustsson, R. A.; Boucher, S.; Harrison, M.; Junge, K.; Savin, E.; Smirnov, A. Yu

2017-12-01

To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices, development of an inexpensive, portable, easy-to-manufacture linac system is very important. The bremsstrahlung X-rays produced by relativistic electron beam on a high-Z converter can mimic X-rays radiated from various radioactive sources. Here we consider development of two designs: one matching a Ir-192 source used in radiography with ∼1-1.3 MeV electrons, and another one Cs137 source using 3.5-4 MeV electrons that can be considered for borehole logging. Both designs use standing wave, high group velocity, cm- wave, accelerating structure. The logging tool conceptual design is based on KlyLac concept combining a klystron and linac operating in self-oscillating mode and sharing the same vacuum envelop, and electron beam.

Enabling three-dimensional densitometric measurements using laboratory source X-ray micro-computed tomography

NASA Astrophysics Data System (ADS)

Pankhurst, M. J.; Fowler, R.; Courtois, L.; Nonni, S.; Zuddas, F.; Atwood, R. C.; Davis, G. R.; Lee, P. D.

2018-01-01

We present new software allowing significantly improved quantitative mapping of the three-dimensional density distribution of objects using laboratory source polychromatic X-rays via a beam characterisation approach (c.f. filtering or comparison to phantoms). One key advantage is that a precise representation of the specimen material is not required. The method exploits well-established, widely available, non-destructive and increasingly accessible laboratory-source X-ray tomography. Beam characterisation is performed in two stages: (1) projection data are collected through a range of known materials utilising a novel hardware design integrated into the rotation stage; and (2) a Python code optimises a spectral response model of the system. We provide hardware designs for use with a rotation stage able to be tilted, yet the concept is easily adaptable to virtually any laboratory system and sample, and implicitly corrects the image artefact known as beam hardening.

A field programmable gate array-based time-resolved scaler for collinear laser spectroscopy with bunched radioactive potassium beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rossi, D. M., E-mail: rossi@nscl.msu.edu; Davis, M.; Ringle, R.

A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive {sup 37}K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 μs bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 × 10{sup 5} in resonant photon detection measurements. The hyperfine structure of {sup 37}K and its isotope shiftmore » relative to the stable {sup 39}K were determined using 5 × 10{sup 4} s{sup −1} {sup 37}K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A({sup 2}S{sub 1/2}) = 120.3(1.4) MHz, A({sup 2}P{sub 1/2}) = 15.2(1.1) MHz, and A({sup 2}P{sub 3/2}) = 1.4(8) MHz, and the isotope shift δν{sup 39,} {sup 37} = −264(3) MHz are consistent with the previously determined values, where available.« less

Upgrade to the Cryogenic Hydrogen Gas Target Monitoring System

NASA Astrophysics Data System (ADS)

Slater, Michael; Tribble, Robert

2013-10-01

The cryogenic hydrogen gas target at Texas A&M is a vital component for creating a secondary radioactive beam that is then used in experiments in the Momentum Achromat Recoil Spectrometer (MARS). A stable beam from the K500 superconducting cyclotron enters the gas cell and some incident particles are transmuted by a nuclear reaction into a radioactive beam, which are separated from the primary beam and used in MARS experiments. The pressure in the target chamber is monitored so that a predictable isotope production rate can be assured. A ``black box'' received the analog pressure data and sent RS232 serial data through an outdated serial connection to an outdated Visual Basic 6 (VB6) program, which plotted the chamber pressure continuously. The black box has been upgraded to an Arduino UNO microcontroller [Atmel Inc.], which can receive the pressure data and output via USB to a computer. It has been programmed to also accept temperature data for future upgrade. A new computer program, with updated capabilities, has been written in Python. The software can send email alerts, create audible alarms through the Arduino, and plot pressure and temperature. The program has been designed to better fit the needs of the users. Funded by DOE and NSF-REU Program.

Optimising in situ gamma measurements to identify the presence of radioactive particles in land areas.

PubMed

Rostron, Peter D; Heathcote, John A; Ramsey, Michael H

2014-12-01

High-coverage in situ surveys with gamma detectors are the best means of identifying small hotspots of activity, such as radioactive particles, in land areas. Scanning surveys can produce rapid results, but the probabilities of obtaining false positive or false negative errors are often unknown, and they may not satisfy other criteria such as estimation of mass activity concentrations. An alternative is to use portable gamma-detectors that are set up at a series of locations in a systematic sampling pattern, where any positive measurements are subsequently followed up in order to determine the exact location, extent and nature of the target source. The preliminary survey is typically designed using settings of detector height, measurement spacing and counting time that are based on convenience, rather than using settings that have been calculated to meet requirements. This paper introduces the basis of a repeatable method of setting these parameters at the outset of a survey, for pre-defined probabilities of false positive and false negative errors in locating spatially small radioactive particles in land areas. It is shown that an un-collimated detector is more effective than a collimated detector that might typically be used in the field. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ion-beam nanopatterning: experimental results with chemically-assisted beam

NASA Astrophysics Data System (ADS)

Pochon, Sebastien C. R.

2018-03-01

The need for forming gratings (for example used in VR headsets) in materials such as SiO2 has seen a recent surge in the use of Ion beam etching techniques. However, when using an argon-only beam, the selectivity is limited as it is a physical process. Typically, gases such as CHF3, SF6, O2 and Cl2 can be added to argon in order to increase selectivity; depending on where the gas is injected, the process is known as Reactive Ion Beam Etching (RIBE) or Chemically Assisted Ion Beam Etching (CAIBE). The substrate holder can rotate in order to provide an axisymmetric etch rate profile. It can also be tilted over a range of angles to the beam direction. This enables control over the sidewall profile as well as radial uniformity optimisation. Ion beam directionality in conjunction with variable incident beam angle via platen angle setting enables profile control and feature shaping during nanopatterning. These hardware features unique to the Ion Beam etching methods can be used to create angled etch features. The CAIBE technique is also well suited to laser diode facet etch (for optoelectronic devices); these typically use III-V materials like InP. Here, we report on materials such as SiO2 etched without rotation and at a fixed platen angle allowing the formation of gratings and InP etched at a fixed angle with rotation allowing the formation of nanopillars and laser facets.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Vinita J.; Schaefer, Charles; Kahnhauser, Henry

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was shut down in September 2014. Lead bricks used as radiological shadow shielding within the accelerator were exposed to stray radiation fields during normal operations. The FLUKA code, a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter, was used to estimate induced radioactivity in this shielding and stainless steel beam pipe from known beam losses. The FLUKA output was processed using MICROSHIELD® to estimate on-contact exposure rates with individually exposed bricks to help design and optimize the radiological survey process. Thismore » entire process can be modeled using FLUKA, but use of MICROSHIELD® as a secondary method was chosen because of the project’s resource constraints. Due to the compressed schedule and lack of shielding configuration data, simple FLUKA models were developed in this paper. FLUKA activity estimates for stainless steel were compared with sampling data to validate results, which show that simple FLUKA models and irradiation geometries can be used to predict radioactivity inventories accurately in exposed materials. During decommissioning 0.1% of the lead bricks were found to have measurable levels of induced radioactivity. Finally, post-processing with MICROSHIELD® provides an acceptable secondary method of estimating residual exposure rates.« less

Energy release, beam attenuation radiation damage, gas production and accumulation of long-lived activity in Pb, Pb-Bi and Hg targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shubin, Yu.N.

1996-06-01

The calculation and analysis of the nuclei concentrations and long-lived residual radioactivity accumulated in Pb, Pb-Bi and Hg targets irradiated by 800 MeV, 30 mA proton beam have been performed. The dominating components to the total radioactivity of radionuclides resulting from fission and spallation reactions and radiative capture by both target nuclei and accumulated radioactive nuclei for various irradiation and cooling times were analyzed. The estimations of spectral component contributions of neutron and proton fluxes to the accumulated activity were carried out. The contributions of fission products to the targets activity and partial activities of main long-lived fission products tomore » the targets activity and partial activities of main long-lived fission products were evaluated. The accumulation of Po isotopes due to reactions induced by secondary alpha-particles were found to be important for the Pb target as compared with two-step radiative capture. The production of Tritium in the targets and its contribution to the total targets activity was considered in detail. It is found that total activities of both targets are close to one another.« less

Status of the Beam Thermalization Area at the NSCL

NASA Astrophysics Data System (ADS)

Cooper, Kortney; Barquest, Bradley; Morrissey, David; Rodriguez, Jose Alberto; Schwarz, Stefan; Sumithrarachchi, Chandana; Kwarsick, Jeff; Savard, Guy

2013-10-01

Beam thermalization is a necessary process for the production of low-energy ion beams at projectile fragmentation facilities. Present beam thermalization techniques rely on passing high-energy ion beams through solid degraders followed by a gas cell where the remaining kinetic energy is dissipated through collisions with buffer gas atoms. Recently, the National Superconducting Cyclotron Laboratory (NSCL) upgraded its thermalization area with the implementation of new large acceptance beam lines and a large RF-gas catcher constructed by Argonne National Lab (ANL). Two high-energy beam lines were commissioned along with the installation and commissioning of this new device in late 2012. Low-energy radioactive ion beams have been successfully delivered to the Electron Beam Ion Trap (EBIT) charge breeder for the ReA3 reaccelerator, the SuN detector, the Low Energy Beam Ion Trap (LEBIT) penning trap, and the Beam Cooler and Laser Spectroscopy (BeCoLa) collinear laser beamline. Construction of a gas-filled reverse cyclotron dubbed the CycStopper is also underway. The status of the beam thermalization area will be presented and the overall efficiency of the system will be discussed.

Design of An 18 MW Beam Dump for 500 GeV Electron/Positron Beams at An ILC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amann, John; /SLAC; Arnold, Ray

This article presents a report on the progress made in designing 18 MW water based Beam Dumps for electrons or positrons for an International Linear Collider (ILC). Multi-dimensional technology issues have to be addressed for the successful design of the Beam Dump. They include calculations of power deposition by the high energy electron/positron beam bunch trains, computational fluid dynamic analysis of turbulent water flow, mechanical design, process flow analysis, hydrogen/oxygen recombiners, handling of radioactive 7Be and 3H, design of auxiliary equipment, provisions for accident scenarios, remote window exchanger, radiation shielding, etc. The progress made to date is summarized, the currentmore » status, and also the issues still to be addressed.« less

Remote balance weighs accurately amid high radiation

NASA Technical Reports Server (NTRS)

Eggenberger, D. N.; Shuck, A. B.

1969-01-01

Commercial beam-type balance, modified and outfitted with electronic controls and digital readout, can be remotely controlled for use in high radiation environments. This allows accurate weighing of breeder-reactor fuel pieces when they are radioactively hot.

Production cross sections of neutron-rich No-263261 isotopes

NASA Astrophysics Data System (ADS)

Li, Jingjing; Li, Cheng; Zhang, Gen; Zhu, Long; Liu, Zhong; Zhang, Feng-Shou

2017-05-01

The fusion excitation functions of No-263249 are studied by using various reaction systems based on the dinuclear system model. The neutron-rich radioactive beam 22O is used to produce neutron-rich nobelium isotopes, and the new neutron-rich isotopes No-263261 are synthesized by 242Pu(22O,3 n )261No , 244Pu(22O,4 n )262No , and 244Pu(22O,3 n )263No reactions, respectively. The corresponding maximum evaporation residue cross sections are 0.628, 4.649, and 1.638 μ b , respectively. The effects of the three processes (capture, fusion, and survival) in the complete fusion reaction are also analyzed. From investigation, a neutron-rich radioactive beam as the projectile and neutron-rich actinide as the target could be a new selection of the projectile-target combination to produce a neutron-rich heavy nuclide.

Cluster-transfer reactions with radioactive beams: A spectroscopic tool for neutron-rich nuclei

DOE PAGES

Bottoni, S.; Leoni, S.; Fornal, B.; ...

2015-08-27

An exploratory experiment performed at REX-ISOLDE to investigate cluster-transfer reactions with radioactive beams in inverse kinematics is presented. The aim of the experiment was to test the potential of cluster-transfer reactions at the Coulomb barrier as a mechanism to explore the structure of exotic neutron-rich nuclei. The reactions 7Li( 98Rb,αxn) and 7Li( 98Rb,txn) were studied through particle-γ coincidence measurements, and the results are presented in terms of the observed excitation energies and spins. Moreover, the reaction mechanism is qualitatively discussed as a transfer of a clusterlike particle within a distorted-wave Born approximation framework. The results indicate that cluster-transfer reactions canmore » be described well as a direct process and that they can be an efficient method to investigate the structure of neutron-rich nuclei at medium-high excitation energies and spins.« less

Research and development on materials for the SPES target

NASA Astrophysics Data System (ADS)

Corradetti, Stefano; Andrighetto, Alberto; Manzolaro, Mattia; Scarpa, Daniele; Vasquez, Jesus; Rossignoli, Massimo; Monetti, Alberto; Calderolla, Michele; Prete, Gianfranco

2014-03-01

The SPES project at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro) is focused on the production of radioactive ion beams. The core of the SPES facility is constituted by the target, which will be irradiated with a 40 MeV, 200 µA proton beam in order to produce radioactive species. In order to efficiently produce and release isotopes, the material constituting the target should be able to work under extreme conditions (high vacuum and temperatures up to 2000 °C). Both neutron-rich and proton-rich isotopes will be produced; in the first case, carbon dispersed uranium carbide (UCx) will be used as a target, whereas to produce p-rich isotopes, several types of targets will have to be irradiated. The synthesis and characterization of different types of material will be reported. Moreover, the results of irradiation and isotopes release tests on different uranium carbide target prototypes will be discussed.

Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

NASA Astrophysics Data System (ADS)

Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.; D'Agostini, F.

2016-02-01

In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

Neutron-rich isotope production using a uranium carbide - carbon nanotubes SPES target prototype

NASA Astrophysics Data System (ADS)

Corradetti, S.; Biasetto, L.; Manzolaro, M.; Scarpa, D.; Carturan, S.; Andrighetto, A.; Prete, G.; Vasquez, J.; Zanonato, P.; Colombo, P.; Jost, C. U.; Stracener, D. W.

2013-05-01

The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

High energy flux thermo-mechanical test of 1D-carbon-carbon fibre composite prototypes for the SPIDER diagnostic calorimeter

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Muri, M., E-mail: michela.demuri@igi.cnr.it; Pasqualotto, R.; Dalla Palma, M.

2014-02-15

Operation of the thermonuclear fusion experiment ITER requires additional heating via injection of neutral beams from accelerated negative ions. In the SPIDER test facility, under construction in Padova, the production of negative ions will be studied and optimised. STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) is a diagnostic used to characterise the SPIDER beam during short pulse operation (several seconds) to verify if the beam meets the ITER requirements about the maximum allowed beam non-uniformity (below ±10%). The major components of STRIKE are 16 1D-CFC (Carbon-Carbon Fibre Composite) tiles, observed at the rear side by a thermal camera. This contribution givesmore » an overview of some tests under high energy particle flux, aimed at verifying the thermo-mechanical behaviour of several CFC prototype tiles. The tests were performed in the GLADIS facility at IPP (Max-Plank-Institut für Plasmaphysik), Garching. Dedicated linear and nonlinear simulations were carried out to interpret the experiments and a comparison of the experimental data with the simulation results is presented. The results of some morphological and structural studies on the material after exposure to the GLADIS beam are also given.« less

A high-resolution x-ray spectrometer for a kaon mass measurement

NASA Astrophysics Data System (ADS)

Phelan, Kevin; Suzuki, Ken; Zmeskal, Johann; Tortorella, Daniele; Bühler, Matthias; Hertrich, Theo

2017-02-01

The ASPECT consortium (Adaptable Spectrometer Enabled by Cryogenic Technology) is currently constructing a generalised cryogenic platform for cryogenic detector work which will be able to accommodate a wide range of sensors. The cryogenics system is based on a small mechanical cooler with a further adiabatic demagnetisation stage and will work with cryogenic detectors at sub-Kelvin temperatures. The commercial aim of the consortium is to produce a compact, user-friendly device with an emphasis on reliability and portability which can easily be transported for specialised on-site work, such as beam-lines or telescope facilities. The cryogenic detector platform will accommodate a specially developed cryogenic sensor, either a metallic magnetic calorimeter or a magnetic penetration-depth thermometer. The detectors will be designed to work in various temperatures regions with an emphasis on optimising the various detector resolutions for specific temperatures. One resolution target is of about 10 eV at the energies range typically created in kaonic atoms experiments (soft x-ray energies). A following step will see the introduction of continuous, high-power, sub-Kelvin cooling which will bring the cryogenic basis for a high resolution spectrometer system to the market. The scientific goal of the project will produce an experimental set-up optimised for kaon-mass measurements performing high-resolution x-ray spectroscopy on a beam-line provided foreseeably by the J-PARC (Tokai, Japan) or DAΦNE (Frascati, Italy) facilities.

Handling Radioactive Waste from the Proton Accelerator Facility at the Paul Scherrer Institut (PSI) - Always Surprising? - 13320

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueth, Joachim

The Paul Scherrer Institut (PSI) is the largest national research centre in Switzerland. Its multidisciplinary research is dedicated to a wide field in natural science and technology as well as particle physics. In this context, PSI is operating, amongst others, a large proton accelerator facility since more than 30 years. In two cyclotrons, protons are accelerated to high speeds and then guided along roughly 100 m of beam line to three different target stations to produce secondary particles like mesons and neutrons for experiments and a separately beam line for UCN. The protons induce spallation processes in the target materials,more » and also at other beam loss points along the way, with emission of protons, neutrons, hydrogen, tritium, helium, heavier fragments and fission processes. In particular the produced neutrons, due to their large penetration depth, will then interact also with the surrounding materials. These interactions of radiation with matter lead to activation and partly to contamination of machine components and the surrounding infrastructures. Maintenance, operation and decommissioning of installations generate inevitably substantial amounts of radioactive operational and dismantling waste like targets, magnets, collimators, shielding (concrete, steel) and of course secondary waste. To achieve an optimal waste management strategy for interim storage or final disposal, radioactive waste has to be characterized, sorted and treated. This strategy is based on radiation protection demands, raw waste properties (size, material, etc.), and requirements to reduce the volume of waste, mainly for legal and economical reasons. In addition, the radiological limitations for transportation of the waste packages to a future disposal site have to be taken into account, as well as special regulatory demands. The characterization is a task of the waste producer. The conditioning processes and quality checks for radioactive waste packages are part of an accredited waste management process of PSI, especially of the Section Dismantling and Waste Management. Strictly proven and accepted methods needed to be developed and enhanced for safe treatment, transport, conditioning and storage. But in the field of waste from research activities, individual and new solutions have to be found in an increasingly growing administrative environment. Furthermore, a wide variety of components, with a really large inventory of radioactive nuclides, has to be handled. And there are always surprising challenges concerning the unusual materials or the nuclide inventory. In case of the operational and dismantling radioactive accelerator waste, the existing conditioning methods are in the process of a continuous enhancement - technically and administratively. The existing authorized specifications of conditioning processes have to be extended to optimize and fully describe the treatment of the inevitably occurring radioactive waste from the accelerator facility. Additional challenges are the changes with time concerning the legal and regulatory requirements - or do we have to consider it as business as usual? This paper gives an overview of the current practices in radioactive waste management and decommissioning of the existing operational accelerator waste. (authors)« less

Proton beam writing of long, arbitrary structures for micro/nano photonics and fluidics applications

NASA Astrophysics Data System (ADS)

Udalagama, Chammika; Teo, E. J.; Chan, S. F.; Kumar, V. S.; Bettiol, A. A.; Watt, F.

2011-10-01

The last decade has seen proton beam writing maturing into a versatile lithographic technique able to produce sub-100 nm, high aspect ratio structures with smooth side walls. However, many applications in the fields of photonics and fluidics require the fabrication of structures with high spatial resolution that extends over several centimetres. This cannot be achieved by purely magnetic or electrostatic beam scanning due to the large off-axis beam aberrations in high demagnification systems. As a result, this has limited us to producing long straight structures using a combination of beam and stage scanning. In this work we have: (1) developed an algorithm to include any arbitrary pattern into the writing process by using a more versatile combination of beam and stage scanning while (2) incorporating the use of the ubiquitous AutoCAD DXF (drawing exchange format) into the design process. We demonstrate the capability of this approach in fabricating structures such as Y-splitters, Mach-Zehnder modulators and microfluidic channels that are over several centimetres in length, in polymer. We also present optimisation of such parameters as scanning speed and scanning loops to improve on the surface roughness of the structures. This work opens up new possibilities of using CAD software in PBW for microphotonics and fluidics device fabrication.

Treatment of surfaces with low-energy electrons

NASA Astrophysics Data System (ADS)

Frank, L.; Mikmeková, E.; Lejeune, M.

2017-06-01

Electron-beam-induced deposition of various materials from suitable precursors has represented an established branch of nanotechnology for more than a decade. A specific alternative is carbon deposition on the basis of hydrocarbons as precursors that has been applied to grow various nanostructures including masks for subsequent technological steps. Our area of study was unintentional electron-beam-induced carbon deposition from spontaneously adsorbed hydrocarbon molecules. This process traditionally constitutes a challenge for scanning electron microscopy practice preventing one from performing any true surface studies outside an ultrahigh vacuum and without in-situ cleaning of samples, and also jeopardising other electron-optical devices such as electron beam lithographs. Here we show that when reducing the energy of irradiating electrons sufficiently, the e-beam-induced deposition can be converted to e-beam-induced release causing desorption of hydrocarbons and ultimate cleaning of surfaces in both an ultrahigh and a standard high vacuum. Using series of experiments with graphene samples, we demonstrate fundamental features of e-beam-induced desorption and present results of checks for possible radiation damage using Raman spectroscopy that led to optimisation of the electron energy for damage-free cleaning. The method of preventing carbon contamination described here paves the way for greatly enhanced surface sensitivity of imaging and substantially reduced demands on vacuum systems for nanotechnological applications.

Leakage of radioactive materials from particle accelerator facilities by non-radiation disasters like fire and flooding and its environmental impacts

NASA Astrophysics Data System (ADS)

Lee, A.; Jung, N. S.; Mokhtari Oranj, L.; Lee, H. S.

2018-06-01

The leakage of radioactive materials generated at particle accelerator facilities is one of the important issues in the view of radiation safety. In this study, fire and flooding at particle accelerator facilities were considered as the non-radiation disasters which result in the leakage of radioactive materials. To analyse the expected effects at each disaster, the case study on fired and flooded particle accelerator facilities was carried out with the property investigation of interesting materials presented in the accelerator tunnel and the activity estimation. Five major materials in the tunnel were investigated: dust, insulators, concrete, metals and paints. The activation levels on the concerned materials were calculated using several Monte Carlo codes (MCNPX 2.7+SP-FISPACT 2007, FLUKA 2011.4c and PHITS 2.64+DCHAIN-SP 2001). The impact weight to environment was estimated for the different beam particles (electron, proton, carbon and uranium) and the different beam energies (100, 430, 600 and 1000 MeV/nucleon). With the consideration of the leakage path of radioactive materials due to fire and flooding, the activation level of selected materials, and the impacts to the environment were evaluated. In the case of flooding, dust, concrete and metal were found as a considerable object. In the case of fire event, dust, insulator and paint were the major concerns. As expected, the influence of normal fire and flooding at electron accelerator facilities would be relatively low for both cases.

Distribution uniformity of laser-accelerated proton beams

NASA Astrophysics Data System (ADS)

Zhu, Jun-Gao; Zhu, Kun; Tao, Li; Xu, Xiao-Han; Lin, Chen; Ma, Wen-Jun; Lu, Hai-Yang; Zhao, Yan-Ying; Lu, Yuan-Rong; Chen, Jia-Er; Yan, Xue-Qing

2017-09-01

Compared with conventional accelerators, laser plasma accelerators can generate high energy ions at a greatly reduced scale, due to their TV/m acceleration gradient. A compact laser plasma accelerator (CLAPA) has been built at the Institute of Heavy Ion Physics at Peking University. It will be used for applied research like biological irradiation, astrophysics simulations, etc. A beamline system with multiple quadrupoles and an analyzing magnet for laser-accelerated ions is proposed here. Since laser-accelerated ion beams have broad energy spectra and large angular divergence, the parameters (beam waist position in the Y direction, beam line layout, drift distance, magnet angles etc.) of the beamline system are carefully designed and optimised to obtain a radially symmetric proton distribution at the irradiation platform. Requirements of energy selection and differences in focusing or defocusing in application systems greatly influence the evolution of proton distributions. With optimal parameters, radially symmetric proton distributions can be achieved and protons with different energy spread within ±5% have similar transverse areas at the experiment target. Supported by National Natural Science Foundation of China (11575011, 61631001) and National Grand Instrument Project (2012YQ030142)

Nuclear-Structure Physics with MINIBALL at HIE-ISOLDE

NASA Astrophysics Data System (ADS)

Reiter, P.; MINIBALL Collaboration

2018-02-01

The MINIBALL spectrometer utilizes successfully a variety of post-accelerated radioactive ion beams provided by the new HIE-ISOLDE accelerator at CERN. In-beam γ-ray spectroscopy after Coulomb excitation (CE) or transfer reactions is performed with optimized setups of ancillary detectors for particle detection. The physics program covers a wide range of shell model investigations. Exotic heavy ion beams will enable unique studies of collective properties up to the actinide region. First data taking with HIE-ISOLDE beams started recently. The higher energies and intensities of the new post-accelerator provides a promising perspective for a new generation of MINIBALL experiments. Intriguing first results were obtained by employing beams of 74,76,78Zn, 110,132Sn, 144Xe with beam energies in the range of 4.0 - 5.5 MeV/u for CE experiments at ‘safe’ energies. In all cases first results for various B(Eλ) values for these isotopes were obtained.

The laser and optical system for the RIBF-PALIS experiment

NASA Astrophysics Data System (ADS)

Sonoda, T.; Iimura, H.; Reponen, M.; Wada, M.; Katayama, I.; Sonnenschein, V.; Takamatsu, T.; Tomita, H.; Kojima, T. M.

2018-01-01

This paper describes the laser and optical system for the Parasitic radioactive isotope (RI) beam production by Laser Ion-Source (PALIS) in the RIKEN fragment separator facility. This system requires an optical path length of 70 m for transporting the laser beam from the laser light source to the place for resonance ionization. To accomplish this, we designed and implemented a simple optical system consisting of several mirrors equipped with compact stepping motor actuators, lenses, beam spot screens and network cameras. The system enables multi-step laser resonance ionization in the gas cell and gas jet via overlap with a diameter of a few millimeters, between the laser photons and atomic beam. Despite such a long transport distance, we achieved a transport efficiency for the UV laser beam of about 50%. We also confirmed that the position stability of the laser beam stays within a permissible range for dedicated resonance ionization experiments.

Beam Profile Studies for a One Eighth Betatron Wavelength Final Focusing Cell Following Phase Mixed Transport

DTIC Science & Technology

1988-10-26

concentrated into this off- axis peak is then considered. Estimates of the source brightness ( extraction ion diode source current density divided by the square...radioactive contamination of the accelerator. One possible scheme for avoiding this problem is to use extraction geometry ion diodes to focus the ion beams...annular region. These results will be coupled to two simple models of extraction ion diodes to determihe the ion source brightness requirements. These

Design of SECAR a recoil mass separator for astrophysical capture reactions with radioactive beams

NASA Astrophysics Data System (ADS)

Berg, G. P. A.; Couder, M.; Moran, M. T.; Smith, K.; Wiescher, M.; Schatz, H.; Hager, U.; Wrede, C.; Montes, F.; Perdikakis, G.; Wu, X.; Zeller, A.; Smith, M. S.; Bardayan, D. W.; Chipps, K. A.; Pain, S. D.; Blackmon, J.; Greife, U.; Rehm, K. E.; Janssens, R. V. F.

2018-01-01

A recoil mass separator SECAR has been designed for the purpose of studying low-energy (p , γ) and (α , γ) reactions in inverse kinematics with radioactive beams for masses up to about A = 65. Their reaction rates are of importance for our understanding of the energy production and nucleosynthesis during explosive hydrogen and helium burning. The radiative capture reactions take place in a windowless hydrogen or He gas target at the entrance of the separator, which consists of four Sections. The first Section selects the charge state of the recoils. The second and third Sections contain Wien Filters providing high mass resolving power to separate efficiently the intense beam from the few reaction products. In the following fourth Section, the reaction products are guided into a detector system capable of position, angle and time-of-flight measurements. In order to accept the complete kinematic cone of recoil particles including multiple scattering in the target in the center of mass energy range of 0.2 MeV to 3.0 MeV, the system must have a large polar angle acceptance of ± 25 mrad. This requires a careful minimization of higher order aberrations. The present system will be installed at the NSCL ReA3 accelerator and will be used with the much higher beam intensities of the FRIB facility when it becomes available.

Design of SECAR a recoil mass separator for astrophysical capture reactions with radioactive beams

DOE PAGES

Berg, G. P. A.; Couder, M.; Moran, M. T.; ...

2017-09-25

A recoil mass separator SECAR has been designed for the purpose of studying low-energy (p,γ) and (α,γ) reactions in inverse kinematics with radioactive beams for masses up to about A = 65. Their reaction rates are of importance for our understanding of the energy production and nucleosynthesis during explosive hydrogen and helium burning. The radiative capture reactions take place in a windowless hydrogen or He gas target at the entrance of the separator, which consists of four Sections. The first Section selects the charge state of the recoils. The second and third Sections contain Wien Filters providing high mass resolvingmore » power to separate efficiently the intense beam from the few reaction products. In the following fourth Section, the reaction products are guided into a detector system capable of position, angle and time-of-flight measurements. In order to accept the complete kinematic cone of recoil particles including multiple scattering in the target in the center of mass energy range of 0.2 MeV to 3.0 MeV, the system must have a large polar angle acceptance of ± 25 mrad. This requires a careful minimization of higher order aberrations. Furthermore, the present system will be installed at the NSCL ReA3 accelerator and will be used with the much higher beam intensities of the FRIB facility when it becomes available.« less

A multi-layered active target for the study of neutron-unbound nuclides at NSCL

NASA Astrophysics Data System (ADS)

Freeman, Jessica; Gueye, Paul; Redpath, Thomas; MoNA Collaboration

2017-01-01

The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented. DoE/NNSA - DE-NA0000979.

Coulomb excitation of radioactive Na21 and its stable mirror Ne21

NASA Astrophysics Data System (ADS)

Schumaker, M. A.; Cline, D.; Hackman, G.; Morton, A. C.; Pearson, C. J.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.

2008-10-01

The low-energy structures of the mirror nuclei Ne21 and radioactive Na21 have been examined by using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ~5×106 ions/s were accelerated to 1.7 MeV/A and Coulomb excited in a 0.5 mg/cm2 natTi target. Scattered beam and target particles were detected by the segmented Si detector BAMBINO, while γ rays were observed by using two TIGRESS HPGe clover detectors perpendicular to the beam axis. For each isobar, Coulomb excitation from the (3)/(2)+ ground state to the first excited (5)/(2)+ state was observed and B(E2) values were determined by using the 2+→0+ de-excitation in Ti48 as a reference. The ϕ segmentation of BAMBINO was used to deduce tentative assignments for the signs of the mixing ratios between the E2 and M1 components of the transitions. The resulting B(E2)↑ values are 131±9e2 fm4 (25.4±1.7 W.u.) for Ne21 and 205±14e2 fm4 (39.7±2.7 W.u.) for Na21. The fit to the present data and the known lifetimes determined E2/M1 mixing ratios and B(M1)↓ values of δ=(-)0.0767±0.0027 and 0.1274±0.0025μN2 and δ=(+)0.0832±0.0028 and 0.1513±0.0017μN2 for Ne21 and Na21, respectively (with Krane and Steffen sign convention). By using the effective charges ep=1.5e and en=0.5e, the B(E2) values produced by the p-sd shell model are 30.7 and 36.4 W.u. for Ne21 and Na21, respectively. This analysis resolves a significant discrepancy between a previous experimental result for Na21 and shell-model calculations.

Thin layer activation-based evaluation of tribological behaviour of light ion-implanted metallic samples

NASA Astrophysics Data System (ADS)

Racolta, P. M.; Popa-Simil, L.; Alexandreanu, B.; Mateescu, L.

1997-05-01

In our Cyclotron Laboratory wear and/or corrosion studies of metallic machine parts are performed on a routine basis by using the Charged Particle Surface Activation method, also commonly known as the Thin Layer Activation (TLA) technique. In principle, this method consists of an ion beam irradiation of the surface of interest (typically using proton and deuteron beams), followed by in-situ radioactivity monitoring, on a testing bench or in normal running conditions. The observed changes in radioactivity are then transformed in mass losses, by using a specific calibration procedure. In spite of the high reliability of the method, which allows fast and accurate determinations under real operating conditions, the issue of possible influence of ion bombardment upon the tribologic properties of irradiated components had yet to be clarified. To do that, a dedicated set-up was designed so as to ensure a simultaneous irradiation of the disk-shaped samples at various incident beam energies and doses. Since the expected structural modifications were associated not only to ion-induced damages, but also to the local heating, we tried to outline the contribution of each of the two above-mentioned effects. Consequently, the microstructure effects have been investigated by both electronic and metallography microscopy. The Vickers micro-hardness test has been taken before and after irradiation of each sample. Two main outcomes can be reported: the use of radioactive labelling for wear and corrosion control using MeV beams with doses below 10 17 ions/cm 2 of light particles such as protons and deuterons does not lead to significant changes of the tribologic properties of the studied machine part; and besides, wear diagrams (wear levels vs. running time) for Carbon Steel Alloy (OL-45 in Romanian standard, 0.45% carbon) and {Cu63}/{Zn37} brass irradiated at different doses (10 17 - 10 18 ions/cm 2) have been obtained.

The ATLAS multi-user upgrade and potential applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mustapha, B.; Nolen, J. A.; Savard, G.

With the recent integration of the CARIBU-EBIS charge breeder into the ATLAS accelerator system to provide for more pure and efficient charge breeding of radioactive beams, a multi-user upgrade of the ATLAS facility is being proposed to serve multiple users simultaneously. ATLAS was the first superconducting ion linac in the world and is the US DOE low-energy Nuclear Physics National User Facility. The proposed upgrade will take advantage of the continuous-wave nature of ATLAS and the pulsed nature of the EBIS charge breeder in order to simultaneously accelerate two beams with very close mass-to-charge ratios; one stable from the existingmore » ECR ion source and one radioactive from the newly commissioned EBIS charge breeder. In addition to enhancing the nuclear physics program, beam extraction at different points along the linac will open up the opportunity for other potential applications; for instance, material irradiation studies at ~ 1 MeV/u and isotope production at ~ 6 MeV/u or at the full ATLAS energy of ~ 15 MeV/u. The concept and proposed implementation of the ATLAS multi-user upgrade will be presented. Future plans to enhance the flexibility of this upgrade will also be presented.« less

Composite uranium carbide targets at TRIUMF: Development and characterization with SEM, XRD, XRF and L-edge densitometry

NASA Astrophysics Data System (ADS)

Kunz, Peter; Bricault, Pierre; Dombsky, Marik; Erdmann, Nicole; Hanemaayer, Vicky; Wong, John; Lützenkirchen, Klaus

2013-09-01

The production of radioactive ion beams (RIB) from spallation targets by irradiation with a continuous 500 MeV proton beam, has been routine at TRIUMF for several years. Based on the experience with composite refractory carbide targets a procedure for the fabrication of UC2/C targets was developed. It includes the preparation of UC2 by carbothermal reduction of UO2, the slip-casting of fine-grained UC2/C slurry on graphite foil under inert gas atmosphere and the cutting of composite target discs which are stacked up to a lamellar structure. The thermal properties of such an arrangement are adequate to withstand the high power deposition of an intense, continuous proton beam and also beneficial for the fast release of short-lived radioactive isotopes. Molecular structure, particle size and the impact of sintering of the target discs were investigated via XRD and SEM. Thickness and mass distribution were measured with position-sensitive LIII-edge densitometry. The results confirm that the properties of the UC2/C target material are well suited for RIB production at TRIUMF while there is still room for improvement with regard to uniformity of mass distribution in target disc thickness.

The ATLAS multi-user upgrade and potential applications

NASA Astrophysics Data System (ADS)

Mustapha, B.; Nolen, J. A.; Savard, G.; Ostroumov, P. N.

2017-12-01

With the recent integration of the CARIBU-EBIS charge breeder into the ATLAS accelerator system to provide for more pure and efficient charge breeding of radioactive beams, a multi-user upgrade of the ATLAS facility is being proposed to serve multiple users simultaneously. ATLAS was the first superconducting ion linac in the world and is the US DOE low-energy Nuclear Physics National User Facility. The proposed upgrade will take advantage of the continuous-wave nature of ATLAS and the pulsed nature of the EBIS charge breeder in order to simultaneously accelerate two beams with very close mass-to-charge ratios; one stable from the existing ECR ion source and one radioactive from the newly commissioned EBIS charge breeder. In addition to enhancing the nuclear physics program, beam extraction at different points along the linac will open up the opportunity for other potential applications; for instance, material irradiation studies at ~1 MeV/u, isotope production and radiobiological studies at ~6 MeV/u and at the full ATLAS energy of ~15 MeV/u. The concept and proposed implementation of the ATLAS multi-user upgrade will be discussed. Future plans to enhance the flexibility of this upgrade will be presented.

Measurement of activation of helium gas by 238U beam irradiation at about 11 A MeV

NASA Astrophysics Data System (ADS)

Akashio, A.; Tanaka, K.; Imao, H.; Uwamino, Y.

2017-09-01

A new helium-gas stripper system has been applied at the 11 A MeV uranium beam of the Radioactive Isotope Beam Factory of the RIKEN accelerator facility. Although the gas stripper is important for the heavy-ion accelerator facility, the residual radiation that is generated is a serious problem for maintenance work. The residual dose was evaluated by using three-layered activation samples of aluminium and bismuth. The γ-rays from produced radionuclides with in-flight fission of the 238U beam and from the material of the chamber activated by neutrons were observed by using a Ge detector and compared with the values calculated by using the Monte-Carlo simulation code PHITS.

{sup 25}Na and {sup 25}Mg fragmentation on {sup 12}C at 9.23 MeV per nucleon at TRIUMF

DOE Office of Scientific and Technical Information (OSTI.GOV)

St-Onge, Patrick; Boisjoli, Mark; Fregeau, Marc-Olivier

2012-10-20

HERACLES is a multidetector that is used to study heavy-ion collisions, with ion beams with an energy range between 8 to 15 MeV per nucleon. It has 78 detectors axially distributed around the beam axis in 6 rings allowing detection of multiple charged fragments from nuclear reactions. HERACLES has 4 different types of detectors, BC408/BaF{sub 2} phoswich, Si/CsI(Tl) telescope, BC408/BC444 phoswich and CsI(Tl) detectors. The multidetector has been run with a radioactive {sup 25}Na beam and a stable {sup 25}Mg beam at 9.23 MeV per nucleon on a carbon target.

A gas circulation and purification system for gas-cell-based low-energy RI-beam production.

PubMed

Sonoda, T; Tsubota, T; Wada, M; Katayama, I; Kojima, T M; Reponen, M

2016-06-01

A gas circulation and purification system was developed at the RIKEN Radioactive Isotope Beam Factory that can be used for gas-cell-based low-energy RI-beam production. A high-flow-rate gas cell filled with one atmosphere of buffer gas (argon or helium) is used for the deceleration and thermalization of high-energy RI-beams. The exhausted buffer gas is efficiently collected using a compact dry pump and returned to the gas cell with a recovery efficiency of >97%. The buffer gas is efficiently purified using two gas purifiers as well as collision cleaning, which eliminates impurities in the gas. An impurity level of one part per billion is achieved with this method.

A gas circulation and purification system for gas-cell-based low-energy RI-beam production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sonoda, T.; Wada, M.; Katayama, I.

A gas circulation and purification system was developed at the RIKEN Radioactive Isotope Beam Factory that can be used for gas-cell-based low-energy RI-beam production. A high-flow-rate gas cell filled with one atmosphere of buffer gas (argon or helium) is used for the deceleration and thermalization of high-energy RI-beams. The exhausted buffer gas is efficiently collected using a compact dry pump and returned to the gas cell with a recovery efficiency of >97%. The buffer gas is efficiently purified using two gas purifiers as well as collision cleaning, which eliminates impurities in the gas. An impurity level of one part permore » billion is achieved with this method.« less

Physics with heavy neutron-rich RIBs at the HRIBF

NASA Astrophysics Data System (ADS)

Radford, D. C.; Baktash, C.; Galindo-Uribarri, A.; Gross, C. J.; Lewis, T. A.; Mueller, P. E.; Hausladen, P. A.; Shapira, D.; Stracener, D. W.; Yu, C.-H.; Fuentes, B.; Padilla, E.; Hartley, D. J.; Barton, C. J.; Caprio, M.; Zamfir, N. V.

The Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory has recently produced the world's first post-accelerated beams of heavy neutron-rich nuclei. The first experiments with these beam are described, and the results discussed. B(E2;0+ --> 2+) values for neutron-rich 126,128Sn and 132,134,136Te isotopes have been measured by Coulomb excitation in inverse kinematics. The results for 132Te and 134Te (N = 80, 82) show excellent agreement with systematics of lighter Te isotopes, but the B(E2) value for 136Te (N = 84) is unexpectedly small. Single-neutron transfer reactions with a 134Te beam on natBe and 13C targets at energies just above the Coulomb barrier have also been studied.

Possibility of a crossed-beam experiment involving slow-neutron capture by unstable nuclei - ``rapid-process tron''

NASA Astrophysics Data System (ADS)

Yamazaki, T.; Katayama, I.; Uwamino, Y.

1993-02-01

The possibility of a crossed beam facility of slow neutrons capturing unstable nuclei is examined in connection with the Japanese Hadron Project. With a pulsed proton beam of 50 Hz repetition and with a 100 μA average beam current, one obtains a spallation neutron source of 2.4 × 10 8 thermal neutrons/cm 3/spill over a 60 cm length with a 3 ms average duration time by using a D 2O moderator. By confining radioactive nuclei of 10 9 ions in a beam circulation ring of 0.3 MHz revolution frequency, so that nuclei pass through the neutron source, one obtains a collision luminosity of 3.9 × 10 24/cm 2/s. A new research domain aimed at studying rapid processes in nuclear genetics in a laboratory will be created.

Analysis of activation and shutdown contact dose rate for EAST neutral beam port

NASA Astrophysics Data System (ADS)

Chen, Yuqing; Wang, Ji; Zhong, Guoqiang; Li, Jun; Wang, Jinfang; Xie, Yahong; Wu, Bin; Hu, Chundong

2017-12-01

For the safe operation and maintenance of neutral beam injector (NBI), specific activity and shutdown contact dose rate of the sample material SS316 are estimated around the experimental advanced superconducting tokamak (EAST) neutral beam port. Firstly, the neutron emission intensity is calculated by TRANSP code while the neutral beam is co-injected to EAST. Secondly, the neutron activation and shutdown contact dose rates for the neutral beam sample materials SS316 are derived by the Monte Carlo code MCNP and the inventory code FISPACT-2007. The simulations indicate that the primary radioactive nuclides of SS316 are 58Co and 54Mn. The peak contact dose rate is 8.52 × 10-6 Sv/h after EAST shutdown one second. That is under the International Thermonuclear Experimental Reactor (ITER) design values 1 × 10-5 Sv/h.

Electron string ion sources for carbon ion cancer therapy accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boytsov, A. Yu.; Donets, D. E.; Donets, E. D.

2015-08-15

The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C{sup 4+} and C{sup 6+} ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 10{sup 10} C{sup 4+} ions per pulse and about 5 × 10{sup 9} C{sup 6+} ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 10{sup 11} C{sup 6+} ions per second at the 100 Hz repetition rate, and the repetition rate can bemore » increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the {sup 11}C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C{sup 4+} ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of {sup 11}C, transporting to the tumor with the primary accelerated {sup 11}C{sup 4+} beam, this efficiency is preliminarily considered to be large enough to produce the {sup 11}C{sup 4+} beam from radioactive methane and to inject this beam into synchrotrons.« less

Trials for the cosmological 7Li problem with 7Be beams at CRIB and collaborating studies

NASA Astrophysics Data System (ADS)

Hayakawa, S.

2017-09-01

For many years, the cosmological ^7 Li problem has been tackled from various aspects. The nuclear reaction data have also been improved, but still there remains some ambiguities. We review our experimental plans to measure the cross sections of three key reactions which act to destroy ^7 Be during the Big-Bang Nucleosynthesis (BBN). These experiments are all based on ^7 Be beams produced at Center-for-Nuclear-Study Radioactive Ion Beam separator (CRIB) in collaborations mainly with research groups from INFN-LNS and RCNP. The preliminary result of the previous experiment and the future plan are discussed.

Preliminary safety analysis of the Baita Bihor radioactive waste repository, Romania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Little, Richard; Bond, Alex; Watson, Sarah

2007-07-01

A project funded under the European Commission's Phare Programme 2002 has undertaken an in-depth analysis of the operational and post-closure safety of the Baita Bihor repository. The repository has accepted low- and some intermediate-level radioactive waste from industry, medical establishments and research activities since 1985 and the current estimate is that disposals might continue for around another 20 to 35 years. The analysis of the operational and post-closure safety of the Baita Bihor repository was carried out in two iterations, with the second iteration resulting in reduced uncertainties, largely as a result taking into account new information on the hydrologymore » and hydrogeology of the area, collected as part of the project. Impacts were evaluated for the maximum potential inventory that might be available for disposal to Baita Bihor for a number of operational and postclosure scenarios and associated conceptual models. The results showed that calculated impacts were below the relevant regulatory criteria. In light of the assessment, a number of recommendations relating to repository operation, optimisation of repository engineering and waste disposals, and environmental monitoring were made. (authors)« less

Cone beam computed tomography in paediatric dentistry: overview of recent literature.

PubMed

Aps, J K M

2013-06-01

The use of cone beam computed tomography (CBCT) in paediatric dentistry has been mentioned in numerous publications and case reports. The indications for the use of CBCT in paediatric dentistry, however, have not yet been properly addressed. On the other hand, the three basic principles of radiation protection (justification, limitation and optimisation) should suffice. A review of the current literature was used to assess the indications and contra-indications for the use of CBCT in paediatric dentistry. Paramount is the fact that CBCT generates a higher effective dose to the tissues than traditional dental radiographic exposures do. The effective radiation dose should not be underestimated, especially not in children, who are much more susceptible to stochastic biological effects. The thyroid gland in particular should be kept out of the primary beam as much as possible. As with any other radiographical technique, routine use of CBCT is not acceptable clinical practice. CBCT certainly has a place in paediatric dentistry, but its use must be justified on a patient case individual basis.

Semi-commercial scale production of carrageenan plant growth promoter by E-beam technology

NASA Astrophysics Data System (ADS)

Abad, Lucille V.; Dean, Giuseppe Filam O.; Magsino, Gil L.; Dela Cruz, Rafael Miguel M.; Tecson, Mariel G.; Abella, Matt Ezekiel S.; Hizon, Mark Gil S.

2018-02-01

The plant growth promoter (PGP) effect of different formulations of gamma-irradiated carrageenan solutions were tested on rice by foliar spraying. The best formulation was produced in large quantity for field application. Multilocation trials of around 1600 ha rice field in different regions of the Philippines indicated increase in yield of an average of around 20%. Increased resistance to tungro virus was also noted. Likewise, there was extensive root growth, increase in number of tillers, and development of sturdy stems that prevented lodging of rice plant. E-beam irradiation of carrageenan PGP was also studied to increase its throughput of production. Degradation of carrageenan by e-beam irradiation is inhibited by the formation of crosslinks. Optimisation by addition of hydrogen peroxide to improve degradation is discussed. A continuous flow liquid handling system has been fabricated to increase throughput of the carrageenan PGP. Using the optimized parameters, the system can produce a volume of approximately 1700 L/h.

Tomotherapy as a tool in image-guided radiation therapy (IGRT): theoretical and technological aspects

PubMed Central

Yartsev, S; Kron, T; Van Dyk, J

2007-01-01

Helical tomotherapy (HT) is a novel treatment approach that combines Intensity-Modulate Radiation Therapy (IMRT) delivery with in-built image guidance using megavoltage (MV) CT scanning. The technique utilises a 6 MV linear accelerator mounted on a CT type ring gantry. The beam is collimated to a fan beam, which is intensity modulated using a binary multileaf collimator (MLC). As the patient advances slowly through the ring gantry, the linac rotates around the patient with a leaf-opening pattern optimised to deliver a highly conformal dose distribution to the target in the helical beam trajectory. The unit also allows the acquisition of MVCT images using the same radiation source detuned to reduce its effective energy to 3.5 MV, making the dose required for imaging less than 3 cGy. This paper discusses the major features of HT and describes the advantages and disadvantages of this approach in the context of the commercial Hi-ART system. PMID:21614257

Studies of X-ray burst reactions with radioactive ion beams from RESOLUT

NASA Astrophysics Data System (ADS)

Blackmon, J. C.; Wiedenhöver, I.; Belarge, J.; Kuvin, S. A.; Anastasiou, M.; Baby, L. T.; Baker, J.; Colbert, K.; Deibel, C. M.; de Lucio, O.; Gardiner, H. E.; Gay, D. L.; Good, E.; Höflich, P.; Hood, A. A. D.; Keely, N.; Lai, J.; Laminack, A.; Linhardt, L. E.; Lighthall, J.; Macon, K. T.; Need, E.; Quails, N.; Rasco, B. C.; Rijal, N.; Volya, A.

2018-01-01

Reactions on certain proton-rich, radioactive nuclei have been shown to have a significant influence on X-ray bursts. We provide an overview of two recent measurements of important X-ray burst reactions using in-flight radioactive ion beams from the RESOLUT facility at the J. D. Fox Superconducting Accelerator Laboratory at Florida State University. The 17F(d,n)18Ne reaction was measured, and Asymptotic Normalization Coefficients were extracted for bound states in 18Ne that determine the direct-capture cross section dominating the 17F(p,γ)18Ne reaction rate for T≲ 0.45 GK. Unbound resonant states were also studied, and the single-particle strength for the 4.523-MeV (3+) state was found to be consistent with previous results. The 19Ne(d,n)20Na proton transfer reaction was used to study resonances in the 19Ne(p,γ)20Na reaction. The most important 2.65-MeV state in 20Na was observed to decay by proton emission to both the ground and first-excited states in 19Ne, providing strong evidence for a 3+ spin assignment and indicating that proton capture on the thermally-populated first-excited state in 19Ne is an important contributor to the 19Ne(p,γ)20Na reaction rate.

Astrophysics at RIA (ARIA) Working Group

NASA Astrophysics Data System (ADS)

Smith, Michael S.; Schatz, Hendrik; Timmes, Frank X.; Wiescher, Michael; Greife, Uwe

2006-07-01

The Astrophysics at RIA (ARIA) Working Group has been established to develop and promote the nuclear astrophysics research anticipated at the Rare Isotope Accelerator (RIA). RIA is a proposed next-generation nuclear science facility in the U.S. that will enable significant progress in studies of core collapse supernovae, thermonuclear supernovae, X-ray bursts, novae, and other astrophysical sites. Many of the topics addressed by the Working Group are relevant for the RIKEN RI Beam Factory, the planned GSI-Fair facility, and other advanced radioactive beam facilities.

Elastic scattering and total reaction cross section of {sup 6}He+{sup 120}Sn

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faria, P. N. de; Lichtenthaeler, R.; Pires, K. C. C.

The elastic scattering of {sup 6}He on {sup 120}Sn has been measured at four energies above the Coulomb barrier using the {sup 6}He beam produced at the RIBRAS (Radioactive Ion Beams in Brasil) facility. The elastic angular distributions have been analyzed with the optical model and three- and four-body continuum-discretized coupled-channels calculations. The total reaction cross sections have been derived and compared with other systems of similar masses.

Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

NASA Astrophysics Data System (ADS)

Fedosseev, Valentin; Chrysalidis, Katerina; Day Goodacre, Thomas; Marsh, Bruce; Rothe, Sebastian; Seiffert, Christoph; Wendt, Klaus

2017-08-01

At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments. This article belongs to the Focus on Exotic Beams at ISOLDE: A Laboratory Portrait special issue.

Examination of the properties of IMRT and VMAT beams and evaluation against pre-treatment quality assurance results

NASA Astrophysics Data System (ADS)

Crowe, S. B.; Kairn, T.; Middlebrook, N.; Sutherland, B.; Hill, B.; Kenny, J.; Langton, C. M.; Trapp, J. V.

2015-03-01

This study aimed to provide a detailed evaluation and comparison of a range of modulated beam evaluation metrics, in terms of their correlation with QA testing results and their variation between treatment sites, for a large number of treatments. Ten metrics including the modulation index (MI), fluence map complexity, modulation complexity score (MCS), mean aperture displacement (MAD) and small aperture score (SAS) were evaluated for 546 beams from 122 intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) treatment plans targeting the anus, rectum, endometrium, brain, head and neck and prostate. The calculated sets of metrics were evaluated in terms of their relationships to each other and their correlation with the results of electronic portal imaging based quality assurance (QA) evaluations of the treatment beams. Evaluation of the MI, MAD and SAS suggested that beams used in treatments of the anus, rectum, head and neck were more complex than the prostate and brain treatment beams. Seven of the ten beam complexity metrics were found to be strongly correlated with the results from QA testing of the IMRT beams (p < 0.00008). For example, values of SAS (with multileaf collimator apertures narrower than 10 mm defined as ‘small’) less than 0.2 also identified QA passing IMRT beams with 100% specificity. However, few of the metrics are correlated with the results from QA testing of the VMAT beams, whether they were evaluated as whole 360° arcs or as 60° sub-arcs. Select evaluation of beam complexity metrics (at least MI, MCS and SAS) is therefore recommended, as an intermediate step in the IMRT QA chain. Such evaluation may also be useful as a means of periodically reviewing VMAT planning or optimiser performance.

Optimised Combined Angular and Energy Dispersive Diffraction at the PSICHE Beam Line of the SOLEIL Synchrotron for Fast, High Q-range Structure Determination at High Pressure and Temperature.

NASA Astrophysics Data System (ADS)

King, A.; Guignot, N.; Boulard, E.; Deslandes, J. P.; Clark, A. N.; Morard, G.; Itié, J. P.

2017-12-01

Synchrotron diffraction is an ideal technique for investigating materials at high pressure and temperature, because the penetrating nature of high-energy X-rays allows measurements to be made inside pressure cells or sample environments. Wang et al. described the CAESAR acquisition strategy, in which energy and angular dispersive techniques are combined to produce an instrument particularly suitable for quantitative measurements from samples inside high-pressure apparati [1]. The PSICHE beam line of the SOLEIL Synchrotron is equipped with such a CAESAR system. Uniquely, this system allows energy dispersive diffraction spectra to be acquired at scattering angles between -5 and +30 degrees two theta, while maintaining a sphere of confusion at the measurement position in the order of 10 microns. The slits used to define the scattering angle act as Soller slits and select the diffracted volume, separating the sample from its environment. By developing an optimised acquisition strategy we are able to obtain data covering a very wide Q range (to 160nm-1 or more), while minimising the total acquisition time (one hour per complete acquisition). In addition, the 2D nature (angle and energy) of the acquired dataset enables the effective incident spectrum to be efficiently determined with no addition measurements, in order to normalise the acquired data. The resulting profile of scattered intensity as a function of Q is suitable for Fourier transform analysis of liquid or amorphous structures. PSICHE is a multi technique beam line, with a part of the beam time dedicated to parallel beam absorption and phase contrast radiography and tomography [2]. Examples will be given to show how these techniques can be combined with diffraction techniques to greatly enrich studies of materials at extreme conditions. [1] Wang, Y., Uchida, T., Von Dreele, R., Rivers, M. L., Nishiyama, N., Funakoshi, K., Nozawa, A., and Keneko, H., J. Appl. Crystallogr. 37, 947 (2004). [2] King, A., Guignot, N., Zerbino, P., Boulard, E., Desjardins, K., Bourdessoule, M., Leclerq, N., Le, S., Renaud, G., Cerato, M., Bornert, M., Lenoir, N., Delzon, S., Perrillat, J.-P., Legodec, Y., Itié, J.-P. Rev. Sci. Instrum. 87, 093704 (2016).

Thick-target transmission method for excitation functions of interaction cross sections

NASA Astrophysics Data System (ADS)

Aikawa, M.; Ebata, S.; Imai, S.

2016-09-01

We propose a method, called as thick-target transmission (T3) method, to obtain an excitation function of interaction cross sections. In an ordinal experiment to measure the excitation function of interaction cross sections by the transmission method, we need to change the beam energy for each cross section. In the T3 method, the excitation function is derived from the beam attenuations measured at the targets of different thicknesses without changing the beam energy. The advantage of the T3 method is the simplicity and availability for radioactive beams. To confirm the availability, we perform a simulation for the 12C + 27Al system with the PHITS code instead of actual experiments. Our results have large uncertainties but well reproduce the tendency of the experimental data.

Simulations for the future converter of the e-linac for the TRIUMF ARIEL facility

NASA Astrophysics Data System (ADS)

Lebois, M.; Bricault, P.

2011-09-01

In the next years, TRIUMF activity will be focused on building a new facility to produce very intense neutron rich radioactive ion beams. Unlike others ISOL facilities, the e-linac primary beam, that will induce the fission, is an intense electron beam (50 MeV energy and 10 mA intensity). This challenging choice, which make this installation unique, despite the ALTO facility, makes an average fission rate of 1013-14fissions/s in the target.This beam is sent on an uranium carbide target (UCx), but due to its power, it is essential to insert a "converter" on the beam path to avoid a target overheating. The purpose of this converter is to convert electrons into Bremsstralhung radiation. The γ rays produce excite the dipole resonance of 23892U (15 MeV) inducing fission. Energy deposition, fission rate and thermal behavior were simulated using Monte Carlo techniques are presented in this paper

Laboratory Astrophysics Prize: Laboratory Astrophysics with Nuclei

NASA Astrophysics Data System (ADS)

Wiescher, Michael

2018-06-01

Nuclear astrophysics is concerned with nuclear reaction and decay processes from the Big Bang to the present star generation controlling the chemical evolution of our universe. Such nuclear reactions maintain stellar life, determine stellar evolution, and finally drive stellar explosion in the circle of stellar life. Laboratory nuclear astrophysics seeks to simulate and understand the underlying processes using a broad portfolio of nuclear instrumentation, from reactor to accelerator from stable to radioactive beams to map the broad spectrum of nucleosynthesis processes. This talk focuses on only two aspects of the broad field, the need of deep underground accelerator facilities in cosmic ray free environments in order to understand the nucleosynthesis in stars, and the need for high intensity radioactive beam facilities to recreate the conditions found in stellar explosions. Both concepts represent the two main frontiers of the field, which are being pursued in the US with the CASPAR accelerator at the Sanford Underground Research Facility in South Dakota and the FRIB facility at Michigan State University.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knight, Stephen P, E-mail: stephen.knight@health.qld.gov.au

The aim of this review was to develop a radiographic optimisation strategy to make use of digital radiography (DR) and needle phosphor computerised radiography (CR) detectors, in order to lower radiation dose and improve image quality for paediatrics. This review was based on evidence-based practice, of which a component was a review of the relevant literature. The resulting exposure chart was developed with two distinct groups of exposure optimisation strategies – body exposures (for head, trunk, humerus, femur) and distal extremity exposures (elbow to finger, knee to toe). Exposure variables manipulated included kilovoltage peak (kVp), target detector exposure and milli-ampere-secondsmore » (mAs), automatic exposure control (AEC), additional beam filtration, and use of antiscatter grid. Mean dose area product (DAP) reductions of up to 83% for anterior–posterior (AP)/posterior–anterior (PA) abdomen projections were recorded postoptimisation due to manipulation of multiple-exposure variables. For body exposures, the target EI and detector exposure, and thus the required mAs were typically 20% less postoptimisation. Image quality for some distal extremity exposures was improved by lowering kVp and increasing mAs around constant entrance skin dose. It is recommended that purchasing digital X-ray equipment with high detective quantum efficiency detectors, and then optimising the exposure chart for use with these detectors is of high importance for sites performing paediatric imaging. Multiple-exposure variables may need to be manipulated to achieve optimal outcomes.« less

Simulation and Optimization of an Astrophotonic Reformatter

NASA Astrophysics Data System (ADS)

Anagnos, Th; Harris, R. J.; Corrigan, M. K.; Reeves, A. P.; Townson, M. J.; MacLachlan, D. G.; Thomson, R. R.; Morris, T. J.; Schwab, C.; Quirrenbach, A.

2018-05-01

Image slicing is a powerful technique in astronomy. It allows the instrument designer to reduce the slit width of the spectrograph, increasing spectral resolving power whilst retaining throughput. Conventionally this is done using bulk optics, such as mirrors and prisms, however more recently astrophotonic components known as PLs and photonic reformatters have also been used. These devices reformat the MM input light from a telescope into SM outputs, which can then be re-arranged to suit the spectrograph. The PD is one such device, designed to reduce the dependence of spectrograph size on telescope aperture and eliminate modal noise. We simulate the PD, by optimising the throughput and geometrical design using Soapy and BeamProp. The simulated device shows a transmission between 8 and 20 %, depending upon the type of AO correction applied, matching the experimental results well. We also investigate our idealised model of the PD and show that the barycentre of the slit varies only slightly with time, meaning that the modal noise contribution is very low when compared to conventional fibre systems. We further optimise our model device for both higher throughput and reduced modal noise. This device improves throughput by 6.4 % and reduces the movement of the slit output by 50%, further improving stability. This shows the importance of properly simulating such devices, including atmospheric effects. Our work complements recent work in the field and is essential for optimising future photonic reformatters.

The radioactive beam facility ALTO

NASA Astrophysics Data System (ADS)

Essabaa, Saïd; Barré-Boscher, Nicole; Cheikh Mhamed, Maher; Cottereau, Evelyne; Franchoo, Serge; Ibrahim, Fadi; Lau, Christophe; Roussière, Brigitte; Saïd, Abdelhakim; Tusseau-Nenez, Sandrine; Verney, David

2013-12-01

The Transnational Access facility ALTO (TNA07-ENSAR/FP7) has been commissioned and received from the French safety authorities, the operation license. It is allowed to run at nominal intensity to produce 1011 fissions/s in a thick uranium carbide target by photo-fission using a 10 μA, 50 MeV electron beam. In addition the recent success in operating the selective laser ion source broadens the physics program with neutron-rich nuclear beams possible at this facility installed at IPN Orsay. The facility also aims at being a test bench for the SPIRAL2 project. In that framework an ambitious R&D program on the target ion source system is being developed.

Small plasma focus as neutron pulsed source for nuclides identification

NASA Astrophysics Data System (ADS)

Milanese, M.; Niedbalski, J.; Moroso, R.; Barbaglia, M.; Mayer, R.; Castillo, F.; Guichón, S.

2013-10-01

In this paper, we present preliminary results on the feasibility of employing a low energy (2 kJ, 31 kV) plasma focus device as a portable source of pulsed neutron beams (2.45 MeV) generated by nuclear fusion reactions D-D, for the "in situ" analysis of substances by nuclear activation. This source has the relevant advantage of being pulsed at requirement, transportable, not permanently radioactive, without radioactive waste, cheap, among others. We prove the feasibility of using this source showing several spectra of the characteristic emission line for manganese, gold, lead, and silver.

Small plasma focus as neutron pulsed source for nuclides identification.

PubMed

Milanese, M; Niedbalski, J; Moroso, R; Barbaglia, M; Mayer, R; Castillo, F; Guichón, S

2013-10-01

In this paper, we present preliminary results on the feasibility of employing a low energy (2 kJ, 31 kV) plasma focus device as a portable source of pulsed neutron beams (2.45 MeV) generated by nuclear fusion reactions D-D, for the "in situ" analysis of substances by nuclear activation. This source has the relevant advantage of being pulsed at requirement, transportable, not permanently radioactive, without radioactive waste, cheap, among others. We prove the feasibility of using this source showing several spectra of the characteristic emission line for manganese, gold, lead, and silver.

Fourteenth Exotic Beam Summer School EBSS 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiedenhoever, Ingo

The Fourteenth Annual Exotic Beam Summer School EBSS 2015 was held August 2nd - August 7th, 2015, and belongs to the series of summer programs aimed at educating future workforce in nuclear physics-related areas, mostly about the challenges of radioactive ion beam physics. Through these schools the research community will be able to exploit fully the opportunities created by the exotic beam facilities. These facilities in the US include CARIBU at ANL, the NSCL and the future FRIB laboratory as well as smaller-scale university laboratories. The skill set needed by the future workforce is very diverse and a fundamental understandingmore » of theoretical, technical, computational and applied fields are all important. Therefore, the Exotic Beam Summer Schools follow a unique approach, in which the students not only receive lectures but also participate in hands-on activities. The lectures covered broad topics in both the experimental and theoretical physics of nuclei far from stability as well as radioactive ions production and applications. The afternoons provided opportunities for "hands-on" projects with experimental equipment and techniques useful in FRIB research. Five activities were performed in groups of eight students, rotating through the activities over the five afternoons of the school. The center of the activities was an experiment at the FSU tandem accelerator, measuring the angular distribution and cross section of the 12C(d,p) 13C transfer reaction, measured with a silicon telescope in a scattering chamber. The experimental data were analyzed by performing a DWBA calculation with the program DWUCK, and the resulting spectroscopic factors were compared to a shell model calculation. The other activities included target preparation, digital gamma-spectroscopy and modern neutron detection methods.« less

A neutron beam facility for radioactive ion beams and other applications

NASA Astrophysics Data System (ADS)

Tecchio, L. B.

1999-06-01

In the framework of the Italian participation in the project of a high intensity proton facility for the energy amplifier and nuclear waste transmutations, LNL is involved in the design and construction of same prototypes of the injection system of the 1 GeV linac that consists of a RFQ (5 MeV, 30 mA) followed by a 100 MeV linac. This program has already been supported financially and the work is in progress. In this context LNL has proposed a project for the construction of a second generation facility for the production of radioactive ion beams (RIBs) by means of the ISOL method. The final goal is the production of neutron rich RIBs with masses ranging from 30 to 150 by using primary beams of protons, deuterons and light ions with energy of 100 MeV and 100 kW power. This project is expected to be developed in about 10 years from new and intermediate milestones and experiments are foreseen and under consideration for the next INFN five year plan (1999-2003). During that period the construction of a proton/deuteron accelerator of 10 MeV energy and 10 mA current, consisting of a RFQ (5 MeV, 30 mA) and a linac (10 MeV, 10 mA), and of a neutron area dedicated to the RIBs production and to the neutron physics, is proposed. Some remarks on the production methods will be presented. The possibility of producing radioisotopes by means of the fission induced by neutrons will be investigated and the methods of production of neutrons will be discussed. Besides the RIBs production, neutron beams for the BNCT applications and neutron physics are also planned.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moon, Chang-Bum, E-mail: cbmoon@hoseo.edu

This paper outlines the new physics possibilities that fall within the field of nuclear structure and astrophysics based on experiments with radioactive ion beams at the future Rare Isotope Beams Accelerator facility in Korea. This ambitious multi-beam facility has both an Isotope Separation On Line (ISOL) and fragmentation capability to produce rare isotopes beams (RIBs) and will be capable of producing and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. The large dynamic range of reaccelerated RIBs will allow the optimization in each nuclear reaction case with respect to crossmore » section and channel opening. The low energy RIBs around Coulomb barrier offer nuclear reactions such as elastic resonance scatterings, one or two particle transfers, Coulomb multiple-excitations, fusion-evaporations, and direct capture reactions for the study of the very neutron-rich and proton-rich nuclides. In contrast, the high energy RIBs produced by in-flight fragmentation with reaccelerated ions from the ISOL enable to explore the study of neutron drip lines in intermediate mass regions. The proposed studies aim at investigating the exotic nuclei near and beyond the nucleon drip lines, and to explore how nuclear many-body systems change in such extreme regions by addressing the following topics: the evolution of shell structure in areas of extreme proton to neutron imbalance; the study of the weak interaction in exotic decay schemes such as beta-delayed two-neutron or two-proton emission; the change of isospin symmetry in isobaric mirror nuclei at the drip lines; two protons or two neutrons radioactivity beyond the drip lines; the role of the continuum states including resonant states above the particle-decay threshold in exotic nuclei; and the effects of nuclear reaction rates triggered by the unbound proton-rich nuclei on nuclear astrophysical processes.« less

Radiological Environmental Protection for LCLS-II High Power Operation

NASA Astrophysics Data System (ADS)

Liu, James; Blaha, Jan; Cimeno, Maranda; Mao, Stan; Nicolas, Ludovic; Rokni, Sayed; Santana, Mario; Tran, Henry

2017-09-01

The LCLS-II superconducting electron accelerator at SLAC plans to operate at up to 4 GeV and 240 kW average power, which would create higher radiological impacts particularly near the beam loss points such as beam dumps and halo collimators. The main hazards to the public and environment include direct or skyshine radiation, effluent of radioactive air such as 13N, 15O and 41Ar, and activation of groundwater creating tritium. These hazards were evaluated using analytic methods and FLUKA Monte Carlo code. The controls (mainly extensive bulk shielding and local shielding around high loss points) and monitoring (neutron/photon detectors with detection capabilities below natural background at site boundary, site-wide radioactive air monitors, and groundwater wells) were designed to meet the U.S. DOE and EPA, as well as SLAC requirements. The radiological design and controls for the LCW systems [including concrete housing shielding for 15O and 11C circulating in LCW, 7Be and erosion/corrosion products (22Na, 54Mn, 60Co, 65Zn, etc.) captured in resin and filters, leak detection and containment of LCW with 3H and its waste water discharge; explosion from H2 build-up in surge tank and release of radionuclides] associated with the high power beam dumps are also presented.

The MedAustron project

NASA Astrophysics Data System (ADS)

Griesmayer, E.; Schreiner, T.; Pavlovič, M.

2007-05-01

The Austrian government has approved its financial contribution to the MedAustron project in October 2004. MedAustron, the Austrian ion therapy and cancer research centre, should be set into operation in 2010. MedAustron combines medical cancer treatment and cancer research and non-clinical research. For medical treatment and cancer research active scanning of a proton and a carbon-ion beam is provided. The beam energy must correspond to the desirable penetration range of the beam in the patient body, which translates into the energy interval of 60-220 MeV protons and 120-400 MeV per nucleon carbon ions. The intensity of extracted beam is 1010 protons per spill and four times 108 carbon ions per spill. Spill duration can be varied from 1 s to 10 s. For a spill lasting 1 s the beam intensity is equivalent to an electrical beam current of 1.6 nA for protons and 0.38 nA for carbon ions. Although the machine parameters must be optimised for therapy needs, additional beam features can be offered by a modern medical accelerator for non-clinical research. Various ions with energies up to 400 MeV per nucleon can be used for irradiation purposes. For synchrotrons such as proposed in the Design Study the magnetic rigidity would allow to accelerate protons up to 1.18 GeV when using an appropriate RF-system. Two beam lines are proposed for non-clinical research, such as biomedicine, medical physics, physics or industrial technological research. The experimental facility of MedAustron will be offered to research institutes and to industry on an international level.

Precision Gamma-Ray Branching Ratios for Long-Lived Radioactive Nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tonchev, Anton

Many properties of the high-energy-density environments in nuclear weapons tests, advanced laser-fusion experiments, the interior of stars, and other astrophysical bodies must be inferred from the resulting long-lived radioactive nuclei that are produced. These radioactive nuclei are most easily and sensitively identified by studying the characteristic gamma rays emitted during decay. Measuring a number of decays via detection of the characteristic gamma-rays emitted during the gamma-decay (the gamma-ray branching ratio) of the long-lived fission products is one of the most straightforward and reliable ways to determine the number of fissions that occurred in a nuclear weapon test. The fission productsmore » 147Nd, 144Ce, 156Eu, and certain other long-lived isotopes play a crucial role in science-based stockpile stewardship, however, the large uncertainties (about 8%) on the branching ratios measured for these isotopes are currently limiting the usefulness of the existing data [1,2]. We performed highly accurate gamma-ray branching-ratio measurements for a group of high-atomic-number rare earth isotopes to greatly improve the precision and reliability with which the fission yield and reaction products in high-energy-density environments can be determined. We have developed techniques that take advantage of new radioactive-beam facilities, such as DOE's CARIBU located at Argonne National Laboratory, to produce radioactive samples and perform decay spectroscopy measurements. The absolute gamma-ray branching ratios for 147Nd and 144Ce are reduced <2% precision. In addition, high-energy monoenergetic neutron beams from the FN Tandem accelerator in TUNL at Duke University was used to produce 167Tm using the 169Tm(n,3n) reaction. Fourtime improved branching ratio of 167Tm is used now to measure reaction-in-flight (RIF) neutrons from a burning DT capsule at NIF [10]. This represents the first measurement of RIF neutrons in any laboratory fusion system, and the magnitude of the signal has important implications for fundamental plasma science and for weapons physics.« less

High Spin Isomers and Super Heavy Elements (SHE) Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popescu, Domitian G.

2010-04-30

To get closer to the SHE-Island the new radioactive beams are proposed for future fusion reaction. We suggest something different: to use the advantage of High Spin Isomer States, by tacking into account the importance of the G (spin-isospin cupling) suggested by Ripka 1.

An Orthotropic Oven for Loading Vapor Traps

NASA Astrophysics Data System (ADS)

Maddi, J.; Dinneen, T.; Gould, H.

1998-05-01

Orthotropic ovens(T. Dinneen, A. Ghiorso, and H. Gould, Rev. Sci. Inst. 67, 752 (1996) ) produce collimated beams of alkali atoms with high efficiency. They are useful for producing beams of rare species such as short-lived radioactive atoms. We describe the design and operation of the UHV orthotropic oven used in vapor-capture trapping and cooling(Z.-T. Lu, K.L. Corwin, K.R. Vogel, C.E. Wieman, T.P. Dinneen, J. Maddi, and H. Gould, Phys. Rev. Lett. 79, 994 (1997)) of ^221Fr, and recent improvments in its design.

β -delayed neutron emission from 85Ga

NASA Astrophysics Data System (ADS)

Miernik, K.; Rykaczewski, K. P.; Grzywacz, R.; Gross, C. J.; Madurga, M.; Miller, D.; Stracener, D. W.; Batchelder, J. C.; Brewer, N. T.; Korgul, A.; Mazzocchi, C.; Mendez, A. J.; Liu, Y.; Paulauskas, S. V.; Winger, J. A.; Wolińska-Cichocka, M.; Zganjar, E. F.

2018-05-01

Decay of 85Ga was studied by means of β -neutron-γ spectroscopy. A pure beam of 85Ga was produced at the Holifield Radioactive Ion Beam Facility using a resonance ionization laser ion source and a high-resolution electromagnetic separator. The β -delayed neutron emission probability was measured for the first time, yielding 70(5)%. An upper limit of 0.1% for β -delayed two-neutron emission was also experimentally established for the first time. A detailed decay scheme including absolute γ -ray intensities was obtained. Results are compared with theoretical β -delayed emission models.

Physics and applications of positron beams in an integrated PET/MR.

PubMed

Watson, Charles C; Eriksson, Lars; Kolb, Armin

2013-02-07

In PET/MR systems having the PET component within the uniform magnetic field interior to the MR, positron beams can be injected into the PET field of view (FOV) from unshielded emission sources external to it, as a consequence of the action of the Lorentz force on the transverse components of the positron's velocity. Such beams may be as small as a few millimeters in diameter, but extend 50 cm or more axially without appreciable divergence. Larger beams form 'phantoms' of annihilations in air that can be easily imaged, and that are essentially free of γ-ray attenuation and scatter effects, providing a unique tool for characterizing PET systems and reconstruction algorithms. Thin targets intersecting these beams can produce intense annihilation sources having the thickness of a sheet of paper, which are very useful for high resolution measurements, and difficult to achieve with conventional sources. Targeted beams can provide other point, line and surface sources for various applications, all without the need to have radioactivity within the FOV. In this paper we discuss the physical characteristics of positron beams in air and present examples of their applications.

IBM-2 calculation with configuration mixing for Ge isotopes

NASA Astrophysics Data System (ADS)

Padilla-Rodal, Elizabeth; Galindo-Uribarri, Alfredo

2005-04-01

Recent results on Coulomb excitation experiments of radioactive neutron-rich Ge isotopes at the Holifield Radioactive Ion Beam Facility allow the study of the systematic trend of B(E2; 0^+ ->2^+) between the sub-shell closures at N=40 and the N=50 [1]. The new information on the E2 transition strengths constitutes a stringent test for the nuclear models and has motivated us to revisit the use of Interacting Boson Model in this region. We show that the IBM-2 with configuration mixing is a successful model to describe the shape transition phenomena that take place around N=40 in stable germanium isotopes, as well as the predictions given by this model about the evolution of the structure for the radioactive ^78, 80, 82Ge nuclei. [1] E. Padilla-Rodal Ph.D. Thesis UNAM; submitted for publication.

Nuclear Structure Research at TRIUMF

NASA Astrophysics Data System (ADS)

Garrett, P. E.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Chakrawarthy, R. S.; Cline, D.; Cooper, R. J.; Churchman, R.; Cross, D.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gagon-Miosan, F.; Gallant, A. T.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Hackman, G.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Kulp, W. D.; Leach, K. G.; Lee, G.; Leslie, J. R.; Martin, J.-P.; Mattoon, C.; Mills, W. J.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Padilla-Rodal, E.; Pearson, C. J.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Savajols, H.; Sarazin, F.; Schumaker, M. A.; Scraggs, D. P.; Scraggs, H. C.; Strange, M. D.; Svensson, C. E.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.; Wood, J. L.; Wu, C. Y.; Zganjar, E. F.

2007-04-01

The radioactive beam laboratory at TRIUMF is currently the highest power ISOL facility in the world. Taking advantage of the high-intensity beams, major programs in nuclear astrophysics, nuclear structure, and weak interaction studies have begun. The low-energy area, ISAC-I, is capable of delivering beams up to mass 30 at approx 1.7 MeV/u or 60 keV up to the mass of the primary target, whereas ISAC-II will ultimately provide beams up to mass 150 and approx 6.5 MeV/u. Major gamma -ray spectrometers for nuclear structure research consist of the 8pi spectrometer at ISAC-I, and the TIGRESS spectrometer now being constructed for ISAC-II. Results from recent experiments investigating the beta -decay of nuclei near N=90 and Coulomb excitation of 20,21Na are presented that highlight the capabilities of the spectrometers.

Proposed BISOL Facility - a Conceptual Design

NASA Astrophysics Data System (ADS)

Ye, Yanlin

2018-05-01

In China, a new large-scale nuclear-science research facility, namely the "Beijing Isotope-Separation-On-Line neutron-rich beam facility (BISOL)", has been proposed and reviewed by the governmental committees. This facility aims at both basic science and application goals, and is based on a double-driver concept. On the basic science side, the radioactive ion beams produced from the ISOL device, driven by a research reactor or by an intense deuteron-beam ac- celerator, will be used to study the new physics and technologies at the limit of the nuclear stability in the medium mass region. On the other side regarding to the applications, the facility will be devoted to the material research asso- ciated with the nuclear energy system, by using typically the intense neutron beams produced from the deuteron-accelerator driver. The initial design will be outlined in this report.

A 6He production facility and an electrostatic trap for measurement of the beta-neutrino correlation

NASA Astrophysics Data System (ADS)

Mukul, I.; Hass, M.; Heber, O.; Hirsh, T. Y.; Mishnayot, Y.; Rappaport, M. L.; Ron, G.; Shachar, Y.; Vaintraub, S.

2018-08-01

A novel experiment has been commissioned at the Weizmann Institute of Science for the study of weak interactions via a high-precision measurement of the beta-neutrinoangular correlation in the radioactive decay of short-lived 6He. The facility consists of a 14 MeV d + t neutron generator to produce atomic 6He, followed by ionization and bunching in an electron beam ion source, and injection into an electrostatic ion beam trap. This ion trap has been designed for efficient detection of the decay products from trapped light ions. The storage time in the trap for different stable ions was found to be in the range of 0.6 to 1.2 s at the chamber pressure of ∼7 × 10-10 mbar. We present the initial test results of the facility, and also demonstrate an important upgrade of an existing method (Stora et al., 2012) for production of light radioactive atoms, viz. 6He, for the precision measurement. The production rate of 6He atoms in the present setup has been estimated to be ∼ 1 . 45 × 10-4 atoms per neutron, and the system efficiency was found to be 4.0 ± 0.6%. An improvement to this setup is also presented for the enhanced production and diffusion of radioactive atoms for future use.

Metrology conditions for thin layer activation in wear and corrosion studies

NASA Astrophysics Data System (ADS)

Lacroix, O.; Sauvage, T.; Blondiaux, G.; Racolta, P. M.; Popa-Simil, L.; Alexandreanu, B.

1996-02-01

Thin Layer Activation (TLA) is an ion beam technique. This method consists of an accelerated ion bombardment of the surface of interest of a machine part subjected to wear. Radioactive tracers are created by nuclear reactions in a well defined volume of material. Loss of material owing to wear, corrosion or abrasion phenomena is characterized by monitoring the resulting changes in radioactivity. For the industrial application of this method, special attention has been paid during irradiation to the range of activated thickness, yields and activation homogeneity and to on-line radioactivity measurements. There are two basic methods for measuring the material loss by TLA technique. One of them is based on remanant radioactivity measurements using a previously obtained calibration curve. The second is based on measuring the increasing radioactivity in the lubricant due to suspended wear particles. In this paper, we have chosen to present some calibration curves for both proton and deuteron irradiation of Fe, Cr, Cu, Ti and Ni samples. Thickness ranges are indicated and intrinsic error checking and calculational procedures are also presented. The article ends with a review of some typical experiments involving running-in programme optimization and lubricants certifying procedures.

Timepix Device Efficiency for Pattern Recognition of Tracks Generated by Ionizing Radiation

NASA Astrophysics Data System (ADS)

Leroy, Claude; Asbah, Nedaa; Gagnon, Louis-Guilaume; Larochelle, Jean-Simon; Pospisil, Stanislav; Soueid, Paul

2014-06-01

A hybrid silicon pixelated TIMEPIX detector (256 × 256 pixels with 55 μm pitch) operated in Time Over Threshold (TOT) mode was exposed to radioactive sources (241Am, 106Ru, 137Cs), protons and alpha-particles after Rutherford Backscattering on a thin gold foil of protons and alpha-particles beams delivered by the Tandem Accelerator of Montreal University. Measurements were also performed with different mixed radiation fields of heavy charged particles (protons and alpha-particles), photons and electrons produced by simultaneous exposure of TIMEPIX to the radioactive sources and to protons beams on top of the radioactive sources. All measurements were performed in vacuum. The TOT mode of operation has allowed the direct measurement of the energy deposited in each pixel. The efficiency of track recognition with this device was tested by comparing the experimental activities (determined from number of tracks measurements) of the radioactive sources with their expected activities. The efficiency of track recognition of incident protons and alpha-particles of different energies as a function of the incidence angle was measured. The operation of TIMEPIX in TOT mode has allowed a 3D mapping of the charge sharing effect in the whole volume of the silicon sensor. The effect of the bias voltage on charge sharing was investigated as the level of charge sharing is related to the local profile of the electric field in the sensor. The results of the present measurements demonstrate the TIMEPIX capability of differentiating between different types of particles species from mixed radiation fields and measuring their energy deposition. Single track analysis gives a good precision (significantly better than the 55 μm size of one detector pixel) on the coordinates of the impact point of protons interacting in the TIMEPIX silicon layer.

Better powder diffractometers. II—Optimal choice of U, V and W

NASA Astrophysics Data System (ADS)

Cussen, L. D.

2007-12-01

This article presents a technique for optimising constant wavelength (CW) neutron powder diffractometers (NPDs) using conventional nonlinear least squares methods. This is believed to be the first such design optimisation for a neutron spectrometer. The validity of this approach and discussion should extend beyond the Gaussian element approximation used and also to instruments using different radiation, such as X-rays. This approach could later be extended to include vertical and perhaps horizontal focusing monochromators and probably other types of instruments such as three axis spectrometers. It is hoped that this approach will help in comparisons of CW and time-of-flight (TOF) instruments. Recent work showed that many different beam element combinations can give identical resolution on CW NPDs and presented a procedure to find these combinations and also find an "optimum" choice of detector collimation. Those results enable the previous redundancy in the description of instrument performance to be removed and permit a least squares optimisation of design. New inputs are needed and are identified as the sample plane spacing ( dS) of interest in the measurement. The optimisation requires a "quality factor", QPD, chosen here to be minimising the worst Bragg peak separation ability over some measurement range ( dS) while maintaining intensity. Any other QPD desired could be substituted. It is argued that high resolution and high intensity powder diffractometers (HRPDs and HIPDs) should have similar designs adjusted by a single scaling factor. Simulated comparisons are described suggesting significant improvements in performance for CW HIPDs. Optimisation with unchanged wavelength suggests improvements by factors of about 2 for HRPDs and 25 for HIPDs. A recently quantified design trade-off between the maximum line intensity possible and the degree of variation of angular resolution over the scattering angle range leads to efficiency gains at short wavelengths. This in turn leads in practice to another trade-off between this efficiency gain and losses at short wavelength due to technical effects. The exact gains from varying wavelength depend on the details of the short wavelength technical losses. Simulations suggest that the total potential PD performance gains may be very significant-factors of about 3 for HRPDs and more than 90 for HIPDs.

Evaluation of the dose received in the tissues of the neck during quantification of iodine in the thyroid by X-ray fluorescence spectrometry

NASA Astrophysics Data System (ADS)

Portararo, Antonio; Licour, Caroline; Gerardy, Isabelle; Pozuelo Navarro, Fausto

2018-04-01

The determination of the iodine content in the thyroid is of great interest for many investigations of this gland. The conventional scintigraphic method, using radionuclides, is efficient but delivers a significant dose to the patient. The X-ray fluorescence spectrometry could give information about the iodine content in the thyroid. The measured signal is obtained after stimulation of the stable iodine contained in the gland by X-rays. The advantage of this technique is the complete absence of radioactive isotope injected into the patient body. By applying this, a decrease in effective dose to the patient should be obtained. In this work, the study of the dose received by a thyroid phantom (surrounded by the different tissues of the neck) was performed. The phantom is made of PLA. The dose is measured in optimised conditions defined for the analytical technique. A total head-neck phantom was also used in order to consider the absorbed dose in each different tissues and organs as spinal cord or eyes. Thermo-luminescence dosimeters were chosen for their small size, their sensitivity and the easy positioning on the surface of the phantom but also inside of it to evaluate dose to internal organs. Those LiF 100 dosimeters have been calibrated within the X-ray beam also used for the analysis of iodine. The repeatability and reproducibility of the method has been evaluated. The influence of parameters as concentration of iodine in the thyroid, distance between the X-ray generator and the neck, thickness of the tissues surrounding the thyroid, has been investigated in terms of modifying parameters of the dose received by different tissues situated in the neck and the head.

Natural radioactivity in some rocks employed as dimension and decorative stones in the Nigerian building industry.

PubMed

Tubosun, I A; Tchokossa, P; Balogun, F A; Fasasi, M K; Ocan, O; Adesanmi, C A

2013-12-01

The natural radioactivity in some selected granites and allied rocks from the Basement Complex of Nigeria for use as dimension/decorative stones was measured by gamma-ray spectrometry. The average activity concentrations observed for the selected rock samples range from 9 to 124 Bq kg⁻¹; 13 to 60 Bq kg⁻¹ and 1360 to 2326 Bq kg⁻¹ for ²²⁶Ra, ²³²Th and ⁴⁰K, respectively. The mean radiological hazard indices were 121.62 nGy h⁻¹; 239.73 Bq kg⁻¹; 0.65 Bq kg⁻¹ and 0.77 Bq kg⁻¹ for the absorbed dose rate, radium equivalent, external hazard and internal hazard, respectively. The results obtained were examined on the basis of existing International recommended limits and compared with data on similar rocks from other parts of the world. The values obtained for the rocks, except one, were found to be lower than the values recommended for building materials, and the rocks are considered safe for use as decorative stones as defined by OECD criteria (NEA-OCED Nuclear Energy Agency Dose Constraints in Optimisation of Occupational Radiological Protection Report by NEA Group Experts, OCED, France (2011)). Results highlight the fact that, despite meeting certain suitability criteria such as colour, texture, etc., the radioactivity content of the rocks is another factor of importance for their continued application in the human environment/building industry.

Is blue dye still required during sentinel lymph node biopsy for breast cancer?

PubMed

Peek, Mirjam Cl; Kovacs, Tibor; Baker, Rose; Hamed, Hisham; Kothari, Ash; Douek, Michael

2016-01-01

In early breast cancer, the optimal technique for sentinel lymph node biopsy (SLNB) is the combined technique (radioisotope and Patent Blue V) which achieves high identification rates. Despite this, many centres have decided to stop using blue dye due to blue-dye-related complications (tattoo, anaphylaxis). We evaluated the SLNB identification rate using the combined technique with and without Patent Blue V and the blue-dye-related complication rates. Clinical and histological data were analysed on patients undergoing SLNB between March 2014 and April 2015. SLNB was performed following standard hospital protocols using the combined technique. A total of 208 patients underwent SLNB and 160 patients (342 nodes) with complete operation notes were available for final analysis. The identification rate with the combined technique was 98.8% ( n = 158/160), with blue dye alone 92.5% ( n = 148/160) and with radioisotope alone 97.5% ( n = 156/160). A total of 76.9% (263/342) of nodes were radioactive and blue, 15.5% (53/342) only radioactive and 2.3% (8/342) only blue, 5.3% (18/342) were neither radioactive nor blue. No anaphylactic reactions were reported and blue skin staining was reported in six (3.8%) patients. The combined technique should continue be the preferred technique for SLNB and should be standardised. Radioisotope alone (but not blue dye alone) has comparable sentinel node identification rates in experienced hands. National guidelines are required to optimise operative documentation.

Influence of standing positions and beam projections on effective dose and eye lens dose of anaesthetists in interventional procedures.

PubMed

Kong, Y; Struelens, L; Vanhavere, F; Vargas, C S; Schoonjans, W; Zhuo, W H

2015-02-01

More and more anaesthetists are getting involved in interventional radiology procedures and so it is important to know the radiation dose and to optimise protection for anaesthetists. In this study, based on Monte Carlo simulations and field measurements, both the whole-body doses and eye lens dose of anaesthetists were studied. The results showed that the radiation exposure to anaesthetists not only depends on their workload, but also largely varies with their standing positions and beam projections during interventional procedures. The simulation results showed that the effective dose to anaesthetists may vary with their standing positions and beam projections to more than a factor of 10, and the eye lens dose may vary with the standing positions and beam projections to more than a factor of 200. In general, a close position to the bed and the left lateral (LLAT) beam projection will bring a high exposure to anaesthetists. Good correlations between the eye lens dose and the doses at the neck, chest and waist over the apron were observed from the field measurements. The results indicate that adequate arrangements of anaesthesia device or other monitoring equipment in the fluoroscopy rooms are useful measures to reduce the radiation exposure to anaesthetists, and anaesthetists should be aware that they will receive the highest doses under left lateral beam projection. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

R-process experiments with the Advanced Implantation Detector Array

NASA Astrophysics Data System (ADS)

Estrade, Alfredo; Griffin, Chris; Davinson, Tom; Bruno, Carlo; Hall, Oscar; Liu, Zhong; Woods, Phil; Coleman-Smith, Patrick; Labiche, Marc; Lazarus, Ian; Pucknell, Victor; Simpson, John; Harkness-Brennan, Laura; Page, Robert; Kiss, Gabor; Liu, Jiajiang; Matsui, Keishi; Nishimura, Shunji; Phong, Vi; Lorusso, Giuseppe; Montes, Fernando; Nepal, Neerajan; Briken Collaboration; Ribf106 Experiment Team

2017-09-01

Decay properties of neutron rich isotopes, such as half-lives and β-delayed neutron emission probabilities, are an important input for astrophysical models of the r-process. A new generation of fragmentation beam facilities has made it possible to access large regions of the nuclear chart that are close to the path of the r-process for some astrophysical models. The Advanced Implantation Detector Array (AIDA) is a segmented active-stopper detector designed for decay experiments with fast ion beams, which was recently commissioned at the Radioactive Ion Beam Factory in RIKEN, Japan. In this presentation we describe the main characteristics of AIDA, and present preliminary results of the first experiments in the region of neutron-rich selenium isotopes and along the N=82 shell closure.

Progress towards a semiconductor Compton camera for prompt gamma imaging during proton beam therapy for range and dose verification

NASA Astrophysics Data System (ADS)

Gutierrez, A.; Baker, C.; Boston, H.; Chung, S.; Judson, D. S.; Kacperek, A.; Le Crom, B.; Moss, R.; Royle, G.; Speller, R.; Boston, A. J.

2018-01-01

The main objective of this work is to test a new semiconductor Compton camera for prompt gamma imaging. Our device is composed of three active layers: a Si(Li) detector as a scatterer and two high purity Germanium detectors as absorbers of high-energy gamma rays. We performed Monte Carlo simulations using the Geant4 toolkit to characterise the expected gamma field during proton beam therapy and have made experimental measurements of the gamma spectrum with a 60 MeV passive scattering beam irradiating a phantom. In this proceeding, we describe the status of the Compton camera and present the first preliminary measurements with radioactive sources and their corresponding reconstructed images.

Persistence of the Z =28 Shell Gap Around 78Ni: First Spectroscopy of 79Cu

NASA Astrophysics Data System (ADS)

Olivier, L.; Franchoo, S.; Niikura, M.; Vajta, Z.; Sohler, D.; Doornenbal, P.; Obertelli, A.; Tsunoda, Y.; Otsuka, T.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Gillibert, A.; Isobe, T.; Lapoux, V.; Matsushita, M.; Momiyama, S.; Motobayashi, T.; Otsu, H.; Péron, C.; Peyaud, A.; Pollacco, E. C.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Sasano, M.; Shiga, Y.; Takeuchi, S.; Taniuchi, R.; Uesaka, T.; Wang, H.; Yoneda, K.; Browne, F.; Chung, L. X.; Dombradi, Z.; Flavigny, F.; Giacoppo, F.; Gottardo, A.; Hadyńska-Klek, K.; Korkulu, Z.; Koyama, S.; Kubota, Y.; Lee, J.; Lettmann, M.; Louchart, C.; Lozeva, R.; Matsui, K.; Miyazaki, T.; Nishimura, S.; Ogata, K.; Ota, S.; Patel, Z.; Sahin, E.; Shand, C.; Söderström, P.-A.; Stefan, I.; Steppenbeck, D.; Sumikama, T.; Suzuki, D.; Werner, V.; Wu, J.; Xu, Z.

2017-11-01

In-beam γ -ray spectroscopy of 79Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a 80Zn beam at 270 MeV /nucleon . The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z =28 gap at N =50 remains large. The results show that the 79Cu nucleus can be described in terms of a valence proton outside a 78Ni core, implying the magic character of the latter.

Negative ion beam characterisation in BATMAN by mini-STRIKE: Improved design and new measurements

NASA Astrophysics Data System (ADS)

Serianni, G.; Bonomo, F.; Brombin, M.; Cervaro, V.; Chitarin, G.; Cristofaro, S.; Delogu, R.; De Muri, M.; Fasolo, D.; Fonnesu, N.; Franchin, L.; Franzen, P.; Ghiraldelli, R.; Molon, F.; Muraro, A.; Pasqualotto, R.; Ruf, B.; Schiesko, L.; Tollin, M.; Veltri, P.

2015-04-01

The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features of the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.

Negative ion beam characterisation in BATMAN by mini-STRIKE: Improved design and new measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serianni, G., E-mail: gianluigi.serianni@igi.cnr.it; Brombin, M.; Cervaro, V.

The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features ofmore » the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.« less

A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging.

PubMed

Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

2015-01-01

Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies.

Radiation protection recommendations as applied to the disposal of long-lived solid radioactive waste. A report of The International Commission on Radiological Protection.

PubMed

1998-01-01

(79) Waste, by definition, has no benefit. It should be viewed as one aspect of the beneficial practice that gave rise to it. Furthermore, radioactive waste management should be placed in the context of the management of society's waste in general. (80) A major issue in evaluating the acceptability of a disposal system for long-lived solid radioactive waste is that doses or risks may arise from exposures in the distant future. There is uncertainty surrounding any estimate of these doses or risks due to lack of knowledge about future conditions. Such exposures are treated as potential exposures as their magnitude depends on future processes and conditions that have probabilities associated with them. (81) Nevertheless, the Commission recognises a basic principle that individuals and populations in the future should be afforded at least the same level of protection from the action of disposing of radioactive waste today as is the current generation. This implies use of the current quantitative dose and risk criteria derived from considering associated health detriment. Therefore, protection of future generations should be achieved by applying these dose or risk criteria to the estimated future doses or risks in appropriately defined critical groups. These estimates should not be regarded as measures of health detriment beyond times of around several hundreds of years into the future. In the case of these longer time periods, they represent indicators of the protection afforded by the disposal system. (82 Constrained optimisation is the central approach to evaluating the radiological acceptability of a waste disposal system; dose or risk constraints are used rather than dose or risk limits. By this transition from limitation to optimisation, the needs of practical application of the radiological protection system to the disposal of long-lived solid waste disposal are met: determination of acceptability now for exposures that may occur in the distant future. Optimisation should be applied in an iterative manner during the disposal system development process and should particularly cover both site selection and repository design. (83) Two broad categories of exposure situations should be considered: natural processes and human intrusion. The latter only refers to intrusion that is inadvertent. The radiological implications of deliberate intrusion into a repository are the responsibility of the intruder. Assessed doses or risks arising from natural processes should be compared with a dose constraint of 0.3 mSv per year or its risk equivalent of around 10(-5) per year. With regard to human intrusion, the consequences from one or more plausible stylized scenarios should be considered in order to evaluate the resilience of the repository to such events. (84) The Commission considers that in circumstances where human intrusion could lead to doses to those living around the site sufficiently high that intervention on current criteria would almost always be justified, reasonable efforts should be made at the repository development stage to reduce the probability of human intrusion or to limit its consequences. In this respect, the Commission has previously advised that an existing annual dose of around 10 mSv per year may be used as a generic reference level below which intervention is not likely to be justifiable. Conversely, an existing annual dose of around 100 mSv per year may be used as a generic reference level above which intervention should be considered almost always justifiable. Similar considerations apply in situations where the thresholds for deterministic effects in relevant organs are exceeded. (85) Compliance with the constraints can be assessed by utilising either an aggregated risk-oriented approach, with a risk constraint, or a disaggregated dose/probability approach, with a dose constraint, or a combination of both. A similar level of protection can be achieved by any of these approaches; however, more information may

Status of the SPES project, a new tool for fundamental and apply science studies with exotic ion beams at LNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Napoli, D. R., E-mail: napoli@lnl.infn.it; Andrighetto, A.; Antonini, P.

SPES, a new accelerator facility for both the production of exotic ion beams and radio-pharmaceuticals, is presently being installed at the Laboratori Nazionali di Legnaro in Italy (LNL). The new cyclotron, which will provide high intensity proton beams for the production of the rare isotopes, has been installed and is now in the commissioning phase. We present here the status of the part of the project devoted to the production and acceleration of fission fragments created in the interaction of an intense proton beam on a production target of UCx. The expected SPES radioactive beams intensities, their quality and theirmore » maximum energies (up to 11 MeV/A for A=130) will permit to perform forefront research in nuclear structure and nuclear dynamics far from the stability valley. Another low energy section of the facility is foreseen for new and challenging research, both in the nuclear physics and in the material science frameworks.« less

A proposed intense slow positron source based on 58Co

NASA Astrophysics Data System (ADS)

Brown, Benjamin L.; Denison, Art; Makowitz, Henry; Gidley, Dave; Frieze, Bill; Griffin, Henry; Encarnación, Pedro

1994-06-01

Positron beams have proven very useful for condensed matter and surface research. The highest intensity of the current operating positron beams is ˜109 slow e+/second. The goal of our proposal is to build an Intense Slow Positron Source (ISPS) demonstration beam (Phase I) of unprecedented brightness at the Idaho National Engineering Laboratory, INEL (up to 1010 slow e+/s at 5 keV over a <0.03 cm. diameter). This Phase I beam will prove the principles necessary to build a larger facility scale ISPS Phase II beam which will have a potential of 1013 e+/s, or ≳1012 e+/s over 0.03 cm. The INEL is an ideal location for the ISPS because of the fast breeder reactor EBR-II, which is perfectly suited to creating the positron emitting isotope 58Co, and the excellent radioactive materials handling capability and expertise. Sufficient expertise is available at INEL for the construction and operation of a user facility (Phase II).

Design approach for the development of a cryomodule for compact crab cavities for Hi-Lumi LHC

NASA Astrophysics Data System (ADS)

Pattalwar, Shrikant; Jones, Thomas; Templeton, Niklas; Goudket, Philippe; McIntosh, Peter; Wheelhouse, Alan; Burt, Graeme; Hall, Ben; Wright, Loren; Peterson, Tom

2014-01-01

A prototype Superconducting RF (SRF) cryomodule, comprising multiple compact crab cavities is foreseen to realise a local crab crossing scheme for the "Hi-Lumi LHC", a project launched by CERN to increase the luminosity performance of LHC. A cryomodule with two cavities will be initially installed and tested on the SPS drive accelerator at CERN to evaluate performance with high-intensity proton beams. A series of boundary conditions influence the design of the cryomodule prototype, arising from; the complexity of the cavity design, the requirement for multiple RF couplers, the close proximity to the second LHC beam pipe and the tight space constraints in the SPS and LHC tunnels. As a result, the design of the helium vessel and the cryomodule has become extremely challenging. This paper assesses some of the critical cryogenic and engineering design requirements and describes an optimised cryomodule solution for the evaluation tests on SPS.

Technique for measurement of energy loss of proton in target medium

NASA Astrophysics Data System (ADS)

Khadke, U. V.

2018-05-01

Energy loss (EL) of charged particles in target medium needs special attention, when measurements are required to be done repeatedly over periods of couple of days. It is imperative to ensure that the measurements are not affected by the long term drifts of the accelerator beam energy and the associated electronic modules. For one such situation in measurement of EL of proton beam in thick target, we optimised and standardized the technique of measuring most probable energy loss of 24.774 MeV proton in aluminium target of thickness 330 mg/cm2. The paper described the method that we developed to ensure that our EL measurements were free from effects of drifts due to any associated electronic modules. The details of the energy spectrometer, basic principle and technique for energy loss measurements in target medium are described in this paper.

MCNP simulation to optimise in-pile and shielding parts of the Portuguese SANS instrument.

PubMed

Gonçalves, I F; Salgado, J; Falcão, A; Margaça, F M A; Carvalho, F G

2005-01-01

A Small Angle Neutron Scattering instrument is being installed at one end of the tangential beam tube of the Portuguese Research Reactor. The instrument is fed using a neutron scatterer positioned in the middle of the beam tube. The scatterer consists of circulating H2O contained in a hollow disc of Al. The in-pile shielding components and the shielding installed around the neutron selector have been the object of an MCNP simulation study. The quantities calculated were the neutron and gamma-ray fluxes in different positions, the energy deposited in the material by the neutron and gamma-ray fields, the material activation resulting from the neutron field and radiation doses at the exit wall of the shutter and around the shielding. The MCNP results are presented and compared with results of an analytical approach and with experimental data collected after installation.

Dynamic laser piercing of thick section metals

NASA Astrophysics Data System (ADS)

Pocorni, Jetro; Powell, John; Frostevarg, Jan; Kaplan, Alexander F. H.

2018-01-01

Before a contour can be laser cut the laser first needs to pierce the material. The time taken to achieve piercing should be minimised to optimise productivity. One important aspect of laser piercing is the reliability of the process because industrial laser cutting machines are programmed for the minimum reliable pierce time. In this work piercing experiments were carried out in 15 mm thick stainless steel sheets, comparing a stationary laser and a laser which moves along a circular trajectory with varying processing speeds. Results show that circular piercing can decrease the pierce duration by almost half compared to stationary piercing. High speed imaging (HSI) was employed during the piercing process to understand melt behaviour inside the pierce hole. HSI videos show that circular rotation of the laser beam forces melt to eject in opposite direction of the beam movement, while in stationary piercing the melt ejects less efficiently in random directions out of the hole.

Numerical Assessment of the Diagnostic Capabilities of the Instrumented Calorimeter for SPIDER (STRIKE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dalla Palma, M.; Pasqualotto, R.; Rizzolo, A.

An important feature of the ITER project is represented by additional heating via injection of neutral beams from accelerated negative ions. To study and optimise their production, the SPIDER test facility is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation.STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) is a diagnostic to characterise the SPIDER negative ion beam during short operation (several seconds). During long pulse operations, STRIKE is parked off-beam in the vacuum vessel. The most important measurements are beam uniformity, beamlet divergence and stripping losses. STRIKE is directly exposed to themore » beam and is formed of 16 tiles, one for each beamlet groups. The measurements are provided by thermal cameras, current sensors, thermocouples and electrostatic sensors. This paper presents the investigation of the influence on the response of STRIKE of: thermal characteristics of the tile material, exposure angle, features of some dedicated diagnostics. The uniformity of the beam will be studied by measurements of the current flowing through each tile and by thermal cameras. Simulations show that it will be possible to verify experimentally whether the beam meets the ITER requirement about the maximum allowed beam non-uniformity (below {+-}10%). In the simulations also the influence of the beam halo has been included; the effect of off-perveance conditions has been studied. To estimate the beamlet divergence, STRIKE can be moved along the beam direction at two different distances from the accelerator. The optimal positions have been defined taking into account design constraints. The effect of stripping on the comparison between currents and heat loads has been assessed; this will allow to obtain an experimental estimate of stripping. Electrostatic simulations have provided the suitable tile biasing voltage in order to reabsorb secondary particles into the same tile as the one where they were emitted from.« less

The role of accelerators in the nuclear fuel cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, Hiroshi.

1990-01-01

The use of neutrons produced by the medium energy proton accelerator (1 GeV--3 GeV) has considerable potential in reconstructing the nuclear fuel cycle. About 1.5 {approximately} 2.5 ton of fissile material can be produced annually by injecting a 450 MW proton beam directly into fertile materials. A source of neutrons, produced by a proton beam, to supply subcritical reactors could alleviate many of the safety problems associated with critical assemblies, such as positive reactivity coefficients due to coolant voiding. The transient power of the target can be swiftly controlled by controlling the power of the proton beam. Also, the usemore » of a proton beam would allow more flexibility in the choice of fuel and structural materials which otherwise might reduce the reactivity of reactors. This paper discusses the rate of accelerators in the transmutation of radioactive wastes of the nuclear fuel cycles. 34 refs., 17 figs., 9 tabs.« less

Measurements and analyses of the distribution of the radioactivity induced by the secondary neutrons produced by 17-MeV protons in compact cyclotron facility

NASA Astrophysics Data System (ADS)

Matsuda, Norihiro; Izumi, Yuichi; Yamanaka, Yoshiyuki; Gandou, Toshiyuki; Yamada, Masaaki; Oishi, Koji

2017-09-01

Measurements of reaction rates by secondary neutrons produced from beam losses by 17-MeV protons are conducted at a compact cyclotron facility with the foil activation method. The experimentally obtained distribution of the reaction rates of 197Au (n, γ) 198Au on the concrete walls suggests that a target and an electrostatic deflector as machine components for beam extraction of the compact cyclotron are principal beam loss points. The measurements are compared with calculations by the Monte Carlo code: PHITS. The calculated results based on the beam losses are good agreements with the measured ones within 21%. In this compact cyclotron facility, exponential attenuations with the distance from the electrostatic deflector in the distributions of the measured reaction rates were observed, which was looser than that by the inverse square of distance.

A combined thermal dissociation and electron impact ionization source for RIB generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alton, G.D.; Williams, C.

1995-12-31

The probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecular feed materials with conventional, hot-cathode, electron-impact ion sources is low and consequently, the ion beams from these sources often appear as mixtures of several molecular sideband beams. This fragmentation process leads to dilution of the intensity of the species of interest for RIB applications where beam intensity is at a premium. We have conceived an ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high ionization efficiency characteristics of an electron impact ionization source that will, in principle, overcome thismore » handicap. The source concept will be evaluated as a potential candidate for use for RIB generation at the Holifield Radioactive Ion Beam Facility (HRIBF), now under construction at the Oak Ridge National Laboratory. The design features and principles of operation of the source are described in this article.« less

Core Vessel Insert Handling Robot for the Spallation Neutron Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graves, Van B; Dayton, Michael J

2011-01-01

The Spallation Neutron Source provides the world's most intense pulsed neutron beams for scientific research and industrial development. Its eighteen neutron beam lines will eventually support up to twenty-four simultaneous experiments. Each beam line consists of various optical components which guide the neutrons to a particular instrument. The optical components nearest the neutron moderators are the core vessel inserts. Located approximately 9 m below the high bay floor, these inserts are bolted to the core vessel chamber and are part of the vacuum boundary. They are in a highly radioactive environment and must periodically be replaced. During initial SNS construction,more » four of the beam lines received Core Vessel Insert plugs rather than functional inserts. Remote replacement of the first Core Vessel Insert plug was recently completed using several pieces of custom-designed tooling, including a highly complicated Core Vessel Insert Robot. The design of this tool are discussed.« less

Remanent dose rates around the collimators of the LHC beam cleaning insertions.

PubMed

Brugger, M; Roesler, S

2005-01-01

The LHC will require an extremely powerful and unprecedented collimation system. As approximately 30% of the LHC beam is lost in the cleaning insertions, these will become some of the most radioactive locations around the entire LHC ring. Thus, remanent dose rates to be expected during later repair or maintenance interventions must be considered in the design phase itself. As a consequence, the beam cleaning insertions form a unique test bed for a recently developed approach to calculate remanent dose rates. A set of simulations, different in complexity, is used in order to evaluate methods for the estimation of remanent dose rates. The scope, as well as the restrictions, of the omega-factor method are shown and compared with the explicit simulation approach. The latter is then used to calculate remanent dose rates in the beam cleaning insertions. Furthermore, a detailed example for maintenance dose planning is given.

Characterisation and optimisation of the new Prompt Gamma-ray Activation Analysis (PGAA) facility at FRM II

NASA Astrophysics Data System (ADS)

Canella, Lea; Kudějová, Petra; Schulze, Ralf; Türler, Andreas; Jolie, Jan

2011-04-01

At the research reactor Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) a new Prompt Gamma-ray Activation Analysis (PGAA) facility was installed. The instrument was originally built and operating at the spallation source at the Paul Scherrer Institute in Switzerland. After a careful re-design in 2004-2006, the new PGAA instrument was ready for operation at FRM II. In this paper the main characteristics and the current operation conditions of the facility are described. The neutron flux at the sample position can reach up 6.07×1010 [cm-2 s-1], thus the optimisation of some parameters, e.g. the beam background, was necessary in order to achieve a satisfactory analytical sensitivity for routine measurements. Once the optimal conditions were reached, detection limits and sensitivities for some elements, like for example H, B, C, Si, or Pb, were calculated and compared with other PGAA facilities. A standard reference material was also measured in order to show the reliability of the analysis under different conditions at this instrument.

Ion traps for precision experiments at rare-isotope-beam facilities

NASA Astrophysics Data System (ADS)

Kwiatkowski, Anna

2016-09-01

Ion traps first entered experimental nuclear physics when the ISOLTRAP team demonstrated Penning trap mass spectrometry of radionuclides. From then on, the demand for ion traps has grown at radioactive-ion-beam (RIB) facilities since beams can be tailored for the desired experiment. Ion traps have been deployed for beam preparation, from bunching (thereby allowing time coincidences) to beam purification. Isomerically pure beams needed for nuclear-structure investigations can be prepared for trap-assisted or in-trap decay spectroscopy. The latter permits studies of highly charged ions for stellar evolution, which would be impossible with traditional experimental nuclear-physics methods. Moreover, the textbook-like conditions and advanced ion manipulation - even of a single ion - permit high-precision experiments. Consequently, the most accurate and precise mass measurements are now performed in Penning traps. After a brief introduction to ion trapping, I will focus on examples which showcase the versatility and utility of the technique at RIB facilities. I will demonstrate how this atomic-physics technique has been integrated into nuclear science, accelerator physics, and chemistry. DOE.

Charge state breeding experiences and plans at TRIUMF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ames, F., E-mail: ames@triumf.ca; Marchetto, M.; Mjøs, A.

At the Isotope Separation and ACceleration (ISAC) facility at TRIUMF, an electron cyclotron resonance ion source (ECRIS) has been set up for the charge state breeding of radioactive ions. In order to reduce background from stable ions generated in the ECRIS, several measures, including changing materials for the plasma chamber and the surrounding components, have been implemented. Further reduction has been achieved by using the post-accelerator chain as a mass filter. Since the implementation of those measures in 2013, physics experiments with accelerated radioactive isotopes of Rb, Sr, K, and Mg have been performed. In most cases, a charge breedingmore » efficiency of several percent has been achieved. With the planned expansion of the isotope production capabilities at TRIUMF within the Advanced Rare IsotopE Laboratory project, two new target stations, one using photo-fission induced by a high-power electron beam at 50 MeV and the other one using 480 MeV protons as at ISAC, will be put into operation within the next 5 yr. Additionally, a new electron beam ion source (EBIS) based charge state breeding system will be installed. Background from such a source is expected to be much lower. The drawback is that for the efficient operation of such a system, pulsed beam operation is required, which makes the installation of an additional ion buncher in front of the EBIS necessary.« less

Neutronics performance and activation calculation of dense tungsten granular target for China-ADS

NASA Astrophysics Data System (ADS)

Zhang, Yaling; Li, Jianyang; Zhang, Xunchao; Cai, Hanjie; Yan, Xuesong; Yu, Lin; Fu, Fen; Lin, Ping; Gao, Xiaofei; Zhang, Zhilei; Zhang, Yanshi; Yang, Lei

2017-11-01

Spallation target, which constitutes the physical and functional interface between the high power accelerator and the subcritical core, is one of the most important components in Accelerator Driven Subcritical System (ADS). In this paper, we investigated the neutronics performance, the radiation damage and the activation of dense tungsten granular flow spallation target by using the Monte Carlo programs GMT and FLUKA at the proton energy of 250 MeV with a beam current of 10 mA . First, the leaking neutron yield, leaking neutron energy spectrum and laterally leaking neutron distribution at several time nodes and with different target parameters are explored. After that, the displacement per atom (DPA) and the helium/hydrogen production for tungsten grains and structural materials with stainless steel 316L are estimated. Finally, the radioactivity, residual dose rate and afterheat of granular target are presented. Results indicate that granule diameter below 1 cm and the beam profile diameter have negligible impact on neutronics performance, while the target diameter and volume fraction of grain have notable influence. The maximum DPA for target vessel (beam tube) is about 1.0 (1.6) DPA/year in bare target, and increased to 2.6 (2.8) DPA/year in fission environment. Average DPA for tungsten grains is relatively low. The decline rate of radioactivity and afterheat with cooling time grows with the decrease of the irradiation time.

Physics division progress report for period ending September 30 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livingston, A.B.

1992-03-01

This report discusses research being conducted at Oak Ridge National Laboratory in physics. The areas covered are: Holifield Heavy Ion Research Facility; low/medium energy nuclear physics; high energy experimental physics; the Unisor program; experimental atomic physics; laser and electro-optics lab; theoretical physics; compilations and evaluations; and radioactive ion beam development. (LSP)

Graphite sample preparation for AMS in a high pressure and temperature press

USGS Publications Warehouse

Rubin, M.; Mysen, B.O.; Polach, H.

1984-01-01

A high pressure-high temperature press is used to make target material for accelerator mass spectrometry. Graphite was produced from typical 14C samples including oxalic acid and carbonates. Beam strength of 12C was generally adequate, but random radioactive contamination by 14C made age measurements impractical. ?? 1984.

Graphite sample preparation for AMS in a high pressure and temperature press

USGS Publications Warehouse

Rubin, Meyer; Mysen, Bjorn O.; Polach, Henry

1984-01-01

A high pressure-temperature press is used to make target material for accelerator mass spectrometry. Graphite was produced from typical **1**4C samples including oxalic acid and carbonates. Beam strength of **1**2C was generally adequate, but random radioactive contamination by **1**4C made age measurements impractical.

Direct Reactions at the Facility for Experiments on Nuclear Reactions in Stars (FENRIS)

NASA Astrophysics Data System (ADS)

Longland, Richard; Kelley, John; Marshall, Caleb; Portillo, Federico; Setoodehnia, Kiana

2017-09-01

Nuclear cross sections are a key ingredient in stellar models designed to understand how stars evolve. Determining these cross sections, therefore, is critical for obtaining reliable predictions from stellar models. While many charged-particle reaction cross sections can be measured in the laboratory, the Coulomb barrier means that they cannot always be measured at the low energies relevant to astrophysics. In other cases, radioactive targets make the measurements unfeasible. Radioactive ion beam experiments in inverse kinematics are one solution, but low beam intensities mean that cross sections plague these attempts further. Direct measurements, particularly particle transfer experiments, are one tool in our inventory that provides us with the necessary information to infer reaction cross sections at stellar energies. I will present an overview of one facility: the Facility for Experiments on Nuclear Reactions in Stars (FENRIS), which is dedicated to performing particle transfer measurements for astrophysical cross sections. Over the past few years, FENRIS has been fully upgraded and characterized. I will show highlights of our upgrade activities and current capabilities. I will also highlight our recent experimental results and discuss current upgrade efforts.

Breakthrough: Record-Setting Cavity

ScienceCinema

Ciovati, Gianluigi

2018-02-06

Gianluigi "Gigi" Ciovati, a superconducting radiofrequency scientist, discusses how scientists at the U.S. Department of Energy's Jefferson Lab in Newport News, VA, used ARRA funds to fabricate a niobium cavity for superconducting radiofrequency accelerators that has set a world record for energy efficiency. Jefferson Lab's scientists developed a new, super-hot treatment process that could soon make it possible to produce cavities more quickly and at less cost, benefitting research and healthcare around the world. Accelerators are critical to our efforts to study the structure of matter that builds our visible universe. They also are used to produce medical isotopes and particle beams for diagnosing and eradicating disease. And they offer the potential to power future nuclear power plants that produce little or no radioactive waste.around the world. Accelerators are critical to our efforts to study the structure of matter that builds our visible universe. They also are used to produce medical isotopes and particle beams for diagnosing and eradicating disease. And they offer the potential to power future nuclear power plants that produce little or no radioactive waste.

First results on Ge resonant laser photoionization in hollow cathode lamp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scarpa, Daniele, E-mail: daniele.scarpa@lnl.infn.it; Andrighetto, Alberto; Barzakh, Anatoly

2016-02-15

In the framework of the research and development activities of the SPES project regarding the optimization of the radioactive beam production, a dedicated experimental study has been recently started in order to investigate the possibility of in-source ionization of germanium using a set of tunable dye lasers. Germanium is one of the beams to be accelerated by the SPES ISOL facility, which is under construction at Legnaro INFN Laboratories. The three-step, two color ionization schemes have been tested using a Ge hollow cathode lamp. The slow and the fast optogalvanic signals were detected and averaged by an oscilloscope as amore » proof of the laser ionization inside the lamp. As a result, several wavelength scans across the resonances of ionization schemes were collected with the fast optogalvanic signal. Some comparisons of ionization efficiency for different ionization schemes were made. Furthermore, saturation curves of the first excitation transitions have been obtained. This investigation method and the setup built in the laser laboratory of the SPES project can be applied for the photo-ionization scheme studies also for the other possible radioactive elements.« less

Design and simulation of ion optics for ion sources for production of singly charged ions

NASA Astrophysics Data System (ADS)

Zelenak, A.; Bogomolov, S. L.

2004-05-01

During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments.

A system for monitoring the radiation effects of a proton linear accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skorkin, V. M., E-mail: skorkin@inr.ru; Belyanski, K. L.; Skorkin, A. V.

2016-12-15

The system for real-time monitoring of radioactivity of a high-current proton linear accelerator detects secondary neutron emission from proton beam losses in transport channels and measures the activity of radionuclides in gas and aerosol emissions and the radiation background in the environment affected by a linear accelerator. The data provided by gamma, beta, and neutron detectors are transferred over a computer network to the central server. The system allows one to monitor proton beam losses, the activity of gas and aerosol emissions, and the radiation emission level of a linear accelerator in operation.

ICRP PUBLICATION 122: radiological protection in geological disposal of long-lived solid radioactive waste.

PubMed

Weiss, W; Larsson, C-M; McKenney, C; Minon, J-P; Mobbs, S; Schneider, T; Umeki, H; Hilden, W; Pescatore, C; Vesterlind, M

2013-06-01

This report updates and consolidates previous recommendations of the International Commission on Radiological Protection (ICRP) related to solid waste disposal (ICRP, 1985, 1997b, 1998). The recommendations given apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the ICRP system of radiological protection described in Publication 103 (ICRP, 2007) can be applied in the context of the geological disposal of long-lived solid radioactive waste. Although the report is written as a standalone document, previous ICRP recommendations not dealt with in depth in the report are still valid. The 2007 ICRP system of radiological protection evolves from the previous process-based protection approach relying on the distinction between practices and interventions by moving to an approach based on the distinction between three types of exposure situation: planned, emergency and existing. The Recommendations maintains the Commission's three fundamental principles of radiological protection namely: justification, optimisation of protection and the application of dose limits. They also maintain the current individual dose limits for effective dose and equivalent dose from all regulated sources in planned exposure situations. They re-enforce the principle of optimisation of radiological protection, which applies in a similar way to all exposure situations, subject to restrictions on individual doses: constraints for planned exposure situations, and reference levels for emergency and existing exposure situations. The Recommendations also include an approach for developing a framework to demonstrate radiological protection of the environment. This report describes the different stages in the life time of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that influences the application of the protection system over the different phases in the life time of a disposal facility is the level of oversight or 'watchful care' that is present. The level of oversight affects the capability to control the source, i.e. the waste and the repository, and to avoid or reduce potential exposures. Three main time frames are considered: time of direct oversight, when the disposal facility is being implemented and is under active supervision; time of indirect oversight, when the disposal facility is sealed and oversight is being exercised by regulators or special administrative bodies or society at large to provide additional assurance on behalf of society; and time of no oversight, when oversight is no longer exercised in case memory of the disposal facility is lost. Copyright © 2013. Published by Elsevier Ltd.

The South African isotope facility project

NASA Astrophysics Data System (ADS)

Bark, R. A.; Barnard, A. H.; Conradie, J. L.; de Villiers, J. G.; van Schalkwyk, P. A.

2018-05-01

The South African Isotope Facility (SAIF) is a project in which iThemba LABS plans to build a radioactive-ion beam (RIB) facility. The project is divided into the Accelerator Centre of Exotic Isotopes (ACE Isotopes) and the Accelerator Centre for Exotic Beams (ACE Beams). For ACE Isotopes, a high-current, 70 MeV cyclotron will be acquired to take radionuclide production off the existing Separated Sector Cyclotron (SSC). A freed up SSC will then be available for an increased tempo of nuclear physics research and to serve as a driver accelerator for the ACE Beams project, in which protons will be used for the direct fission of Uranium, producing beams of fission fragments. The ACE Beams project has begun with "LeRIB" - a Low Energy RIB facility, now under construction. In a collaboration with INFN Legnaro, the target/ion-source "front-end" will be a copy of the front-end developed for the SPES project. A variety of targets may be inserted into the SPES front-end; a uranium-carbide target has been designed to produce up to 2 × 1013 fission/s using a 70 MeV proton beam of 150 µA intensity.

Development and test of a cryogenic trap system dedicated to confinement of radioactive volatile isotopes in SPIRAL2 post-accelerator

NASA Astrophysics Data System (ADS)

Souli, M.; Dolégiéviez, P.; Fadil, M.; Gallardo, P.; Levallois, R.; Munoz, H.; Ozille, M.; Rouillé, G.; Galet, F.

2011-12-01

A cryogenic trap system called Cryotrap has been studied and developed in the framework of nuclear safety studies for SPIRAL2 accelerator. The main objective of Cryotrap is to confine and reduce strongly the migration of radioactive volatile isotopes in beam lines. These radioactive gases are produced after interaction between a deuteron beam and a fissile target. Mainly, Cryotrap is composed by a vacuum vessel and two copper thermal screens maintained separately at two temperatures T1=80 K and T2=20 K. A Cryocooler with two stages at previous temperatures is used to remove static heat losses of the cryostat and ensure an efficient cooling of the system. Due to strong radiological constraints that surround Cryotrap, the coupling system between Cryocooler and thermal screens is based on aluminum thermo-mechanical contraction. The main objective of this original design is to limit direct human maintenance interventions and provide maximum automated operations. A preliminary prototype of Cryotrap has been developed and tested at GANIL laboratory to validate its design, and determine its thermal performance and trapping efficiency. In this paper, we will first introduce briefly SPIRAL2 project and discuss the main role of Cryotrap in nuclear safety of the accelerator. Then, we will describe the proposed conceptual design of Cryotrap and its main characteristics. After that, we will focus on test experiment and analyze experimental data. Finally, we will present preliminary results of gas trapping efficiency tests.

Optimising Laser Tattoo Removal

PubMed Central

Sardana, Kabir; Ranjan, Rashmi; Ghunawat, Sneha

2015-01-01

Lasers are the standard modality for tattoo removal. Though there are various factors that determine the results, we have divided them into three logical headings, laser dependant factors such as type of laser and beam modifications, tattoo dependent factors like size and depth, colour of pigment and lastly host dependent factors, which includes primarily the presence of a robust immune response. Modifications in the existing techniques may help in better clinical outcome with minimal risk of complications. This article provides an insight into some of these techniques along with a detailed account of the factors involved in tattoo removal. PMID:25949018

Optimised design of a ROTAX-type instrument

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tietze-Jaensch, H.

1997-09-01

The rotating analyser (ROTAX) spectrometer has been devised and installed at ISIS. Practical scans in (Q{h_bar}{omega}) space with a nearly arbitrary scan direction, i.e. polarisation of q vs. Q are possible and feasible with no compromises on the resolution. Valuable technological and methodological knowledge has been compiled for an improved version of such a type of instrument. At present ROTAX lacks competitiveness with other spectrometers from an unexpectedly weak neutron flux of its particular beam-line and an unfavourable adaption of the analyser`s drive power to the time frame or neutron source frequency.

Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

DOEpatents

Lasche, George P.

1988-01-01

A high-power-density laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems.

Porcelain-coated antenna for radio-frequency driven plasma source

DOEpatents

Leung, Ka-Ngo; Wells, Russell P.; Craven, Glen E.

1996-01-01

A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ion because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile.

Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

DOEpatents

Lasche, G.P.

1987-02-20

A high-power-density-laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems. 25 figs.

Measurement of Neutron Reaction Cross Sections between 8 and 14 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mannhart, Wolf; Schmidt, Dankwart

2005-05-24

Cross-section measurements were performed with special emphasis on access to the 'blind spot' in the neutron energy range from 10 to 13 MeV. The use of a conventional D(d,n) neutron source in combination with TOF measurements of the D(d,np) break-up component allows the precise determination of monoenergetic cross-section data in this range. The procedure is demonstrated with the measurement of the cross sections of 64Zn(n,p)64Cu, 64Zn(n,2n)63Zn, 63Cu(n,2n)62Cu, and 65Cu(n,2n)64Cu. With all reaction products being strong positron emitters, the radioactivity-counting process has been optimised for a perfect registration of the associated annihilation radiation.

Measurement of Neutron Reaction Cross Sections between 8 and 14 MeV

NASA Astrophysics Data System (ADS)

Mannhart, Wolf; Schmidt, Dankwart

2005-05-01

Cross-section measurements were performed with special emphasis on access to the "blind spot" in the neutron energy range from 10 to 13 MeV. The use of a conventional D(d,n) neutron source in combination with TOF measurements of the D(d,np) break-up component allows the precise determination of monoenergetic cross-section data in this range. The procedure is demonstrated with the measurement of the cross sections of 64Zn(n,p)64Cu, 64Zn(n,2n)63Zn, 63Cu(n,2n)62Cu, and 65Cu(n,2n)64Cu. With all reaction products being strong positron emitters, the radioactivity-counting process has been optimised for a perfect registration of the associated annihilation radiation.

Perspective of Muon Production Target at J-PARC MLF MUSE

NASA Astrophysics Data System (ADS)

Makimura, Shunsuke; Matoba, Shiro; Kawamura, Naritoshi; Matsuzawa, Yukihiro; Tabe, Masato; Aoyagi, Hiroyuki; Kondo, Hiroto; Kobayashi, Yasuo; Fujimori, Hiroshi; Ikedo, Yutaka; Kadono, Ryosuke; Koda, Akihiro; Kojima, Kenji M.; Miyake, Yasuhiro; Nakamura, Jumpei G.; Oishi, Yu; Okabe, Hirotaka; Shimomura, Koichiro; Strasser, Patrick

A pulsed muon beam with unprecedented intensity will be generated by a 3-GeV 333-microA proton beam on a muon target made of 20-mm thick isotropic graphite at J-PARC MLF MUSE (Muon Science Establishment). The first muon beam was successfully generated on September 26th, 2008. Gradually upgrading the beam intensity, continuous 300-kW proton beam has been operated by a fixed target method without replacements till June of 2014. However, the lifetime of the fixed target was anticipated to be less than 1 year by the proton-irradiation damage of the graphite through 1-MW beam operation. To extend the lifetime, a muon rotating target, in which the radiation damage is distributed to a wider area, was installed in September of 2014, and continuous and stable operation has been successfully performed. Because the muon target becomes highly radioactive by the proton irradiation, the maintenance is conducted by remote handling in the Hot cell. In September of 2015, a scraper No. 1 to collimate the proton beam scattered by the target was replaced for further high-power beam operation. Recently, new developments on monitoring and maintenance of the muon target for higher power operation are in progress. In this article, perspective of muon production target at J-PARC MLF MUSE will be described.

Fast pixelated sensors for radiation detection and imaging based on quantum confined structures in III/V semiconductors

NASA Astrophysics Data System (ADS)

Tortora, M.; Biasiol, G.; Cautero, G.; Menk, R. H.; Plaisier, J. R.; Antonelli, M.

2017-03-01

In order to improve the characterisation of the delivered beams in many types of photon sources, innovative beam profilers based on III/V semiconductor materials (InGaAs/InAlAs) have been deeply investigated. Owing to a tunable and direct band gap these devices allow radiation detection in a wide spectral range. In order to increase the sensitivity of the device in radiation detection charge amplification on the sensor level is implemented. This is obtained by exploiting In0.75Ga0.25As/In0.75Al0.25As quantum wells (QW) hosting a two-dimensional electron gas (2DEG) through molecular beam epitaxy (MBE). Internal charge-amplification mechanism can be achieved for very low applied voltages, while the high carrier mobility allows the design of very fast photon detectors with sub-nanosecond response times. This technology has been preliminarily exploited to fabricate prototype beam profilers with a strip geometry (with 50-μm-wide strips). Tests were carried out both with conventional X-ray tubes and at the Elettra synchrotron facility. The results testify how these profilers are capable of reconstructing the shape of the beam, as well as estimating the position of the beam centroid with a precision of about 400 nm. Further measurements with different samples of decreasing thickness have shown how this precision could be further improved by an optimised microfabrication. For this reason a new design, based on a membrane-photodetector, is proposed. Results regarding the spatial resolution as function of the sensor thickness will be presented and discussed.

Note: Establishing α-particle radiation damage experiments using the Dalton Cumbrian Facility's 5 MV tandem pelletron.

PubMed

Bower, W R; Smith, A D; Pattrick, R A D; Pimblott, S M

2015-04-01

Evaluating the radiation stability of mineral phases is a vital research challenge when assessing the performance of the materials employed in a Geological Disposal Facility for radioactive waste. This report outlines the setup and methodology for efficiently allowing the determination of the dose dependence of damage to a mineral from a single ion irradiated sample. The technique has been deployed using the Dalton Cumbrian Facility's 5 MV tandem pelletron to irradiate a suite of minerals with a controlled α-particle ((4)He(2+)) beam. Such minerals are proxies for near-field clay based buffer material surrounding radioactive canisters, as well as the sorbent components of the host rock.

Note: Establishing α-particle radiation damage experiments using the Dalton Cumbrian Facility's 5 MV tandem pelletron

NASA Astrophysics Data System (ADS)

Bower, W. R.; Smith, A. D.; Pattrick, R. A. D.; Pimblott, S. M.

2015-04-01

Evaluating the radiation stability of mineral phases is a vital research challenge when assessing the performance of the materials employed in a Geological Disposal Facility for radioactive waste. This report outlines the setup and methodology for efficiently allowing the determination of the dose dependence of damage to a mineral from a single ion irradiated sample. The technique has been deployed using the Dalton Cumbrian Facility's 5 MV tandem pelletron to irradiate a suite of minerals with a controlled α-particle (4He2+) beam. Such minerals are proxies for near-field clay based buffer material surrounding radioactive canisters, as well as the sorbent components of the host rock.

Cross Section Measurements of the Radioactive 107Pd and Stable 105,108Pd Nuclei at J-PARC/MLF/ANNRI

NASA Astrophysics Data System (ADS)

Nakamura, S.; Kimura, A.; Kitatani, F.; Ohta, M.; Furutaka, K.; Goko, S.; Hara, K. Y.; Harada, H.; Hirose, K.; Kin, T.; Koizumi, M.; Oshima, M.; Toh, Y.; Kino, K.; Hiraga, F.; Kamiyama, T.; Kiyanagi, Y.; Katabuchi, T.; Mizumoto, M.; Igashira, M.; Hori, J.; Fujii, T.; Fukutani, S.; Takamiya, K.

2014-05-01

The measurements of the neutron-capture cross sections were performed for the radioactive 107Pd and stable 105,108Pd nuclei by the time-of flight method using an apparatus called “Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI)” installed at the neutron Beam Line No.4 of the Materials and Life science experimental Facility (MLF) in the J-PARC. The neutron-capture cross sections of 107Pd and 105,108Pd have been measured in the low energy region from the thermal to a few hundreds eV. From the measurements, new information was obtained for some resonances of these Pd nuclei.

Status and Perspectives of the INFN-LNS In-Flight Fragment Separator

NASA Astrophysics Data System (ADS)

Russotto, P.; Calabretta, L.; Cardella, G.; Cosentino, G.; De Filippo, E.; Gnoffo, B.; La Cognata, M.; Martorana, N. S.; Pagano, E. V.; Pizzone, R. G.; Quattrocchi, L.; Romano, S.; Russo, A. D.; Santonocito, D.

2018-05-01

In the last 15 years the FRIBs@LNS facility has successfully produced Radioactive Ion Beams using the In-Flight technique. We report on the current status and future perspectives opened by FRAISE, a new fragment separator that will be build in connection with the upgrade of Superconducting Cyclotron of the INFN-LNS laboratories.

Development of a Compton suppressed gamma spectrometer using Monte Carlo techniques

NASA Astrophysics Data System (ADS)

Britton, Richard

Gamma ray spectroscopy is routinely used to measure radiation in a number of situations. These include security applications, nuclear forensics studies, characterisation of radioactive sources, and environmental monitoring. For routine studies of environmental materials, the amount of radioactivity present is often very low, requiring spectroscopy systems which have to monitor the source for up to 7 days to achieve the required sensitivity. Recent developments in detector technology and data processing techniques have opened up the possibility of developing a highly efficient Compton Suppressed system, that was previously the preserve of large experimental collaborations. The accessibility of Monte-Carlo toolkits such as GEANT4 also provide the opportunity to optimise these systems using computer simulations, greatly reducing the need for expensive (and inefficient) testing in the laboratory. This thesis details the development of such a Compton Suppressed, planar HPGe detector system. Using the GEANT4 toolkit in combination with the experimental facilities at AWE, Aldermaston (which include HPGe detection systems, scintillator based detector systems, advanced shielding materials and gamma-gamma coincidence systems), simulations were built and validated to reproduce the detector response seen in the 'real-life' systems. This resulted in several improvements to the current system; for the shielding materials used, terrestrial and cosmic radiation were minimised, while reducing the X-ray fluorescence seen in the primary HPGe detector by an order of magnitude. With respect to the HPGe detector itself, an optimum thickness was identified for low energy (<300 keV) radiation, which maximised the efficiency for the energy range of interest while minimising the interaction probability for higher energy radionuclides (which are the primary cause of the Compton continuum that obscures lower energy decays). A combination of secondary detectors were then optimised to design a Compton Suppression system for the primary detector, which could improve the performance of the current Compton Suppression system by an order of magnitude. This equates to a reduction of the continuum by up to a factor of 240 for a nuclide such as Co-60, which is crucial for the detection of low-energy, low-activity emitters typically swamped by such a continuum. Finally, thoroughly optimised acquisition and analysis software has also been written to process data created by future high sensitivity gamma coincidence systems. This includes modules for the creation of histograms, coincidence matrices, and an ASCII to binary converter (for historical data) that has resulted in an analysis speed increase of up to 20000 times when compared to the software originally used for the extraction of coincidence information. Modules for low-energy time-walk correction and the removal of accidental coincidences are also included, which represent a capability that was not previously available.

Dose- and LET-painting with particle therapy.

PubMed

Bassler, Niels; Jäkel, Oliver; Søndergaard, Christian Skou; Petersen, Jørgen B

2010-10-01

Tumour hypoxia is one of the limiting factors in obtaining tumour control in radiotherapy. The high-LET region of a beam of heavy charged particles such as carbon ions is located in the distal part of the Bragg peak. A modulated or spread out Bragg peak (SOBP) is a weighted function of several Bragg peaks at various energies, which however results in a dilution of the dose-average LET in the target volume. Here, we investigate the possibility to redistribute the LET by dedicated treatment plan optimisation, in order to maximise LET in the target volume. This may be a strategy to potentially overcome hypoxia along with dose escalation or dose painting. The high-LET region can be shaped in very different ways, while maintaining the distribution of the absorbed dose or biological effective dose. Treatment plans involving only carbon ion beams, show very different LET distributions depending on how the fields are arranged. Alternatively, a LET boost can be applied in multi-modal treatment planning, such as combining carbon ions with protons and/or photons. For such mixed radiation modalities, significant "LET boosts" can be achieved at nearly arbitrary positions within the target volume. Following the general understanding of the relationship between hypoxia, LET and the oxygen enhancement ratio (OER), we conclude, that an additional therapeutic advantage can be achieved by confining the high-LET part of the radiation in hypoxic compartments of the tumour, and applying low-LET radiation to the normoxic tissue. We also anticipate that additional advantages may be achieved by deliberate sparing of normal tissue from high LET regions. Consequently, treatment planning based on simultaneous dose and LET optimisation has a potential to achieve higher tumour control and/or reduced normal tissue control probability (NTCP).

The Impact of Subsidies on the Ecological Sustainability and Future Profits from North Sea Fisheries

PubMed Central

Heymans, Johanna Jacomina; Mackinson, Steven; Sumaila, Ussif Rashid; Dyck, Andrew; Little, Alyson

2011-01-01

Background This study examines the impact of subsidies on the profitability and ecological stability of the North Sea fisheries over the past 20 years. It shows the negative impact that subsidies can have on both the biomass of important fish species and the possible profit from fisheries. The study includes subsidies in an ecosystem model of the North Sea and examines the possible effects of eliminating fishery subsidies. Methodology/Principal Findings Hindcast analysis between 1991 and 2003 indicates that subsidies reduced the profitability of the fishery even though gross revenue might have been high for specific fisheries sectors. Simulations seeking to maximise the total revenue between 2004 and 2010 suggest that this can be achieved by increasing the effort of Nephrops trawlers, beam trawlers, and the pelagic trawl-and-seine fleet, while reducing the effort of demersal trawlers. Simulations show that ecological stability can be realised by reducing the effort of the beam trawlers, Nephrops trawlers, pelagic- and demersal trawl-and-seine fleets. This analysis also shows that when subsidies are included, effort will always be higher for all fleets, because it effectively reduces the cost of fishing. Conclusions/Significance The study found that while removing subsidies might reduce the total catch and revenue, it increases the overall profitability of the fishery and the total biomass of commercially important species. For example, cod, haddock, herring and plaice biomass increased over the simulation when optimising for profit, and when optimising for ecological stability, the biomass for cod, plaice and sole also increased. When subsidies are eliminated, the study shows that rather than forcing those involved in the fishery into the red, fisheries become more profitable, despite a decrease in total revenue due to a loss of subsidies from the government. PMID:21637848

Study of the 249-251Cf + 48Ca reactions: recent results and outlook

NASA Astrophysics Data System (ADS)

Voinov, A. A.; Oganessian, Yu Ts; Abdullin, F. Sh; Brewer, N. T.; Dmitriev, S. N.; Grzywacz, R. K.; Hamilton, J. H.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Rykaczewski, K. P.; Sabelnikov, A. V.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu S.; Utyonkov, V. K.; Vostokin, G. K.

2018-02-01

Experiment aiming at the synthesis of heavy isotopes of Z=118 (Og) using beam of 48Ca and a target of 249-251Cf was undertaken in October 2015 - April 2016 employing the Dubna Gas-Filled Recoil Separator (FLNR JINR). The target of mixed isotopes of 249-251Cf (50.7% of 249Cf, 12.9% of 250Cf, and 36.4% of 251Cf) was irradiated by 48Ca ions at two beam energies of 252 and 258 MeV with the corresponding accumulated beam doses of 1.6×1019 and 1.1×1019. A single event observed at lower beam energy was assigned to the isotope 294Og, the product of the reaction 249Cf(48Ca, 3n); its decay pattern and the observed radioactive properties of the nuclides in the decay chain reproduce in full those observed for 294Og in our earlier experiments of 2002-2005 and 2012. At higher beam energy we observed no decay chains that could be attributed to the isotopes of Og. The possibility of renewal of this experiment in the future is discussed.

Comprehensive description of the Orion laser facility

NASA Astrophysics Data System (ADS)

Hopps, Nicholas; Oades, Kevin; Andrew, Jim; Brown, Colin; Cooper, Graham; Danson, Colin; Daykin, Simon; Duffield, Stuart; Edwards, Ray; Egan, David; Elsmere, Stephen; Gales, Steve; Girling, Mark; Gumbrell, Edward; Harvey, Ewan; Hillier, David; Hoarty, David; Horsfield, Colin; James, Steven; Leatherland, Alex; Masoero, Stephen; Meadowcroft, Anthony; Norman, Michael; Parker, Stefan; Rothman, Stephen; Rubery, Michael; Treadwell, Paul; Winter, David; Bett, Thomas

2015-06-01

The Orion laser facility at the atomic weapons establishment (AWE) in the UK has been operational since April 2013, fielding experiments that require both its long and short pulse capability. This paper provides a full description of the facility in terms of laser performance, target systems and diagnostics currently available. Inevitably, this is a snapshot of current capability—the available diagnostics and the laser capability are evolving continuously. The laser systems consist of ten beams, optimised around 1 ns pulse duration, which each provide a nominal 500 J at a wavelength of 351 nm. There are also two short pulse beams, which each provide 500 J in 0.5 ps at 1054 nm. There are options for frequency doubling one short pulse beam to enhance the pulse temporal contrast. More recently, further contrast enhancement, based on optical parametric amplification (OPA) in the front end with a pump pulse duration of a few ps, has been installed. An extensive suite of diagnostics are available for users, probing the optical emission, x-rays and particles produced in laser-target interactions. Optical probe diagnostics are also available. A description of the diagnostics is provided.

High-resolution γ-ray spectroscopy: a versatile tool for nuclear β-decay studies at TRIUMF-ISAC

NASA Astrophysics Data System (ADS)

Ball, G. C.; Achtzehn, T.; Albers, D.; Khalili, J. S. Al; Andreoiu, C.; Andreyev, A.; Ashley, S. F.; Austin, R. A. E.; Becker, J. A.; Bricault, P.; Chan, S.; Chakrawarthy, R. S.; Churchman, R.; Coombes, H.; Cunningham, E. S.; Daoud, J.; Dombsky, M.; Drake, T. E.; Eshpeter, B.; Finlay, P.; Garrett, P. E.; Geppert, C.; Grinyer, G. F.; Hackman, G.; Hanemaayer, V.; Hyland, B.; Jones, G. A.; Koopmans, K. A.; Kulp, W. D.; Lassen, J.; Lavoie, J. P.; Leslie, J. R.; Litvinov, Y.; Macdonald, J. A.; Mattoon, C.; Melconian, D.; Morton, A. C.; Osborne, C. J.; Pearson, C. J.; Pearson, M.; Phillips, A. A.; Ressler, J. J.; Sarazin, F.; Schumaker, M. A.; Schwarzenberg, J.; Scraggs, H. C.; Smith, M. B.; Svensson, C. E.; Valiente-Dobon, J. J.; Waddington, J. C.; Walker, P. M.; Wendt, K.; Williams, S. J.; Wood, J. L.; Zganjar, E. F.

2005-10-01

High-resolution γ-ray spectroscopy is essential to fully exploit the unique, high-quality beams available at the next generation of radioactive ion beam facilities such as the TRIUMF isotope separator and accelerator (ISAC). The 8π spectrometer, which consists of 20 Compton-suppressed HPGe detectors, has recently been reconfigured for a vigorous research programme in weak interaction and nuclear structure physics. With the addition of a variety of ancillary detectors it has become the world's most powerful device dedicated to β-decay studies. This paper provides a brief overview of the apparatus and highlights from recent experiments.

Multi-channel probes to understand fission dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosby, Shea Morgan

2016-04-15

Explaining the origin of the elements is a major outstanding question in nuclear astrophysics. Observed elemental abundance distribution shows strong nuclear physics effects. In conclusion, neutron-induced reactions are important for nuclear astrophysics and applied fields in nuclear energy and security. LANSCE has a program to address many of these questions directly with neutron beams on (near-)stable nuclei. Increasing demand for correlated data to test details of fission models poses additional challenges. Possibilities exist to extend existing experimental efforts to radioactive beam facilities. Kinematic focusing from using inverse kinematics has potential to circumvent some challenges associated with measuring correlations between fissionmore » output channels.« less

Preliminary design of a high-intensity continuous-wave deuteron RFQ

NASA Astrophysics Data System (ADS)

Liu, X.; Kamigaito, O.; Sakamoto, N.; Yamada, K.

2017-07-01

A high-intensity deuteron linear accelerator is currently being studied as a promising candidate to treat high-level radioactive waste through the nuclear transmutation process. This paper presents the study on a design of a 75.5 MHz, 400 mA, continuous-wave deuteron radio-frequency quadrupole (RFQ), which is proposed as the front-end of such a linear accelerator. The results of the beam dynamics simulation suggest that the designed RFQ can accelerate a 400-mA deuteron beam from 100 keV to 2.5 MeV with a transmission rate of 92.0 ∼ 93.3%, depending on the assumed input transverse emittance.

Development of time projection chamber for precise neutron lifetime measurement using pulsed cold neutron beams

NASA Astrophysics Data System (ADS)

Arimoto, Y.; Higashi, N.; Igarashi, Y.; Iwashita, Y.; Ino, T.; Katayama, R.; Kitaguchi, M.; Kitahara, R.; Matsumura, H.; Mishima, K.; Nagakura, N.; Oide, H.; Otono, H.; Sakakibara, R.; Shima, T.; Shimizu, H. M.; Sugino, T.; Sumi, N.; Sumino, H.; Taketani, K.; Tanaka, G.; Tanaka, M.; Tauchi, K.; Toyoda, A.; Tomita, T.; Yamada, T.; Yamashita, S.; Yokoyama, H.; Yoshioka, T.

2015-11-01

A new time projection chamber (TPC) was developed for neutron lifetime measurement using a pulsed cold neutron spallation source at the Japan Proton Accelerator Research Complex (J-PARC). Managing considerable background events from natural sources and the beam radioactivity is a challenging aspect of this measurement. To overcome this problem, the developed TPC has unprecedented features such as the use of polyether-ether-ketone plates in the support structure and internal surfaces covered with 6Li-enriched tiles to absorb outlier neutrons. In this paper, the design and performance of the new TPC are reported in detail.

Temperature dependence of yields from multi-foil SPES target

NASA Astrophysics Data System (ADS)

Corradetti, S.; Biasetto, L.; Manzolaro, M.; Scarpa, D.; Andrighetto, A.; Carturan, S.; Prete, G.; Zanonato, P.; Stracener, D. W.

2011-10-01

The temperature dependence of neutron-rich isotope yields was studied within the framework of the HRIBF-SPES Radioactive Ion Beams (RIB) project. On-line release measurements of fission fragments from a uranium carbide target at ensuremath 1600 {}^{circ}C , ensuremath 1800 {}^{circ}C and ensuremath 2000 {}^{circ}C were performed at ORNL (USA). The fission reactions were induced by a 40MeV proton beam accelerated into a uranium carbide target coupled to a plasma ion source. The experiments allowed for tests of performance of the SPES multi-foil target prototype loaded with seven UC2/graphite discs (ratio C/ U = 4 with density about 4g/cm3.

Monte Carlo simulations for the shielding of the future high-intensity accelerator facility FAIR at GSI.

PubMed

Radon, T; Gutermuth, F; Fehrenbacher, G

2005-01-01

The Gesellschaft für Schwerionenforschung (GSI) is planning a significant expansion of its accelerator facilities. Compared to the present GSI facility, a factor of 100 in primary beam intensities and up to a factor of 10,000 in secondary radioactive beam intensities are key technical goals of the proposal. The second branch of the so-called Facility for Antiproton and Ion Research (FAIR) is the production of antiprotons and their storage in rings and traps. The facility will provide beam energies a factor of approximately 15 higher than presently available at the GSI for all ions, from protons to uranium. The shielding design of the synchrotron SIS 100/300 is shown exemplarily by using Monte Carlo calculations with the FLUKA code. The experimental area serving the investigation of compressed baryonic matter is analysed in the same way. In addition, a dose comparison is made for an experimental area operated with medium energy heavy-ion beams. Here, Monte Carlo calculations are performed by using either heavy-ion primary particles or proton beams with intensities scaled by the mass number of the corresponding heavy-ion beam.

Radiation effects program

NASA Astrophysics Data System (ADS)

1985-09-01

No existing LINAC Based Beam Heating facility comes within a factor of ten of the needs of a high heating rate thermodynamic properties research facility. The facility could be built at the Naval Research Lab. for a cost in the neighborhood of 2 million dollars. The 10 MeV electron beam would not produce any serious radioactivity but would provide unprecedented beam power for such other applications as food processing, sewer treatment, materials curing, radiation hardness assurance, etc. One can always achieve lower current densities by scattering the beam and moving the device under test further away from the scatterer. In this case one must rely on the TLD readings to indicate the dose rate at the point of interest. For general utility with the beam covering about four TLD's fairly evenly one can claim that the NRL LINAC can produce a maximum dose rate of about 6 x 10 to the 10th power rads (Si) per second for a pulse length of 1.5 microseconds, and about 1.4 x 10 to the 11th power rads (Si) per second in a 50 nanosecond pulse. In both cases the beam area is about 0.4 square centimeters.

Effect of nuclear-reaction mechanisms on the population of excited nuclear states and isomeric ratios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skobelev, N. K., E-mail: skobelev@jinr.ru

2016-07-15

Experimental data on the cross sections for channels of fusion and transfer reactions induced by beams of radioactive halo nuclei and clustered and stable loosely bound nuclei were analyzed, and the results of this analysis were summarized. The interplay of the excitation of single-particle states in reaction-product nuclei and direct reaction channels was established for transfer reactions. Respective experiments were performed in stable ({sup 6}Li) and radioactive ({sup 6}He) beams of the DRIBs accelerator complex at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, and in deuteron and {sup 3}He beams of the U-120M cyclotron at themore » Nuclear Physics Institute, Academy Sciences of Czech Republic (Řež and Prague, Czech Republic). Data on subbarrier and near-barrier fusion reactions involving clustered and loosely bound light nuclei ({sup 6}Li and {sup 3}He) can be described quite reliably within simple evaporation models with allowance for different reaction Q-values and couple channels. In reactions involving halo nuclei, their structure manifests itself most strongly in the region of energies below the Coulomb barrier. Neutron transfer occurs with a high probability in the interactions of all loosely bound nuclei with light and heavy stable nuclei at positive Q-values. The cross sections for such reactions and the respective isomeric ratios differ drastically for nucleon stripping and nucleon pickup mechanisms. This is due to the difference in the population probabilities for excited single-particle states.« less

New production systems at ISOLDE

NASA Astrophysics Data System (ADS)

Hagebø, E.; Hoff, P.; Jonsson, O. C.; Kugler, E.; Omtvedt, J. P.; Ravn, H. L.; Steffensen, K.

1992-08-01

New target systems for the ISOLDE on-line mass separator facility are presented. Targets of carbides, metal/graphite mixtures, foils of refractory metals, molten metals and oxides have been tested. Beams of high intensity of neutron-rich isotopes of a large number of elements are obtained from a uranium carbide target with a hot plasma-discharge ion source. A target of ZrO 2 has been shown to provide high intensity beams of neutron-deficient isotopes of Mn, Cu, Zn, Ga, Ge, As, Se, Br, Kr and Rb, while a SiC target with a hot plasma ion source gives intense beams of radioactive isotopes of a number of light elements. All these systems are rather chemically unselective. Chemically selective performance has been obtained for several systems, i.e.: the production of neutron-deficient Au from ( 3He, pχn) reactions on a Pt/graphite target with a hot plasma ion source; the production of neutron-deficient Lu and LuF + and Hf and HfF 3+ from a Ta-foil target with a hot plasma ion source under CF 4 addition; the production of neutron-deficient Sr as SrF + and Y as YF 2+ form a Nb-foil target with a W surface ionizer under CF 4 addition; the production of neutron-deficient Se as COSe + from a ZrO 2 target with a hot plasma ion source under O 2 addition; and the production of radioactive F from a SiC target with a hot plasma ion source operating in Al vapour.

Optimisation of environmental remediation: how to select and use the reference levels.

PubMed

Balonov, M; Chipiga, L; Kiselev, S; Sneve, M; Yankovich, T; Proehl, G

2018-06-01

A number of past industrial activities and accidents have resulted in the radioactive contamination of large areas at many sites around the world, giving rise to a need for remediation. According to the International Commission on Radiological Protection (ICRP) and International Atomic Energy Agency (IAEA), such situations should be managed as existing exposure situations (ExESs). Control of exposure to the public in ExESs is based on the application of appropriate reference levels (RLs) for residual doses. The implementation of this potentially fruitful concept for the optimisation of remediation in various regions is hampered by a lack of practical experience and relevant guidance. This paper suggests a generic methodology for the selection of numeric values of relevant RLs both in terms of residual annual effective dose and derived RLs (DRLs) based on an appropriate dose assessment. The value for an RL should be selected in the range of the annual residual effective dose of 1-20 mSv, depending on the prevailing circumstances for the exposure under consideration. Within this range, RL values should be chosen by the following assessment steps: (a) assessment of the projected dose, i.e. the dose to a representative person without remedial actions by means of a realistic model as opposed to a conservative model; (b) modelling of the residual dose to a representative person following application of feasible remedial actions; and (c) selection of an RL value between the projected and residual doses, taking account of the prevailing social and economic conditions. This paper also contains some recommendations for practical implementation of the selected RLs for the optimisation of public protection. The suggested methodology used for the selection of RLs (in terms of dose) and the calculation of DRLs (in terms of activity concentration in food, ambient dose rate, etc) has been illustrated by a retrospective analysis of post-Chernobyl monitoring and modelling data from the Bryansk region, Russia, 2001. From this example, it follows that analysis of real data leads to the selection of an RL from a relatively narrow annual dose range (in this case, about 2-3 mSv), from which relevant DRLs can be calculated and directly used for optimisation of the remediation programme.

Porcelain-coated antenna for radio-frequency driven plasma source

DOEpatents

Leung, K.N.; Wells, R.P.; Craven, G.E.

1996-12-24

A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ions because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile. 8 figs.

Monitoring System for the Gold Target by Radiation Detectors in Hadron Experimental Facility at J-PARC

NASA Astrophysics Data System (ADS)

Muto, Ryotaro; Agari, Keizo; Aoki, Kazuya; Bessho, Kotaro; Hagiwara, Masayuki; Hirose, Erina; Ieiri, Masaharu; Iwasaki, Ruri; Katoh, Yohji; Kitagawa, Jun-ichi; Minakawa, Michifumi; Morino, Yuhei; Saito, Kiwamu; Sato, Yoshinori; Sawada, Shin'ya; Shirakabe, Yoshihisa; Suzuki, Yoshihiro; Takahashi, Hitoshi; Tanaka, Kazuhiro; Toyoda, Akihisa; Watanabe, Hiroaki; Yamanoi, Yutaka

2017-09-01

At the Hadron Experimental Facility in J-PARC, we inject a 30-GeV proton beam into a gold target to produce secondary particle beams required for various particle and nuclear physics experiments. The gold target is placed in a hermetic chamber, and helium gas is circulated in the chamber to monitor the soundness of the target. The radioactivity in helium gas is continuously monitored by gamma-ray detectors such as a germanium detector and a NaI(Tl) detector. Beam operations with those target-monitoring systems were successfully performed from April to June and October to December 2015, and from May to June 2016. In this paper, the details of the helium gas circulation system and gamma-ray detectors and the analysis results of the obtained gamma-ray spectra are reported.

Annular structures formed in a beam of ions during their collective acceleration in a system with dielectric anode

NASA Astrophysics Data System (ADS)

Lopatin, V. S.; Remnev, G. E.; Martynenko, A. A.

2017-05-01

We have studied the collective acceleration of protons and deuterons in an electron beam emitted from plasma formed at the surface of a dielectric anode insert. The experiments were performed with a pulsed electron accelerator operating at an accelerating voltage up to 1 MV, current amplitude up to 40 kA, and pulse duration of 50 ns. Reduction of the accelerating voltage pulse front width and optimization of the diode unit and drift region ensured the formation of several annular structures in the electron beam. As a result, up to 50% of the radioactivity induced in a copper target was concentrated in a ring with 4.5-cm diameter and 0.2-cm width. The formation of high energy density in these circular traces and the appearance of an axial component of the self-generated magnetic field of the electron beam are related with the increasing efficiency of acceleration of the most intense group of ions.

Design of a single magnet separator with mass resolving power m/Δm ≈ 20, 000

NASA Astrophysics Data System (ADS)

Breitenfeldt, Martin; Augustin, Mathieu; Catherall, Richard; Giles, Tim; Schoerling, Daniel; Tveten, Gry M.

2016-06-01

ISOLDE at CERN is a leading radioactive ion beam facility. With its upgrade, the HIE-ISOLDE project, an increase in primary beam intensity and energy is envisaged and the aim is a significant increase in intensity of the exotic beams. The high resolution separator (HRS) after the upgrade is required to suppress contaminations almost completely when the masses differ to the beam of interest by Δm / m > 1 / 20, 000 . Here a 120° magnet with a bending radius of 1.25 m has been chosen. The magnetic rigidity is 0.625 Tm (B-field of 0.5 T) to allow for separation of molecules of up to a mass of 300 u. The magnet comprises a yoke in wedged H-type configuration for stability and precision and pole face conductors for focusing and compensation of aberrations. The concept was derived analytically, refined with the OPERA 2D software and tested with the ray-tracing module of OPERA 3D.

Automation of experiments at Dubna Gas-Filled Recoil Separator

NASA Astrophysics Data System (ADS)

Tsyganov, Yu. S.

2016-01-01

Approaches to solving the problems of automation of basic processes in long-term experiments in heavy ion beams of the Dubna Gas-Filled Recoil Separator (DGFRS) facility are considered. Approaches in the field of spectrometry, both of rare α decays of superheavy nuclei and those for constructing monitoring systems to provide accident-free experiment running with highly radioactive targets and recording basic parameters of experiment, are described. The specific features of Double Side Silicon Strip Detectors (DSSSDs) are considered, special attention is paid to the role of boundary effects of neighboring p-n transitions in the "active correlations" method. An example of an off-beam experiment attempting to observe Zeno effect is briefly considered. Basic examples for nuclear reactions of complete fusion at 48Ca ion beams of U-400 cyclotron (LNR, JINR) are given. A scenario of development of the "active correlations" method for the case of very high intensity beams of heavy ions at promising accelerators of LNR, JINR, is presented.

The Alto Tandem and Isol Facility at IPN Orsay

NASA Astrophysics Data System (ADS)

Franchoo, Serge

Alto is an infrastructure for experimental nuclear physics in France that comprises both an on-line isotope-separation facility based on the photofission of uranium and a stable-ion beam facility based on a 14.5-MV tandem accelerator. The isotope-separation on-line section of Alto is dedicated to the production of neutron-rich radioactive ion beams (RIB) from the interaction of the γ-flux induced by a 50-MeV 10-µA electron beam in a uranium-carbide target. It is dimensioned for 1011 fissions per second. The RIB facility is exploited in alternating mode with the tandem-based section of Alto, capable of accelerating both light ions for nuclear astrophysics and heavy ions for γ-spectroscopy. The facility thereby offers the opportunity to deliver beams to a large range of physics programmes from nuclear to interdisciplinary physics. In this article, we present the Alto facility as well as some of the highlights and prospects of the experimental programme.

Photo-ionization of aluminum in a hot cavity for the selective production of exotic species project

NASA Astrophysics Data System (ADS)

Scarpa, D.; Makhathini, L.; Tomaselli, A.; Grassi, D.; Corradetti, S.; Manzolaro, M.; Vasquez, J.; Calderolla, M.; Rossignoli, M.; Monetti, A.; Andrighetto, A.; Prete, G.

2014-02-01

SPES (Selective Production of Exotic Species) is an Isotope Separation On-Line (ISOL) based accelerator facility that will be built in the Legnaro-Istituto Nazionale di Fisica Nucleare (INFN) Laboratory (Italy), intended to provide intense neutron-rich radioactive ion beams obtained by proton-induced fission of a uranium carbide (UCx) target. Besides this main target material, silicon carbide (SiC) will be the first to be used to deliver p-rich beams. This target will also validate the functionality of the SPES facility with aluminum beam as result of impinging SiC target with proton beam. In the past, off line studies on laser photoionization of aluminum have been performed in Pavia Spectroscopy Laboratory and in Laboratori Nazionali di Legnaro; a XeCl excimer laser was installed in order to test the laser ionization in the SPES hot cavity. With the new Wien filter installed a better characterization of the ionization process in terms of efficiency was performed and results are discussed.

Radioactive ion beams at ISOLDE/CERN recent developments and perspectives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Georg, U.; Catherall, R.; Giles, T.

1999-11-16

Since the move of ISOLDE from CERN's synchrocyclotron (SC) to the Proton Synchrotron Booster (PSB) in 1992 extensive work has been devoted to the development of new beams, i.e. the production of new isotopes, beams of higher intensity and the ionization of further elements. Most of these developments were driven by the particular needs of the physics community proposing new experiments. The main achievements were the adaption of liquid metal targets to the pulsed proton beam to prevent shockwaves and splashing inside the target container and systematic studies on the time structure of the release of the isotopes from themore » target. Furthermore the work on laser ion-sources already started at ISOLDE-2 was continued, the so-called RIST target was developed, and most recently first tests on the isotope production while increasing the proton energy from 1 GeV to 1.4 GeV were done. The latter topics are discussed in this paper.« less

Radioactive Ion Beams at ISOLDE/CERN Recent Developments and Perspectives

DOE Office of Scientific and Technical Information (OSTI.GOV)

U. Georg; J.R.J. Bennett; U.C. Bergmann

1999-12-31

Since the move of ISOLDE from CERN's synchrocyclotron (SC) to the Proton Synchrotron Booster (PSB) in 1992 extensive work has been devoted to the development of new beams, i.e. the production of new isotopes, beams of higher intensity and the ionization of further elements. Most of these developments were driven by the particular needs of the physics community proposing new experiments. The main achievements were the adaption of liquid metal targets to the pulsed proton beam to prevent shockwaves and splashing inside the target container and systematic studies on the time structure of the release of the isotopes from themore » target. Furthermore the work on laser ion-sources already started at ISOLDE-2 was continued, the so-called RIST target was developed, and most recently first tests on the isotope production while increasing the proton energy from 1 GeV to 1.4 GeV were done. The latter topics are discussed in this paper.« less

The ideal neutrino beams

NASA Astrophysics Data System (ADS)

Lindroos, Mats

2009-06-01

The advance in neutrino oscillation physics is driven by the availability of well characterized and high flux neutrino beams. The three present options for the next generation neutrino oscillation facility are super beams, neutrino factories and beta-beams. A super-beam is a very high intensity classical neutrino beam generated by protons impinging on a target where the neutrinos are generated by the secondary particles decaying in a tunnel down streams of the target. In a neutrino factory the neutrinos are generated from muons decaying in a storage ring with long straight sections pointing towards the detectors. In a beta-beam the neutrinos are also originating from decay in a storage ring but the decaying particles are radioactive ions rather than muons. I will in this presentation review the three options and discuss the pros and cons of each. The present joint design effort for a future high intensity neutrino oscillation in Europe within a common EU supported design study, EURONU, will also be presented. The design study will explore the physics reach, the detectors, the feasibility, the safety issues and the cost for each of the options so that the the community can take a decision on what to build when the facilities presently under exploitation and construction have to be replaced.

Positron annihilation lifetime and Doppler broadening spectroscopy at the ELBE facility

NASA Astrophysics Data System (ADS)

Wagner, Andreas; Butterling, Maik; Liedke, Maciej O.; Potzger, Kay; Krause-Rehberg, Reinhard

2018-05-01

The Helmholtz-Zentrum Dresden-Rossendorf operates a superconducting linear accelerator for electrons with energies up to 35 MeV and average beam currents up to 1.6 mA with bunch charges up to 120 pC. The electron beam is employed to produce several secondary beams including X-rays from bremsstrahlung production, coherent IR light in a Free Electron Laser, superradiant THz radiation, neutrons, and positrons. The secondary positron beam after moderation feeds the Monoenergetic Positron Source (MePS) where positron annihilation lifetime (PALS) and positron annihilation Doppler-broadening experiments in materials science are performed. The adjustable repetition rate of the continuous-wave electron beams allows matching of the pulse separation to the positron lifetime in the sample under study. The energy of the positron beam can be set between 0.5 keV and 20 keV to perform depth resolved defect spectroscopy and porosity studies especially for thin films. Bulk materials, fluids, gases, and even radioactive samples can be studied at the unique Gamma-induced Positron Source (GiPS) where an intense bremsstrahlung source generates positrons directly inside the material under study. A 22Na-based monoenergetic positron beam serves for offline experiments and additional depth-resolved Doppler-broadening studies complementing both accelerator-based sources.

A non-radioisotopic quantitative competitive polymerase chain reaction method: application in measurement of human herpesvirus 7 load.

PubMed

Kidd, I M; Clark, D A; Emery, V C

2000-06-01

Quantitative-competitive polymerase chain reaction (QCPCR) is a well-optimised and objective methodology for the determination of viral load in clinical specimens. A major advantage of QCPCR is the ability to control for the differential modulation of the PCR process in the presence of potentially inhibitory material. QCPCR protocols were developed previously for CMV, HHV-6, HHV-7 and HHV-8 and relied upon radioactively labelled primers, followed by autoradiography of the separated and digested PCR products to quantify viral load. Whilst this approach offers high accuracy and dynamic range, non-radioactive approaches would be attractive. Here, an alternative detection system is reported, based on simple ethidium bromide staining and computer analysis of the separated reaction products, which enables its adoption in the analysis of a large number of samples. In calibration experiments using cloned HHV-7 DNA, the ethidium bromide detection method showed an improved correlation with known copy number over that obtained with the isotopic method. In addition, 67 HHV-7 PCR positive blood samples, derived from immunocompromised patients, were quantified using both detection techniques. The results showed a highly significant correlation with no significant difference between the two methods. The applicability of the computerised densitometry method in the routine laboratory is discussed.

Fast pulsed operation of a small non-radioactive electron source with continuous emission current control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochems, P.; Kirk, A. T.; Bunert, E.

Non-radioactive electron sources are of great interest in any application requiring the emission of electrons at atmospheric pressure, as they offer better control over emission parameters than radioactive electron sources and are not subject to legal restrictions. Recently, we published a simple electron source consisting only of a vacuum housing, a filament, and a single control grid. In this paper, we present improved control electronics that utilize this control grid in order to focus and defocus the electron beam, thus pulsing the electron emission at atmospheric pressure. This allows short emission pulses and excellent stability of the emitted electron currentmore » due to continuous control, both during pulsed and continuous operations. As an application example, this electron source is coupled to an ion mobility spectrometer. Here, the pulsed electron source allows experiments on gas phase ion chemistry (e.g., ion generation and recombination kinetics) and can even remove the need for a traditional ion shutter.« less

HIAF: New opportunities for atomic physics with highly charged heavy ions

NASA Astrophysics Data System (ADS)

Ma, X.; Wen, W. Q.; Zhang, S. F.; Yu, D. Y.; Cheng, R.; Yang, J.; Huang, Z. K.; Wang, H. B.; Zhu, X. L.; Cai, X.; Zhao, Y. T.; Mao, L. J.; Yang, J. C.; Zhou, X. H.; Xu, H. S.; Yuan, Y. J.; Xia, J. W.; Zhao, H. W.; Xiao, G. Q.; Zhan, W. L.

2017-10-01

A new project, High Intensity heavy ion Accelerator Facility (HIAF), is currently being under design and construction in China. HIAF will provide beams of stable and unstable heavy ions with high energies, high intensities and high quality. An overview of new opportunities for atomic physics using highly charged ions and radioactive heavy ions at HIAF is given.

C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

DOE PAGES

Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; ...

2015-06-02

Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.

Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

Reactor operations informal monthly report, May 1, 1995--May 31, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hauptman, H.M.; Petro, J.N.; Jacobi, O.

1995-05-01

This document is an informal progress report for the operational performance of the Brookhaven Medical Research Reactor, and the Brookhaven High Flux Beam Reactor, for the month of May, 1995. Both machines ran well during this period, with no reportable instrumentation problems, all scheduled maintenance performed, and only one reportable occurance, involving a particle on Vest Button, Personnel Radioactive Contamination.

New separators at the ATLAS facility

NASA Astrophysics Data System (ADS)

Back, Birger; Agfa Collaboration; Airis Team

2015-10-01

Two new separators are being built for the ATLAS facility. The Argonne Gas-Filled Analyzer (AGFA) is a novel design consisting of a single quadrupole and a multipole magnet that has both dipole and quadrupole field components. The design allows for placing Gammasphere at the target position while providing a solid angle of ~ 22 msr for capturing recoil products emitted at zero degrees. This arrangement enables studies of prompt gamma ray emission from weakly populated trans-fermium nuclei and those near the doubly-magic N = Z = 50 shell closure measured in coincidence with the recoils registered by AGFA. The Argonne In-flight Radioactive Ion Separator (AIRIS) is a magnetic chicane that will be installed immediately downstream of the last ATLAS cryostat and serve to separate radioactive ion beams generated in flight at an upstream high intensity production target. These beams will be further purified by a downstream RF sweeper and transported into a number of target stations including HELIOS, the Enge spectrograph, the FMA and Gammasphere. This talk will present the status of these two projects. This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

Estimation of Risk of Normal-tissue Toxicity Following Gastric Cancer Radiotherapy with Photon- or Scanned Proton-beams.

PubMed

Mondlane, Gracinda; Ureba, Ana; Gubanski, Michael; Lind, Pehr A; Siegbahn, Albert

2018-05-01

Gastric cancer (GC) radiotherapy involves irradiation of large tumour volumes located in the proximities of critical structures. The advantageous dose distributions produced by scanned-proton beams could reduce the irradiated volumes of the organs at risk (OARs). However, treatment-induced side-effects may still appear. The aim of this study was to estimate the normal tissue complication probability (NTCP) following proton therapy of GC, compared to photon radiotherapy. Eight GC patients, previously treated with volumetric-modulated arc therapy (VMAT), were retrospectively planned with scanned proton beams carried out with the single-field uniform-dose (SFUD) method. A beam-specific planning target volume was used for spot positioning and a clinical target volume (CTV) based robust optimisation was performed considering setup- and range-uncertainties. The dosimetric and NTCP values obtained with the VMAT and SFUD plans were compared. With SFUD, lower or similar dose-volume values were obtained for OARs, compared to VMAT. NTCP values of 0% were determined with the VMAT and SFUD plans for all OARs (p>0.05), except for the left kidney (p<0.05), for which lower toxicity was estimated with SFUD. The NTCP reduction, determined for the left kidney with SFUD, can be of clinical relevance for preserving renal function after radiotherapy of GC. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Physics division. Progress report for period ending September 30, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ball, S.J.

1997-04-01

This report covers the research and development activities of the Physics Division for the 1995 and 1996 fiscal years, beginning October 1, 1994, and ending September 30, 1996. The activities of the Division continue to be concentrated in the areas of experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. In addition, there are smaller programs in plasma diagnostics and data compilation and evaluation. During the period of this report, there has been considerable success in bringing the Holifield Radioactive Ion Beam Facility (HRIBF) into routine operation. The budgets of the nuclear physics portion of the Divisionmore » have increased each year in nearly all areas, and several new members have been added to the Division research and development staff. On August 30, 1996, the HRIBF successfully accelerated its first radioactive ion beams, {sup 69}As and {sup 70}As. Prior to this, the heart of the facility, the RIB injector system, was completed, including installation of a remote handling system for the target/ion source assembly. Target and ion source development is likely to be the technical key to success of the HRIBF. We have expanded our efforts in those development areas. Of special note is the development of highly permeable composite targets which have now been shown to allow release of difficult-to-produce radioactive ions such as {sup 17,18}F. A summary of the HRIBF work is provided in Chapter 1, along with supporting activities of the Joint Institute for Heavy Ion Research.« less

Global nuclear industry views: challenges arising from the evolution of the optimisation principle in radiological protection.

PubMed

Saint-Pierre, S

2012-01-01

Over the last few decades, the steady progress achieved in reducing planned exposures of both workers and the public has been admirable in the nuclear sector. However, the disproportionate focus on tiny public exposures and radioactive discharges associated with normal operations came at a high price, and the quasi-denial of a risk of major accident and related weaknesses in emergency preparedness and response came at an even higher price. Fukushima has unfortunately taught us that radiological protection (RP) for emergency and post-emergency situations can be much more than a simple evacuation that lasts 24-48 h, with people returning safely to their homes soon afterwards. On optimisation of emergency and post-emergency exposures, the only 'show in town' in terms of international RP policy improvements has been the issuance of the 2007 Recommendations of the International Commission on Radiological Protection (ICRP). However, no matter how genuine these improvements are, they have not been 'road tested' on the practical reality of severe accidents. Post-Fukushima, there is a compelling case to review the practical adequacy of key RP notions such as optimisation, evacuation, sheltering, and reference levels for workers and the public, and to amend these notions with a view to making the international RP system more useful in the event of a severe accident. On optimisation of planned exposures, the reality is that, nowadays, margins for further reductions of public doses in the nuclear sector are very small, and the smaller the dose, the greater the extra effort needed to reduce the dose further. If sufficient caution is not exercised in the use of RP notions such as dose constraints, there is a real risk of challenging nuclear power technologies beyond safety reasons. For nuclear new build, it is the optimisation of key operational parameters of nuclear power technologies (not RP) that is of paramount importance to improve their overall efficiency. In pursuing further improvements in the international RP system, it should be clearly borne in mind that the system is generally based on protection against the risk of cancer and hereditary diseases. The system also protects against deterministic non-cancer effects on tissues and organs. In seeking refinements of such protective notions, ICRP is invited to pay increased attention to the fact that a continued balance must be struck between beneficial activities that cause exposures and protection. The global nuclear industry is committed to help overcome these key RP issues as part of the RP community's upcoming international deliberations towards a more efficient international RP system. Copyright © 2012. Published by Elsevier Ltd.

Biological effective dose evaluation in gynaecological brachytherapy: LDR and HDR treatments, dependence on radiobiological parameters, and treatment optimisation.

PubMed

Bianchi, C; Botta, F; Conte, L; Vanoli, P; Cerizza, L

2008-10-01

This study was undertaken to compare the biological efficacy of different high-dose-rate (HDR) and low-dose-rate (LDR) treatments of gynaecological lesions, to identify the causes of possible nonuniformity and to optimise treatment through customised calculation. The study considered 110 patients treated between 2001 and 2006 with external beam radiation therapy and/or brachytherapy with either LDR (afterloader Selectron, (137)Cs) or HDR (afterloader microSelectron Classic, (192)Ir). The treatments were compared in terms of biologically effective dose (BED) to the tumour and to the rectum (linear-quadratic model) by using statistical tests for comparisons between independent samples. The difference between the two treatments was statistically significant in one case only. However, within each technique, we identified considerable nonuniformity in therapeutic efficacy due to differences in fractionation schemes and overall treatment time. To solve this problem, we created a Microsoft Excel spreadsheet allowing calculation of the optimal treatment for each patient: best efficacy (BED(tumour)) without exceeding toxicity threshold (BED(rectum)). The efficacy of a treatment may vary as a result of several factors. Customised radiobiological evaluation is a useful adjunct to clinical evaluation in planning equivalent treatments that satisfy all dosimetric constraints.

Simulations of multi-contrast x-ray imaging using near-field speckles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zdora, Marie-Christine; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom and Department of Physics & Astronomy, University College London, London, WC1E 6BT; Thibault, Pierre

2016-01-28

X-ray dark-field and phase-contrast imaging using near-field speckles is a novel technique that overcomes limitations inherent in conventional absorption x-ray imaging, i.e. poor contrast for features with similar density. Speckle-based imaging yields a wealth of information with a simple setup tolerant to polychromatic and divergent beams, and simple data acquisition and analysis procedures. Here, we present a simulation software used to model the image formation with the speckle-based technique, and we compare simulated results on a phantom sample with experimental synchrotron data. Thorough simulation of a speckle-based imaging experiment will help for better understanding and optimising the technique itself.

Software/hardware optimization for attenuation-based microtomography using SR at PETRA III (Conference Presentation)

NASA Astrophysics Data System (ADS)

Beckmann, Felix

2016-10-01

The Helmholtz-Zentrum Geesthacht, Germany, is operating the user experiments for microtomography at the beamlines P05 and P07 using synchrotron radiation produced in the storage ring PETRA III at DESY, Hamburg, Germany. In recent years the software pipeline, sample changing hardware for performing high throughput experiments were developed. In this talk the current status of the beamlines will be given. Furthermore, optimisation and automatisation of scanning techniques, will be presented. These are required to scan samples which are larger than the field of view defined by the X-ray beam. The integration into an optimized reconstruction pipeline will be shown.

Human radiation studies: Remembering the early years. Oral history of biophysicist Cornelius A. Tobias, Ph.D., January 16, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-07-01

Dr. Cornelius A. Tobias was interviewed by representatives of US DOE Office of Human Radiation Experiments (OHRE). He was chosen for this interview because of his extensive biophysics and medical physics research activities while he was employed by the University of California, Berkeley and San Francisco and at the Donner Laboratory. He discusses his involvement in wartime studies of effects of high altitude on aviators, carbon monoxide with radioactive tracers, blood studies with radioactive iron, human use committees, heavy-ion research with the Bevatron, boron isotope research, classified research involving human subjects, heavy-particle radiography, heavy- particle beams and medical research, andmore » pituitary irradiation studies,.« less

Comparing the new generation accelerator driven subcritical reactor system (ADS) to traditional critical reactors

NASA Astrophysics Data System (ADS)

Kemah, Elif; Akkaya, Recep; Tokgöz, Seyit Rıza

2017-02-01

In recent years, the accelerator driven subcritical reactors have taken great interest worldwide. The Accelerator Driven System (ADS) has been used to produce neutron in subcritical state by the external proton beam source. These reactors, which are hybrid systems, are important in production of clean and safe energy and conversion of radioactive waste. The ADS with the selection of reliability and robust target materials have been the new generation of fission reactors. In addition, in the ADS Reactors the problems of long-lived radioactive fission products and waste actinides encountered in the fission process of the reactor during incineration can be solved, and ADS has come to the forefront of thorium as fuel for the reactors.

Molecular beam epitaxy of quasi-freestanding transition metal disulphide monolayers on van der Waals substrates: a growth study

NASA Astrophysics Data System (ADS)

Hall, Joshua; Pielić, Borna; Murray, Clifford; Jolie, Wouter; Wekking, Tobias; Busse, Carsten; Kralj, Marko; Michely, Thomas

2018-04-01

Based on an ultra-high vacuum compatible two-step molecular beam epitaxy synthesis with elemental sulphur, we grow clean, well-oriented, and almost defect-free monolayer islands and layers of the transition metal disulphides MoS2, TaS2 and WS2. Using scanning tunneling microscopy and low energy electron diffraction we investigate systematically how to optimise the growth process, and provide insight into the growth and annealing mechanisms. A large band gap of 2.55 eV and the ability to move flakes with the scanning tunneling microscope tip both document the weak interaction of MoS2 with its substrate consisting of graphene grown on Ir(1 1 1). As the method works for the synthesis of a variety of transition metal disulphides on different substrates, we speculate that it could be of great use for providing hitherto unattainable high quality monolayers of transition metal disulphides for fundamental spectroscopic investigations.

Nanobits, Nembranes and Micro Four-Point Probes: Customizable Tools for insitu Manipulation and Characterisation of Nanostructures

NASA Astrophysics Data System (ADS)

Boggild, Peter; Hjorth Petersen, Dirch; Sardan Sukas, Ozlem; Dam, Henrik Friis; Lei, Anders; Booth, Timothy; Molhave, Kristian; Eicchorn, Volkmar

2010-03-01

We present a range of highly adaptable microtools for direct interaction with nanoscale structures; (i) semiautomatic pick-and-place assembly of multiwalled carbon nanotubes onto cantilevers for high-aspect ratio scanning probe microscopy, using electrothermal microgrippers inside a SEM. Topology optimisation was used to calculate the optimal gripper shape defined by the boundary conditions, resulting in 10-100 times better performance. By instead pre-defining detachable tips using electron beam lithography, free-form scanning probe tips (Nanobits) can be mounted in virtually any position on a cantilever; (ii) scanning micro four point probes allow fast, non- destructive mapping of local electrical properties (sheet resistance and Hall mobility) and hysteresis effects of graphene sheets; (iii) sub 100 nm freestanding devices with wires, heaters, actuators, sensors, resonators and probes were defined in a 100 nm thin membrane with focused ion beam milling. By patterning generic membrane templates (Nembranes) the fabrication time of a TEM compatible NEMS device is effectively reduced to less around 20 minutes.

Design and optimisation of low heat load liquid helium cryostat to house cryogenic current comparator in antiproton decelerator at CERN

NASA Astrophysics Data System (ADS)

Lees, A.; Koettig, T.; Fernandes, M.; Tan, J.

2017-02-01

The Cryogenic Current Comparator (CCC) is installed in the low-energy Antiproton Decelerator (AD) at CERN to make an absolute measurement of the beam intensity. Operating below 4.2 K, it is based on a superconducting quantum interference device (SQUID) and employs a superconducting niobium shield to supress magnetic field components not linked to the beam current. The AD contains no permanent cryogenic infrastructure so the local continuous liquefaction of helium using a pulse-tube is required; limiting the available cooling power to 0.69 W at 4.2K. Due to the sensitivity of the SQUID to variations in magnetic fields, the CCC is highly sensitive to mechanical vibration which is limited to a minimum by the support systems of the cryostat. This article presents the cooling system of the cryostat and discusses the design challenges overcome to minimise the transmission of vibration to the CCC while operating within the cryogenic limits imposed by the cooling system.

Can Collimated Extraterrestrial Signals be Intercepted?

NASA Astrophysics Data System (ADS)

Forgan, D. H.

2014-06-01

The Optical Search for Extraterrestrial Intelligence (OSETI) attempts to detect collimated, narrow-band pulses of electromagnetic radiation. These pulses may either consist of signals intentionally directed at the Earth, or signals between two star systems with a vector that unintentionally intersects the Solar System, allowing Earth to intercept the communication. But should we expect to be able to intercept these unintentional signals? And what constraints can we place upon the frequency of intelligent civilisations if we do? We carry out Monte Carlo Realisation simulations of interstellar communications between civilisations in the Galactic Habitable Zone (GHZ) using collimated beams. We measure the frequency with which beams between two stars are intercepted by a third. The interception rate increases linearly with the fraction of communicating civilisations, and as the cube of the beam opening angle, which is somewhat stronger than theoretical expectations, which we argue is due to the geometry of the GHZ. We find that for an annular GHZ containing 10,000 civilisations, intersections are unlikely unless the beams are relatively uncollimated. These results indicate that optical SETI is more likely to find signals deliberately directed at the Earth than accidentally intercepting collimated communications. Equally, civilisations wishing to establish a network of communicating species may use weakly collimated beams to build up the network through interception, if they are willing to pay a cost penalty that is lower than that meted by fully isotropic beacons. Future SETI searches should consider the possibility that communicating civilisations will attempt to strike a balance between optimising costs and encouraging contact between civilisations, and look for weakly collimated pulses as well as narrow-beam pulses directed deliberately at the Earth.

Temporally separating Cherenkov radiation in a scintillator probe exposed to a pulsed X-ray beam.

PubMed

Archer, James; Madden, Levi; Li, Enbang; Carolan, Martin; Petasecca, Marco; Metcalfe, Peter; Rosenfeld, Anatoly

2017-10-01

Cherenkov radiation is generated in optical systems exposed to ionising radiation. In water or plastic devices, if the incident radiation has components with high enough energy (for example, electrons or positrons with energy greater than 175keV), Cherenkov radiation will be generated. A scintillator dosimeter that collects optical light, guided by optical fibre, will have Cherenkov radiation generated throughout the length of fibre exposed to the radiation field and compromise the signal. We present a novel algorithm to separate Cherenkov radiation signal that requires only a single probe, provided the radiation source is pulsed, such as a linear accelerator in external beam radiation therapy. We use a slow scintillator (BC-444) that, in a constant beam of radiation, reaches peak light output after 1 microsecond, while the Cherenkov signal is detected nearly instantly. This allows our algorithm to separate the scintillator signal from the Cherenkov signal. The relative beam profile and depth dose of a linear accelerator 6MV X-ray field were reconstructed using the algorithm. The optimisation method improved the fit to the ionisation chamber data and improved the reliability of the measurements. The algorithm was able to remove 74% of the Cherenkov light, at the expense of only 1.5% scintillation light. Further characterisation of the Cherenkov radiation signal has the potential to improve the results and allow this method to be used as a simpler optical fibre dosimeter for quality assurance in external beam therapy. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Measuring one nucleon transfer reaction 24Mg( p, d)23Mg for astrophysical reaction rates

NASA Astrophysics Data System (ADS)

Lee, E. J.; Chae, K. Y.

2017-12-01

The level structure of a radionuclide 23Mg has been studied by using the 24Mg( p, d)23Mg one nucleon transfer reaction measurement for the astrophysical 19Ne(α, γ)23Mg reaction rate. A 41 MeV proton beam was produced and accelerated at the 25 MV tandem accelerator of the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory in the United States. The beam particles impinged on an isotopically-enriched 24Mg solid target. Angular distributions of recoiling deuterons were extracted by using a large area silicon strip detector array. By comparing the experimentally-obtained angular distributions with zero range distorted wave Born approximation calculations, spins and parities of three energy levels of 23Mg could be constrained for the first time, which is very important information needed to understand the 19Ne(α, γ)23Mg reaction rate.

Lifetime and g-factor measurements of excited states using Coulomb excitation and alpha transfer reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guevara, Z. E., E-mail: zjguevaram@unal.edu.co; Torres, D. A., E-mail: datorresg@unal.edu.co

2016-07-07

In this contribution the challenges in the use of a setup to simultaneously measure lifetimes and g-factor values will be presented. The simultaneous use of the transient field technique and the Doppler Shift Attenuation Method, to measure magnetic moments and lifetimes respectively, allows to obtain a complete characterization of the currents of nucleons and the deformation in excited states close to the ground state. The technique is at the moment limited to Coulomb excitation and alpha-transfer reactions, what opens an interesting perspective to consider this type of experiments with radioactive beams. The use of deep-inelastic and fusion-evaporation reactions will bemore » discussed. An example of a setup that makes use of a beam of {sup 106}Cd to study excited states of {sup 110}Sn and the beam nuclei itself will be presented.« less

/B(E2) values from low-energy Coulomb excitation at an ISOL facility: the /N=80,82 Te isotopes

NASA Astrophysics Data System (ADS)

Barton, C. J.; Caprio, M. A.; Shapira, D.; Zamfir, N. V.; Brenner, D. S.; Gill, R. L.; Lewis, T. A.; Cooper, J. R.; Casten, R. F.; Beausang, C. W.; Krücken, R.; Novak, J. R.

2003-01-01

B(E2;0+1→2+1) values for the unstable, neutron-rich nuclei 132,134Te were determined through Coulomb excitation, in inverse kinematics, of accelerated beams of these nuclei. The systematics of measured B(E2) values from the ground state to the first excited state have been extended to the N=82 shell closure in the Te nuclei and have been compared with the predictions of different theories. The measurements were performed at the Holifield Radioactive Ion Beam Facility (HRIBF) using the GRAFIK detector. The success of this approach, which couples a 5.7% efficient through-well NaI(Tl) γ-ray detector with thin foil microchannel plate beam detectors, also demonstrates the feasibility for Coulomb excitation studies of neutron-rich nuclei even further from the valley of beta stability, both at present-generation ISOL facilities and at the proposed Rare Isotope Accelerator.

The PX-AMS system and its applications at CIAE

NASA Astrophysics Data System (ADS)

He, Ming; Jiang, Shan; Jiang, Songsheng; Wu, ShaoYong; Guo, Gang

2004-08-01

The projectile X-ray detection method (PXD) has been set up in the China Institute of Atomic Energy AMS system. Using this method, the half-life of 79Se and 75Se have been measured, the intensity of 64Cu radioactive nuclear beams have been identified, and the upper limit of transition probability of the first excited state of 64Cu was obtained.

The SPEDE spectrometer

NASA Astrophysics Data System (ADS)

Papadakis, P.; Cox, D. M.; O'Neill, G. G.; Borge, M. J. G.; Butler, P. A.; Gaffney, L. P.; Greenlees, P. T.; Herzberg, R.-D.; Illana, A.; Joss, D. T.; Konki, J.; Kröll, T.; Ojala, J.; Page, R. D.; Rahkila, P.; Ranttila, K.; Thornhill, J.; Tuunanen, J.; Van Duppen, P.; Warr, N.; Pakarinen, J.

2018-03-01

The electron spectrometer, SPEDE, has been developed and will be employed in conjunction with the Miniball spectrometer at the HIE-ISOLDE facility, CERN. SPEDE allows for direct measurement of internal conversion electrons emitted in-flight, without employing magnetic fields to transport or momentum filter the electrons. Together with the Miniball spectrometer, it enables simultaneous observation of γ rays and conversion electrons in Coulomb excitation experiments using radioactive ion beams.

Lifetimes of relativistic heavy-ion beams in the High Energy Storage Ring of FAIR

NASA Astrophysics Data System (ADS)

Shevelko, V. P.; Litvinov, Yu. A.; Stöhlker, Th.; Tolstikhina, I. Yu.

2018-04-01

The High Energy Storage Ring, HESR, will be constructed at the Facility for Antiproton and Ion Research, FAIR, Darmstadt. For the first time, it will be possible to perform experiments with cooled high-intensity stable and radioactive heavy ions at highly relativistic energies. To design experiments at the HESR, realistic estimations of beam lifetimes are indispensable. Here we report calculated cross sections and lifetimes for typical U88+ , U90+ , U92+ , Sn49+ and Sn50+ ions in the energy range E = 400 MeV/u-5 GeV/u, relevant for the HESR. Interactions with the residual gas and with internal gas-jet targets are also considered.

ARIEL e-LINAC: Commissioning and Development

NASA Astrophysics Data System (ADS)

Laxdal, R. E.; Zvyagintsev, V.

2016-09-01

A superconducting electron Linac (e-Linac) will be a part of the ARIEL facility for the production of radioactive ion beams (RIB) at TRIUMF. The e-Linac will consist of five 1.3GHz 9-cell cavities in three cryomodules delivering a 50MeV 10mA beam. The baseline operation will be single pass but a re-circulating ring is planned to allow either energy boost or energy recovery operation. The first stage of the accelerator which consists of two cryomodules has been successfully commissioned in 2014. The paper will discuss the superconducting radio-frequency (SRF) challenges of the accelerator. Cavities, crymodules and RF system design, preparation, and performance will be presented.

(n,xn) cross section measurements for Y-89 foils used as detectors for high energy neutron measurements in the deeply subcritical assembly "QUINTA"

NASA Astrophysics Data System (ADS)

Bielewicz, Marcin; Kilim, Stanisław; Strugalska-Gola, Elżbieta; Szuta, Marcin; Wojciechowski, Andrzej; Tyutyunnikov, Sergey; Prokofiev, Alexander; Passoth, Elke

2017-09-01

Study of the deep subcritical systems (QUINTA) using relativistic beams is performed within the project "Energy and Transmutation of Radioactive Wastes" (E&T - RAW). The experiment assembly was irradiated by deuteron/proton beam (Dubna NUCLOTRON). We calculated the neutron energy spectrum inside the whole assembly by using threshold energy (n,xn) reactions in yttrium (Y-89) foils. There are almost no experimental cross section data for those reactions. New Y-89(n,xn) cross section measurements were carried out at The Svedberg laboratory (TSL) in Uppsala, Sweden in 2015. In this paper we present preliminary results of those experiments.

Neutron-rich isotope production using the uranium carbide multi-foil SPES target prototype

NASA Astrophysics Data System (ADS)

Scarpa, D.; Biasetto, L.; Corradetti, S.; Manzolaro, M.; Andrighetto, A.; Carturan, S.; Prete, G.; Zanonato, P.; Stracener, D. W.

2011-03-01

In the framework of the R&D program for the SPES (Selective Production of Exotic Species) project of the Istituto Nazionale di Fisica Nucleare (INFN), production yields of neutron-rich isotopes have been measured at the Holifield Radioactive Ion Beam Facility (HRIBF, Oak Ridge National Laboratory, USA). This experiment makes use of the multi-foil SPES target prototype composed of 7 uranium carbide discs, with excess of graphite (ratio C/ U = 4 . 77 isotopes of medium mass (between 72 and 141amu), produced via proton-induced fission of uranium using a 40MeV proton beam, have been collected and analyzed for the target heated at 2000 ° C target temperature.

The development and optimisation of 3D black-blood R2* mapping of the carotid artery wall.

PubMed

Yuan, Jianmin; Graves, Martin J; Patterson, Andrew J; Priest, Andrew N; Ruetten, Pascal P R; Usman, Ammara; Gillard, Jonathan H

2017-12-01

To develop and optimise a 3D black-blood R 2 * mapping sequence for imaging the carotid artery wall, using optimal blood suppression and k-space view ordering. Two different blood suppression preparation methods were used; Delay Alternating with Nutation for Tailored Excitation (DANTE) and improved Motion Sensitive Driven Equilibrium (iMSDE) were each combined with a three-dimensional (3D) multi-echo Fast Spoiled GRadient echo (ME-FSPGR) readout. Three different k-space view-order designs: Radial Fan-beam Encoding Ordering (RFEO), Distance-Determined Encoding Ordering (DDEO) and Centric Phase Encoding Order (CPEO) were investigated. The sequences were evaluated through Bloch simulation and in a cohort of twenty volunteers. The vessel wall Signal-to-Noise Ratio (SNR), Contrast-to-Noise Ratio (CNR) and R 2 *, and the sternocleidomastoid muscle R 2 * were measured and compared. Different numbers of acquisitions-per-shot (APS) were evaluated to further optimise the effectiveness of blood suppression. All sequences resulted in comparable R 2 * measurements to a conventional, i.e. non-blood suppressed sequence in the sternocleidomastoid muscle of the volunteers. Both Bloch simulations and volunteer data showed that DANTE has a higher signal intensity and results in a higher image SNR than iMSDE. Blood suppression efficiency was not significantly different when using different k-space view orders. Smaller APS achieved better blood suppression. The use of blood-suppression preparation methods does not affect the measurement of R 2 *. DANTE prepared ME-FSPGR sequence with a small number of acquisitions-per-shot can provide high quality black-blood R 2 * measurements of the carotid vessel wall. Copyright © 2017 Elsevier Inc. All rights reserved.

High and low energy gamma beam dump designs for the gamma beam delivery system at ELI-NP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yasin, Zafar, E-mail: zafar.yasin@eli-np.ro; Matei, Catalin; Ur, Calin A.

The Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is under construction in Magurele, Bucharest, Romania. The facility will use two 10 PW lasers and a high intensity, narrow bandwidth gamma beam for stand-alone and combined laser-gamma experiments. The accurate estimation of particle doses and their restriction within the limits for both personel and general public is very important in the design phase of any nuclear facility. In the present work, Monte Carlo simulations are performed using FLUKA and MCNPX to design 19.4 and 4 MeV gamma beam dumps along with shielding of experimental areas. Dose rate contour plots from both FLUKAmore » and MCNPX along with numerical values of doses in experimental area E8 of the facility are performed. The calculated doses are within the permissible limits. Furthermore, a reasonable agreement between both codes enhances our confidence in using one or both of them for future calculations in beam dump designs, radiation shielding, radioactive inventory, and other calculations releated to radiation protection. Residual dose rates and residual activity calculations are also performed for high-energy beam dump and their effect is negligible in comparison to contributions from prompt radiation.« less

Indirect studies on astrophysical reactions at the low-energy RI beam separator CRIB

NASA Astrophysics Data System (ADS)

Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Yang, L.; Shimizu, H.; Sakaguchi, Y.; Abe, K.; Wakabayashi, Y.; Hashimoto, T.; Nakao, T.; Kubono, S.; Suhara, T.; Iwasa, N.; Kim, A.; Kim, D. H.; Cha, S. M.; Kwag, M. S.; Lee, J. H.; Lee, E. J.; Chae, K. Y.; Imai, N.; Kitamura, N.; Lee, P.; Moon, J. Y.; Lee, K. B.; Akers, C.; Jung, H. S.; Duy, N. N.; Khiem, L. H.; Lee, C. S.; Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; Cognata, M. La; Lamia, L.; Romano, S.; Coc, A.; de Sereville, N.; Hammache, F.; Kiss, G.; Bishop, S.; Teranishi, T.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.

2018-04-01

Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the radioactive-isotope (RI) beams at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study (CNS), the University of Tokyo. A type of measurement to study astophysical reactions at CRIB is by the elastic resonant scattering with the thick-target method in inverse kinematics. An example is the α resonant scattering with 7Be beam, related to the astrophysical 7Be(α,γ) reactions, which is relevant in the hot p-p chain and νp-process in supernovae. Other α resonant scattering measurements with 30S, 10Be, 15O, and 18Ne beams have been performed at CRIB, using the thick-target method. There have also been measurements based on other experimental methods. The first Trojan horse method (THM) measurement using an RI beam has been performed at CRIB, to study the 18F(p, α)15O reaction at astrophysical energies via the three body reaction 2H(18F, α15O)n. The 18F(p, α)15O reaction rate is crucial to understand the 511-keV γ-ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.

Activation of QA devices and phantom materials under clinical scanning proton beams-a gamma spectrometry study.

PubMed

Hanušová, Tereza; Johnová, Kamila; Navrátil, Matěj; Valenta, Jiří; Müller, Lutz

2018-06-07

Activation of detectors and phantoms used for commissioning and quality assurance of clinical proton beams may lead to radiation protection issues. Good understanding of the activation nuclide vectors involved is necessary to assess radiation risk for the personnel working with these devices on a daily basis or to fulfill legal requirements regarding transport of radioactive material and its release to the public. 11 devices and material samples were irradiated with a 220 MeV proton pencil beam (PBS, Proton Therapy Center, Prague). This study focuses on devices manufactured by IBA Dosimetry GmbH: MatriXX PT, PPC05, Stingray, Zebra, Lynx, a Blue Phantom rail and samples of RW3, PMMA, titanium, copper and carbon fibre plastic. Monitor units (MU) were monitored during delivery. Gamma spectrometry was then performed for each item using a HPGe detector, with a focus on longer lived gamma emitting radionuclides. Activities were quantified for all found isotopes and compared to relevant legal limits for exemption and clearance of radioactive objects. Activation was found to be significant after long irradiation sessions, as done during commissioning of a proton therapy room. Some of the investigated devices may also cumulate activity in time, depending on the scenario of periodic irradiation in routine clinical practice. However, the levels of activity and resulting beta/gamma doses are more comparable to internationally recommended concentration limits for exemption than to dose limits for radiation workers. Results of this study will help to determine nuclide inventories required by some legal authorities for radiation protection purposes.

Very-low-energy-spread ion sources

NASA Astrophysics Data System (ADS)

Lee, Y.

1997-05-01

Ion beams with low axial energy spread are required in many applications such as ion projection lithography, isobaric separation in radioactive ion beam experiments, and ion beam deposition processes. In an ion source, the spread of the axial ion energy is caused by the nonuniformity of the plasma potential distribution along the source axis. Multicusp ion sources are capable of production positive and negative ions with good beam quality and relatively low energy spread. By intorducing a magnetic filter inside the multicusp source chamber, the axial plasma potential distribution is modified and the energy spread of positive hydrogen ions can be reduced to as low as 1 eV. The energy spread measurements of multicusp sources have been conducted by employing three different techniques: an electrostatic energy analyzer at the source exit; a magnetic deflection spectrometer; and a retarding-field energy analyzer for the accelerated beam. These different measurements confirmed tha! t ! the axial energy spread of positive and negative ions generated in the filter-equipped multicusp sources are small. New ion source configurations are now being investigated at LBNL with the purpose of achieving enen lower energy spread (<1eV) and of maximizing source performance such as reliability and lifetime.

Experimental verification of a 4D MLEM reconstruction algorithm used for in-beam PET measurements in particle therapy

NASA Astrophysics Data System (ADS)

Stützer, K.; Bert, C.; Enghardt, W.; Helmbrecht, S.; Parodi, K.; Priegnitz, M.; Saito, N.; Fiedler, F.

2013-08-01

In-beam positron emission tomography (PET) has been proven to be a reliable technique in ion beam radiotherapy for the in situ and non-invasive evaluation of the correct dose deposition in static tumour entities. In the presence of intra-fractional target motion an appropriate time-resolved (four-dimensional, 4D) reconstruction algorithm has to be used to avoid reconstructed activity distributions suffering from motion-related blurring artefacts and to allow for a dedicated dose monitoring. Four-dimensional reconstruction algorithms from diagnostic PET imaging that can properly handle the typically low counting statistics of in-beam PET data have been adapted and optimized for the characteristics of the double-head PET scanner BASTEI installed at GSI Helmholtzzentrum Darmstadt, Germany (GSI). Systematic investigations with moving radioactive sources demonstrate the more effective reduction of motion artefacts by applying a 4D maximum likelihood expectation maximization (MLEM) algorithm instead of the retrospective co-registration of phasewise reconstructed quasi-static activity distributions. Further 4D MLEM results are presented from in-beam PET measurements of irradiated moving phantoms which verify the accessibility of relevant parameters for the dose monitoring of intra-fractionally moving targets. From in-beam PET listmode data sets acquired together with a motion surrogate signal, valuable images can be generated by the 4D MLEM reconstruction for different motion patterns and motion-compensated beam delivery techniques.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cosentino, L.; Pappalardo, A.; Piscopo, M.

During 2014, the second experimental area (EAR2) was completed at the n-TOF neutron beam facility at CERN (n-TOF indicates neutron beam measurements by means of time of flight technique). The neutrons are produced via spallation, by means of a high-intensity 20 GeV pulsed proton beam impinging on a thick target. The resulting neutron beam covers the energy range from thermal to several GeV. In this paper, we describe two beam diagnostic devices, both exploiting silicon detectors coupled with neutron converter foils containing {sup 6}Li. The first one is based on four silicon pads and allows monitoring of the neutron beammore » flux as a function of the neutron energy. The second one, in beam and based on position sensitive silicon detectors, is intended for the reconstruction of the beam profile, again as a function of the neutron energy. Several electronic setups have been explored in order to overcome the issues related to the gamma flash, namely, a huge pulse present at the start of each neutron bunch which may blind the detectors for some time. The two devices were characterized with radioactive sources and also tested at the n-TOF facility at CERN. The wide energy and intensity range they proved capable of sustaining made them attractive and suitable to be used in both EAR1 and EAR2 n-TOF experimental areas, where they became immediately operational.« less

CHICO2, a two-dimensional pixelated parallel-plate avalanche counter

DOE PAGES

Wu, C. Y.; Cline, D.; Hayes, A.; ...

2016-01-27

CHICO 2 (Compact Heavy Ion COunter), is a large solid-angle, charged-particle detector array developed to provide both θ and Φ angle resolutions matching those of GRETINA (Gamma-Ray Energy Tracking In-beam Nuclear Array). CHICO 2 was successfully tested at the Argonne National Laboratory where it was fielded as an auxiliary detector with GRETINA for γ-ray spectroscopic studies of nuclei using a 252Cf spontaneous fission source, stable beams, and radioactive beams from CARIBU. In field tests of the 72,76Ge beams on a 0.5 mg/cm 2208Pb target at the sub-barrier energy, CHICO 2 provided charged-particle angle resolutions (FWHM) of 1.55° in θ andmore » 2.47° in Φ. This achieves the design goal for both coordinates assuming a beam-spot size (>3 mm) and the target thickness (>0.5 mg/cm 2). The combined angular resolution of GRETINA/CHICO 2 resulted in a Doppler-shift corrected energy resolution of 0.60% for 1 MeV coincident de-excitation γ-rays. This is nearly a factor of two improvements in resolution and sensitivity compared to Gammasphere/CHICO. Kinematically-coincident detection of scattered ions by CHICO 2 still maintains the mass resolution (ΔM/M) of ~5% that enhanced isolation of scattered weak beams of interest from scattered contaminant beams.« less

Upstream Optioneering: Optimising Higher Activity Waste Management

DOE Office of Scientific and Technical Information (OSTI.GOV)

McTeer, Jennifer; Morris, Jenny; Wickham, Stephen

2013-07-01

The Upstream Optioneering project was created by the Nuclear Decommissioning Authority (NDA) Radioactive Waste Management Directorate (RWMD) to support the development and implementation of opportunities to optimise the management of UK higher activity waste, spent fuel and other materials that may be disposed of in a geological disposal facility. The project works in an integrative manner with the NDA, RWMD and waste producers, and was split into three phases: - In Phase 1 waste management opportunities were identified and collated from across the NDA estate. - In Phase 2, opportunities collated during Phase 1, were further consolidated, analysed and prioritisedmore » to develop a three year work programme. Prioritisation ensured that resources were deployed appropriately and opportunities can be realised before the potential benefit diminishes. - Phase 3, which began in April 2012, comprises a three year work programme to address the prioritised opportunities. Work varies from direct implementation of opportunities to scoping studies that may pave the way for more detailed subsequent work by Site Licence Companies. The work programme is flexible and, subject to change control, varies depending on the needs of project sponsors (RWMD, NDA Strategy and NDA Delivery). This paper provides an overview of the Upstream Optioneering project (focusing particularly on Phases 2 and 3), summarises work carried out to date within the three year work programme, and provides some examples of the main findings concerning specific opportunities from Year One of the Phase 3 work programme. (authors)« less

Radioactive ion beams produced by neutron-induced fission at ISOLDE

NASA Astrophysics Data System (ADS)

Catherall, R.; Lettry, J.; Gilardoni, S.; Köster, U.; Isolde Collaboration

2003-05-01

The production rates of neutron-rich fission products for the next-generation radioactive beam facility EURISOL [EU-RTD Project EURISOL (HPRI-CT-1999-50001)] are mainly limited by the maximum amount of power deposited by protons in the target. An alternative approach is to use neutron beams to induce fission in actinide targets. This has the advantage of reducing: the energy deposited by the proton beam in the target; contamination from neutron-deficient isobars that would be produced by spallation; and mechanical stress on the target. At ISOLDE CERN [E. Kugler, Hyperfine Interact. 129 (2000) 23], tests have been made on standard ISOLDE actinide targets using fast-neutron bunches produced by bombarding thick, high- Z metal converters with 1 and 1.4 GeV proton pulses. This paper reviews the first applications of converters used at ISOLDE. It highlights the different geometries and the techniques used to compare fission yields produced by the proton beam directly on the target with neutron-induced fission. Results from the six targets already tested, namely UC 2/graphite and ThO 2 targets with tungsten and tantalum converters, are presented. To gain further knowledge for the design of a dedicated target as required by the TARGISOL project [EU-RTD Project TARGISOL (HPRI-CT-2001-50033)], the results are compared to simulations, using the MARS [N.V. Mokhov, S.I. Striganov, A. Van Ginneken, S.G. Mashnik, A.J. Sierk, J. Ranft, MARS code developments, in: 4th Workshop on Simulating Accelerator Radiation Environments, SARE-4, Knoxville, USA, 14-15.9.1998, FERMILAB-PUB-98-379, nucl-th/9812038; N.V. Mokhov, The Mars Code System User's Guide, Fermilab-FN-628, 1995; N.V. Mokhov, MARS Code Developments, Benchmarking and Applications, Fermilab-Conf-00-066, 2000; O.E. Krivosheev, N.V. Mokhov, A New MARS and its Applications, Fermilab-Conf-98/43, 1998] code interfaced with MCNP [J.S. Hendrics, MCNP4C LANL Memo X-5; JSH-2000-3; J.F. Briemesteir (Ed.), MCNP - A General Montecarlo N-Particle Transport Code, Version 4C, LA-13709-M] libraries, of the neutron flux from the converters interacting with the actinide targets.

Radioactive ion beams produced by neutron-induced fission at ISOLDE

NASA Astrophysics Data System (ADS)

Isolde Collaboration; Catherall, R.; Lettry, J.; Gilardoni, S.; Köster, U.

2003-05-01

The production rates of neutron-rich fission products for the next-generation radioactive beam facility EURISOL [EU-RTD Project EURISOL (HPRI-CT-1999-50001)] are mainly limited by the maximum amount of power deposited by protons in the target. An alternative approach is to use neutron beams to induce fission in actinide targets. This has the advantage of reducing: the energy deposited by the proton beam in the target; contamination from neutron-deficient isobars that would be produced by spallation; and mechanical stress on the target. At ISOLDE CERN [E. Kugler, Hyperfine Interact. 129 (2000) 23], tests have been made on standard ISOLDE actinide targets using fast-neutron bunches produced by bombarding thick, high-/Z metal converters with 1 and 1.4 GeV proton pulses. This paper reviews the first applications of converters used at ISOLDE. It highlights the different geometries and the techniques used to compare fission yields produced by the proton beam directly on the target with neutron-induced fission. Results from the six targets already tested, namely UC2/graphite and ThO2 targets with tungsten and tantalum converters, are presented. To gain further knowledge for the design of a dedicated target as required by the TARGISOL project [EU-RTD Project TARGISOL (HPRI-CT-2001-50033)], the results are compared to simulations, using the MARS [N.V. Mokhov, S.I. Striganov, A. Van Ginneken, S.G. Mashnik, A.J. Sierk, J. Ranft, MARS code developments, in: 4th Workshop on Simulating Accelerator Radiation Environments, SARE-4, Knoxville, USA, 14-15.9.1998, FERMILAB-PUB-98-379, nucl-th/9812038; N.V. Mokhov, The Mars Code System User's Guide, Fermilab-FN-628, 1995; N.V. Mokhov, MARS Code Developments, Benchmarking and Applications, Fermilab-Conf-00-066, 2000; O.E. Krivosheev, N.V. Mokhov, A New MARS and its Applications, Fermilab-Conf-98/43, 1998] code interfaced with MCNP [J.S. Hendrics, MCNP4C LANL Memo X-5; JSH-2000-3; J.F. Briemesteir (Ed.), MCNP - A General Montecarlo N-Particle Transport Code, Version 4C, LA-13709-M] libraries, of the neutron flux from the converters interacting with the actinide targets.

Quasifree (p ,p N ) scattering of light neutron-rich nuclei near N =14

NASA Astrophysics Data System (ADS)

Díaz Fernández, P.; Alvarez-Pol, H.; Crespo, R.; Cravo, E.; Atar, L.; Deltuva, A.; Aumann, T.; Avdeichikov, V.; Beceiro-Novo, S.; Bemmerer, D.; Benlliure, J.; Bertulani, C. A.; Boillos, J. M.; Boretzky, K.; Borge, M. J. G.; Caamaño, M.; Cabanelas, P.; Caesar, C.; Casarejos, E.; Catford, W.; Cederkäll, J.; Chartier, M.; Chulkov, L. V.; Cortina-Gil, D.; Datta Pramanik, U.; Dillmann, I.; Elekes, Z.; Enders, J.; Ershova, O.; Estradé, A.; Farinon, F.; Fernández-Domínguez, B.; Fraile, L. M.; Freer, M.; Galaviz, D.; Geissel, H.; Gernhäuser, R.; Golubev, P.; Göbel, K.; Hagdahl, J.; Heftrich, T.; Heil, M.; Heine, M.; Heinz, A.; Henriques, A.; Holl, M.; Hufnagel, A.; Ignatov, A.; Johansson, H. T.; Jonson, B.; Jurčiukonis, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Kelic-Heil, A.; Knyazev, A.; Kröll, T.; Kurz, N.; Labiche, M.; Langer, C.; Le Bleis, T.; Lemmon, R.; Lindberg, S.; Machado, J.; Marganiec, J.; Moro, A. M.; Movsesyan, A.; Nacher, E.; Najafi, A.; Nikolskii, E.; Nilsson, T.; Nociforo, C.; Panin, V.; Paschalis, S.; Perea, A.; Petri, M.; Pietras, B.; Pietri, S.; Plag, R.; Reifarth, R.; Ribeiro, G.; Rigollet, C.; Rossi, D.; Röder, M.; Savran, D.; Scheit, H.; Simon, H.; Sorlin, O.; Syndikus, I.; Taylor, J. T.; Tengblad, O.; Thies, R.; Togano, Y.; Vandebrouck, M.; Velho, P.; Volkov, V.; Wagner, A.; Wamers, F.; Weick, H.; Wheldon, C.; Wilson, G.; Winfield, J. S.; Woods, P.; Yakorev, D.; Zhukov, M.; Zilges, A.; Zuber, K.; R³B Collaboration

2018-02-01

Background: For many years, quasifree scattering reactions in direct kinematics have been extensively used to study the structure of stable nuclei, demonstrating the potential of this approach. The R 3B collaboration has performed a pilot experiment to study quasifree scattering reactions in inverse kinematics for a stable 12C beam. The results from that experiment constitute the first quasifree scattering results in inverse and complete kinematics. This technique has lately been extended to exotic beams to investigate the evolution of shell structure, which has attracted much interest due to changes in shell structure if the number of protons or neutrons is varied. Purpose: In this work we investigate for the first time the quasifree scattering reactions (p ,p n ) and (p ,2 p ) simultaneously for the same projectile in inverse and complete kinematics for radioactive beams with the aim to study the evolution of single-particle properties from N =14 to N =15 . Method: The structure of the projectiles 23O, 22O, and 21N has been studied simultaneously via (p ,p n ) and (p ,2 p ) quasifree knockout reactions in complete inverse kinematics, allowing the investigation of proton and neutron structure at the same time. The experimental data were collected at the R3B -LAND setup at GSI at beam energies of around 400 MeV/u. Two key observables have been studied to shed light on the structure of those nuclei: the inclusive cross sections and the corresponding momentum distributions. Conclusions: The knockout reactions (p ,p n ) and (p ,2 p ) with radioactive beams in inverse kinematics have provided important and complementary information for the study of shell evolution and structure. For the (p ,p n ) channels, indications of a change in the structure of these nuclei moving from N =14 to N =15 have been observed, i.e., from the 0 d5 /2 shell to the 1 s1 /2 . This supports previous observations of a subshell closure at N =14 for neutron-rich oxygen isotopes and its weakening for the nitrogen isotopes.

Image reconstruction from cone-beam projections with attenuation correction

NASA Astrophysics Data System (ADS)

Weng, Yi

1997-07-01

In single photon emission computered tomography (SPECT) imaging, photon attenuation within the body is a major factor contributing to the quantitative inaccuracy in measuring the distribution of radioactivity. Cone-beam SPECT provides improved sensitivity for imaging small organs. This thesis extends the results for 2D parallel- beam and fan-beam geometry to 3D parallel-beam and cone- beam geometries in order to derive filtered backprojection reconstruction algorithms for the 3D exponential parallel-beam transform and for the exponential cone-beam transform with sampling on a sphere. An exact inversion formula for the 3D exponential parallel-beam transform is obtained and is extended to the 3D exponential cone-beam transform. Sampling on a sphere is not useful clinically and current cone-beam tomography, with the focal point traversing a planar orbit, does not acquire sufficient data to give an accurate reconstruction. Thus a data acquisition method that obtains complete data for cone-beam SPECT by simultaneously rotating the gamma camera and translating the patient bed, so that cone-beam projections can be obtained with the focal point traversing a helix that surrounds the patient was developed. First, an implementation of Grangeat's algorithm for helical cone- beam projections was developed without attenuation correction. A fast new rebinning scheme was developed that uses all of the detected data to reconstruct the image and properly normalizes any multiply scanned data. In the case of attenuation no theorem analogous to Tuy's has been proven. We hypothesized that an artifact-free reconstruction could be obtained even if the cone-beam data are attenuated, provided the imaging orbit satisfies Tuy's condition and the exact attenuation map is known. Cone-beam emission data were acquired by using a circle- and-line and a helix orbit on a clinical SPECT system. An iterative conjugate gradient reconstruction algorithm was used to reconstruct projection data with a known attenuation map. The quantitative accuracy of the attenuation-corrected emission reconstruction was significantly improved.

Prompt radiation, shielding and induced radioactivity in a high-power 160 MeV proton linac

NASA Astrophysics Data System (ADS)

Magistris, Matteo; Silari, Marco

2006-06-01

CERN is designing a 160 MeV proton linear accelerator, both for a future intensity upgrade of the LHC and as a possible first stage of a 2.2 GeV superconducting proton linac. A first estimate of the required shielding was obtained by means of a simple analytical model. The source terms and the attenuation lengths used in the present study were calculated with the Monte Carlo cascade code FLUKA. Detailed FLUKA simulations were performed to investigate the contribution of neutron skyshine and backscattering to the expected dose rate in the areas around the linac tunnel. An estimate of the induced radioactivity in the magnets, vacuum chamber, the cooling system and the concrete shield was performed. A preliminary thermal study of the beam dump is also discussed.

Electrodeposition of actinide compounds from an aqueous ammonium acetate matrix. Experimental development and optimization

DOE PAGES

Boll, Rose Ann; Matos, Milan; Torrico, Matthew N.

2015-03-27

Electrodeposition is a technique that is routinely employed in nuclear research for the preparation of thin solid films of actinide materials which can be used in accelerator beam bombardments, irradiation studies, or as radioactive sources. The present study investigates the deposition of both lanthanides and actinides from an aqueous ammonium acetate electrolyte matrix. Electrodepositions were performed primarily on stainless steel disks; with yield analysis evaluated using -spectroscopy. Experimental parameters were studied and modified in order to optimize the uniformity and adherence of the deposition while maximizing the yield. The initial development utilized samarium as the plating material, with and withoutmore » a radioactive tracer. As a result, surface characterization studies were performed by scanning electron microscopy, electron microprobe analysis, radiographic imaging, and x-ray diffraction.« less

High intensity positron source at HFR: Basic concept, scoring and design optimisation

NASA Astrophysics Data System (ADS)

Zeman, A.; Tuček, K.; Debarberis, L.; Hogenbirk, A.

2012-01-01

Recent applications of positron beam techniques in various fields of research have led to an increasing demand for high intensity positron sources required for advanced applications, particularly in materials science. Considerable efforts are being made worldwide to design and set-up high intensity positron sources and beam systems that are based on several principles. Such positron sources could be used in fundamental and applied research experiments, as well as in industrial applications, especially in the field of condensed matter characterisation at the nanometre scale. Phenomena involving positrons are also important in other applied science fields such as medicine, biology, physics, energy, etc. However, such studies are often limited due to the relative lack of suitable positron sources. Results from the recently completed Exploratory Research Project called "HIPOS" are discussed in this paper, which describes the principles behind such a powerful very high intensity positron beam experimental facility that is based on a reactor source. Details of a proposed concept that uses nuclear reactions [(n, γ) and (γ, pair)] within a designed positron generator at the High Flux Reactor (HFR) in Petten are also discussed. The HIPOS source has been designed to produce slow positrons with intensity of the order of 10 10 e +/s.

VALOR joint oscillation analysis using multiple LAr-TPCs in the Booster Neutrino Beam at Fermilab

NASA Astrophysics Data System (ADS)

Andreopoulos, C.; Barry, C.; Bench, F.; Chappell, A.; Dealtry, T.; Dennis, S.; Escudero, L.; Jones, R.; Grant, N.; Roda, M.; Sgalaberna, D.; Shah, R.

2017-09-01

Anomalies observed by different experiments, the most significant ones being the ∼3.8 sigma νe appearance in a ∼50 MeV νµ beam from muon decay at rest observed by the LSND experiment and the ∼3.8 sigma νe and {\\bar{ν }}e appearance in a ∼1 GeV neutrino beam from pion decay in flight observed by MiniBooNE, suggest the existence of sterile neutrinos. The Short Baseline Neutrino (SBN) program at Fermilab aims to perform a sensitive search for sterile neutrinos by performing analyses of νe appearance and νµ disappearance employing three Liquid Argon Time Projection Chambers (LAr-TPCs) at different baselines. The VALOR neutrino fitting group was established within the T2K experiment and has led numerous flagship T2K oscillation analyses, and provided sensitivity and detector optimisation studies for DUNE and Hyper-K. The neutrino oscillation framework developed by this group is able to perform fits of several samples and systematic parameters within different neutrino models and experiments. Thus, VALOR is an ideal environment for the neutrino oscillation fits using multiple LAr-TPC detectors with proper treatment of correlated systematic uncertainties necessary for the SBN analyses.

Theoretical investigation of the thermal hydraulic behaviour of a slab-type liquid metal target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dury, T.V.; Smith, B.L.

1996-06-01

The thermal hydraulics codes CFDS-FLOW3D and ASTEC have been used to simulate a slabtype design of ESS spallation target. This design is single-skinned, and of tapering form (in the beam direction), with rounded sides in a cross-section through a plane normal to the beam. The coolant fluid used is mercury, under forced circulation, with an inlet temperature of 180{degrees}C. The goal of these computer studies was to understand the behaviour of the coolant flow, and hence to arrive at a design which optimises the heat extraction for a given beam power - in the sense of: (1) minimising the peakmore » local fluid temperature within the target, (2) maintaining an acceptable temperature level and distribution over and through the target outer wall, (3) keeping the overall fluid pressure loss through the complete target to a minimum, (4) staying within the physical limits of overall size required, particularly in the region of primary spallation. Two- and three-dimensional models have been used, with different arrangements and design of internal baffles, and different coolant flow distributions at the target inlet. Nominal total inlet mass flow was 245 kg/s, and a heat deposition profile used which was based on the proton beam energy distribution. This gave a nominal total heat load of 3.23 MW - of which 8.2kW were deposited in the window steel.« less

Design of an X -band electron linear accelerator dedicated to decentralized 99Mo/99mTc supply: From beam energy selection to yield estimation

NASA Astrophysics Data System (ADS)

Jang, Jaewoong; Yamamoto, Masashi; Uesaka, Mitsuru

2017-10-01

The most frequently used radionuclide in diagnostic nuclear medicine, 99mTc, is generally obtained by the decay of its parent radionuclide, 99Mo. Recently, concerns have been raised over shortages of 99Mo/99mTc, owing to aging of the research reactors which have been supplying practically all of the global demand for 99Mo in a centralized fashion. In an effort to prevent such 99Mo/99mTc supply disruption and, furthermore, to ameliorate the underlying instability of the centralized 99Mo/99mTc supply chain, we designed an X -band electron linear accelerator which can be distributed over multiple regions, whereby 99Mo/99mTc can be supplied with improved accessibility. The electron beam energy was designed to be 35 MeV, at which an average beam power of 9.1 kW was calculated by the following beam dynamics analysis. Subsequent radioactivity modeling suggests that 11 of the designed electron linear accelerators can realize self-sufficiency of 99Mo/99mTc in Japan.

Compact 2.45 GHz ECR Ion Source for generation of singly-charged ions

NASA Astrophysics Data System (ADS)

Fatkullin, Riyaz; Bogomolov, Sergey; Kuzmenkov, Konstantin; Efremov, Andrey

2018-04-01

2.45 GHz ECR ion sources are widely used for production of protons, single charged heavy ions and secondary radioactive ion beams. This paper describes the development of a compact ECR ion source based on 2.45 GHz coaxial resonator. The first results of extracted current measurements at different resonator configuration as a function of UHF frequency, power and gas flow are presented.

Status and Prospects of Hirfl Experiments on Nuclear Physics

NASA Astrophysics Data System (ADS)

Xu, H. S.; Zheng, C.; Xiao, G. Q.; Zhan, W. L.; Zhou, X. H.; Zhang, Y. H.; Sun, Z. Y.; Wang, J. S.; Gan, Z. G.; Huang, W. X.; Ma, X. W.

HIRFL is an accelerator complex consisting of 3 accelerators, 2 radioactive beams lines, 1 storage rings and a number of experimental setups. The research activities at HIRFL cover the fields of radio-biology, material science, atomic physics, and nuclear physics. This report mainly concentrates on the experiments of nuclear physics with the existing and planned experimental setups such as SHANS, RIBLL1, ETF, CSRe, PISA and HPLUS at HIRFL.

Radioactive by-products of a self-shielded cyclotron and the liquid target system for F-18 routine production.

PubMed

Kambali, I; Suryanto, H; Parwanto

2016-06-01

Routine production of F-18 radionuclide using proton beams accelerated in a cyclotron could potentially generate residual radioisotopes in the cyclotron vicinity which eventually become major safety concerns over radiation exposure to the workers. In this investigation, a typical 11-MeV proton, self-shielded cyclotron has been assessed for its residual radiation sources in the cyclotron's shielding, tank/chamber, cave wall as well as target system. Using a portable gamma ray spectroscopy system, the radiation measurement in the cyclotron environment has been carried out. Experimental results indicate that relatively long-lived radioisotopes such as Mn-54, Zn-65 and Eu-152 are detected in the inner and outer surface of the cyclotron shielding respectively while Mn-54 spectrum is observed around the cyclotron chamber. Weak intensity of Eu-152 radioisotope is again spotted in the inner and outer surface of the cyclotron cave wall. Angular distribution measurement of the Eu-152 shows that the intensity slightly drops with increasing observation angle relative to the proton beam incoming angle. In the target system, gamma rays from Co-56, Mn-52, Co-60, Mn-54, Ag-110 m are identified. TALYS-calculated nuclear cross-section data are used to study the origins of the radioactive by-products.

Improving Vector Evaluated Particle Swarm Optimisation by Incorporating Nondominated Solutions

PubMed Central

Lim, Kian Sheng; Ibrahim, Zuwairie; Buyamin, Salinda; Ahmad, Anita; Naim, Faradila; Ghazali, Kamarul Hawari; Mokhtar, Norrima

2013-01-01

The Vector Evaluated Particle Swarm Optimisation algorithm is widely used to solve multiobjective optimisation problems. This algorithm optimises one objective using a swarm of particles where their movements are guided by the best solution found by another swarm. However, the best solution of a swarm is only updated when a newly generated solution has better fitness than the best solution at the objective function optimised by that swarm, yielding poor solutions for the multiobjective optimisation problems. Thus, an improved Vector Evaluated Particle Swarm Optimisation algorithm is introduced by incorporating the nondominated solutions as the guidance for a swarm rather than using the best solution from another swarm. In this paper, the performance of improved Vector Evaluated Particle Swarm Optimisation algorithm is investigated using performance measures such as the number of nondominated solutions found, the generational distance, the spread, and the hypervolume. The results suggest that the improved Vector Evaluated Particle Swarm Optimisation algorithm has impressive performance compared with the conventional Vector Evaluated Particle Swarm Optimisation algorithm. PMID:23737718

Improving Vector Evaluated Particle Swarm Optimisation by incorporating nondominated solutions.

PubMed

Lim, Kian Sheng; Ibrahim, Zuwairie; Buyamin, Salinda; Ahmad, Anita; Naim, Faradila; Ghazali, Kamarul Hawari; Mokhtar, Norrima

2013-01-01

The Vector Evaluated Particle Swarm Optimisation algorithm is widely used to solve multiobjective optimisation problems. This algorithm optimises one objective using a swarm of particles where their movements are guided by the best solution found by another swarm. However, the best solution of a swarm is only updated when a newly generated solution has better fitness than the best solution at the objective function optimised by that swarm, yielding poor solutions for the multiobjective optimisation problems. Thus, an improved Vector Evaluated Particle Swarm Optimisation algorithm is introduced by incorporating the nondominated solutions as the guidance for a swarm rather than using the best solution from another swarm. In this paper, the performance of improved Vector Evaluated Particle Swarm Optimisation algorithm is investigated using performance measures such as the number of nondominated solutions found, the generational distance, the spread, and the hypervolume. The results suggest that the improved Vector Evaluated Particle Swarm Optimisation algorithm has impressive performance compared with the conventional Vector Evaluated Particle Swarm Optimisation algorithm.

Cryogenic molecular separation system for radioactive (11)C ion acceleration.

PubMed

Katagiri, K; Noda, A; Suzuki, K; Nagatsu, K; Boytsov, A Yu; Donets, D E; Donets, E D; Donets, E E; Ramzdorf, A Yu; Nakao, M; Hojo, S; Wakui, T; Noda, K

2015-12-01

A (11)C molecular production/separation system (CMPS) has been developed as part of an isotope separation on line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive (11)C ion beams. In the ISOL system, (11)CH4 molecules will be produced by proton irradiation and separated from residual air impurities and impurities produced during the irradiation. The CMPS includes two cryogenic traps to separate specific molecules selectively from impurities by using vapor pressure differences among the molecular species. To investigate the fundamental performance of the CMPS, we performed separation experiments with non-radioactive (12)CH4 gases, which can simulate the chemical characteristics of (11)CH4 gases. We investigated the separation of CH4 molecules from impurities, which will be present as residual gases and are expected to be difficult to separate because the vapor pressure of air molecules is close to that of CH4. We determined the collection/separation efficiencies of the CMPS for various amounts of air impurities and found desirable operating conditions for the CMPS to be used as a molecular separation device in our ISOL system.

Space pruning monotonic search for the non-unique probe selection problem.

PubMed

Pappalardo, Elisa; Ozkok, Beyza Ahlatcioglu; Pardalos, Panos M

2014-01-01

Identification of targets, generally viruses or bacteria, in a biological sample is a relevant problem in medicine. Biologists can use hybridisation experiments to determine whether a specific DNA fragment, that represents the virus, is presented in a DNA solution. A probe is a segment of DNA or RNA, labelled with a radioactive isotope, dye or enzyme, used to find a specific target sequence on a DNA molecule by hybridisation. Selecting unique probes through hybridisation experiments is a difficult task, especially when targets have a high degree of similarity, for instance in a case of closely related viruses. After preliminary experiments, performed by a canonical Monte Carlo method with Heuristic Reduction (MCHR), a new combinatorial optimisation approach, the Space Pruning Monotonic Search (SPMS) method, is introduced. The experiments show that SPMS provides high quality solutions and outperforms the current state-of-the-art algorithms.

Advanced low-activation materials. Fibre-reinforced ceramic composites

NASA Astrophysics Data System (ADS)

Fenici, P.; Scholz, H. W.

1994-09-01

A serious safety and environmental concern for thermonuclear fusion reactor development regards the induced radioactivity of the first wall and structural components. The use of low-activation materials (LAM) in a demonstration reactor would reduce considerably its potential risk and facilitate its maintenance. Moreover, decommissioning and waste management including disposal or even recycling of structural materials would be simplified. Ceramic fibre-reinforced SiC materials offer highly appreciable low activation characteristics in combination with good thermomechanical properties. This class of materials is now under experimental investigation for structural application in future fusion reactors. An overview on the recent results is given, covering coolant leak rates, thermophysical properties, compatibility with tritium breeder materials, irradiation effects, and LAM-consistent purity. SiC/SiC materials present characteristics likely to be optimised in order to meet the fusion application challenge. The scope is to put into practice the enormous potential of inherent safety with fusion energy.

Focal ratio degradation: a new perspective

NASA Astrophysics Data System (ADS)

Haynes, Dionne M.; Withford, Michael J.; Dawes, Judith M.; Haynes, Roger; Bland-Hawthorn, Joss

2008-07-01

We have developed an alternative FRD empirical model for the parallel laser beam technique which can accommodate contributions from both scattering and modal diffusion. It is consistent with scattering inducing a Lorentzian contribution and modal diffusion inducing a Gaussian contribution. The convolution of these two functions produces a Voigt function which is shown to better simulate the observed behavior of the FRD distribution and provides a greatly improved fit over the standard Gaussian fitting approach. The Voigt model can also be used to quantify the amount of energy displaced by FRD, therefore allowing astronomical instrument scientists to identify, quantify and potentially minimize the various sources of FRD, and optimise the fiber and instrument performance.

Studies for the electro-magnetic calorimeter SplitCal for the SHiP experiment at CERN with shower direction reconstruction capability

NASA Astrophysics Data System (ADS)

Bonivento, Walter M.

2018-02-01

This paper describes the basic ideas and the first simulation results of a new electro-magnetic calorimeter concept, named SplitCal, aimed at optimising the measurement of photon direction in fixed-target experiment configuration, with high photon detection efficiency. This calorimeter was designed for the invariant mass reconstruction of axion-like particles decaying into two photons in the mass range 200 MeV to 1 GeV for the proposed proton beam dump experiment SHiP at CERN. Preliminary results indicate that angular resolutions better than obtained by past experiments can be achieved with this design. An implementation of this concept with real technologies is under study.

Grey-box state-space identification of nonlinear mechanical vibrations

NASA Astrophysics Data System (ADS)

Noël, J. P.; Schoukens, J.

2018-05-01

The present paper deals with the identification of nonlinear mechanical vibrations. A grey-box, or semi-physical, nonlinear state-space representation is introduced, expressing the nonlinear basis functions using a limited number of measured output variables. This representation assumes that the observed nonlinearities are localised in physical space, which is a generic case in mechanics. A two-step identification procedure is derived for the grey-box model parameters, integrating nonlinear subspace initialisation and weighted least-squares optimisation. The complete procedure is applied to an electrical circuit mimicking the behaviour of a single-input, single-output (SISO) nonlinear mechanical system and to a single-input, multiple-output (SIMO) geometrically nonlinear beam structure.

Methods of measuring radioactivity in the environment

NASA Astrophysics Data System (ADS)

Isaksson, Mats

In this thesis a variety of sampling methods have been utilised to assess the amount of deposited activity, mainly of 137Cs, from the Chernobyl accident and from the nuclear weapons tests. Starting with the Chernobyl accident in 1986 sampling of air and rain was used to determine the composition and amount of radioactive debris from this accident, brought to southern Sweden by the weather systems. The resulting deposition and its removal from urban areas was than studied through measurements on sewage sludge and water. The main part of the thesis considers methods of determining the amount of radiocaesium in the ground through soil sampling. In connection with soil sampling a method of optimising the sampling procedure has been developed and tested in the areas of Sweden which have a comparatively high amount of 137Cs from the Chernobyl accident. This method was then used in a survey of the activity in soil in Lund and Skane, divided between nuclear weapons fallout and fallout from the Chernobyl accident. By comparing the results from this survey with deposition calculated from precipitation measurements it was found possible to predict the deposition pattern over Skane for both nuclear weapons fallout and fallout from the Chernobyl accident. In addition, the vertical distribution of 137Cs has been modelled and the temporal variation of the depth distribution has been described.

Enhancement of light yield and stability of radio-pure tetraphenyl-butadiene based coatings for VUV light detection in cryogenic environments

NASA Astrophysics Data System (ADS)

Baudis, L.; Benato, G.; Dressler, R.; Piastra, F.; Usoltsev, I.; Walter, M.

2015-09-01

The detection of VUV scintillation light in (liquid) argon (LAr) detectors commonly includes a reflector with a fluorescent coating, converting UV photons to visible light. The light yield of these detectors depends directly on the conversion efficiency. Several coating/reflector combinations were produced using VM2000, a specular reflecting multi-layer polymer, and Tetratex®, a diffuse reflecting PTFE fabric, as reflector foils. The light yield of these coatings was optimised and has been measured in a dedicated liquid argon setup built at the University of Zurich. It employs a small, 1.3 kg LAr cell viewed by a 3-inch, low radioactivity PMT of type R11065-10 from Hamamatsu. The cryogenic stability of these coatings was additionally studied. The optimum reflector/coating combination was found to be Tetratex® dip-coated with Tetraphenyl-butadiene with a thickness of 0.9 mg/cm2, resulting in a 3.6 times higher light yield compared to uncoated VM2000. Its performance was stable in long-term measurements, performed up to 100 days in liquid argon. This coated reflector was also investigated concerning radioactive impurities and found to be suitable for current and upcoming low-background experiments. Therefore it is used for the liquid argon veto in Phase II of the GERDA neutrinoless double beta decay experiment.

Elastic scattering and total reaction cross section for the 6He +58Ni system

NASA Astrophysics Data System (ADS)

Morcelle, V.; Lichtenthäler, R.; Lépine-Szily, A.; Guimarães, V.; Mendes, D. R., Jr.; Pires, K. C. C.; de Faria, P. N.; Barioni, A.; Gasques, L.; Morais, M. C.; Shorto, J. M. B.; Zamora, J. C.; Scarduelli, V.; Condori, R. Pampa; Leistenschneider, E.

2014-11-01

Elastic scattering measurements of 6He + 58Ni system have been performed at the laboratory energy of 21.7 MeV. The 6He secondary beam was produced by a transfer reaction 9Be (7Li , 6He ) and impinged on 58Ni and 197Au targets, using the Radioactive Ion Beam (RIB) facility, RIBRAS, installed in the Pelletron Laboratory of the Institute of Physics of the University of São Paulo, Brazil. The elastic angular distribution was obtained in the angular range from 15° to 80° in the center of mass frame. Optical model calculations have been performed using a hybrid potential to fit the experimental data. The total reaction cross section was derived.

Future Facility: FAIR at GSI

NASA Astrophysics Data System (ADS)

Rosner, Guenther

2007-05-01

The Facility for Antiproton and Ion Research, FAIR, is a new particle accelerator facility to be built at the GSI site in Germany. The research at FAIR will cover a wide range of topics in nuclear and hadron physics, high density plasma and atomic physics, and applications in condensed matter physics and biology. A 1.1 km circumference double ring of rapidly cycling 100 and 300 Tm synchrotrons, will be FAIR's central accelerator system. It will be used to produce, inter alia, high intensity secondary beams of antiprotons and short-lived radioactive nuclei. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experiments are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

Online time-differential perturbed angular correlation study with an 19O beam - Residence sites of oxygen atoms in highly oriented pyrolytic graphite

NASA Astrophysics Data System (ADS)

Sato, W.; Ueno, H.; Watanabe, H.; Miyoshi, H.; Yoshimi, A.; Kameda, D.; Ito, T.; Shimada, K.; Kaihara, J.; Suda, S.; Kobayashi, Y.; Shinohara, A.; Ohkubo, Y.; Asahi, K.

2008-01-01

The online time-differential perturbed angular correlation (TDPAC) method was applied to a study of the physical states of a probe 19F, the β- decay product of 19O (t1/2 = 26.9 s), implanted in highly oriented pyrolytic graphite. The observed magnitude of the electric field gradient at the probe nucleus, ∣Vzz∣ = 2.91(17) × 1022 V m-2, suggests that the incident 19O atoms are stabilized at an interlayer position with point group C3v. Exhibiting observed TDPAC spectra having a clear sample-to-detector configuration dependence, we demonstrate the applicability of the present online method with a short-lived radioactive 19O beam.

Preliminary results utilizing high-energy fission product γ-rays to detect fissionable material in cargo

NASA Astrophysics Data System (ADS)

Slaughter, D. R.; Accatino, M. R.; Bernstein, A.; Church, J. A.; Descalle, M. A.; Gosnell, T. B.; Hall, J. M.; Loshak, A.; Manatt, D. R.; Mauger, G. J.; Moore, T. L.; Norman, E. B.; Pohl, B. A.; Pruet, J. A.; Petersen, D. C.; Walling, R. S.; Weirup, D. L.; Prussin, S. G.; McDowell, M.

2005-12-01

A concept for detecting the presence of special nuclear material (235U or 239Pu) concealed in intermodal cargo containers is described. It is based on interrogation with a pulsed beam of 7 MeV neutrons that produce fission events and their β-delayed neutron emission or β-delayed high-energy γ radiation between beam pulses provide the detection signature. Fission product β-delayed γ-rays above 3 MeV are nearly 10 times more abundant than β-delayed neutrons and are distinct from natural radioactivity and from nearly all of the induced activity in a normal cargo. Detector backgrounds and potential interferences with the fission signature radiation have been identified and quantified.

Conceptual design of the AGATA 1 π array at GANIL

NASA Astrophysics Data System (ADS)

Clément, E.; Michelagnoli, C.; de France, G.; Li, H. J.; Lemasson, A.; Barthe Dejean, C.; Beuzard, M.; Bougault, P.; Cacitti, J.; Foucher, J.-L.; Fremont, G.; Gangnant, P.; Goupil, J.; Houarner, C.; Jean, M.; Lefevre, A.; Legeard, L.; Legruel, F.; Maugeais, C.; Ménager, L.; Ménard, N.; Munoz, H.; Ozille, M.; Raine, B.; Ropert, J. A.; Saillant, F.; Spitaels, C.; Tripon, M.; Vallerand, Ph.; Voltolini, G.; Korten, W.; Salsac, M.-D.; Theisen, Ch.; Zielińska, M.; Joannem, T.; Karolak, M.; Kebbiri, M.; Lotode, A.; Touzery, R.; Walter, Ch.; Korichi, A.; Ljungvall, J.; Lopez-Martens, A.; Ralet, D.; Dosme, N.; Grave, X.; Karkour, N.; Lafay, X.; Legay, E.; Kojouharov, I.; Domingo-Pardo, C.; Gadea, A.; Pérez-Vidal, R. M.; Civera, J. V.; Birkenbach, B.; Eberth, J.; Hess, H.; Lewandowski, L.; Reiter, P.; Nannini, A.; De Angelis, G.; Jaworski, G.; John, P.; Napoli, D. R.; Valiente-Dobón, J. J.; Barrientos, D.; Bortolato, D.; Benzoni, G.; Bracco, A.; Brambilla, S.; Camera, F.; Crespi, F. C. L.; Leoni, S.; Million, B.; Pullia, A.; Wieland, O.; Bazzacco, D.; Lenzi, S. M.; Lunardi, S.; Menegazzo, R.; Mengoni, D.; Recchia, F.; Bellato, M.; Isocrate, R.; Egea Canet, F. J.; Didierjean, F.; Duchêne, G.; Baumann, R.; Brucker, M.; Dangelser, E.; Filliger, M.; Friedmann, H.; Gaudiot, G.; Grapton, J.-N.; Kocher, H.; Mathieu, C.; Sigward, M.-H.; Thomas, D.; Veeramootoo, S.; Dudouet, J.; Stézowski, O.; Aufranc, C.; Aubert, Y.; Labiche, M.; Simpson, J.; Burrows, I.; Coleman-Smith, P. J.; Grant, A.; Lazarus, I. H.; Morrall, P. S.; Pucknell, V. F. E.; Boston, A.; Judson, D. S.; Lalović, N.; Nyberg, J.; Collado, J.; González, V.; Kuti, I.; Nyakó, B. M.; Maj, A.; Rudigier, M.

2017-05-01

The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This set-up exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam γ-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy γ rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA 1 π array are presented.

Low-lying structure and shape evolution in neutron-rich Se isotopes

NASA Astrophysics Data System (ADS)

Chen, S.; Doornenbal, P.; Obertelli, A.; Rodríguez, T. R.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Lapoux, V.; Motobayashi, T.; Niikura, M.; Paul, N.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Steppenbeck, D.; Taniuchi, R.; Uesaka, T.; Ando, T.; Arici, T.; Blazhev, A.; Browne, F.; Bruce, A. M.; Caroll, R.; Chung, L. X.; Cortés, M. L.; Dewald, M.; Ding, B.; Flavigny, F.; Franchoo, S.; Górska, M.; Gottardo, A.; Jungclaus, A.; Lee, J.; Lettmann, M.; Linh, B. D.; Liu, J.; Liu, Z.; Lizarazo, C.; Momiyama, S.; Moschner, K.; Nagamine, S.; Nakatsuka, N.; Nita, C. R.; Nobs, C.; Olivier, L.; Orlandi, R.; Patel, Z.; Podolyak, Zs.; Rudigier, M.; Saito, T.; Shand, C.; Söderström, P.-A.; Stefan, I.; Vaquero, V.; Werner, V.; Wimmer, K.; Xu, Z.

2017-04-01

Neutron-rich 88,90,92,94Se isotopes were studied via in-beam γ -ray spectroscopy after nucleon removal reactions at intermediate energies at the Radioactive Isotope Beam Factory. Based on γ -γ coincidence analysis, low-lying excitation level schemes are proposed for these nuclei, including the 21+, 41+ states and 22+ states at remarkably low energies. The low-lying 22+ states, along with other features, indicate triaxiality in these nuclei. The experimental results are in good overall agreement with self-consistent beyond-mean-field calculations based on the Gogny D1S interaction, which suggests both triaxial degree of freedom and shape coexistence playing important roles in the description of intrinsic deformations in neutron-rich Se isotopes.

Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

DOEpatents

Lasche, G.P.

1983-09-29

The invention is a laser or particle-beam-driven fusion reactor system which takes maximum advantage of both the very short pulsed nature of the energy release of inertial confinement fusion (ICF) and the very small volumes within which the thermonuclear burn takes place. The pulsed nature of ICF permits dynamic direct energy conversion schemes such as magnetohydrodynamic (MHD) generation and magnetic flux compression; the small volumes permit very compact blanket geometries. By fully exploiting these characteristics of ICF, it is possible to design a fusion reactor with exceptionally high power density, high net electric efficiency, and low neutron-induced radioactivity. The invention includes a compact blanket design and method and apparatus for obtaining energy utilizing the compact blanket.

Dissipative Dynamics with Exotic Beams

NASA Astrophysics Data System (ADS)

di Toro, M.; Colonna, M.; Greco, V.; Ferini, G.; Rizzo, C.; Rizzo, J.; Baran, V.; Wolter, H. H.; Zielinska-Pfabe, M.

2008-04-01

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation and at high nucleon momenta. In this report we present a selection of reaction observables particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS) At low and Fermi energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. Predictions are shown for fusion, deep-inelastic and fragmentation collisions induced by neutron rich projectiles. At all energies the isospin transport data are supplying valuable information on value and slope of the symmetry term below saturation. The importance of studying violent collisions with radioactive beams in this energy range is finally stressed.

Optimal moderator materials at various proton energies considering photon dose rate after irradiation for an accelerator-driven ⁹Be(p, n) boron neutron capture therapy neutron source.

PubMed

Hashimoto, Y; Hiraga, F; Kiyanagi, Y

2015-12-01

We evaluated the accelerator beam power and the neutron-induced radioactivity of (9)Be(p, n) boron neutron capture therapy (BNCT) neutron sources having a MgF2, CaF2, or AlF3 moderator and driven by protons with energy from 8 MeV to 30 MeV. The optimal moderator materials were found to be MgF2 for proton energies less than 10 MeV because of lower required accelerator beam power and CaF2 for higher proton energies because of lower photon dose rate at the treatment position after neutron irradiation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Test of 1D carbon-carbon composite prototype tiles for the SPIDER diagnostic calorimeter

NASA Astrophysics Data System (ADS)

Serianni, G.; Pimazzoni, A.; Canton, A.; Palma, M. Dalla; Delogu, R.; Fasolo, D.; Franchin, L.; Pasqualotto, R.; Tollin, M.

2017-08-01

Additional heating will be provided to the thermonuclear fusion experiment ITER by injection of neutral beams from accelerated negative ions. In the SPIDER test facility, under construction at Consorzio RFX in Padova (Italy), the production of negative ions will be studied and optimised. To this purpose the STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) diagnostic will be used to characterise the SPIDER beam during short operation (several seconds) and to verify if the beam meets the ITER requirement regarding the maximum allowed beam non-uniformity (below ±10%). The most important measurements performed by STRIKE are beam uniformity, beamlet divergence and stripping losses. The major components of STRIKE are 16 1D-CFC (Carbon matrix-Carbon Fibre reinforced Composite) tiles, observed at the rear side by a thermal camera. The requirements of the 1D CFC material include a large thermal conductivity along the tile thickness (at least 10 times larger than in the other directions); low specific heat and density; uniform parameters over the tile surface; capability to withstand localised heat loads resulting in steep temperature gradients. So 1D CFC is a very anisotropic and delicate material, not commercially available, and prototypes are being specifically realised. This contribution gives an overview of the tests performed on the CFC prototype tiles, aimed at verifying their thermal behaviour. The spatial uniformity of the parameters and the ratio between the thermal conductivities are assessed by means of a power laser at Consorzio RFX. Dedicated linear and non-linear simulations are carried out to interpret the experiments and to estimate the thermal conductivities; these simulations are described and a comparison of the experimental data with the simulation results is presented.

Reuse of Material Containing Natural Radionuclides - 12444

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metlyaev, E.G.; Novikova, N.J.

2012-07-01

Disposal of and use of wastes containing natural radioactive material (NORM) or technologically enhanced natural radioactive material (TENORM) with excessive natural background as a building material is very important in the supervision body activity. At the present time, the residents of Octyabrsky village are under resettlement. This village is located just near the Priargunsky mining and chemical combine (Ltd. 'PPGHO'), one of the oldest uranium mines in our country. The vacated wooden houses in the village are demolished and partly used as a building material. To address the issue of potential radiation hazard of the wooden beams originating from demolitionmore » of houses in Octyabrsky village, the contents of the natural radionuclides (K-40, Th-232, Ra-226, U- 238) are being determined in samples of the wooden beams of houses. The NORM contents in the wooden house samples are higher, on average, than their content in the reference sample of the fresh wood shavings, but the range of values is rather large. According to the classification of waste containing the natural radionuclides, its evaluation is based on the effective specific activity. At the effective specific activity lower 1.5 kBq/kg and gamma dose rate lower 70 μR/h, the material is not considered as waste and can be used in building by 1 - 3 classes depending upon A{sub eff} value. At 1.5 kBq/kg < A{sub eff} ≤ 4 kBq/kg (4 class), the wooden beams might be used for the purpose of the industrial building, if sum of ratios between the radionuclide specific activity and its specific activity of minimum significance is lower than unit. The material classified as the waste containing the natural radionuclides has A{sub eff} higher 1.5 kBq /kg, and its usage for the purpose of house-building and road construction is forbidden. As for the ash classification and its future usage, such usage is unreasonable, because, according to the provided material, more than 50% of ash samples are considered as radioactive waste containing natural radionuclides. All materials originated from demolition of houses in Octyabrsky village are subjected to the obligatory radiation control. The decision to use the wooden beams shall enter into force after agreement with the State Sanitary and Epidemiological Supervision bodies. Conclusions: 1 - The wooden beam originated from the house demolition in Octyabrsky village might be used as the construction material only in case of compliance with the requirements of the regulatory documents, as well as under approval of the authorities responsible for the state sanitary and epidemiological supervision in this area. 2 - The industrial control is introduced to verify the compliance with the current regulations. 3 - The material originated from the house demolition might be used only if such usage does not cause increasing radiation exposure to the public. (authors)« less

Design of optimised backstepping controller for the synchronisation of chaotic Colpitts oscillator using shark smell algorithm

NASA Astrophysics Data System (ADS)

Fouladi, Ehsan; Mojallali, Hamed

2018-01-01

In this paper, an adaptive backstepping controller has been tuned to synchronise two chaotic Colpitts oscillators in a master-slave configuration. The parameters of the controller are determined using shark smell optimisation (SSO) algorithm. Numerical results are presented and compared with those of particle swarm optimisation (PSO) algorithm. Simulation results show better performance in terms of accuracy and convergence for the proposed optimised method compared to PSO optimised controller or any non-optimised backstepping controller.

Direct and compound reactions induced by unstable helium beams near the Coulomb barrier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Navin, A.; Tripathi, V.; Chatterjee, A.

2004-10-01

Reactions induced by radioactive {sup 6,8}He beams from the SPIRAL facility were studied on {sup 63,65}Cu and {sup 188,190,192}Os targets and compared to reactions with the stable {sup 4}He projectiles from the Mumbai Pelletron. Partial residue cross sections for fusion and neutron transfer obtained from the measured intensities of characteristic in-beam {gamma} rays for the {sup 6}He+{sup 63,65}Cu systems are presented. Coincidence measurements of heavy reaction products, identified by their characteristic {gamma} rays, with projectilelike charged particles, provide direct evidence for a large transfer cross section with Borromean nuclei {sup 6}He at 19.5 and 30 MeV and {sup 8}He atmore » 27 MeV. Reaction cross sections were also obtained from measured elastic angular distributions for {sup 6,8}He+Cu systems. Cross sections for fusion and direct reactions with {sup 4,6}He beams on heavier targets of {sup 188,192}Os at 30 MeV are also presented. The present work underlines the need to distinguish between various reaction mechanisms leading to the same products before drawing conclusions about the effect of weak binding on the fusion process. The feasibility of extracting small cross sections from inclusive in-beam {gamma}-ray measurements for reaction studies near the Coulomb barrier with low intensity isotope separation on-line beams is highlighted.« less

Optimizing charge breeding techniques for ISOL facilities in Europe: Conclusions from the EMILIE project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delahaye, P., E-mail: delahaye@ganil.fr; Jardin, P.; Maunoury, L.

The present paper summarizes the results obtained from the past few years in the framework of the Enhanced Multi-Ionization of short-Lived Isotopes for Eurisol (EMILIE) project. The EMILIE project aims at improving the charge breeding techniques with both Electron Cyclotron Resonance Ion Sources (ECRIS) and Electron Beam Ion Sources (EBISs) for European Radioactive Ion Beam (RIB) facilities. Within EMILIE, an original technique for debunching the beam from EBIS charge breeders is being developed, for making an optimal use of the capabilities of CW post-accelerators of the future facilities. Such a debunching technique should eventually resolve duty cycle and time structuremore » issues which presently complicate the data-acquisition of experiments. The results of the first tests of this technique are reported here. In comparison with charge breeding with an EBIS, the ECRIS technique had lower performance in efficiency and attainable charge state for metallic ion beams and also suffered from issues related to beam contamination. In recent years, improvements have been made which significantly reduce the differences between the two techniques, making ECRIS charge breeding more attractive especially for CW machines producing intense beams. Upgraded versions of the Phoenix charge breeder, originally developed by LPSC, will be used at SPES and GANIL/SPIRAL. These two charge breeders have benefited from studies undertaken within EMILIE, which are also briefly summarized here.« less

Resonance ionization laser ion sources for on-line isotope separators (invited).

PubMed

Marsh, B A

2014-02-01

A Resonance Ionization Laser Ion Source (RILIS) is today considered an essential component of the majority of Isotope Separator On Line (ISOL) facilities; there are seven laser ion sources currently operational at ISOL facilities worldwide and several more are under development. The ionization mechanism is a highly element selective multi-step resonance photo-absorption process that requires a specifically tailored laser configuration for each chemical element. For some isotopes, isomer selective ionization may even be achieved by exploiting the differences in hyperfine structures of an atomic transition for different nuclear spin states. For many radioactive ion beam experiments, laser resonance ionization is the only means of achieving an acceptable level of beam purity without compromising isotope yield. Furthermore, by performing element selection at the location of the ion source, the propagation of unwanted radioactivity downstream of the target assembly is reduced. Whilst advances in laser technology have improved the performance and reliability of laser ion sources and broadened the range of suitable commercially available laser systems, many recent developments have focused rather on the laser/atom interaction region in the quest for increased selectivity and/or improved spectral resolution. Much of the progress in this area has been achieved by decoupling the laser ionization from competing ionization processes through the use of a laser/atom interaction region that is physically separated from the target chamber. A new application of gas catcher laser ion source technology promises to expand the capabilities of projectile fragmentation facilities through the conversion of otherwise discarded reaction fragments into high-purity low-energy ion beams. A summary of recent RILIS developments and the current status of laser ion sources worldwide is presented.

The radioactive ion beams facility project for the legnaro laboratories

NASA Astrophysics Data System (ADS)

Tecchio, Luigi B.

1999-04-01

In the frame work of the Italian participation to the project of a high intensity proton facility for the energy amplifier and nuclear waste transmutations, LNL is involving in the design and construction of prototypes of the injection system of the 1 GeV linac that consists of a RFQ (5 MeV, 30 mA) followed by a 100 MeV linac. This program has been already financially supported and the work is actually in progress. In this context, the LNL has been proposed a project for the construction of a second generation facility for the production of radioactive ion beams (RIBs) by using the ISOL method. The final goal consists in the production of neutron rich RIBs with masses ranging from 80 to 160 by using primary beams of protons, deuterons and light ions with energy of 100 MeV and 100 kW power. This project is proposed to be developed in about 10 years from now and intermediate milestones and experiments are foreseen and under consideration for the next INFN five year plan (1999-2003). In such period of time is proposed the construction of a proton/deuteron accelerator of 10 MeV energy and 10 mA current, consisting of a RFQ (5 MeV, 30 mA) and a linac (10 MeV, 10 mA), and of a neutron area dedicated to the RIBs production, to the BNCT applications and to the neutron physics. Some remarks on the production methods will be presented. The possibility of producing radioisotopes by means of the fission induced by neutrons will be investigated and the methods of production of neutrons will be discussed.

Investigation of the thermonuclear 18Ne(α,p)21Na reaction rate via resonant elastic scattering of 21Na + p

NASA Astrophysics Data System (ADS)

Zhang, L. Y.; He, J. J.; Parikh, A.; Xu, S. W.; Yamaguchi, H.; Kahl, D.; Kubono, S.; Mohr, P.; Hu, J.; Ma, P.; Chen, S. Z.; Wakabayashi, Y.; Wang, H. W.; Tian, W. D.; Chen, R. F.; Guo, B.; Hashimoto, T.; Togano, Y.; Hayakawa, S.; Teranishi, T.; Iwasa, N.; Yamada, T.; Komatsubara, T.; Zhang, Y. H.; Zhou, X. H.

2014-01-01

The 18Ne(α,p)21Na reaction is thought to be one of the key breakout reactions from the hot CNO cycles to the rp process in type I x-ray bursts. In this work, the resonant properties of the compound nucleus 22Mg have been investigated by measuring the resonant elastic scattering of 21Na + p. An 89-MeV 21Na radioactive beam delivered from the CNS Radioactive Ion Beam Separator bombarded an 8.8 mg/cm2 thick polyethylene (CH2)n target. The 21Na beam intensity was about 2×105 pps, with a purity of about 70% on target. The recoiled protons were measured at the center-of-mass scattering angles of θc.m.≈175.2∘, 152.2∘, and 150.5∘ by three sets of ΔE-E telescopes, respectively. The excitation function was obtained with the thick-target method over energies Ex(22Mg)=5.5-9.2 MeV. In total, 23 states above the proton-threshold in 22Mg were observed, and their resonant parameters were determined via an R-matrix analysis of the excitation functions. We have made several new Jπ assignments and confirmed some tentative assignments made in previous work. The thermonuclear 18Ne(α,p)21Na rate has been recalculated based on our recommended spin-parity assignments. The astrophysical impact of our new rate has been investigated through one-zone postprocessing x-ray burst calculations. We find that the 18Ne(α,p)21Na rate significantly affects the peak nuclear energy generation rate, reaction fluxes, and onset temperature of this breakout reaction in these astrophysical phenomena.

TIGRESS: TRIUMF-ISAC gamma-ray escape-suppressed spectrometer

NASA Astrophysics Data System (ADS)

Svensson, C. E.; Amaudruz, P.; Andreoiu, C.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Boston, A. J.; Chakrawarthy, R. S.; Chen, A. A.; Churchman, R.; Drake, T. E.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hyland, B.; Jones, B.; Kanungo, R.; Maharaj, R.; Martin, J. P.; Morris, D.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Ressler, J. J.; Roy, R.; Sarazin, F.; Schumaker, M. A.; Scraggs, H. C.; Smith, M. B.; Starinsky, N.; Valiente-Dobón, J. J.; Waddington, J. C.; Watters, L. M.

2005-10-01

The TRIUMF-ISAC gamma-ray escape-suppressed spectrometer (TIGRESS) is a new γ-ray detector array being developed for use at TRIUMF's Isotope Separator and Accelerator (ISAC) radioactive ion beam facility. TIGRESS will comprise 12 32-fold segmented clover-type HPGe detectors coupled with 20-fold segmented modular Compton suppression shields and custom digital signal processing electronics. This paper provides an overview of the TIGRESS project and progress in its development to date.

Gamma-Ray Spectroscopy at TRIUMF-ISAC

NASA Astrophysics Data System (ADS)

Garrett, P. E.; Svensson, C. E.; Ball, G. C.; Hackman, G.; Zganjar, E. F.; Andreoiu, C.; Andreyev, A.; Ashley, S. F.; Austin, R. A. E.; Bandyopadhyay, D.; Becker, J. A.; Chan, S.; Coombes, H.; Churchman, R.; Chakrawarthy, R. S.; Finlay, P.; Grinyer, G. F.; Hyland, B.; Illes, E.; Jones, G. A.; Kulp, W. D.; Leslie, J. R.; Mattoon, C.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Regan, P. H.; Ressler, J. J.; Sarazin, F.; Schumaker, M. A.; Schwarzenberg, J.; Smith, M. B.; Valiente-Dobón, J. J.; Walker, P. M.; Williams, S. J.; Waddington, J. C.; Watters, L. M.; Wong, J.; Wood, J. L.

2006-03-01

The 8π spectrometer at TRIUMF-ISAC consists of 20 Compton-suppressed germanium detectors and various auxiliary devices. The Ge array, once used for studies of nuclei at high angular momentum, has been transformed into the world's most powerful device dedicated to radioactive-decay studies. Many improvements in the spectrometer have been made, including a high-throughput data acquisition system, installation of a moving tape collector, incorporation of an array of 20 plastic scintillators for β-particle tagging, 5 Si(Li) detectors for conversion electrons, and 10 BaF2 detectors for fast-lifetime measurements. Experiments can be performed where data from all detectors are collected simultaneously, resulting in a very detailed view of the nucleus through radioactive decay. A number of experimental programmes have been launched that take advantage of the versatility of the spectrometer, and the intense beams available at TRIUMF-ISAC.

A novel recession rate physics methodology for space applications at CIRA by means of CIRCE radioactive beam tracers

NASA Astrophysics Data System (ADS)

De Cesare, M.; Di Leva, A.; Del Vecchio, A.; Gialanella, L.

2018-03-01

Thermal protection systems (TPSs) of spacecrafts, either for single use or reusable, experience wear by ablation and erosion, due to the high heat fluxes during a re-entry phase in the atmosphere. The determination of the wear rate is a crucial point, which is presently mainly possible in aerospace on-ground measurements by means of invasive diagnostics. The purpose of this paper is to present novel contactless, online, high-sensitivity and non-intrusive diagnostics for wear measurements based on radioactive tracers. We propose the technique for future on-ground experiments that might later be developed to perform in-flight TPSs monitoring, thus significantly increasing the safety of the aerospace vehicles. The basic ideas of the method, its sensitivity investigated by GEANT4 simulations, and the future experimental validation are outlined.

Femtosecond optical injection of intact plant cells using a reconfigurable platform

NASA Astrophysics Data System (ADS)

Mitchell, Claire A.; Kalies, Stefan; Cizmar, Tomas; Bellini, Nicola; Kubasik-Thayil, Anisha; Heisterkamp, Alexander; Torrance, Lesley; Roberts, Alison G.; Gunn-Moore, Frank J.; Dholakia, Kishan

2014-03-01

The use of ultrashort-pulsed lasers for molecule delivery and transfection has proved to be a non-invasive and highly efficient technique for a wide range of mammalian cells. This present study investigates the effectiveness of femtosecond photoporation in plant cells, a hard-to-manipulate yet agriculturally relevant cell type, specifically suspension tobacco BY-2 cells. Both spatial and temporal shaping of the light field is employed to optimise the delivery of membrane impermeable molecules into plant cells using a reconfigurable optical system designed to be able to switch easily between different spatial modes and pulse durations. The use of a propagation invariant Bessel beam was found to increase the number of cells that could be viably optoinjected, when compared to the use of a Gaussian beam. Photoporation with a laser producing sub-12 fs pulses, coupled with a dispersion compensation system to retain the pulse duration at focus, reduced the power required for efficient optical injection by 1.5-1.8 times when compared to a photoporation with a 140 fs laser output.

Soft X-ray and cathodoluminescence measurement, optimisation and analysis at liquid nitrogen temperatures

NASA Astrophysics Data System (ADS)

MacRae, C. M.; Wilson, N. C.; Torpy, A.; Delle Piane, C.

2018-01-01

Advances in field emission gun electron microprobes have led to significant gains in the beam power density and when analysis at high resolution is required then low voltages are often selected. The resulting beam power can lead to damage and this can be minimised by cooling the sample down to cryogenic temperatures allowing sub-micrometre imaging using a variety of spectrometers. Recent advances in soft X-ray emission spectrometers (SXES) offer a spectral tool to measure both chemistry and bonding and when combined with spectral cathodoluminescence the complementary techniques enable new knowledge to be gained from both mineral and materials. Magnesium and aluminium metals have been examined at both room and liquid nitrogen temperatures by SXES and the L-emission Fermi-edge has been observed to sharpen at the lower temperatures directly confirming thermal broadening of the X-ray spectra. Gains in emission intensity and resolution have been observed in cathodoluminescence for liquid nitrogen cooled quartz grains compared to ambient temperature quartz. This has enabled subtle growth features at quartz to quartz-cement boundaries to be imaged for the first time.

Induced radioactivity in the blood of cancer patients following Boron Neutron Capture Therapy

PubMed Central

Fujiwara, Keiko; Kinashi, Yuko; Takahashi, Tomoyuki; Yashima, Hiroshi; Kurihara, Kouta; Sakurai, Yoshinori; Tanaka, Hiroki; Ono, Koji; Takahashi, Sentaro

2013-01-01

Since 1990, Boron Neutron Capture Therapy (BNCT) has been used for over 400 cancer patients at the Kyoto University Research Reactor Institute (KURRI). After BNCT, the patients are radioactive and their 24Na and 38Cl levels can be detected via a Na-I scintillation counter. This activity is predominantly due to 24Na, which has a half-life of 14.96 h and thus remains in the body for extended time periods. Radioactive 24Na is mainly generated from 23Na in the target tissue that is exposed to the neutron beam in BNCT. The purpose of this study is to evaluate the relationship between the radioactivity of blood 24Na following BNCT and the absorbed gamma ray dose in the irradiated field. To assess blood 24Na, 1 ml of peripheral blood was collected from 30 patients immediately after the exposure, and the radioactivity of blood 24Na was determined using a germanium counter. The activity of 24Na in the blood correlated with the absorbed gamma ray doses in the irradiated field. For the same absorbed gamma ray dose in the irradiated field, the activity of blood 24Na was higher in patients with neck or lung tumors than in patients with brain or skin tumors. The reasons for these findings are not readily apparent, but the difference in the blood volume and the ratio of bone to soft tissue in the irradiated field, as well as the dose that leaked through the clinical collimator, may be responsible. PMID:23392825

Induced radioactivity in the blood of cancer patients following Boron Neutron Capture Therapy.

PubMed

Fujiwara, Keiko; Kinashi, Yuko; Takahashi, Tomoyuki; Yashima, Hiroshi; Kurihara, Kouta; Sakurai, Yoshinori; Tanaka, Hiroki; Ono, Koji; Takahashi, Sentaro

2013-07-01

Since 1990, Boron Neutron Capture Therapy (BNCT) has been used for over 400 cancer patients at the Kyoto University Research Reactor Institute (KURRI). After BNCT, the patients are radioactive and their (24)Na and (38)Cl levels can be detected via a Na-I scintillation counter. This activity is predominantly due to (24)Na, which has a half-life of 14.96 h and thus remains in the body for extended time periods. Radioactive (24)Na is mainly generated from (23)Na in the target tissue that is exposed to the neutron beam in BNCT. The purpose of this study is to evaluate the relationship between the radioactivity of blood (24)Na following BNCT and the absorbed gamma ray dose in the irradiated field. To assess blood (24)Na, 1 ml of peripheral blood was collected from 30 patients immediately after the exposure, and the radioactivity of blood (24)Na was determined using a germanium counter. The activity of (24)Na in the blood correlated with the absorbed gamma ray doses in the irradiated field. For the same absorbed gamma ray dose in the irradiated field, the activity of blood (24)Na was higher in patients with neck or lung tumors than in patients with brain or skin tumors. The reasons for these findings are not readily apparent, but the difference in the blood volume and the ratio of bone to soft tissue in the irradiated field, as well as the dose that leaked through the clinical collimator, may be responsible.

Elastic and inelastic scattering of 134Xe beams on C2D4 targets measured with GODDESS

NASA Astrophysics Data System (ADS)

Sims, Harrison; Cizewski, Jolie; Lapailleur, Alex; Garland, Heather; Xination, Dai; Pain, Steven; Hall, Matthew; Goddess Collaboration

2017-09-01

The GODDESS (Gammasphere-ORRUBA: Dual Detector for Experimental Structure Studies) coupling of the ORRUBA charged-particle array with Gammasphere is designed to enable high-resolution particle-gamma measurements in inverse kinematics with radioactive beams. The high resolution and coverage of GODDESS allows for multiple reaction channels to be studied simultaneously. For the stable-beam commissioning of GODDESS, the 134Xe(d,p γ)135Xe reaction was measured using a beam of 134Xe at 8 MeV/A, delivered by the ATLAS facility at Argonne National Laboratory. The beam impinged on an 800 μg/cm2 C2D4 target, and charged particles were detected in the GODDESS silicon array between 15 and 165 degrees. Coincident gamma rays were measured with Gammasphere, with 10 % efficiency at 1.3 MeV. In the detectors downstream of the target, elastically- and inelastically-scattered target ions (deuterium and carbon) were detected, populating the ground and low-lying excited states in 134Xe. An overview of GODDESS will be presented, along with the analysis of the downstream data, including the differential scattering cross sections and population of collective states in 134Xe. Work supported in part by the U.S. D.O.E. and National Science Foundation.

Brilliant gamma beams for industrial applications: new opportunities, new challenges

NASA Astrophysics Data System (ADS)

Iancu, V.; Suliman, G.; Turturica, G. V.; Iovea, M.; Daito, I.; Ohgaki, H.; Matei, C.; Ur, C. A.; Balabanski, D. L.

2016-10-01

The Nuclear Physics oriented pillar of the pan-European Extreme Light Infrastructure (ELI-NP) will host an ultra-bright, energy tunable, and quasi-monochromatic gamma-ray beam system in the range of 0.2-19.5 MeV produced by laser-Compton backscattering technique. The applied research program envisioned at ELI-NP targets to use nuclear resonance fluorescence (NRF) and computed tomography to provide new opportunities for industry and society. High sensitivity NRF-based investigations can be successfully applied to safeguard applications and management of radioactive wastes as well as to uncharted fields like cultural heritage and medical imaging. Gamma-ray radioscopy and computed tomography performed at ELI-NP has the potential to achieve high resolution in industrial-sized objects provided the detection challenges introduced by the unique characteristics of the gamma beam are overcome. Here we discuss the foreseen industrial applications that will benefit from the high quality and unique characteristics of ELI-NP gamma beam and the challenges they present. We present the experimental setups proposed to be implemented for this goal, discuss their performance based on analytical calculations and numerical Monte-Carlo simulations, and comment about constrains imposed by the limitation of current scintillator detectors. Several gamma-beam monitoring devices based on scintillator detectors will also be discussed.

RF control hardware design for CYCIAE-100 cyclotron

NASA Astrophysics Data System (ADS)

Yin, Zhiguo; Fu, Xiaoliang; Ji, Bin; Zhao, Zhenlu; Zhang, Tianjue; Li, Pengzhan; Wei, Junyi; Xing, Jiansheng; Wang, Chuan

2015-11-01

The Beijing Radioactive Ion-beam Facility project is being constructed by BRIF division of China Institute of Atomic Energy. In this project, a 100 MeV high intensity compact proton cyclotron is built for multiple applications. The first successful beam extraction of CYCIAE-100 cyclotron was done in the middle of 2014. The extracted proton beam energy is 100 MeV and the beam current is more than 20 μA. The RF system of the CYCIAE-100 cyclotron includes two half-wavelength cavities, two 100 kW tetrode amplifiers and power transmission line systems (all above are independent from each other) and two sets of Low Level RF control crates. Each set of LLRF control includes an amplitude control unit, a tuning control unit, a phase control unit, a local Digital Signal Process control unit and an Advanced RISC Machines based EPICS IOC unit. These two identical LLRF control crates share one common reference clock and take advantages of modern digital technologies (e.g. DSP and Direct Digital Synthesizer) to achieve closed loop voltage and phase regulations of the dee-voltage. In the beam commission, the measured dee-voltage stability of RF system is better than 0.1% and phase stability is better than 0.03°. The hardware design of the LLRF system will be reviewed in this paper.

Development of a sensitive setup for laser spectroscopy studies of very exotic calcium isotopes

NASA Astrophysics Data System (ADS)

Garcia Ruiz, R. F.; Gorges, C.; Bissell, M.; Blaum, K.; Gins, W.; Heylen, H.; Koenig, K.; Kaufmann, S.; Kowalska, M.; Krämer, J.; Lievens, P.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Yordanov, D. T.; Yang, X. F.

2017-04-01

An experimental setup for sensitive high-resolution measurements of hyperfine structure spectra of exotic calcium isotopes has been developed and commissioned at the COLLAPS beam line at ISOLDE, CERN. The technique is based on the radioactive detection of decaying isotopes after optical pumping and state selective neutralization (ROC) (Vermeeren et al 1992 Phys. Rev. Lett. 68 1679). The improvements and developments necessary to extend the applicability of the experimental technique to calcium isotopes produced at rates as low as few ions s-1 are discussed. Numerical calculations of laser-ion interaction and ion-beam simulations were explored to obtain the optimum performance of the experimental setup. Among the implemented features are a multi-step optical pumping region for sensitive measurements of isotopes with hyperfine splitting, a high-voltage platform for adequate control of low-energy ion beams and simultaneous β-detection of neutralized and remaining ions. The commissioning of the experimental setup, and the first online results on neutron-rich calcium isotopes are presented.

Development of ion beam sputtering techniques for actinide target preparation

NASA Astrophysics Data System (ADS)

Aaron, W. S.; Zevenbergen, L. A.; Adair, H. L.

1985-06-01

Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.

Nuclear structure study for the neutron-rich nuclei beyond 132Sn: In-beam gamma-ray spectroscopy of 136Sn and 132Cd

NASA Astrophysics Data System (ADS)

Wang, He; Aoi, Nori; Takeuchi, Satoshi; Matsushita, Masafumi; Doornenbal, Pieter; Motobayashi, Tohru; Steppenbeck, David; Yoneda, Kenichiro; Baba, Hidetada; Dombrádi, Zsolt; Kobayashi, Kota; Kondo, Yosuke; Lee, Jenny; Liu, Hong-Na; Minakata, Ryogo; Nishimura, Daiki; Otsu, Hideaki; Sakurai, Hiroyoshi; Sohler, Dora; Sun, Ye-Lei; Tian, Zheng-Yang; Tanaka, Ryuki; Vajta, Zsolt; Yang, Zai-Hong; Yamamoto, Tetsuya; Ye, Yan-Lin; Yokoyama, Rin

2018-05-01

The neutron-rich nuclei 136Sn and 132Cd have been studied in the purpose of nuclear structure for the nuclei beyond the doubly-magic nucleus 132Sn. The 2+1 → 0+ gs transitions were identified for these two nuclei using in-beam γ-ray spectroscopy in coincidence with one- and two-proton removal reactions, respectively, at the RIKEN Radioactive Isotope Beam Factory. The 2+ 1 state in 136Sn is found to be similar to that for 134Sn indicating the seniority scheme may also hold for the heavy tin isotopes beyond N = 82. For 132Cd, the 2+ 1 state provides the first spectroscopic information in the even-even nuclei locating in the region "southeast" of 132Sn and the result is discussed in terms of proton-neutron configuration mixing. In both these two nuclei, it was found that the valence neutrons play an essential role in their low-lying excitations.

The Neutrons for Science Facility at SPIRAL-2

NASA Astrophysics Data System (ADS)

Ledoux, X.; Aïche, M.; Avrigeanu, M.; Avrigeanu, V.; Audouin, L.; Balanzat, E.; Ban-d'Etat, B.; Ban, G.; Barreau, G.; Bauge, E.; Bélier, G.; Bem, P.; Blideanu, V.; Blomgren, J.; Borcea, C.; Bouffard, S.; Caillaud, T.; Chatillon, A.; Czajkowski, S.; Dessagne, P.; Doré, D.; Fallot, M.; Farget, F.; Fischer, U.; Giot, L.; Granier, T.; Guillous, S.; Gunsing, F.; Gustavsson, C.; Herber, S.; Jacquot, B.; Jurado, B.; Kerveno, M.; Klix, A.; Landoas, O.; Lecolley, F. R.; Lecolley, J. F.; Lecouey, J. L.; Majerle, M.; Marie, N.; Materna, T.; Mrazek, J.; Negoita, F.; Novak, J.; Oberstedt, S.; Oberstedt, A.; Panebianco, S.; Perrot, L.; Petrascu, M.; Plompen, A. J. M.; Pomp, S.; Ramillon, J. M.; Ridikas, D.; Rossé, B.; Rudolf, G.; Serot, O.; Shcherbakov, O.; Simakov, S. P.; Simeckova, E.; Smith, A. G.; Steckmeyer, J. C.; Sublet, J. C.; Taïeb, J.; Tassan-Got, L.; Takibayev, A.; Tungborn, E.; Thfoin, I.; Tsekhanovich, I.; Varignon, C.; Wieleczko, J. P.

2011-12-01

The "Neutrons for Science" (NFS) facility will be a component of SPIRAL-2, the future accelerator dedicated to the production of very intense radioactive ion beams, under construction at GANIL in Caen (France). NFS will be composed of a pulsed neutron beam for in-flight measurements and irradiation stations for cross-section measurements and material studies. Continuous and quasi-monokinetic energy spectra will be available at NFS respectively produced by the interaction of deuteron beam on thick a Be converter and by the 7Li(p,n) reaction on a thin converter. The flux at NFS will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV to 40 MeV range. NFS will be a very powerful tool for physics and fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ledoux, X.; Bauge, E.; Belier, G.

The ''Neutrons for Science''(NFS) facility will be a component of SPIRAL-2, the future accelerator dedicated to the production of very intense radioactive ion beams, under construction at GANIL in Caen (France). NFS will be composed of a pulsed neutron beam for in-flight measurements and irradiation stations for cross-section measurements and material studies. Continuous and quasi-monokinetic energy spectra will be available at NFS respectively produced by the interaction of deuteron beam on thick a Be converter and by the {sup 7}Li(p,n) reaction on a thin converter. The flux at NFS will be up to 2 orders of magnitude higher than thosemore » of other existing time-of-flight facilities in the 1 MeV to 40 MeV range. NFS will be a very powerful tool for physics and fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors.« less

Progress Towards an Indirect Neutron Capture Capability at LANSCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koehler, Paul E.; Ullmann, John Leonard; Couture, Aaron Joseph

2017-09-20

There are many neutron-capture cross sections of importance to radiochemical diagnostics and nuclear forensics which are beyond the reach of direct measurements. Hence, we have been developing an apparatus on flight path (FP) 13 at target 1 at LANSCE for tightly constraining these cross sections via determination of the underlying physical quantities. FP-13 was initially a cold-neutron beam line for materials science and therefore required substantial modification for use for nuclear physics. In FY17, we made several improvements to FP-13, demonstrated improved performance due to these changes via measurements on a variety of samples, identified a few more needed improvements,more » and reconfigured the beam line to implement the most important of these. New measurements to assess the impact of the most recent improvement will commence when beam is restored to LANSCE. Although FP-13 has not yet reached the performance required for small radioactive samples, measurements on a gold sample have led to an important science result which we are preparing for publication.« less

Recent advances in β-decay spectroscopy at CARIBU

NASA Astrophysics Data System (ADS)

Mitchell, A. J.; Copp, P.; Savard, G.; Lister, C. J.; Lane, G. J.; Carpenter, M. P.; Clark, J. A.; Zhu, S.; Ayangeakaa, A. D.; Bottoni, S.; Brown, T. B.; Chowdhury, P.; Chillery, T. W.; David, H. M.; Hartley, D. J.; Heckmaier, E.; Janssens, R. V. F.; Kolos, K.; Kondev, F. G.; Lauritsen, T.; McCutchan, E. A.; Norman, E. B.; Padgett, S.; Scielzo, N. D.; Seweryniak, D.; Smith, M. L.; Wilson, G. L.

2016-09-01

β-decay spectroscopy of nuclei far from stability can provide powerful insight into a broad variety of topics in nuclear science, ranging from exotic nuclear structure phenomena, stellar nucleosynthesis processes, and applied topics such as quantifying "decay heat" discrepancies for advanced nuclear fuel cycles. Neutronrich nuclei approaching the drip-line are difficult to access experimentally, leaving many key examples largely under studied. The CARIBU radioactive beam facility at Argonne National Laboratory exploits spontaneous fission of 252Cf in production of such beams. The X-Array and SATURN decay station have been commissioned to perform detailed decay spectroscopy of low-energy CARIBU beams. An extended science campaign was started during 2015; with projects investigating nuclear shape changes, collective octupole vibrations, β-delayed neutron emission, and decay-scheme properties which could explain the reactor antineutrino puzzle. In this article we review the current status of the setup, update on the first results and recent hardware upgrades, and look forward to future possibilities.

An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

NASA Astrophysics Data System (ADS)

Idris, Sarada; Hairaldin, Siti Zulaiha; Tajau, Rida; Karim, Jamilah; Jusoh, Suhaimi; Ghazali, Zulkafli; Ahmad, Shamshad

2014-02-01

In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourless to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.

The Dynamical Dipole Radiation in Dissipative Collisions with Exotic Beams

NASA Astrophysics Data System (ADS)

di Toro, M.; Colonna, M.; Rizzo, C.; Baran, V.

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this work we present a selection of reaction observables in dissipative collisions particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS). At low energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. We will first discuss the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation during the charge equilibration in fusion and deep-inelastic collisions. We will review in detail all the main properties, yield, spectrum, damping and angular distributions, revealing important isospin effects. Reactions induced by unstable 132Sn beams appear to be very promising tools to test the sub-saturation Isovector EoS. Predictions are also presented for deep-inelastic and fragmentation collisions induced by neutron rich projectiles. The importance of studying violent collisions with radioactive beams at low and Fermi energies is finally stressed.

Dual Neutral Particle Beam Interrogation of Intermodal Shipping Containers for Special Nuclear Material

NASA Astrophysics Data System (ADS)

Keith, Rodney Lyman

Intermodal shipping containers entering the United States provide an avenue to smuggle unsecured or stolen special nuclear material (SNM). The only direct method fielded to indicate the presence of SNM is by passive photon/neutron radiation detection. Active interrogation using neutral particle beams to induce fission in SNM is a method under consideration. One by-product of fission is the creation of fragments that undergo radioactive decay over a time period on the order of tens of seconds after the initial event. The "delayed" gamma-rays emitted from these fragments over this period are considered a hallmark for the presence of SNM. A fundamental model is developed using homogenized cargos with a SNM target embedded at the center and computationally interrogated using simultaneous neutron and photon beams. Findings from analysis of the delayed gamma emissions from these experiments are intended to mitigate the effects of poor quality information about the composition and disposition of suspect cargo before examination in an active interrogation portal.

An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Idris, Sarada, E-mail: sarada@nuclearmalaysia.gov.my; Hairaldin, Siti Zulaiha, E-mail: sarada@nuclearmalaysia.gov.my; Tajau, Rida, E-mail: sarada@nuclearmalaysia.gov.my

In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourlessmore » to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.« less

Studies for aluminum photoionization in hot cavity for the selective production of exotic species projecta)

NASA Astrophysics Data System (ADS)

Scarpa, D.; Vasquez, J.; Tomaselli, A.; Grassi, D.; Biasetto, L.; Cavazza, A.; Corradetti, S.; Manzolaro, M.; Montano, J.; Andrighetto, A.; Prete, G.

2012-02-01

Selective production of exotic species (SPES) is an ISOL-based accelerator facility that will be built in the Legnaro INFN Laboratory (Italy), intended to provide an intense neutron-rich radioactive ion beams obtained by proton induced fission of an uranium carbide target. Beside this main target, a silicon carbide (SiC) target will the first to be used to deliver some p-rich beams. This target will validate also the functionality of the SPES facility with aluminum beam as result of hitting SiC target with protons. In the past off-line studies on laser photoionization of aluminum have performed in Pavia Spectroscopy Laboratory and in Laboratori Nazionali di Legnaro where, recently, a XeCl excimer laser was installed in order to test the laser ionization in the SPES hot cavity. Results are promising to justify further studies with this technique, aiming a better characterization of the SPES ion extraction capability under laser photoionization.

Computational design of high efficiency release targets for use at ISOL facilities

NASA Astrophysics Data System (ADS)

Liu, Y.; Alton, G. D.; Middleton, J. W.

1999-06-01

This report describes efforts made at the Oak Ridge National Laboratory to design high-efficiency-release targets that simultaneously incorporate the short diffusion lengths, high permeabilities, controllable temperatures, and heat removal properties required for the generation of useful radioactive ion beam (RIB) intensities for nuclear physics and astrophysics research using the isotope separation on-line (ISOL) technique. Short diffusion lengths are achieved either by using thin fibrous target materials or by coating thin layers of selected target material onto low-density carbon fibers such as reticulated vitreous carbon fiber (RVCF) or carbon-bonded-carbon-fiber (CBCF) to form highly permeable composite target matrices. Computational studies which simulate the generation and removal of primary beam deposited heat from target materials have been conducted to optimize the design of target/heat-sink systems for generating RIBs. The results derived from diffusion release-rate simulation studies for selected targets and thermal analyses of temperature distributions within a prototype target/heat-sink system subjected to primary ion beam irradiation will be presented in this report.

High-efficiency-release targets for use at ISOL facilities: computational design

NASA Astrophysics Data System (ADS)

Liu, Y.; Alton, G. D.

1999-12-01

This report describes efforts made at the Oak Ridge National Laboratory to design high-efficiency-release targets that simultaneously incorporate the short diffusion lengths, high permeabilities, controllable temperatures, and heat-removal properties required for the generation of useful radioactive ion beam (RIB) intensities for nuclear physics and astrophysics research using the isotope separation on-line (ISOL) technique. Short diffusion lengths are achieved either by using thin fibrous target materials or by coating thin layers of selected target material onto low-density carbon fibers such as reticulated-vitreous-carbon fiber (RVCF) or carbon-bonded-carbon fiber (CBCF) to form highly permeable composite target matrices. Computational studies that simulate the generation and removal of primary beam deposited heat from target materials have been conducted to optimize the design of target/heat-sink systems for generating RIBs. The results derived from diffusion release-rate simulation studies for selected targets and thermal analyses of temperature distributions within a prototype target/heat-sink system subjected to primary ion beam irradiation are presented in this report.

Modelling and analysis of piezoelectric cantilever energy harvester for different proof mass and material proportion

NASA Astrophysics Data System (ADS)

Shashank, R.; Harisha, S. K., Dr; Abhishek, M. C.

2018-02-01

Energy harvesting using ambient energy sources is one of the fast growing trends in the world, research and development in the area of energy harvesting is moving progressively to get maximum power output from the existing resources. The ambient sources of energy available in the nature are solar energy, wind energy, thermal energy, vibrational energy etc. out of these methods energy harvesting by vibrational energy sources gain more importance due to its nature of not getting influenced by any environmental parameters and its free availability at anytime and anywhere. The project mainly deals with validating the values of voltage and electrical power output of experimentally conducted energy harvester, varying the parameters of the energy harvester and analyse the effect of the parameters on the performance of the energy harvester and compare the results. The cantilever beam was designed, analysed and simulated using COMSOL multi-physics software. The energy harvester gives an electrical output voltage of the 2.75 volts at a natural frequency of 37.2 Hz and an electrical power of 29μW. Decreasing the percentage of the piezoelectric material and simultaneously increasing the percentage of polymer material (so that total percentage of proportion remains same) increases the electrical voltage and decreases the natural frequency of the beam linearly upto 3.9V and 28.847 Hz till the percentage proportion of the beam was 24% piezoelectric beam and 76% polymer beam when the percentage proportion increased to 26% and 74% natural frequency goes on decreases further but voltage suddenly drops to 2.8V. The voltage generated by energy harvester increases proportionally and reaches 3.7V until weight of the proof mass reaches 4 grams and further increase in the weight of the proof mass decreases the voltage generated by energy harvester. Thus the investigation conveys that the weight of the proof mass and the length of the cantilever beam should be optimised to obtain maximum output efficiency of energy harvester.

Detection efficiency of microchannel plates for e{sup −} and π{sup −} in the momentum range from 17.5 to 345 MeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tulej, M., E-mail: marek.tulej@space.unibe.ch; Meyer, S.; Lüthi, M.

2015-08-15

High-energy e{sup –} and π{sup –} were measured by the multichannel plate (MCP) detector at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The measurements provide the absolute detection efficiencies for these particles: 5.8% ± 0.5% for electrons in the beam momenta range 17.5–300 MeV/c and 6.0% ± 1.3% for pions in the beam momenta range 172–345 MeV/c. The pulse height distribution determined from the measurements is close to an exponential function with negative exponent, indicating that the particles penetrated the MCP material before producing the signal somewhere insidemore » the channel. Low charge extraction and nominal gains of the MCP detector observed in this study are consistent with the proposed mechanism of the signal formation by penetrating radiation. A very similar MCP ion detector will be used in the Neutral Ion Mass (NIM) spectrometer designed for the JUICE mission of European Space Agency (ESA) to the Jupiter system, to perform measurements of the chemical composition of the Galilean moon exospheres. The detection efficiency for penetrating radiation determined in the present studies is important for the optimisation of the radiation shielding of the NIM detector against the high-rate and high-energy electrons trapped in Jupiter’s magnetic field. Furthermore, the current studies indicate that MCP detectors can be useful to measure high-energy particle beams at high temporal resolution.« less

Experimental study of a VBG-based Tm : YLF slab laser at different output coupler parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan, X M; Ding, Y; Dai, T Y

2015-04-30

The performance of a Tm : YLF slab laser is studied at different output coupler parameters. Use is made of a 20-mm-long a-cut slab crystal doped with 2.5 at. % thulium ions. With a volume Bragg grating and a Fabry – Perot etalon, the selected output wavelength of this Tm : YLF slab laser is 1908 nm. For the optimised output coupler with a transmission of 20% and a radius of curvature of 300 mm, the output power exceeds 74.1 W and the slope efficiency with respect to the absorbed pump power reaches 48.4%. In addition, the beam quality ofmore » the Tm : YLF slab laser is improved. (lasers)« less

Improvements in low-cost label-free QPI microscope for live cell imaging

NASA Astrophysics Data System (ADS)

Seniya, C.; Towers, C. E.; Towers, D. P.

2017-07-01

This paper reports an improvement in the development of a low-cost QPI microscope offering new capabilities in term of phase measurement accuracy for label-free live samples in the longer term (i.e., hours to days). The spatially separated scattered and non-scattered image light fields are reshaped in the Fourier plane and modulated to form an interference image at a CCD camera. The apertures that enable these two beams to be generated have been optimised by means of laser-cut apertures placed on the mirrors of a Michelson interferometer and has improved the phase measuring and reconstruction capability of the QPI microscope. The microscope was tested with transparent onion cells as an object of interest.

The Story of the Water Cube

NASA Astrophysics Data System (ADS)

Weaire, Denis

2009-03-01

The National Aquatics Center or ``Water Cube,'' constructed for the Beijing Olympics, is unusual in that its very structure has a physical significance. It consists of a massive framework of steel beams that are arranged as in the Weaire-Phelan structure of an ideal foam, with an outer facing of transparent ``cushions.'' Brilliantly conceived by Tristram Carfrae of the Arup Corporation, it makes a spectacular impression on those who enter. It provokes thoughts on aesthetics, order/disorder, optimisation, and the frequent recurrence of bubbles/foams in our literary and artistic culture. The story of the Water Cube will start in the nineteenth century, when William Thomson (Lord Kelvin) first posed the problem: what kind of foam of equal-sized bubbles minimises area (or energy)?

Lateral mode control in edge-emitting lasers with modified mirrors

NASA Astrophysics Data System (ADS)

Payusov, A.; Serin, A.; Mukhin, I.; Shernyakov, Y.; Zadiranov, Y.; Maximov, M.; Gordeev, N.

2017-11-01

We present a study on lateral mode control in edge-emitting lasers with profiled mirror reflectivity. The object was to eliminate high-order lateral modes in conventional ridge-waveguide InAs/InGaAs QD (quantum dot) lasers with the stripe width of 10 μm. We have used a FIB (focused ion beam) technique to selectively etch windows in the AR (anti-reflection) facet coatings in order to introduce extra mirror losses for the high order modes. This approach allowed us to eliminate the first-order mode lasing without deterioration of the laser parameters. We suppose that further optimisation of the laser heterostructure and window designs may lead to a pure lateral single-mode lasing in the broadened ridge waveguides.

Facility for Antiproton and Ion Research, FAIR, at the GSI site

NASA Astrophysics Data System (ADS)

Rosner, Guenther

2006-11-01

FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

Multipurpose neutron generators based on the radio frequency quadrupole linear accelerator

NASA Astrophysics Data System (ADS)

Hamm, Robert W.

2000-12-01

Neutron generators based on the Radio Frequency Quadrupole accelerator are now used for a variety of applications. These compact linear accelerators can produce from 108 to more than 1013 neutrons/second using either proton or deuteron beams to bombard beryllium targets. They exhibit long lifetimes at full output, as there is little target or beam degradation. Since they do not use radioactive materials, licensing requirements are less stringent than for isotopic sources or tritium sealed tube generators. The light weight and compact size of these robust systems make them transportable. The low divergence output beam from the RFQ also allows use of a remote target, which can reduce the seize of the shielding and moderator. The RFQ linac can be designed with a wide range of output beam energy and used with other targets such as lithium and deuterium to produce a neutron spectrum tailored to a specific application. These pulsed systems are well-suited for applications requiring a high peak neutron flux, including activation analysis of very short-lived reaction products. They can replace conventional sources in non-destructive testing applications such as thermal or fast neutron radiography, and can also be used for cancer therapy.

LANSCE harp upgrade: analysis, design, fabrication and installation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilpatrick, John D; Chacon, Phillip; Martinez, Derwin

2010-01-01

The primary goal of this newly installed beam profile measurement is to provide the facility operators and physicists with a reliable horizontal and vertical projected beam distribution and location with respect to the proton beam target and beam aperture. During a 3000-hour annual run cycle, 5 {mu}C of charge is delivered every 50 milliseconds through this harp to the downstream TRMS Mark III target. The resulting radioactive annual dose near this harp is at least 6 MGy. Because of this harsh environment, the new harp design has been further optimized for robustness. For example, compared to an earlier design, thismore » harp has half of the sensing wires and utilizes only a single bias plane. The sensing fibers are 0.079-mm diameter SiC fibers. To hold these fibers to a rigid ceramic structure, a collet fiber-clamping device accomplishes the three goals of maintaining a mechanical fiber clamp, holding the sense fibers under a slight tensile force, and providing a sense-fiber electrical connection. This paper describes the harp analysis and design, and provides fabrication, assembly, and some installation information, and discusses wiring alterations.« less

Hounsfield unit recovery in clinical cone beam CT images of the thorax acquired for image guided radiation therapy

NASA Astrophysics Data System (ADS)

Slot Thing, Rune; Bernchou, Uffe; Mainegra-Hing, Ernesto; Hansen, Olfred; Brink, Carsten

2016-08-01

A comprehensive artefact correction method for clinical cone beam CT (CBCT) images acquired for image guided radiation therapy (IGRT) on a commercial system is presented. The method is demonstrated to reduce artefacts and recover CT-like Hounsfield units (HU) in reconstructed CBCT images of five lung cancer patients. Projection image based artefact corrections of image lag, detector scatter, body scatter and beam hardening are described and applied to CBCT images of five lung cancer patients. Image quality is evaluated through visual appearance of the reconstructed images, HU-correspondence with the planning CT images, and total volume HU error. Artefacts are reduced and CT-like HUs are recovered in the artefact corrected CBCT images. Visual inspection confirms that artefacts are indeed suppressed by the proposed method, and the HU root mean square difference between reconstructed CBCTs and the reference CT images are reduced by 31% when using the artefact corrections compared to the standard clinical CBCT reconstruction. A versatile artefact correction method for clinical CBCT images acquired for IGRT has been developed. HU values are recovered in the corrected CBCT images. The proposed method relies on post processing of clinical projection images, and does not require patient specific optimisation. It is thus a powerful tool for image quality improvement of large numbers of CBCT images.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuta, K.; Fukuda, M.; Tanigaki, M.

The magnetic moment of the proton drip-line nucleus {sup 9}C(I{sup {pi}}=3/2{sup -}, T{sub {1/2}}=126 ms) has been measured for the first time, using the {beta}-NMR detection technique with polarized radioactive beams. The measured value for the magnetic moment is {vert_bar} {mu}({sup 9}C) {vert_bar} = 1.3914{+-}0.0005 {mu}{sub N}. The deduced spin expectation value<{sigma}> of 1.44 is unusually larger than an other ones of even-odd nuclei.

Mass Chain Evaluation for A=95

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, S.K.; Sonzogni, A.; Basu, Swapan Kr.

2011-08-01

A full evaluation of the mass chain A = 95 has been done in the ENSDF format taking into account all the available data until June 2009. Excited states populated by in-beam nuclear reactions and by radioactive decay have been considered. The 'evp' editor, developed at the NNDC, has been used for the evaluation. This mass chain was last evaluated in 1993. Many new and improved data were reported since then. A total of 13 nuclei have been evaluated.

Nuclear Astrophysics At ISAC With DRAGON

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Auria, John M.

2005-05-24

The unique DRAGON (recoil mass separator) facility is now available to provide measurements of radiative capture reactions involving short-lived exotic reactants which are considered important in explosive stellar scenarios such as novae and X-ray bursts. A description of the first study completed, the 1H(21Na,22Mg){gamma} reaction, will be summarized and updated. In addition, the planned program for DRAGON will be presented along with a summary of the upgrade of the ISAC Radioactive Beams laboratory.

Magnetic Moment of Proton Drip-Line Nucleus (9)C

NASA Technical Reports Server (NTRS)

Matsuta, K.; Fukuda, M.; Tanigaki, M.; Minamisono, T.; Nojiri, Y.; Mihara, M.; Onishi, T.; Yamaguchi, T.; Harada, A.; Sasaki, M.

1994-01-01

The magnetic moment of the proton drip-line nucleus C-9(I(sup (pi)) = 3/2, T(sub 1/2) = 126 ms) has been measured for the first time, using the beta-NMR detection technique with polarized radioactive beams. The measure value for the magnetic moment is 1mu(C-9)! = 1.3914 +/- 0.0005 (mu)N. The deduced spin expectation value of 1.44 is unusually larger than any other ones of even-odd nuclei.

Current developments with TRIUMF's titanium-sapphire laser based resonance ionization laser ion source. An overview

NASA Astrophysics Data System (ADS)

Lassen, J.; Li, R.; Raeder, S.; Zhao, X.; Dekker, T.; Heggen, H.; Kunz, P.; P. Levy, C. D.; Mostanmand, M.; Teigelhöfer, A.; Ames, F.

2017-11-01

Developments at TRIUMF's isotope separator and accelerator (ISAC) resonance ionization laser ion source (RILIS) in the past years have concentrated on increased reliability for on-line beam delivery of radioactive isotopes to experiments, as well as increasing the number of elements available through resonance ionization and searching for ionization schemes with improved efficiency. The current status of these developments is given with a list of two step laser ionization schemes implemented recently.

Closure development for high-level nuclear waste containers for the tuff repository; Phase 1, Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robitz, E.S. Jr.; McAninch, M.D. Jr.; Edmonds, D.P.

1990-09-01

This report summarizes Phase 1 activities for closure development of the high-level nuclear waste package task for the tuff repository. Work was conducted under U.S. Department of Energy (DOE) Contract 9172105, administered through the Lawrence Livermore National Laboratory (LLNL), as part of the Yucca Mountain Project (YMP), funded through the DOE Office of Civilian Radioactive Waste Management (OCRWM). The goal of this phase was to select five closure processes for further evaluation in later phases of the program. A decision tree methodology was utilized to perform an objective evaluation of 15 potential closure processes. Information was gathered via a literaturemore » survey, industrial contacts, and discussions with project team members, other experts in the field, and the LLNL waste package task staff. The five processes selected were friction welding, electron beam welding, laser beam welding, gas tungsten arc welding, and plasma arc welding. These are felt to represent the best combination of weldment material properties and process performance in a remote, radioactive environment. Conceptual designs have been generated for these processes to illustrate how they would be implemented in practice. Homopolar resistance welding was included in the Phase 1 analysis, and developments in this process will be monitored via literature in Phases 2 and 3. Work was conducted in accordance with the YMP Quality Assurance Program. 223 refs., 20 figs., 9 tabs.« less

The Legnaro National Laboratories and the SPES facility: nuclear structure and reactions today and tomorrow

NASA Astrophysics Data System (ADS)

de Angelis, Giacomo; Fiorentini, Gianni

2016-11-01

There is a very long tradition of studying nuclear structure and reactions at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (Italian Institute of Nuclear Physics). The wide expertise acquired in building and running large germanium arrays has made the laboratories one of the most advanced research centers in γ-ray spectroscopy. The ’gamma group’ has been deeply involved in all the national and international developments of the last 20 years and is currently one of the major contributors to the AGATA project, the first (together with its American counterpart GRETINA) γ-detector array based on γ-ray tracking. This line of research is expected to be strongly boosted by the coming into operation of the SPES radioactive ion beam project, currently under construction at LNL. In this report, written on the occasion of the 40th anniversary of the Nobel prize awarded to Aage Bohr, Ben R Mottelson and Leo Rainwater and particularly focused on the physics of nuclear structure, we intend to summarize the different lines of research that have guided nuclear structure and reaction research at LNL in the last decades. The results achieved have paved the way for the present SPES facility, a new laboratories infrastructure producing and accelerating radioactive ion beams of fission fragments and other isotopes.

Characterization of uranium carbide target materials to produce neutron-rich radioactive beams

NASA Astrophysics Data System (ADS)

Tusseau-Nenez, Sandrine; Roussière, Brigitte; Barré-Boscher, Nicole; Gottberg, Alexander; Corradetti, Stefano; Andrighetto, Alberto; Cheikh Mhamed, Maher; Essabaa, Saïd; Franberg-Delahaye, Hanna; Grinyer, Joanna; Joanny, Loïc; Lau, Christophe; Le Lannic, Joseph; Raynaud, Marc; Saïd, Abdelhakim; Stora, Thierry; Tougait, Olivier

2016-03-01

In the framework of a R&D program aiming to develop uranium carbide (UCx) targets for radioactive nuclear beams, the Institut de Physique Nucléaire d'Orsay (IPNO) has developed an experimental setup to characterize the release of various fission fragments from UCx samples at high temperature. The results obtained in a previous study have demonstrated the feasibility of the method and started to correlate the structural properties of the samples and their behavior in terms of nuclear reaction product release. In the present study, seven UCx samples have been systematically characterized in order to better understand the correlation between their physicochemical characteristics and release properties. Two very different samples, the first one composed of dense UC and the second one of highly porous UCx made of multi-wall carbon nanotubes, were provided by the ActILab (ENSAR) collaboration. The others were synthesized at IPNO. The systems for irradiation and heating necessary for the release studies have been improved with respect to those used in previous studies. The results show that the open porosity is hardly the limiting factor for the fission product release. The homogeneity of the microstructure and the pore size distribution contributes significantly to the increase of the release. The use of carbon nanotubes in place of traditional micrometric graphite particles appears to be promising, even if the homogeneity of the microstructure can still be enhanced.

New developments of 11C post-accelerated beams for hadron therapy and imaging

NASA Astrophysics Data System (ADS)

Augusto, R. S.; Mendonca, T. M.; Wenander, F.; Penescu, L.; Orecchia, R.; Parodi, K.; Ferrari, A.; Stora, T.

2016-06-01

Hadron therapy was first proposed in 1946 and is by now widespread throughout the world, as witnessed with the design and construction of the CNAO, HIT, PROSCAN and MedAustron treatment centres, among others. The clinical interest in hadron therapy lies in the fact that it delivers precision treatment of tumours, exploiting the characteristic shape (the Bragg peak) of the energy deposition in the tissues for charged hadrons. In particular, carbon ion therapy is found to be biologically more effective, with respect to protons, on certain types of tumours. Following an approach tested at NIRS in Japan [1], carbon ion therapy treatments based on 12C could be combined or fully replaced with 11C PET radioactive ions post-accelerated to the same energy. This approach allows providing a beam for treatment and, at the same time, to collect information on the 3D distributions of the implanted ions by PET imaging. The production of 11C ion beams can be performed using two methods. A first one is based on the production using compact PET cyclotrons with 10-20 MeV protons via 14N(p,α)11C reactions following an approach developed at the Lawrence Berkeley National Laboratory [2]. A second route exploits spallation reactions 19F(p,X)11C and 23Na(p,X)11C on a molten fluoride salt target using the ISOL (isotope separation on-line) technique [3]. This approach can be seriously envisaged at CERN-ISOLDE following recent progresses made on 11C+ production [4] and proven post-acceleration of pure 10C3/6+ beams in the REX-ISOLDE linac [5]. Part of the required components is operational in radioactive ion beam facilities or commercial medical PET cyclotrons. The driver could be a 70 MeV, 1.2 mA proton commercial cyclotron, which would lead to 8.1 × 10711C6+ per spill. This intensity is appropriate using 11C ions alone for both imaging and treatment. Here we report on the ongoing feasibility studies of such approach, using the Monte Carlo particle transport code FLUKA [6,7] to simulate pristine Bragg Peaks of 11C, in order to compare its performance with 12C, in the context of hadron therapy.

Warpage optimisation on the moulded part with straight-drilled and conformal cooling channels using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

NASA Astrophysics Data System (ADS)

Hazwan, M. H. M.; Shayfull, Z.; Sharif, S.; Nasir, S. M.; Zainal, N.

2017-09-01

In injection moulding process, quality and productivity are notably important and must be controlled for each product type produced. Quality is measured as the extent of warpage of moulded parts while productivity is measured as a duration of moulding cycle time. To control the quality, many researchers have introduced various of optimisation approaches which have been proven enhanced the quality of the moulded part produced. In order to improve the productivity of injection moulding process, some of researches have proposed the application of conformal cooling channels which have been proven reduced the duration of moulding cycle time. Therefore, this paper presents an application of alternative optimisation approach which is Response Surface Methodology (RSM) with Glowworm Swarm Optimisation (GSO) on the moulded part with straight-drilled and conformal cooling channels mould. This study examined the warpage condition of the moulded parts before and after optimisation work applied for both cooling channels. A front panel housing have been selected as a specimen and the performance of proposed optimisation approach have been analysed on the conventional straight-drilled cooling channels compared to the Milled Groove Square Shape (MGSS) conformal cooling channels by simulation analysis using Autodesk Moldflow Insight (AMI) 2013. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 39.1% after optimisation for straight-drilled cooling channels and cooling time is the most significant factor contribute to the warpage condition and warpage have optimised by 38.7% after optimisation for MGSS conformal cooling channels. In addition, the finding shows that the application of optimisation work on the conformal cooling channels offers the better quality and productivity of the moulded part produced.

High temperature EXAFS experiments in molten actinide fluorides: The challenge of a triple containment cell for radioactive and aggressive liquids

NASA Astrophysics Data System (ADS)

Bessada, Catherine; Zanghi, Didier; Pauvert, Olivier; Maksoud, Louis; Gil-Martin, Ana; Sarou-Kanian, Vincent; Melin, Philippe; Brassamin, Séverine; Nezu, Atsushi; Matsuura, Haruaki

2017-10-01

An airtight double barrier cell with simple geometry has been developed for X-rays absorption measurements at high temperature in solid and molten actinide fluorides. The aim was both to improve the air tightness, to avoid any possible leakage and to maintain the high quality of the signal. The dimensions of the heating chamber were also constrained and minimized to be compatible with the limited space available usually on synchrotron beam lines and with a geometry suitable for absorption/diffraction measurements at high temperature. The design of the double barrier cell was also driven by the safety requirements in every experiment involving radioactive materials. The furnace itself was designed to ensure easy operating modes and disassembly, the aim being to consider the furnace as the ultimate containment. The cell has been tested with different molten fluorides up to more than 1000 °C, starting from non-radioactive LiF-ZrF4 mixtures in order to prove that the cell is absolutely airtight and that not any contamination of the environment occurs. Then it has been successfully applied to thorium fluoride- and uranium fluoride-alkali fluorides mixtures.

Using Optimisation Techniques to Granulise Rough Set Partitions

NASA Astrophysics Data System (ADS)

Crossingham, Bodie; Marwala, Tshilidzi

2007-11-01

This paper presents an approach to optimise rough set partition sizes using various optimisation techniques. Three optimisation techniques are implemented to perform the granularisation process, namely, genetic algorithm (GA), hill climbing (HC) and simulated annealing (SA). These optimisation methods maximise the classification accuracy of the rough sets. The proposed rough set partition method is tested on a set of demographic properties of individuals obtained from the South African antenatal survey. The three techniques are compared in terms of their computational time, accuracy and number of rules produced when applied to the Human Immunodeficiency Virus (HIV) data set. The optimised methods results are compared to a well known non-optimised discretisation method, equal-width-bin partitioning (EWB). The accuracies achieved after optimising the partitions using GA, HC and SA are 66.89%, 65.84% and 65.48% respectively, compared to the accuracy of EWB of 59.86%. In addition to rough sets providing the plausabilities of the estimated HIV status, they also provide the linguistic rules describing how the demographic parameters drive the risk of HIV.

The S-Process Branching-Point at 205PB

NASA Astrophysics Data System (ADS)

Tonchev, Anton; Tsoneva, N.; Bhatia, C.; Arnold, C. W.; Goriely, S.; Hammond, S. L.; Kelley, J. H.; Kwan, E.; Lenske, H.; Piekarewicz, J.; Raut, R.; Rusev, G.; Shizuma, T.; Tornow, W.

2017-09-01

Accurate neutron-capture cross sections for radioactive nuclei near the line of beta stability are crucial for understanding s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. We consider photon scattering using monoenergetic and 100% linearly polarized photon beams to obtain the photoabsorption cross section on 206Pb below the neutron separation energy. This observable becomes an essential ingredient in the Hauser-Feshbach statistical model for calculations of capture cross sections on 205Pb. The newly obtained photoabsorption information is also used to estimate the Maxwellian-averaged radiative cross section of 205Pb(n,g)206Pb at 30 keV. The astrophysical impact of this measurement on s-process nucleosynthesis will be discussed. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344.

Comparison of radioactive transmission and mechanical properties of Portland cement and a modified cement with trommel sieve waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boncukcuoglu, Recep; Icelli, Orhan; Erzeneoglu, Salih

2005-06-01

In this study, it was aimed to stabilize trommel sieve waste (TSW) occurring during manufacture of borax from tincal. The effects of TSW added on the mechanical properties and radioactive transmission of modified cement prepared by adding TSW to clinker was investigated. The properties which TSW as additive caused the cement to gain were tested and compared with normal Portland cement. Measurements have been made to determine variation of mass attenuation coefficients of TSW and cement by using an extremely narrow-collimated-beam transmission method in the energy range 15.746-40.930 keV with X-ray transmission method. The characteristic K{alpha} and K{beta} X-rays ofmore » the different elements (Zr, Mo, Ag, In, Sb, Ba and Pr) passed through TSW and cement were detected with a high-resolution Si(Li) detector. Results are presented and discussed in this paper.« less

Assessment of the 3H and 7Be generation in the IFMIF lithium loop

NASA Astrophysics Data System (ADS)

Simakov, S. P.; Fischer, U.; von Möllendorff, U.

2004-08-01

A complete evaluation of the 7Be and tritium inventory induced in the IFMIF lithium loop by deuterons and neutrons was performed on the basis of 3D Monte Carlo calculations with the M CDeLicious code and evaluated d-Li and n-Li cross-section data. The associated reaction cross-sections and thick lithium target yields were checked against available experimental data. The IFMIF calculations showed that the deuteron beam will produce 1.5 g of 7Be and 6 g of 3H per full power year in the lithium jet. The tritium generation in the whole lithium loop due to neutron induced reactions is at a rate of 1.5 g/fpy. The radio-active decay results in an equilibrium concentration 0.3 mg of 7Be and 50 mg of 3H per 1 kg of circulating lithium if no radioactive products are removed from the loop.

Morphological and functional effects of graphene on the synthesis of uranium carbide for isotopes production targets.

PubMed

Biasetto, L; Corradetti, S; Carturan, S; Eloirdi, R; Amador-Celdran, P; Staicu, D; Blanco, O Dieste; Andrighetto, A

2018-05-29

The development of tailored targets for the production of radioactive isotopes represents an active field in nuclear research. Radioactive beams find applications in nuclear medicine, in astrophysics, matter physics and materials science. In this work, we study the use of graphene both as carbon source for UO 2 carbothermal reduction to produce UC x targets, and also as functional properties booster. At fixed composition, the UC x target grain size, porosity and thermal conductivity represent the three main points that affect the target production efficiency. UC x was synthesized using both graphite and graphene as the source of carbon and the target properties in terms of composition, grain size, porosity, thermal diffusivity and thermal conductivity were studied. The main output of this work is related to the remarkable enhancement achieved in thermal conductivity, which can profitably improve thermal dissipation during operational stages of UC x targets.

ReactorHealth Physics operations at the NIST center for neutron research.

PubMed

Johnston, Thomas P

2015-02-01

Performing health physics and radiation safety functions under a special nuclear material license and a research and test reactor license at a major government research and development laboratory encompasses many elements not encountered by industrial, general, or broad scope licenses. This article reviews elements of the health physics and radiation safety program at the NIST Center for Neutron Research, including the early history and discovery of the neutron, applications of neutron research, reactor overview, safety and security of radiation sources and radioactive material, and general health physics procedures. These comprise precautions and control of tritium, training program, neutron beam sample processing, laboratory audits, inventory and leak tests, meter calibration, repair and evaluation, radioactive waste management, and emergency response. In addition, the radiation monitoring systems will be reviewed including confinement building monitoring, ventilation filter radiation monitors, secondary coolant monitors, gaseous fission product monitors, gas monitors, ventilation tritium monitor, and the plant effluent monitor systems.

PET imaging for treatment verification of ion therapy: Implementation and experience at GSI Darmstadt and MGH Boston

NASA Astrophysics Data System (ADS)

Parodi, Katia; Bortfeld, Thomas; Enghardt, Wolfgang; Fiedler, Fine; Knopf, Antje; Paganetti, Harald; Pawelke, Jörg; Shakirin, Georgy; Shih, Helen

2008-06-01

Ion beams offer the possibility of improved conformation of the dose delivered to the tumor with better sparing of surrounding tissue and critical structures in comparison to conventional photon and electron external radiation treatment modalities. Full clinical exploitation of this advantage can benefit from in vivo confirmation of the actual beam delivery and, in particular, of the ion range in the patient. During irradiation, positron emitters like 15O (half-life T1/2≈2 min) and 11C ( T1/2≈20 min) are formed in nuclear interactions between the ions and the tissue. Detection of this transient radioactivity via positron emission tomography (PET) and comparison with the expectation based on the prescribed beam application may serve as an in vivo, non-invasive range validation method of the whole treatment planning and delivery chain. For technical implementation, PET imaging during irradiation (in-beam) requires the development of customized, limited angle detectors with data acquisition synchronized with the beam delivery. Alternatively, commercial PET or PET/CT scanners in close proximity to the treatment site enable detection of the residual activation from long-lived emitters shortly after treatment (offline). This paper reviews two clinical examples using a dedicated in-beam PET scanner for verification of carbon ion therapy at GSI Darmstadt, Germany, as well as a commercial offline PET/CT tomograph for post-radiation imaging of proton treatments at Massachusetts General Hospital, Boston, USA. Challenges as well as pros and cons of the two imaging approaches in dependence of the different ion type and beam delivery system are discussed.

Analysis of optimisation method for a two-stroke piston ring using the Finite Element Method and the Simulated Annealing Method

NASA Astrophysics Data System (ADS)

Kaliszewski, M.; Mazuro, P.

2016-09-01

Simulated Annealing Method of optimisation for the sealing piston ring geometry is tested. The aim of optimisation is to develop ring geometry which would exert demanded pressure on a cylinder just while being bended to fit the cylinder. Method of FEM analysis of an arbitrary piston ring geometry is applied in an ANSYS software. The demanded pressure function (basing on formulae presented by A. Iskra) as well as objective function are introduced. Geometry definition constructed by polynomials in radial coordinate system is delivered and discussed. Possible application of Simulated Annealing Method in a piston ring optimisation task is proposed and visualised. Difficulties leading to possible lack of convergence of optimisation are presented. An example of an unsuccessful optimisation performed in APDL is discussed. Possible line of further optimisation improvement is proposed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Remec, Igor; Ronningen, Reginald Martin

The research studied one-step and two-step Isotope Separation on Line (ISOL) targets for future radioactive beam facilities with high driver-beam power through advanced computer simulations. As a target material uranium carbide in the form of foils was used because of increasing demand for actinide targets in rare-isotope beam facilities and because such material was under development in ISAC at TRIUMF when this project started. Simulations of effusion were performed for one-step and two step targets and the effects of target dimensions and foil matrix were studied. Diffusion simulations were limited by availability of diffusion parameters for UC x material atmore » reduced density; however, the viability of the combined diffusion?effusion simulation methodology was demonstrated and could be used to extract physical parameters such as diffusion coefficients and effusion delay times from experimental isotope release curves. Dissipation of the heat from the isotope-producing targets is the limiting factor for high-power beam operation both for the direct and two-step targets. Detailed target models were used to simulate proton beam interactions with the targets to obtain the fission rates and power deposition distributions, which were then applied in the heat transfer calculations to study the performance of the targets. Results indicate that a direct target, with specification matching ISAC TRIUMF target, could operate in 500-MeV proton beam at beam powers up to ~40 kW, producing ~8 10 13 fission/s with maximum temperature in UCx below 2200 C. Targets with larger radius allow higher beam powers and fission rates. For the target radius in the range 9-mm to 30-mm the achievable fission rate increases almost linearly with target radius, however, the effusion delay time also increases linearly with target radius.« less

Parasitic production of slow RI-beam from a projectile fragment separator by ion guide Laser Ion Source (PALIS)

NASA Astrophysics Data System (ADS)

Sonoda, Tetsu

2009-10-01

The projectile fragment separator BigRIPS of RIBF at RIKEN provides a wide variety of short-lived radioactive isotope (RI) ions without restrictions on their lifetime or chemical properties. A universal slow RI-beam facility (SLOWRI) to decelerate the beams from BigRIPS using an RF-carpet ion guide has been proposed as a principal facility of RIBF. However, beam time at such a modern accelerator facility is always limited and operational costs are high. We therefore propose an additional scheme as a complementary option to SLOWRI to drastically enhance the usability of such an expensive facility. In BigRIPS, a single primary beam produces thousands of isotopes but only one isotope is used for an experiment while the other >99.99% of isotopes are simply dumped in the slits or elsewhere in the fragment separator. We plan to locate a compact gas cell with 1 bar Ar at the slits. The thermalized ions in the cell will be quickly neutralized and transported to the exit by gas flow and resonantly re-ionized by lasers. Such low energy RI-beams will always be provided without any restriction to the main experiment. It will allow us to run parasitic experiments for precision atomic or decay spectroscopy, mass measurements. Furthermore, the resonance ionization in the cell itself can be used for high-sensitive laser spectroscopy, which will expand our knowledge of the ground state property of unstable nuclei.

56Co-labelled radioactive Fe3O4 nanoparticles for in vitro uptake studies on Balb/3T3 and Caco-2 cell lines

NASA Astrophysics Data System (ADS)

Marmorato, P.; Simonelli, F.; Abbas, K.; Kozempel, J.; Holzwarth, U.; Franchini, F.; Ponti, J.; Gibson, N.; Rossi, F.

2011-12-01

Magnetite nanoparticles (Fe3O4 NPs) are manufactured nanomaterials increasingly used in healthcare for different medical applications ranging from diagnosis to therapy. This study deals with the irradiation of Fe3O4 NPs with a proton beam in order to produce 56Co as radiolabel and also with the possible use of nuclear techniques for the quantification of Fe3O4 NPs in biological systems. Particular attention has been focused on the size distribution (in the range of 100 nm) and the surface charge of the NPs characterizing them before and after the irradiation process in order to verify if these essential properties would be preserved during irradiation. Moreover, X-ray diffraction studies have been performed on radioactive and non-radioactive NPs, to assess if major changes in NPs structure might occur due to thermal and/or radiation effects. The radiation emitted from the radiolabels has been used to quantify the cellular uptake of the NPs in in vitro studies. As for the biological applications two cell lines have been selected: immortalized mouse fibroblast cell line (Balb/3T3) and human epithelial colorectal adenocarcinoma cell line (Caco-2). The cell uptake has been quantified by radioactivity measurements of the 56Co radioisotope performed with high resolution γ-ray spectrometry equipment. This study has showed that, under well-established irradiation conditions, Fe3O4 NPs do not undergo significant structural modifications and thus the obtained results are in line with the uptake studies carried out with the same non-radioactive nanomaterials (NMs). Therefore, the radiolabelling method can be fruitfully applied to uptake studies because of the low-level exposure where higher sensitivity is required.

Laser polishing of 3D printed mesoscale components

NASA Astrophysics Data System (ADS)

Bhaduri, Debajyoti; Penchev, Pavel; Batal, Afif; Dimov, Stefan; Soo, Sein Leung; Sten, Stella; Harrysson, Urban; Zhang, Zhenxue; Dong, Hanshan

2017-05-01

Laser polishing of various engineered materials such as glass, silica, steel, nickel and titanium alloys, has attracted considerable interest in the last 20 years due to its superior flexibility, operating speed and capability for localised surface treatment compared to conventional mechanical based methods. The paper initially reports results from process optimisation experiments aimed at investigating the influence of laser fluence and pulse overlap parameters on resulting workpiece surface roughness following laser polishing of planar 3D printed stainless steel (SS316L) specimens. A maximum reduction in roughness of over 94% (from ∼3.8 to ∼0.2 μm Sa) was achieved at the optimised settings (fluence of 9 J/cm2 and overlap factors of 95% and 88-91% along beam scanning and step-over directions respectively). Subsequent analysis using both X-ray photoelectron spectroscopy (XPS) and glow discharge optical emission spectroscopy (GDOES) confirmed the presence of surface oxide layers (predominantly consisting of Fe and Cr phases) up to a depth of ∼0.5 μm when laser polishing was performed under normal atmospheric conditions. Conversely, formation of oxide layers was negligible when operating in an inert argon gas environment. The microhardness of the polished specimens was primarily influenced by the input thermal energy, with greater sub-surface hardness (up to ∼60%) recorded in the samples processed with higher energy density. Additionally, all of the polished surfaces were free of the scratch marks, pits, holes, lumps and irregularities that were prevalent on the as-received stainless steel samples. The optimised laser polishing technology was consequently implemented for serial finishing of structured 3D printed mesoscale SS316L components. This led to substantial reductions in areal Sa and St parameters by 75% (0.489-0.126 μm) and 90% (17.71-1.21 μm) respectively, without compromising the geometrical accuracy of the native 3D printed samples.

Isolation of 236U and 239,240Pu from seawater samples and its determination by Accelerator Mass Spectrometry.

PubMed

López-Lora, Mercedes; Chamizo, Elena; Villa-Alfageme, María; Hurtado-Bermúdez, Santiago; Casacuberta, Núria; García-León, Manuel

2018-02-01

In this work we present and evaluate a radiochemical procedure optimised for the analysis of 236 U and 239,240 Pu in seawater samples by Accelerator Mass Spectrometry (AMS). The method is based on Fe(OH) 3 co-precipitation of actinides and uses TEVA® and UTEVA® extraction chromatography resins in a simplified way for the final U and Pu purification. In order to improve the performance of the method, the radiochemical yields are analysed in 1 to 10L seawater volumes using alpha spectrometry (AS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Robust 80% plutonium recoveries are obtained; however, it is found that Fe(III) concentration in the precipitation solution and sample volume are the two critical and correlated parameters influencing the initial uranium extraction through Fe(OH) 3 co-precipitation. Therefore, we propose an expression that optimises the sample volume and Fe(III) amounts according to both the 236 U and 239,240 Pu concentrations in the samples and the performance parameters of the AMS facility. The method is validated for the current setup of the 1MV AMS system (CNA, Sevilla, Spain), where He gas is used as a stripper, by analysing a set of intercomparison seawater samples, together with the Laboratory of Ion Beam Physics (ETH, Zürich, Switzerland). Copyright © 2017 Elsevier B.V. All rights reserved.

Fast radioactive seed localization in intraoperative cone beam CT for low-dose-rate prostate brachytherapy

NASA Astrophysics Data System (ADS)

Hu, Yu-chi; Xiong, Jian-ping; Cohan, Gilad; Zaider, Marco; Mageras, Gig; Zelefsky, Michael

2013-03-01

A fast knowledge-based radioactive seed localization method for brachytherapy was developed to automatically localize radioactive seeds in an intraoperative volumetric cone beam CT (CBCT) so that corrections, if needed, can be made during prostate implant surgery. A transrectal ultrasound (TRUS) scan is acquired for intraoperative treatment planning. Planned seed positions are transferred to intraoperative CBCT following TRUS-to-CBCT registration using a reference CBCT scan of the TRUS probe as a template, in which the probe and its external fiducial markers are pre-segmented and their positions in TRUS are known. The transferred planned seeds and probe serve as an atlas to reduce the search space in CBCT. Candidate seed voxels are identified based on image intensity. Regions are grown from candidate voxels and overlay regions are merged. Region volume and intensity variance is checked against known seed volume and intensity profile. Regions meeting the above criteria are flagged as detected seeds; otherwise they are flagged as likely seeds and sorted by a score that is based on volume, intensity profile and distance to the closest planned seed. A graphical interface allows users to review and accept or reject likely seeds. Likely seeds with approximately twice the seed volume are automatically split. Five clinical cases are tested. Without any manual correction in seed detection, the method performed the localization in 5 seconds (excluding registration time) for a CBCT scan with 512×512×192 voxels. The average precision rate per case is 99% and the recall rate is 96% for a total of 416 seeds. All false negative seeds are found with 15 in likely seeds and 1 included in a detected seed. With the new method, updating of calculations of dose distribution during the procedure is possible and thus facilitating evaluation and improvement of treatment quality.

Superconducting Ring Cyclotron for Riken RI Beam Factory in Japan

NASA Astrophysics Data System (ADS)

Okuno, H.; Dantsuka, T.; Yamada, K.; Kase, M.; Maie, T.; Kamigaito, O.

2010-04-01

Since 1997, RIKEN Nishina Center has been constructing the Radioactive Isotope Beam Factory (RIBF) and succeeded in beam commissioning of its accelerator complex at the end of 2006. The world's first superconducting ring cyclotron (SRC) is the final booster in the RIBF accelerator complex which is able to accelerate all-element heavy ions to a speed of about 70% of the velocity of light. The ring cyclotron consists of 6 major superconducting sector magnets with a maximum field of 3.8 T. The total stored energy is 235 MJ, and its overall sizes are 19 m diameter, 8 m height and 8,300 tons. The magnet system assembly was completed in August 2005, and successfully reached the maximum field in November 2005. The first beam was extracted at the end of 2006 and the first uranium beam was extracted in March 2007. However operation of the helium refrigerator was not satisfactory although the commissioning of SRC was successful. Operation was stopped every two month due to degradation of its cooling power. In February 2008 the reason of the degradation was revealed to be oil contamination. Operation of the cryogenic system was restarted from August 2008 after hard task to clean up the helium refrigerator and to add oil separators to the compressor. After restoration long-term steady operation to keep the magnet superconducting continued for about 8 months with no sign of degradation of cooling capacity.

Multidisciplinary design optimisation of a recurve bow based on applications of the autogenetic design theory and distributed computing

NASA Astrophysics Data System (ADS)

Fritzsche, Matthias; Kittel, Konstantin; Blankenburg, Alexander; Vajna, Sándor

2012-08-01

The focus of this paper is to present a method of multidisciplinary design optimisation based on the autogenetic design theory (ADT) that provides methods, which are partially implemented in the optimisation software described here. The main thesis of the ADT is that biological evolution and the process of developing products are mainly similar, i.e. procedures from biological evolution can be transferred into product development. In order to fulfil requirements and boundary conditions of any kind (that may change at any time), both biological evolution and product development look for appropriate solution possibilities in a certain area, and try to optimise those that are actually promising by varying parameters and combinations of these solutions. As the time necessary for multidisciplinary design optimisations is a critical aspect in product development, ways to distribute the optimisation process with the effective use of unused calculating capacity, can reduce the optimisation time drastically. Finally, a practical example shows how ADT methods and distributed optimising are applied to improve a product.

Superallowed Fermi β decay studies at TRIUMF-ISAC

NASA Astrophysics Data System (ADS)

Svensson, C. E.; Dunlop, R.; Finlay, P.; Ball, G. C.; Ettenauer, S.; Leslie, J. R.; Towner, I. S.; Andreoiu, C.; Austin, R. A. E.; Bandyopadhyay, D.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Demand, G.; Djongolov, M.; Garnsworthy, A. B.; Garrett, P. E.; Green, K. L.; Glister, J.; Grinyer, G. F.; Hackman, G.; Hadinia, B.; Leach, K. G.; Pearson, C. J.; Phillips, A. A.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C. S.; Tardiff, E. R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.

2013-10-01

A program of high-precision superallowed Fermi β decay studies is being carried out at the Isotope Separator and Accelerator (ISAC) radioactive ion beam facility at TRIUMF. Recent high-precision branching ratio measurements for the superallowed decays of 74Rb and 26Alm, as well as a half-life measurement for 26Alm that is the most precise half-life measurement for any superallowed emitter to date, are reported. These results provide demanding tests of the theoretical isospin symmetry breaking corrections in superallowed Fermi β decays.

Laser-induced caesium-137 decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barmina, E V; Simakin, A V; Shafeev, G A

2014-08-31

Experimental data are presented on the laser-induced beta decay of caesium-137. We demonstrate that the exposure of a gold target to a copper vapour laser beam (wavelengths of 510.6 and 578.2 nm, pulse duration of 15 ns) for 2 h in an aqueous solution of a caesium-137 salt reduces the caesium-137 activity by 70%, as assessed from the gamma activity of the daughter nucleus {sup 137m}Ba, and discuss potential applications of laser-induced caesium-137 decay in radioactive waste disposal. (letters)

Influence of target thickness on the release of radioactive atoms

NASA Astrophysics Data System (ADS)

Guillot, Julien; Roussière, Brigitte; Tusseau-Nenez, Sandrine; Barré-Boscher, Nicole; Borg, Elie; Martin, Julien

2017-03-01

Nowadays, intense exotic beams are needed in order to study nuclei with very short half-life. To increase the release efficiency of the fission products, all the target characteristics involved must be improved (e.g. chemical composition, dimensions, physicochemical properties such as grain size, porosity, density…). In this article, we study the impact of the target thickness. Released fractions measured from graphite and uranium carbide pellets are presented as well as Monte-Carlo simulations of the Brownian motion.

Trojan Horse Method for neutrons-induced reaction studies

NASA Astrophysics Data System (ADS)

Gulino, M.; Asfin Collaboration

2017-09-01

Neutron-induced reactions play an important role in nuclear astrophysics in several scenario, such as primordial Big Bang Nucleosynthesis, Inhomogeneous Big Bang Nucleosynthesis, heavy-element production during the weak component of the s-process, explosive stellar nucleosynthesis. To overcome the experimental problems arising from the production of a neutron beam, the possibility to use the Trojan Horse Method to study neutron-induced reactions has been investigated. The application is of particular interest for reactions involving radioactive nuclei having short lifetime.

Optimisation in radiotherapy. III: Stochastic optimisation algorithms and conclusions.

PubMed

Ebert, M

1997-12-01

This is the final article in a three part examination of optimisation in radiotherapy. Previous articles have established the bases and form of the radiotherapy optimisation problem, and examined certain types of optimisation algorithm, namely, those which perform some form of ordered search of the solution space (mathematical programming), and those which attempt to find the closest feasible solution to the inverse planning problem (deterministic inversion). The current paper examines algorithms which search the space of possible irradiation strategies by stochastic methods. The resulting iterative search methods move about the solution space by sampling random variates, which gradually become more constricted as the algorithm converges upon the optimal solution. This paper also discusses the implementation of optimisation in radiotherapy practice.

Efficiency Measurement of VANDLE Modules

NASA Astrophysics Data System (ADS)

Peters, William; Matei, C.; Cizewski, J. A.; O'Malley, P. D.; Spassova, I.; Bardayan, D.; Blackmon, J. C.; Brune, C.; Massey, T.; Grzywacz, R. K.; Madurga, M.; Sarazin, F.; Raiola, F.

2010-02-01

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new array of plastic scintillator bars being developed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). The modular design enables optimization of different configurations for particular experiments, such as (d,n) and beta-delayed neutron-decay experiments, with rare ion beams. Two prototype modules were moved to the Edwards Accelerator Laboratory at Ohio University to measure their efficiency using a calibrated ^27Al(d,n) reaction as a neutron source. Results show that one bar with a cross section of 3x3 cm^2 is over 25% efficient to neutrons around 1 MeV with sensitivity down to 100 keV neutrons. Other design features such as wrapping and coupling will be presented, as well as results from resolution tests. )

Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion

PubMed Central

Ferrer, R.; Barzakh, A.; Bastin, B.; Beerwerth, R.; Block, M.; Creemers, P.; Grawe, H.; de Groote, R.; Delahaye, P.; Fléchard, X.; Franchoo, S.; Fritzsche, S.; Gaffney, L. P.; Ghys, L.; Gins, W.; Granados, C.; Heinke, R.; Hijazi, L.; Huyse, M.; Kron, T.; Kudryavtsev, Yu.; Laatiaoui, M.; Lecesne, N.; Loiselet, M.; Lutton, F.; Moore, I. D.; Martínez, Y.; Mogilevskiy, E.; Naubereit, P.; Piot, J.; Raeder, S.; Rothe, S.; Savajols, H.; Sels, S.; Sonnenschein, V.; Thomas, J-C; Traykov, E.; Van Beveren, C.; Van den Bergh, P.; Van Duppen, P.; Wendt, K.; Zadvornaya, A.

2017-01-01

Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency. PMID:28224987

Commissioning of the Active-Target Time Projection Chamber

NASA Astrophysics Data System (ADS)

Bradt, J.; Bazin, D.; Abu-Nimeh, F.; Ahn, T.; Ayyad, Y.; Beceiro Novo, S.; Carpenter, L.; Cortesi, M.; Kuchera, M. P.; Lynch, W. G.; Mittig, W.; Rost, S.; Watwood, N.; Yurkon, J.

2017-12-01

The Active-Target Time Projection Chamber (AT-TPC) was recently built and commissioned at the National Superconducting Cyclotron Laboratory at Michigan State University. This gas-filled detector uses an active-target design where the gas acts as both the tracking medium and the reaction target. Operating inside a 2T solenoidal magnetic field, the AT-TPC records charged particle tracks that can be reconstructed to very good energy and angular resolutions. The near- 4 π solid angle coverage and thick target of the detector are well-suited to experiments with low secondary beam intensities. In this paper, the design and instrumentation of theAT-TPC are described along with the methods used to analyze the data it produces. A simulation of the detector's performance and some results from its commissioning with a radioactive 46Ar beam are also presented.

Facility for Antiproton and Ion Research, FAIR, at the GSI site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosner, Guenther

FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ionmore » and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.« less

Spectroscopic study of the radionuclide 21Na for the astrophysical 17F(α ,p )20Ne reaction rate

NASA Astrophysics Data System (ADS)

Cha, S. M.; Chae, K. Y.; Ahn, S.; Bardayan, D. W.; Chipps, K. A.; Cizewski, J. A.; Howard, M. E.; Kozub, R. L.; Kwak, K.; Manning, B.; Matos, M.; O'Malley, P. D.; Pain, S. D.; Peters, W. A.; Pittman, S. T.; Ratkiewicz, A.; Smith, M. S.; Strauss, S.

2017-08-01

The 24Mg(p ,α )21Na reaction was measured at the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory to study the spectroscopy of the radionuclide 21Na. A 31-MeV proton beam from the 25 MV tandem accelerator bombarded isotopically enriched 24Mg targets. Recoiling 4He particles were identified by an annular silicon strip detector array. Two energy levels at Ex=6.594 and 7.132 MeV were observed for the first time. By comparing the experimentally obtained angular distributions and distorted wave Born approximation calculations, the spins and parities of 21Na energy levels were constrained. The astrophysically-important 17F(α ,p )20Ne reaction rate was also calculated for the first time using resonance parameters for 12 energy levels.

Beta-decay spectroscopy of neutron-rich 84-86Ga isotopes

NASA Astrophysics Data System (ADS)

Naqvi, Farheen; Xu, Zhengyu; Werner, Volker; Niikura, Megumi; Nishimura, Shunji; Eurica Collaboration

2013-10-01

The low lying excited states in 84-86 Ge were studied via the beta-gamma spectroscopy of 84-86 Ga nuclei. The study focused on the beta-delayed neutron emission probabilities and the beta-decay lifetimes, relevant for the astrophysical r process path in the region. The neutron-rich Ga isotopes were produced by in-flight fragmentation of 238U beam on a 9Be target. The experiment was performed at the Radioactive Ion Beam Facility (RIBF) at RIKEN, Japan. The BigRIPS spectrometer was utilized to identify and separate the reaction residues and the ions of interest were implanted in a segmented Si detector array called WASABI. Gamma rays emitted after the beta decay were identified by the EURICA array. Results of the ongoing analysis will be presented. Work supported by DOE grant no. DE-FG02-91ER-40609.

Observation of a γ-decaying millisecond isomeric state in 128Cd80

NASA Astrophysics Data System (ADS)

Jungclaus, A.; Grawe, H.; Nishimura, S.; Doornenbal, P.; Lorusso, G.; Simpson, G. S.; Söderström, P.-A.; Sumikama, T.; Taprogge, J.; Xu, Z. Y.; Baba, H.; Browne, F.; Fukuda, N.; Gernhäuser, R.; Gey, G.; Inabe, N.; Isobe, T.; Jung, H. S.; Kameda, D.; Kim, G. D.; Kim, Y.-K.; Kojouharov, I.; Kubo, T.; Kurz, N.; Kwon, Y. K.; Li, Z.; Sakurai, H.; Schaffner, H.; Shimizu, Y.; Steiger, K.; Suzuki, H.; Takeda, H.; Vajta, Zs.; Watanabe, H.; Wu, J.; Yagi, A.; Yoshinaga, K.; Benzoni, G.; Bönig, S.; Chae, K. Y.; Coraggio, L.; Daugas, J.-M.; Drouet, F.; Gadea, A.; Gargano, A.; Ilieva, S.; Itaco, N.; Kondev, F. G.; Kröll, T.; Lane, G. J.; Montaner-Pizá, A.; Moschner, K.; Mücher, D.; Naqvi, F.; Niikura, M.; Nishibata, H.; Odahara, A.; Orlandi, R.; Patel, Z.; Podolyák, Zs.; Wendt, A.

2017-09-01

A new high-spin isomer in the neutron-rich nucleus 128Cd was populated in the projectile fission of a 238U beam at the Radioactive Isotope Beam Factory at RIKEN. A half-life of T1/2 = 6.3 (8) ms was measured for the new state which was tentatively assigned a spin/parity of (15-). The experimental results are compared to shell model calculations performed using state-of-the-art realistic effective interactions and to the neighbouring nucleus 129Cd. In the present experiment no evidence was found for the decay of a 18+E6 spin-trap isomer, based on the complete alignment of the two-neutron and two-proton holes in the 0h11/2 and the 0g9/2 orbit, respectively, which is predicted to exist by the shell model.

Elastic scattering and total reaction cross section for the {sup 6}He+{sup 58}Ni system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morcelle, V.; Lichtenthäler, R.; Lépine-Szily, A.

2014-11-11

Elastic scattering measurements of {sup 6}He + {sup 58}Ni system have been performed at the laboratory energy of 21.7 MeV. The {sup 6}He secondary beam was produced by a transfer reaction {sup 9}Be ({sup 7}Li, {sup 6}He) and impinged on {sup 58}Ni and {sup 197}Au targets, using the Radioactive Ion Beam (RIB) facility, RIBRAS, installed in the Pelletron Laboratory of the Institute of Physics of the University of São Paulo, Brazil. The elastic angular distribution was obtained in the angular range from 15° to 80° in the center of mass frame. Optical model calculations have been performed using a hybridmore » potential to fit the experimental data. The total reaction cross section was derived.« less

WE-AB-209-08: Novel Beam-Specific Adaptive Margins for Reducing Organ-At-Risk Doses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsang, H; Kamerling, CP; Ziegenhein, P

2016-06-15

Purpose: Current practice of using 3D margins in radiotherapy with high-energy photon beams provides larger-than-required target coverage. According to the photon depth-dose curve, target displacements in beam direction result in minute changes in dose delivered. We exploit this behavior by generating margins on a per-beam basis which simultaneously account for the relative distance of the target and adjacent organs-at-risk (OARs). Methods: For each beam, we consider only geometrical uncertainties of the target location perpendicular to beam direction. By weighting voxels based on its proximity to an OAR, we generate adaptive margins that yield similar overall target coverage probability and reducedmore » OAR dose-burden, at the expense of increased target volume. Three IMRT plans, using 3D margins and 2D per-beam margins with and without adaptation, were generated for five prostate patients with a prescription dose Dpres of 78Gy in 2Gy fractions using identical optimisation constraints. Systematic uncertainties of 1.1, 1.1, 1.5mm in the LR, SI, and AP directions, respectively, and 0.9, 1.1, 1.0mm for the random uncertainties, were assumed. A verification tool was employed to simulate the effects of systematic and random errors using a population size of 50,000. The fraction of the population that satisfies or violates a given DVH constraint was used for comparison. Results: We observe similar target coverage across all plans, with at least 97.5% of the population meeting the D98%>95%Dpres constraint. When looking at the probability of the population receiving D5<70Gy for the rectum, we observed median absolute increases of 23.61% (range, 2.15%–27.85%) and 6.97% (range, 0.65%–17.76%) using per-beam margins with and without adaptation, respectively, relative to using 3D margins. Conclusion: We observed sufficient and similar target coverage using per-beam margins. By adapting each per-beam margin away from an OAR, we can further reduce OAR dose without significantly lowering target coverage probability by irradiating more less-important tissues. This work is supported by Cancer Research UK under Programme C33589/A19908. Research at ICR is also supported by Cancer Research UK under Programme C33589/A19727 and NHS funding to the NIHR Biomedical Research Centre at RMH and ICR.« less

Intensity limits of the PSI Injector II cyclotron

NASA Astrophysics Data System (ADS)

Kolano, A.; Adelmann, A.; Barlow, R.; Baumgarten, C.

2018-03-01

We investigate limits on the current of the PSI Injector II high intensity separate-sector isochronous cyclotron, in its present configuration and after a proposed upgrade. Accelerator Driven Subcritical Reactors, neutron and neutrino experiments, and medical isotope production all benefit from increases in current, even at the ∼ 10% level: the PSI cyclotrons provide relevant experience. As space charge dominates at low beam energy, the injector is critical. Understanding space charge effects and halo formation through detailed numerical modelling gives clues on how to maximise the extracted current. Simulation of a space-charge dominated low energy high intensity (9.5 mA DC) machine, with a complex collimator set up in the central region shaping the bunch, is not trivial. We use the OPAL code, a tool for charged-particle optics calculations in large accelerator structures and beam lines, including 3D space charge. We have a precise model of the present (production) Injector II, operating at 2.2 mA current. A simple model of the proposed future (upgraded) configuration of the cyclotron is also investigated. We estimate intensity limits based on the developed models, supported by fitted scaling laws and measurements. We have been able to perform more detailed analysis of the bunch parameters and halo development than any previous study. Optimisation techniques enable better matching of the simulation set-up with Injector II parameters and measurements. We show that in the production configuration the beam current scales to the power of three with the beam size. However, at higher intensities, 4th power scaling is a better fit, setting the limit of approximately 3 mA. Currents of over 5 mA, higher than have been achieved to date, can be produced if the collimation scheme is adjusted.

Benchmarking Heavy Ion Transport Codes FLUKA, HETC-HEDS MARS15, MCNPX, and PHITS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronningen, Reginald Martin; Remec, Igor; Heilbronn, Lawrence H.

Powerful accelerators such as spallation neutron sources, muon-collider/neutrino facilities, and rare isotope beam facilities must be designed with the consideration that they handle the beam power reliably and safely, and they must be optimized to yield maximum performance relative to their design requirements. The simulation codes used for design purposes must produce reliable results. If not, component and facility designs can become costly, have limited lifetime and usefulness, and could even be unsafe. The objective of this proposal is to assess the performance of the currently available codes PHITS, FLUKA, MARS15, MCNPX, and HETC-HEDS that could be used for designmore » simulations involving heavy ion transport. We plan to access their performance by performing simulations and comparing results against experimental data of benchmark quality. Quantitative knowledge of the biases and the uncertainties of the simulations is essential as this potentially impacts the safe, reliable and cost effective design of any future radioactive ion beam facility. Further benchmarking of heavy-ion transport codes was one of the actions recommended in the Report of the 2003 RIA R&D Workshop".« less

Low-Z shore of the "island of inversion" and the reduced neutron magicity toward 28O

NASA Astrophysics Data System (ADS)

Doornenbal, P.; Scheit, H.; Takeuchi, S.; Utsuno, Y.; Aoi, N.; Li, K.; Matsushita, M.; Steppenbeck, D.; Wang, H.; Baba, H.; Ideguchi, E.; Kobayashi, N.; Kondo, Y.; Lee, J.; Michimasa, S.; Motobayashi, T.; Otsuka, T.; Sakurai, H.; Takechi, M.; Togano, Y.; Yoneda, K.

2017-04-01

The two odd-even fluorine isotopes F,2927 were studied via in-beam γ -ray spectroscopy at the RIKEN Radioactive Isotope Beam Factory. A secondary beam of 30Ne was used to induce one-proton and one-proton-two-neutron removal reactions on carbon and polyethylene targets at midtarget energies of 228 MeV/u . Excited states were observed at 915(12) keV for 27F and at 1080(18) keV for 29F. Both were assigned a 1 /21+ spin and parity. The low transition energy for 29F largely disagrees with shell model predictions restricted to the s d model space. Calculations using effective interactions that include the neutron p f shell indicate that the N =20 gap is quenched for 29F, thus extending the "island of inversion" to isotopes with proton number Z =9 . Variations of the N =20 gap further reveal a strong correlation to the 1 /21+ level energy in 29F and suggest a persistent reduced neutron gap for 28O.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galatà, A., E-mail: alessio.galata@lnl.infn.it; Mascali, D.; Neri, L.

A Charge Breeder (CB) is a crucial device of an ISOL facility, allowing post-acceleration of radioactive ions: it accepts an incoming 1+ beam, then multiplying its charge with a highly charged q+ beam as an output. The overall performances of the facility (intensity and attainable final energy) critically depend on the charge breeder optimization. Experimental results collected along the years confirm that the breeding process is still not fully understood and room for improvements still exists: a new numerical approach has been therefore developed and applied to the description of a {sup 85}Rb{sup 1+} beam capture by the plasma ofmore » the 14.5 GHz PHOENIX ECR-based CB, installed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and adopted for the Selective Production of Exotic Species project under construction at Laboratori Nazionali di Legnaro. The results of the numerical simulations, obtained implementing a plasma-target model of increasing accuracy and different values for the plasma potential, will be described along the paper: results very well agree with the theoretical predictions and with the experimental results obtained on the LPSC test bench.« less

Investigation of the response of a neutron-Hand monitor dedicated to the powder diffractometer at CENM-Maamora

DOE Office of Scientific and Technical Information (OSTI.GOV)

Messous, M.Y.; Belhorma, B.; Labrim, H.

2015-07-01

Neutrons are used for the study of condensed matter. A neutron beam can indeed easily penetrate the solid material and undergo diffraction phenomena. Analysis of the diffused neutrons allows studying the atomic structure of crossed material. Their neutral electric charge makes them nondestructive probe of a great interest. In general, the size of the powder samples is very small and therefore the centering of the beam on these is very crucial. It is in this context we proceed to test a portable neutron monitor for centering and checking beam leak around the shielding to be installed around the diffractometer inmore » TRIGA Mark II of CENM. It's consisting of a scintillation neutron detector NE426 ({sup 6}LiF + ZnS (Ag)) with electronic module and data acquisition system. The effect of radiation from radioactive neutrons source {sup 252}Cf is shown. Sensitivity and differential linearity are also performed. This study indicates several advantages of this detector with very good detection sensitivity and excellent stability during the counting time. (authors)« less

Optical distribution of local oscillators in future telecommunication satellite payloads

NASA Astrophysics Data System (ADS)

Benazet, Benoît; Sotom, Michel; Maignan, Michel; Berthon, Jacques

2017-11-01

The distribution of high spectral purity reference signals over optical fibre in future telecommunication satellite payloads is presented. Several types of applications are considered, including the distribution of a reference frequency at 10 MHz (Ultra-Stable Reference Oscillator) as well as the distribution of a radiofrequency oscillator around 800 MHz (Master Local Oscillator). The results of both experimental and theoretical studies are reported. In order to meet phase noise requirements for the USRO distribution, the use of an optimised receiver circuit based on an optically synchronised oscillator is investigated. Finally, the optical distribution of microwave local oscillators at frequencies exceeding 20 GHz is described. Such a scheme paves the way to more advanced sub-systems involving optical frequency-mixing and optical transmission of microwave signals, with applications to multiple-beam active antennas.