Production Of Radioactive Beams Research Articles

LISE[formula omitted], the latest generation of the LISE[formula omitted] package, to simulate rare isotope production with fragment-separators

The LISE++ software for fragment separator simulations has undergone a major update. The package, widely used at rare isotope beam facilities, can be used to predict intensities and purities of rare isotope beams and for planning and running of experiments using in-flight separators. It is especially useful for radioactive beam production as its results can be quickly compared to on-line data. The LISE++ package has been ported to the Qt-framework in order to support modern compilers and computing methods. The benefits include 64-bit operation and LISE++ availability on three different platforms: Windows, MacOS and Linux. In addition, the porting provides the ability to take advantage of future computational improvements. The updated package is named LISEcute++ to indicate a major step forward from the previous Borland-based versions. In addition to porting to the new platform, new main features and modifications have been added, mostly devoted to improving models and implementing other codes involved in rare isotope production at FRIB. A summary of modifications completed to improve the functionality of the code are discussed in this work, as well as future plans.

Field-Map And Beam Transport Calculations of The Magnetic Separator At Alto Facility At Orsay

The Institute of Nuclear Physics at Orsay (IPNO) has always been a major player in building accelerators for nuclear physics. The Accelerator Linear Tandem Orsay (ALTO) facility is powered by a 50 MeV/10uA linear electron accelerator dedicated to the production of radioactive beams [1]. The production mode is based on the photo-fission process of a thick UCx target heated up to 2000°C and using the Isotopes Separation On-Line (ISOL) technique [2]. For the ionization of the released fission fragments, three ion source types can be coupled to the target: a Febiad ion source, surface ion source, and laser ion source. The facility can deliver the radioactive ions beams (RIB) to six different experimental setups. The mass of the produced mono-charged Radioactive Ions Beam is selected using a magnetic dipole in order to select a nucleus before its transmission through electrostatic devices up to the experimental setups [3]. This paper is focused on the separator that was built and exploited with success since 43 years. The separator is located closely to the exit of the source of RIB production. We propose to revisit this dipole with a precise field-map calculation and particles transport simulations. These results will be used as a first brick for the understanding and reliability of the transmission along the RIB lines at the ALTO facility.

First results on Ge resonant laser photoionization in hollow cathode lamp

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 a 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.

An intrinsically safe facility for forefront research and training on nuclear technologies — An example of accelerator: the SPES cyclotron

The SPES project, under construction at INFN, Laboratori Nazionali di Legnaro, is a research facility for nuclear and applied physics, based on a high-current H- cyclotron with two exits. One exit will be devoted to supply an ISOL facility for the production of radioactive beams, the second one can be used as driver for the ADS system. The main characteristics of the cyclotron are described together with the main building designed to operate high-current proton beams according to radioprotection rules.

Status of the ion sources developments for the Spiral2 project at GANIL

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.

Gas cell targets for experiments with radioactive beams

In this paper we discuss the properties of gas cell targets used for the production of radioactive beams via the in-flight technique as well as gas cell targets used for studies of nuclear reactions in inverse kinematics at the ATLAS heavy ion accelerator.

High Energy Density Physics Studies at the Facility for Antiprotons and Ion Research: the HEDgeHOB Collaboration

AbstractThe forthcoming Facility for Antiprotons and Ion Research (FAIR) at Darmstadt, is going to be a unique accelerator facility that will deliver high quality, strongly bunched, well focused, intense beams of heavy ions that will lead to unprecedented specific power deposition in solid matter. This will generate macroscopic samples of High Energy Density (HED) matter with fairly uniform physical conditions. These samples can be used to study the thermophysical and transport properties of HED matter. Extensive theoretical work has been carried out over the past decade to design numerous dedicated experiments to study HED physics at the FAIR, which has provided the basis for the HEDgeHOB (High Energy Density Matter Generated by Heavy Ion Beams) scientific proposal. This work is still in progress as the feasibility studies for more experimental schemes are being carried out.Another, very important research area that will benefit tremendously from the FAIR facility, is the production of radioactive beams. A superconducting fragment separator, Super–FRS is being designed for the production and separation of rare radioactive isotopes. Unlike the HED targets, the Super–FRS production target should not be destroyed or damaged by the beam, but should remain intact during the long experimental campaign. However, the high level of specific power deposited in the production target by the high intensity ion beam at FAIR, could cause serious problems to the target survival. These HED issues related to the Super–FRS production target are also discussed in the present paper (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

LISE++: Radioactive beam production with in-flight separators

The program LISE++ is designed to predict intensity and purity for future experiments using radioactive beams with in-flight separators, and for tuning experiments where its results can be quickly compared to on-line data. The name LISE++ denotes the new generation of the LISE program, in which any separator can be built through the use of different sections labeled “blocks”. Its user-friendly interface can be used to quickly construct many separator configurations from the available blocks. The LISE++ package already includes configuration files for most of the existing fragment and recoil separators such as the A1900 and the S800 at the NSCL, LISE3 at GANIL, FRS and SuperFRS at GSI, BigRIPS and RIPS at RIKEN. Projectile fragmentation, fusion–evaporation, fusion–fission, Coulomb fission, abrasion–fission and two body reactions models are included in this program and can be used as the production reaction mechanism to simulate experiments at beam energies above the Coulomb barrier. This program can be downloaded free of charge from the following web site: <http://www.nscl.msu.edu/lise>.

MAYA: An active target detector for the study of extremely exotic nuclei

With the recent improvements on production of radioactive beams at facilities such as SPIRAL at GANIL or ISAC at TRIUMF, a larger area of the nuclear chart is now accessible for experimentation. For these usually low-intensity and low-energy secondary beams, we have developed the new MAYA detector based on the active target concept. This device allows to use a relatively thick target without loss of resolution by using the detection gas as target material. A dedicated 3-D tracking, particle identification, energy loss and range measurements allow complete kinematics reconstruction of reactions taking place inside MAYA. Recent results from studies of 7H nuclear system performed at GANIL and of the outer skin structure of the exotic nucleus 11Li performed at TRIUMF will be reviewed. The capabilities of this new techniques in future experimental studies with secondary exotic beams near and beyond the drip lines, where large kinematics ranges are needed, including regions not accessible with the standard techniques, will be discussed.

7Be radioactive beam production at CIRCE and its utilization in basic and applied physics

A pure 7Be beam with an energy E=1–8MeV is available for nuclear and applied physics at the 3MV Pelletron tandem accelerator CIRCE in Caserta. The beam is produced using an offline technique. Typical analyzed beam intensities are about 2ppA, using cathodes with an activity of the order of 200MBq. The 7Be implantation has been used for both fundamental nuclear physics and applied physics. In particular, different metals have been implanted with 7Be in order to study the influence of the chemical composition and of the number of quasi-free electrons of the host material on the 7Be half-life. In the field of applied physics, the 7Be implantation turns out to be very interesting for wear measurement. In fact, in this case 7Be is used as a depth-sensitive tracer. The continuous detection of the sample activity during the wear allows a high sensitivity measurement of wearing speed. The 7Be beam production at CIRCE, the implantation procedure and the results obtained from the 7Be half-life measurements and the wear characterization of implanted steel samples are described.

MAYA: An active-target detector for binary reactions with exotic beams

With recent improvements in the production of radioactive beams in facilities such as SPIRAL at GANIL, a larger area of the nuclear chart is now accessible for experimentation. For these usually low-intensity and low-energy secondary beams, we have developed the new MAYA detector based on the active-target concept. This device allows to use a relatively thick target without loss of resolution by using the detection gas as target material. Dedicated 3D tracking, particle identification, energy loss and range measurements allow complete kinematic reconstruction of reactions taking place inside MAYA.

Fragmentation cross sections of 290 and 400 MeV/nucleonC12beams on elemental targets

Charge-changing and fragment production cross sections at 0circ have been obtained for interactions of 290 MeV/nucleon and 400MeV/nucleon carbon beams with C, CH2, Al, Cu, Sn, and Pb targets. Thesebeams are relevant to cancer therapy, space radiation, and the productionof radioactive beams. We compare to previously published results using Cand CH2 targets at similar beam energies. Due to ambiguities arising fromthe presence of multiple fragments on many events, previous publicationshave reported only cross sections for B and Be fragments. In this work wehave extracted cross sections for all fragment species, using dataobtained at three distinct values of angular acceptance, supplemented bydata taken with the detector stack placed off the beam axis. A simulationof the experiment with the PHITS Monte Carlo code shows fair agreementwith the data obtained with the large acceptance detectors, but agreementis poor at small acceptance. The measured cross sections are alsocompared to the predictions of the one-dimensional cross section modelsEPAX2 and NUCFRG2; the latter is presently used in NASA's space radiationtransport calculations. Though PHITS and NUCFRG2 reproduce thecharge-changing cross sections with reasonable accuracy, none of themodels is able to accurately predict the fragment cross sections for allfragment species and target materials.

SPIRAL 2 resonators

The SPIRAL 2 project to be built in GANIL is a high intensity ion linear accelerator for radioactive beam production. Most of the acceleration is provided by twenty four 88 MHz quarter wave resonators breaking into two beta families. The first ( β = 0.07) was developed at CEA-Saclay, while the second ( β = 0.12) was studied at IPN-Orsay. Each team has carried out the integration study of the QWRs in their respective cryomodule taking into account tight longitudinal space requirements. Prototypes of each cavity type have been built, prepared and tested in vertical cryostats. We present the RF and mechanical design of the resonators, cryostats, the preparation and test equipment specifically developed for QWRs, as well as the RF test results.

Rare isotope accelerator—conceptual design of target areas

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.

Development of a permanent magnet light ion source at CEA/Saclay

In France, the Spiral 2 project dedicated to radioactive beam production is based on a 40MeV continuous wave (cw) deuteron Linac. This installation will allow extending the variety of accelerated particles to very heavy elements. Such beams will open research domains for the GANIL facility. To inject the requested 5mA deuteron beam into the Spiral 2 Linac, the performance of the high intensity light ion source (SILHI) allowed us to propose such an electron cyclotron resonance source. SILHI, developed at CEA/Saclay, regularly produces high intensity (over 100mA) proton or deuteron beams through a Φ 9mm aperture. So for this project, the main modifications of the source design concern the permanent magnets which provide the axial magnetic configuration and the Φ 3mm aperture. The source produced its first beam (proton) in 2004. This article will report the beam characterization while the source produced D+ beam with intensity as high as 7.0mA. Recently, this permanent magnet source has been equipped with the Φ 9mm plasma electrode. So high intensity proton beams reaching more than 100mA are now extracted from this source.

Muonic radioactive atoms - a unique probe for nuclear structure

Muonic atoms have been a source of high-precision experimental nuclear structure data for decades, through muonic X-rays that yield information on nuclear charge distributions. The intense driver beams for production of radioactive beams in so-called second generation facilities will simultaneously be capable of producing unprecedented amounts of low-energy muons. This paper concerns some of the potential synergies of combining unions with radioactive nuclei. as one possible new tool to be used at future RIB facilities. As a case study, muonic capture rates into highly excited states in Ni-78 have been calculated.

Recent ion source developments for production of radioactive beams (invited)

Presently, worldwide radioactive ion beam facilities based on the separator online are the main instruments for nuclear structure study and for solving many important questions about astrophysics. Investigations of short-lived neutron-rich and neutron-deficient nuclei, that are far from stability give a unique possibility for testing many aspects of modern nuclear structure theory. Therefore, the development of highly efficient, selective, and fast ion source-target systems (ISTS) for modern and next generation ISOL facilities is the crucial point for future progress of nuclear science and experimental astrophysics. The last decade demonstrates a burst of new developments in the field of ion source-target systems for ISOL installation use. The main task of this review is to show the latest results obtained with different types of ion sources, specially designed for short-lived isotope production, and to designate some directions of the ISTS development that can be noticed presently and very likely will be used in the near future.

Heavy-ion beam dynamics in the RIA accelerators

The Nuclear Science Community in the United States has unanimously concluded that developments in both nuclear science and its supporting technologies make building a Rare-Isotope Accelerator (RIA) facility for production of radioactive beams. The RIA development effort involves several US Laboratories (ANL, JLAB, LANL, LBNL, MSU, ORNL). The RIA project includes a continuous wave 1.4 GV driver linac and a 123 MV post-accelerator, both based on superconducting (SC) cavities operating at frequencies from 48 to 805 MHz. Several new conceptual solutions in physics design of heavy-ion SC linacs have been developed recently. In particular, the concept of multiple charge state beam acceleration in SC linacs was tested and will be used in the driver linac to increase available accelerated beam power. A detailed design has been developed for the focusing–accelerating lattice of the RIA linacs which are configured as an array of short SC cavities, each with independently controllable RF phase. Independent phasing allows the velocity profile to be varied: the linac can be tuned to provide higher energies for the lighter ions. For example, the reference design linac can be tuned to provide a uranium beam at an energy of 403 MeV/ u and can be re-tuned to provide a proton beam at 900 MeV. The linac must provide 100 kW beam power with the possibility to upgrade up to 400 kW.

The FLNR JINR wide aperture separator COMBAS

The high-resolution wide aperture separator COMBAS was installed and commissioned in the Flerov Laboratory of Nuclear Reactions, JINR (Dubna) [Nucl. Instr. and Meth. A 306 (1991) 123; 426 (1999) 605; 479 (2002) 467]. It is designed for in-flight radioactive beam production of short-lived isotopes and experiments with them. The separator operates in the (20–50)A MeV ion energy region. It consists of the two stages, dispersive and achromatising. The second half of the separator is a mirror symmetrical counterpart of the first one, the intermediate focal plane being the plane of the symmetry. Multipole magnets with special profiled poles are used to correct higher order aberrations at the intermediate and final foci. The 3D magnetic measurements of the analysing magnets of the separator were done. The KOMPOT program for the 3D magnetic field calculations [Doinikov et al., 1986, Preprint/CNNI atominform: B-0741, 13p; Belyaev et al., Int. Conf. “Optimisation of Finite Element Approximations”, St.Pt., Russia, 25–29 June 1995, p.101; IEEE Transact. On Magnetics, 28 (1) (1992) 908; Frenkel, Selected works, USSR Academy of Sciences publ., Moscow–Leningrad, v.1 (Electrodynamics), 1956; Proc. IEEE, 114 (7) (1967) 995; Livingston, Blewett, Particle accelerators, No. 7, McGraw-Hill, 1962, p. 253] was used for the analysis of these magnetic measurements data, as well as for the reconstruction of the magnet fields inside the total volume closed by the 3D surface, where the magnetic measurements had been performed. As a result of the magnetic field reconstruction we obtained field maps, which would be used in simulations of particle trajectories.

The radioactive beam experiment at ISOLDE, REX‐ISOLDE

Radioactiveion beam (RIB) facilities make rich opportunities available for nuclear structure research well as for nuclear astrophysics and applied physics. RIB facilities dnve the increasing understanding of evolution of nuclear structure and the growing wealth of nuclear structure data. The Radioactive Beam Experiment at ISOLDE, REX ISOLDE, has been the dominant experiment in the past ISOLDE running period [13. REX‐ISOLDE profits from vast experience of ISOLDE production of radioactive beams more than 600 isotopes from elements. In addition the resonant ionisation laser ion source (RILIS) can provide beams with high selectivity, even isomeric beams. Since the end 2001 the LINAC has provided radioactive beams from the ISOLDE online separators with energies of 2. MeVIu towards two target stations One target station is used for efficient y-ray MINIBALL array and one target station is dedicated smaller experimental set-ups. In order make the full variety of beams from ISOLDE available for nuclear physics experiments the method of charge breeding of the singly charged radioactive ions has been employed [3] Hence the concept of REX-ISOLDE based on a large Penning trap which accumulates the radioactive ions from the ISOLDE mass separators and allows phase space cooling of the RIBS prepared, the ions are injected into Electron Beam Ion Source (EBIS), which raises the charge state of radioactive ion to an A/q < 4.5. The extracted highly charged ions are charge state selected with subsequent acceleration in a short LINAC. The LINAC allows the variationofthe beam energy between 0.8 and 2.2 MeVh in order to adjust the beam energy for experimental needs.