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Actinium-225 and 213Bi have been used successfully in targeted alpha therapy (TAT) in preclinical and clinical research. This paper is a continuation of research activities aiming to expand the availability of 225Ac. The high-energy proton spallation reaction on natural thorium metal targets has been utilized to produce millicurie quantities of 225Ac. The results of sixteen irradiation experiments of thorium metal at beam energies between 78 and 192 MeV are summarized in this work. Irradiations have been conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing was carried out at Oak Ridge National Laboratory (ORNL). Excitation functions for actinium and thorium isotopes, as well as for some of the fission products, are presented. The cross sections for production of 225Ac range from 3.6 to 16.7 mb in the incident proton energy range of 78–192 MeV. Based on these data, production of curie quantities of 225Ac is possible by irradiating a 5.0 g cm−2 232Th target for 10 days in either BNL or LANL proton irradiation facilities.

Electroplated depositions of Sm were prepared using a vertical well-type electrodeposition unit with an aqueous ammonium acetate electrolyte system, with an average deposition yield just over 87%. The depositions were analyzed for morphology and thickness by scanning electron microscopy (SEM) and chemical composition by energy dispersion X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) before and after firing. The depositions were fired at 125–700 °C, while varying the heating rate from 0.5 to 10 °C/min in either an oxidizing or reducing atmosphere. A heating rate of 10 °C/min was slow enough to prevent disruption of the deposition morphology during firing. A gas sweep enhanced the removal of any organic substituents, with an oxidizing environment being more advantageous than a reducing environment.

Multi-step resonance laser ionization has become an essential tool for the production of isobarically pure radioactive ion beams at the isotope separator on-line (ISOL) facilities around the world. A resonant ionization laser ion source (RILIS) has been developed for the former Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory. The RILIS employs a hot-cavity ion source and a laser system featuring three grating-tuned and individually pumped Ti:Sapphire lasers, especially designed for stable and simple operation. The RILIS has been installed at the second ISOL production platform of former HRIBF and has successfully provided beams of exotic neutron-rich Ga isotopes for beta decay studies. This paper reports the features, advantages, limitations, and on-line and off-line performance of the RILIS.

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.

Samarium thin-films doped with a 252 Cf radiotracer were used to study the effects of annealing on the release of fission fragments from electrodeposited films. An ammonium acetate molecular plating technique was utilized to perform the depositions. The fission fragment yields were measured using a unique technique involving the exposure of aluminum foils to the deposited material for a fixed time followed by gamma-ray spectroscopy to determine the rate at which the fission fragments implanted into the foils. Annealing of the electrodeposited films was found to have no effect on the release of fission fragments.

Beta decays of mass A = 142 isobaric chain starting from 142 Cs have been investigated by means of Modular Total Absorption Spectrometer (MTAS) and on-line mass separation at Oak Ridge National Laboratory. The beta strength distribution derived for 142 Cs decay from MTAS spectra is showing significant differences in β-feeding pattern when compared to the values listed at nuclear databases. MTAS results are shifting the associated anti-neutrino energy spectrum towards lower energies. A decay pattern deduced for 142 Ba is similar to earlier reported results.

The planned rare isotope accelerator facility RIA in the US would become the most powerful radioactive beam facility in the world. RIA's driver accelerator will be a device capable of providing beams from protons to uranium at energies of at least 400 MeV per nucleon, with beam power up to 400 kW. Radioactive beam production relies on both the in-flight separation of fast beam fragments and on the ISOL technique. In both cases the high beam power poses major challenges for target technology and handling and on the design of the beam production areas. This paper will give a brief overview of RIA and discuss aspects of ongoing conceptual design work for the RIA target areas.

A technique for measuring mass differences has been developed at the Holifield Radioactive Ion Beam Facility (HRIBF) that requires no specialized equipment. Mass differences are measured as position differences between known and unknown-mass isobars, dispersed at the image of the energy-analyzing magnet following the 25 MV tandem post-accelerator, and identified by an energy-loss measurement. The technique has been demonstrated on neutron-rich 77–79Cu and 83–86Ge isotopes produced using the isotope separator online (ISOL) method with the 238U(p,fission) reaction, where a mass accuracy of 500 keV was achieved. These nuclides are well suited to the measurement technique, as they readily migrate out of the production target and to the ion source and comprise the most neutron-rich elements of the isobarically mixed beam. Because modest precision mass values can be obtained with only a few tens of counts of the nuclide of interest among orders of magnitude more of the isobaric neighbors closer to stability, the sensitivity of this technique makes it appropriate for initial mass measurements far from stability.

A variety of ISOL targets for generation of radioactive ion beams have been successfully developed at the Holifield Radioactive Ion Beam Facility. Short-lived ion species generated from fast release targets made up of fibrous materials such as HfO2, and coated low-density carbon foam target matrices such as UC2/RVCF targets have been applied in important research programs of nuclear physics and astrophysics. In this paper, computer modeling of the HRIBF targets are introduced, and the computation results are coincident with the experimental measurements. These studies provide a cost effective method to understand beam power deposition as well as temperature distribution in ISOL target presently utilized at the HRIBF and predict the capability of high power ISOL target designs and the temperature profiles with other target materials and geometries for the future facility upgrade.

A new infiltration coating method has been conceived for uniform and controlled thickness deposition of target materials onto highly permeable, complex-structure matrices to form short-diffusion-length isotope-separator-on-line (ISOL) production targets for radioactive ion beam research applications. In this report, the infiltration technique is described in detail and the universal character of the technique illustrated in the form of SEMs of several metal-carbide, metal-oxide and metal-sulfide targets for potential use at present or future radioactive ion beam research facilities.

Neutron-rich radioactive ion beams available from the HRIBF allow a variety of measurements around the 132Sn region, including Coulomb excitation, fusion-evaporation, and neutron transfer. The B ( E 2 ; 0 + → 2 + ) value for first 2+ excited states of even-even neutron-rich 132–136Te and 126–134Sn have been measured by Coulomb excitation in inverse kinematics. The results are discussed in terms of the shell model and the quasiparticle random phase approximation. Neutron transfer onto a 134Te beam, from 9Be and 13C targets to populate single-particle states in 135Te, has also been studied. Gamma rays from the 13C(134Te, 12C) reaction were used to identify the ν i 13 / 2 state in 135Te, at an energy of 2109 keV. These and other results, and plans for future experiments with these neutron-rich beams, are presented.

Neutron-rich radioactive ion beams available from the HRIBF allow a variety of exciting measurements around the 132 Sn region, including Coulomb excitation, fusion-evaporation, and neutron transfer. The B ( E 2 ; 0 + → 2 + ) value for first 2 + excited states of neutron-rich 132,134,136 Te and 126,128,130,132,134 Sn have been measured by Coulomb excitation in inverse kinematics. The results are discussed in terms of the shell model and the quasiparticle random phase approximation. Neutron transfer onto a 134 Te beam, from 9 Be and 13 C targets to populate single-particle states in 135 Te, has also been studied. Results, and plans for future experiments with these neutron-rich beams, are presented.

Radioactive Ion Beams (RIBs) at the Holifield Radioactive Ion Beam Facility (HRIBF) are produced using the isotope separation on-line technique and are subsequently accelerated up to a few MeV per nucleon for use in nuclear physics experiments. The first RIB experiments at the HRIBF were completed at the end of 1998 using 17F beams. Since then other proton-rich ion beams have been developed and a large number of neutron-rich ion beams are now available. The neutron-rich radioactive nuclei are produced via proton-induced fission of uranium in a low-density matrix of uranium carbide. Recently developed RIBs include 25Al from a silicon carbide target and isobarically pure beams of neutron-rich Ge, Sn, Br and I isotopes from a uranium carbide target.

The evolution of the giant dipole resonance (GDR) in 120 Sn and 208 Pb nuclei at excitation energies in the range of 30–130 MeV and 40–110 MeV, respectively, were studied by measuring high energy γ rays from the decay of the resonance. The excited states were populated by inelastic scattering of α particles at beam energies of 40 and 50 MeV/nucleon for 120 Sn and 40 MeV/nucleon for 208 Pb. A systematic increase of the resonance width with increasing excitation energy was observed for both nuclei. The observed width evolution was compared to calculations employing a model that adiabatically couples the collective excitation to the nuclear shape, and to a model based on the collisional damping of nucleons. The adiabatic coupling model described the width evolution in both nuclei well, whereas the collisional damping calculation could describe the width evolution only in 208 Pb. Light-particle inelastic scattering populates low angular momentum states in the target nucleus. The observed width increase is therefore interpreted to be predominantly due to fluctuations in the nuclear shape induced by temperature. This interpretation is consistent with the adiabatic model calculations and with recent angular momentum-gated measurements of the GDR in excited Sn isotopes.

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.

The recently discovered superdeformed band in one of the strontium isotopes has been identified as belonging to 83Sr from a study with the Gammasphere array and the Microball charged-particle detector system. From its decay pattern, a spin of (81 ± 2) 2 h is deduced for the highest level of this band. Evidence for very fast transition rates and agreement of the characteristics of this band with the theoretical predictions establish the yrast superdeformed nature of this band in 83Sr.

We have developed a method of implanted ion counting in order to determine the absolute decay probability of the 776.5 keV $\ensuremath{\gamma}$-ray transition in the decay sequence of ${}^{82}$Sr${\ensuremath{\rightarrow}}^{82}$Rb${\ensuremath{\rightarrow}}^{82}$Kr. A 215 MeV beam of ${}^{82}$Sr was produced at the Holifield Radioactive Ion Beam Facility and passed through an ionization chamber that counted and identified the ions before they were implanted into thin aluminum foils. Subsequent offline measurements using a Ge detector deduced the probability per decay of ${}^{82}$Rb for the 776.5 keV $\ensuremath{\gamma}$ ray in ${}^{82}$Kr to be 0.1493(37), in agreement with the accepted average value of 0.1508(16). This new technique measures directly the number of decaying nuclei in a given sample and significantly reduces the dependence on knowledge of the complete decay level scheme.

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.

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.

Experiments with reaccelerated beams are an essential component of the science program of existing and future rare isotope beam facilities. NSCL is currently constructing ReA3, a reaccelerator for rare isotopes that have been produced by projectile fragmentation and in-flight fission and that have been thermalized in a gas stopper. The resulting low-energy beam will be brought to an Electron Beam Ion Source/Trap (EBIS/T) in order to obtain highly charged ions at an energy of 12 keV/u. This charge breeder is followed by a compact linear accelerator with a maximum beam energy of 3 MeV/u for 238U and higher energies for lighter isotopes. Next-generation rare isotope beam facilities like the Facility for Rare Isotope Beams FRIB, but also existing Isotope Separator On-line (ISOL) facilities are expected to provide rare-isotope beam rates in the order of 1011 particles per second for reacceleration. At present the most promising scheme to efficiently start the reacceleration of these intense beams is the use of a next-generation high-current charge-breeder based on an EBIS/T. MSU has formed a collaboration to develop an EBIT for this purpose. A new high-current EBIS/T breeder will be developed and constructed at MSU, where also first tests on achievable beam rate capability will be performed. The EBIT is planned to be installed at the Isotope Separator and Accelerator facility ISAC at TRIUMF laboratory for on-line tests with rare isotope beams and to provide intense energetic reaccelerated radioactive beams. The status of the ReA3-EBIS/T in the NSCL reaccelerator project is given with a brief summary of results, followed by a discussion of plans for the future high-intensity EBIS/T charge breeder.

In the framework of the SPES project at LNL [A. Bracco, A. Pisent (Ed.), REP 181/02, LNL-INFN, 2002], the realization of a direct ISOL Target for a mid-term radioactive ion beam facility is in progress. Using a primary proton beam of energy 40 MeV and intensity 0.2 mA, a high number of fission products will be obtained in the SPES multi-foil uranium carbide target, keeping a low power density deposition in the refractory matrix [A. Andrighetto, S. Cevolani, C. Petrovich, Eur. Phys J. A 25 (2005) 41]. The exotic species produced by Uranium fission in the target are collected in the ion source after the diffusion and the effusion processes. When short lived isotopes are produced it is very important to optimize the release properties of the target. To this purpose the RIBO code (radioactive ion beam optimiser) [M. Santana Leitner, A Monte Carlo Code to Optimize the Production of Radioactive Ion Beams by the ISOL Technique, PhD. Thesis, UPC-ETSEIB/CERN] has been used in order to estimate the target release efficiency for some neutron-rich nuclei. A SiC prototype of the target was recently produced at LNL and tested at ORNL using a 42 MeV proton beam. The yield of some aluminum isotopes was measured as a function of the target temperature. Some preliminary results of the data analysis will be presented.

Evaporation residue and fission cross sections of radioactive $$^{132}$$Sn on $$^{64}$$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, no extra fusion enhancement is observed in $$^{132}$$Sn+$$^{64}$$Ni with respect to stable Sn+$$^{64}$$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $$^{112-124}$$Sn and $$^{132}$$Sn with $$^{64}$$Ni is presented.

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, N=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 131Sn from across the N=82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient 106,108Sn. In both cases, measurements of gamma rays in coincidence with charged particles proved to be invaluable., 11 pages, 5 figures, Zakopane Conference on Nuclear Physics "Extremes of the Nuclear Landscape", Zakopane, Poland, August 31 - September 7, 2014

The Department of Energy’s Office of Nuclear Physics, within the Office of Science (SC), has given high priority to consider and analyze design concepts for the target areas for the production of rare isotopes via the ISOL technique at the Rare-Isotope Accelerator (RIA) Facility. Key criteria are the maximum primary beam power of 400 kW, minimizing target change-out time, good radiological protection, flexibility with respect to implementing new target concepts, and the analysis and minimization of hazards associated with the operation of the facility. We will present examples of on-going work on simulations of radiation heating of targets, surrounding components and shielding, component activation, and levels of radiation dose, using the simulation codes MARS, MCNPX, and PHITS. These results are important to make decisions that may have a major impact on the layout, operational efficiency and cost of the facility, hazard analysis, shielding design, civil construction, component design, and material selection overall layout, and remote handling concepts.

{gamma}-ray spectroscopy of {sup 132}Te, obtained from {beta}{sup -} decay of a {sup 132}Sb radioactive beam at the Holifield Radioactive Ion Beam Facility, was performed using the Clarion array. A significantly revised {gamma}-decay scheme for {sup 132}Te was obtained including a number of new, likely 2{sup +}, states below 2.5 MeV and the removal of a 3{sup -} state at 2280 keV. A simple shell-model interpretation is discussed for the low-lying levels.

The Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge is the first ISOL-type facility to provide beams of accelerated radioactive fission products. To generate these beams, products of fission induced by proton bombardment of a uranium carbide target are ionized, charge-exchanged in Cs vapor, and injected into the HRIBF tandem. Using a single stripper foil in the terminal, they can be accelerated to about 3 MeV per nucleon, ideal for Coulomb Excitation studies. Alternatively, they can be accelerated to energies above the Coulomb barrier by means of double-stripping, at the expense of a factor of about five in lost beam intensity. This paper reports on recent experiments using neutron-rich radioactive ion beams (RIBs) from the HRIBF facility. They have performed Coulomb excitation measurements of B(E2; 0{sup +} {yields} 2{sup +}) in {sup 126,128}Sn and {sup 132,134,136}Te, neutron transfer to single-particle states in {sup 135}Te, and fusion-evaporation reactions on light targets to study evaporation residues with {gamma}-{gamma}-recoil coincidence spectroscopy.

132Te has been studied through β- decay of 132Sb radioactive beam at HRIBF leading to a significantly revised level scheme. A number of newly identified, likely 2+ states allows for a test of recent quasiparticle random phase approximation calculations with a density-dependent pairing force. In addition, the removal of a previously proposed 3− state allows for a simple shell model interpretation of the low-lying negative-parity states.

High-spin states in Zr-84 were studied using the early implementation phase of the Gammasphere array and the ''Microball'' charged-particle detector system. A cascade of nine gamma rays with a dyna ...

A pair of rotational bands with 9 and 11 discrete $\ensuremath{\gamma}$ rays with a regular spacing of about 29 keV extending from 1016 to 1340 keV have been identified as belonging to ${}^{147}\mathrm{Gd}$. Evidence from their population, decay characteristics, very large dynamic moments of inertia of ${\ensuremath{\mathfrak{I}}}^{(2)}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}140$ ${\ensuremath{\Elzxh}}^{2}\phantom{\rule{0ex}{0ex}}{\mathrm{MeV}}^{\ensuremath{-}1}$, and agreement with theoretical predictions support the hyperdeformed character of these bands. These band structures correspond to a spheroid with major-to-minor axis ratio of about 3:1.

The Holifield Radioactive Ion Beam Facility (HRIBF) provides high-quality Isotope Separator Online beams of short-lived, radioactive nuclei for nuclear structure and reaction studies, astrophysics research, and interdisciplinary applications. The primary driver, the Oak Ridge Isochronous Cyclotron, produces rare isotopes by bombarding highly refractory targets with light ions. The radioactive isotopes are ionized, formed into a beam, mass selected, injected into the 25 MV tandem, accelerated, and used in experiments. This paper reviews the HRIBF and its users' science.

High energy \ensuremath{\gamma} rays from the decay of the giant dipole resonance built on highly excited states in $^{164}\mathrm{Yb}$ at ${\mathit{E}}_{\mathrm{ex}}$=49 MeV formed in two different reactions have been measured. While standard statistical model calculations can describe the \ensuremath{\gamma}-ray spectrum from the $^{16}\mathrm{O}$ + $^{148}\mathrm{Sm}$ reaction they fail to reproduce the \ensuremath{\gamma}-ray spectra from the more symmetric reaction $^{64}\mathrm{Ni}$ + $^{100}\mathrm{Mo}$. Simple model calculations which include particle evaporation and \ensuremath{\gamma}-ray decay during the formation process suggest that the observed differences may be related to a long fusion time in the more symmetric reaction.

Experiments on electron acceleration and optical diagnostics of laser wakes were performed on the HERCULES facility in a wide range of laser and plasma parameters. Using frequency domain holography we demonstrated single shot visualization of individual plasma waves, produced by 40TW, 30fs laser pulses focused to the intensity of 1019W∕cm2 onto a supersonic He gas jet with plasma densities ne

Recent advancements in laser wakefield accelerators have resulted in the generation of low divergence, hundred MeV, quasimonoenergetic electron beams. The bremsstrahlung produced by these highly energetic electrons in heavy converters includes a large number of MeV γ rays that have been utilized to induce photofission in natural uranium. Analysis of the measured delayed γ emission demonstrates production of greater than 3×105 fission events per joule of laser energy, which is more than an order of magnitude greater than that previously achieved. Monte Carlo simulations model the generated bremsstrahlung spectrum and compare photofission yields as a function of target depth and incident electron energy.