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To replenish a specific consumable material, experimental samples of transport capsules were made, intended for neutron activation analysis for short-lived isotopes. The correspondence of the manufactured capsules to the real conditions of their transportation has been studied. The study of the elemental composition of the capsule material has been carried out. Analysis of the spectra of induced activity showed the presence of metal impurities in polyethylene, which must be taken into account when performing neutron activation analysis.

The formation of carbonyl complexes using atom-at-a-time quantities of short-lived transition metals from fusion and fission reactions was reported in 2012. Numerous studies focussing on this chemical system, which is also applicable for the superheavy elements followed. We report on a novel two-chamber approach for the synthesis of such complexes that allows spatial decoupling of thermalization and gas-phase carbonyl complex synthesis. Neutron induced fission on 235U and spontaneous fission of 248Cm were employed for the production of the fission products. These were stopped inside a gas volume behind the target and flushed with an inert-gas flow into a second chamber. This was flushed with carbon monoxide to allow the gas-phase synthesis of carbonyl complexes. Parameter studies of the transfer from the first into the second chamber as well as on the carbonyl complex formation and transport processes have been performed. High overall efficiencies of more than 50% were reached rendering this approach interesting for studies of superheavy elements. Our results show that carbonyl complex formation of thermalized fission products is a single-atom reaction, and not a hot-atom reaction.

TRIUMF operates the rare ion beam facility ISAC, which provides intense beams of short lived isotopes in the energy range from 0.15 to 5 A MeV for A < 30 to a full suite of world class experimental apparatus, enabling a forefront research program focused on understanding the evolution of nuclear structure towards the limits of existence, the origin of the chemical elements in the universe, searching for physics beyond the standard model of particle physics, and the characterization of magnetic properties of new materials at surfaces and interfaces.

TITAN (TRIUMF's Ion Traps for Atomic and Nuclear science) is a novel online facility for high-precision mass measurements on short-lived isotopes. TITAN is the only such facility that employs an Electron-Beam Ion Trap (EBIT) charge-state breeder to produce highly charged ions for their use to increase the precision of mass measurements. We describe the recently commissioned TITAN EBIT and present the results of first injection, charge breeding, and extraction tests performed with stable and radioactive ions.

Conventional statistical analyses of counting measurements with a paired-count blank and sample yield unacceptably-large estimates of uncertainty that reduce measurement sensitivity when applied to very-low-background detection systems. An alternative is presented here: Bayesian analysis using longer-duration background measurements, appropriate modeling of the background, and a binomial distribution of decay-induced counts valid even for short-lived isotopes. We develop the needed formulae and demonstrate how the decision level and sample measurement duration are optimized jointly to produce the lowest minimum detectable quantity subject to constraints of specified acceptable risks of false detection and false failure to detect. A frequentist’s interpretation is maintained by using equal-likelihood prior distributions.

The Earth’s core for med via a series of high‐energy collisions with already‐differentiated objects, likely resulting in several distinct magma ocean epochs. The cores of these impactors probably underwent only limited emulsification and moderate (~50%) isotopic re‐equilibration with the target mantle during the collision. Later impactors likely originated from more distant regions of the inner Solar System and were plausibly more volatile‐rich and more oxidized than earlier impactors. Short‐lived isotopes, especially the hafnium‐tungsten (Hf‐W) system, provide the strongest constraints on the timescale of accretion and core formation. These short‐ lived isotopes and dynamical models provide a mutually self‐consistent, albeit approximate, chronology. Terrestrial core formation took more than 30 Myr but less than about 200 Myr to complete.

Absolute transition frequencies of the $2s\text{ }{^{2}S}_{1/2}\ensuremath{\rightarrow}2p\text{ }{^{2}P}_{1/2,3/2}$ transitions in ${\mathrm{Be}}^{+}$ were measured for the isotopes $^{7,9--12}\mathrm{Be}$. The fine structure splitting of the $2p$ state and its isotope dependence are extracted and compared to results of ab initio calculations using explicitly correlated basis functions, including relativistic and quantum electrodynamics effects at the order of $m{\ensuremath{\alpha}}^{6}$ and $m{\ensuremath{\alpha}}^{7} \mathrm{ln} \ensuremath{\alpha} $. Accuracy has been improved in both the theory and experiment by 2 orders of magnitude, and good agreement is observed. This represents one of the most accurate tests of quantum electrodynamics for many-electron systems, being insensitive to nuclear uncertainties.

The most recent developments of fast tantalum foil targets for short-lived isotopes are described and the performance of the targets at ISOLDE with beams of 11 Li, 12 Be and 14 Be is given.

Recent experimental challenges to study the explosive hydrogen burning at extremely high temperatures are discussed. Along the nucleosynthetic pathway, discussions were made especially for the medium mass region, where we have possible waiting points and bottle necks which influence not only the light curve but also the production of heavy elements including the anomalously abundant p-nuclei at A = 80-100. Two approaches were discussed for the problem; one is the precision mass measurements and the other one is the half-live measurement of very short lived isotopes. A scope of the field is also discussed.

The only method for in vivo dose delivery verification in proton beam radiotherapy in clinical use today is positron emission tomography (PET) of the positron emitters produced in the patient during irradiation. PET imaging while the beam is on (so called beam-on PET) is an attractive option, providing the largest number of counts, the least biological washout and the fastest feedback. In this implementation, all nuclides, independent of their half-life, will contribute. As a first step towards assessing the relevance of short-lived nuclides (half-life shorter than that of (10)C, T1/2 = 19 s) for in vivo dose delivery verification using beam-on PET, we measured their production in the stopping of 55 MeV protons in water, carbon, phosphorus and calcium The most copiously produced short-lived nuclides and their production rates relative to the relevant long-lived nuclides are: (12)N (T1/2 = 11 ms) on carbon (9% of (11)C), (29)P (T1/2 = 4.1 s) on phosphorus (20% of (30)P) and (38m)K (T1/2 = 0.92 s) on calcium (113% of (38g)K). No short-lived nuclides are produced on oxygen. The number of decays integrated from the start of an irradiation as a function of time during the irradiation of PMMA and 4 tissue materials has been determined. For (carbon-rich) adipose tissue, (12)N dominates up to 70 s. On bone tissue, (12)N dominates over (15)O during the first 8-15 s (depending on carbon-to-oxygen ratio). The short-lived nuclides created on phosphorus and calcium provide 2.5 times more beam-on PET counts than the long-lived ones produced on these elements during a 70 s irradiation. From the estimated number of (12)N PET counts, we conclude that, for any tissue, (12)N PET imaging potentially provides equal to superior proton range information compared to prompt gamma imaging with an optimized knife-edge slit camera. The practical implementation of (12)N PET imaging is discussed.

We give an overview on the historical development and current program for lattice location studies at CERN’s ISOLDE facility, where the EC-SLI (Emission Channeling with Short-Lived Isotopes) collaboration maintains several setups for this type of experiments. We illustrate that the three most decisive factors for the success of the technique are access to facilities producing radioactive isotopes, position-sensitive detectors for the emitted decay particles, and reliable simulation codes which allow for quantitative analysis.

Cross-sections were measured at neutron energies from 13.6 to 14.9 MeV for the reactions 46 Ti(n,p) 46m Sc, 75 As(n,p) 75m Ge and 92 Mo(n,2n) 91m Mo leading to short-lived products. Corrections were made for the effects of gamma ray attenuation, coincidence summing, pulse pile-up, dead time, neutron flux fluctuations and scattered low energy neutrons. Statistical model calculations taking into account precompound effects were also performed.

We have studied the sorption of W on anion-exchange resins from HNO3/HF solutions under on-line conditions using continuous chromatography with the multi-column technique. Kd values and the charge of the W species were determined. In order to achieve an effective separation of mother (W) and daughter (Ta), also the sorption of Ta from HNO3/HF solutions on various anion exchange resins with different functional groups was studied. This investigation serves the purpose to select a suitable anion exchange resin for planned experiments with Sg.

This reprint of an article that first appeared in Nucleonics in 1966 provides a unique perspective of the introduction of the cyclotron into clinical medicine and medical research. The cyclotron offers a potentially powerful tool to biomedical centers. With this accelerator one can produce a variety of short-lived nuclides that are unavailable from other sources.

Trace amounts of lanthanum hexafluoroacetylacetonate and indium acetylacetonate were isolated by combination of methods, which includes synthesis of volatile elements β-diketonates by nucleophilic ligands exchange and fractional sublimation. This method is useful for produce isotope generators.

Some short-lived isotopes of Hf, Ta and W, synthesized at the U-400 cyclotron of JINR-Dubna, have been isolated using a previously elaborated fast continuous method of chemical isolation of element 104 from nuclear reaction products. The products were transported by a NaCl aerosol jet, from the irradiated targets to a separation device in which Hf, Ta and W were isolated by using three coupled ion-exchange columns.

International audience; Facilities reaccelerating radioactive ion beams face diverse technical challenges, from the production of radioactive isotopes to their post-acceleration. First operational at REX-ISOLDE, the charge state breeding in source of highly charged ions has become a key technique for optimizing the capabilities and performances of a post-accelerator. Charge state breeding in Electron Beam Ion Sources or Traps (EBIS/T) or in Electron Cyclotron Resonance Ion Sources (ECRIS) are techniques competing to reach high efficiencies, high charge states, and rapid charge breeding times. Beam purity, efficiency for light ions and short lived isotopes, duty cycles and time structures are still major issues being addressed very differently according to the type of charge breeder. The present performances and limitations for each charge breeder, and directions of the R&D pursued for different major projects are being discussed.

Fuels for future fast reactors will not only produce energy, but they must also actively contribute to the minimisation of long lived wastes produced by these, and other reactor systems. The fuels must incorporate minor actinides (MA = Np, Am, Cm) for neutron transmutation into short lived isotopes. Within Europe oxide fuels are favoured. Transmutation can be considered in homogeneous or heterogeneous reactor recycle modes (i.e. in fuels or targets, respectively). Fabrication of such fuels can be made by advanced liquid processing methods, enabling property determination and screening irradiation experiments. This paper will describe these fabrication processes, and discuss properties and fuel irradiation experiments made to date. Both fertile and inert matrix fuel types are considered., JRC.DG.E.4-Nuclear fuels

This paper proposes a method for estimating the detection limit, which is defined as 3.3 times the standard deviation (S.D.) of blank measurements under the situations where the repetition of measurement is difficult or impossible because of a short half-life of radioactivity. The FUMI theory, which can estimate an S.D. value without repetition in various instrumental analyses, is adopted and proved here to be available in a radio-HPLC system as well. (99m)Tc-ECD (T(1/2)=360.6 min) that is a lipophilic compound for the diagnosis of regional brain perfusion is taken as an example.

A methodology for the optimization of the counting times in a series of measurements of gamma-ray emitters in air filters is presented. In the optimal measurement regime in measurements of all the filters in a batch, the same minimum detectable activity is attained. It is shown how the number of filters, the properties of the gamma-ray emitter and the equipment influence the measurement time of the batch of filters and the minimum detectable activity attained.

A number of techniques have been developed to estimate time scales from magmatic rocks. The techniques may be usefully subdivided into those that yield absolute ages, as from short lived isotopes of the U-series, and those that yield relative ages. The latter include major and trace element profiles modified by diffusion, and they are calculated on the basis of how long individual crystals have been at magmatic temperatures as inferred from the mineralogy of the host rock. They have the advantage that individual rocks can be characterised in terms of the age profiles of their crystal populations. Age information can be obtained from crystals, the whole rocks and the groundmass, and each yield information on different aspects of the evolution of the magmatic system. They range from eruption ages, best determined on minerals from the groundmass, to the pre-eruption crystallisation history inferred from phenocrysts, the residence of magmas in the crust, and the time scales of magma differentiation. One way to assess the geological reliability of the calculated ages is to see if similar ages are obtained from other age dating systems. It is argued that if crystals are very young at the time of bulk rock crystallisation, there may have been insufficient time for fractional crystallisation to have taken place. The estimated time scales for magma differentiation range from 1000 years to 200,000 years, and if differentiation is linked to fractional crystallisation/crustal melting, it is likely to be thermally controlled. Longer time scales are inferred for magmas that crystallised deep in the crust, and there appear to be fewer evolved magmas in areas of high melt generation rates. It is less clear whether there is any link between different magma series and their time scales of differentiation.

Trapped protons are responsible for the main component of LEGRI background. Detailed theoretical model has demonstrated that the proton-induced counting rate is two orders of magnitude larger than the counting rate of the diffuse gamma-ray flux. The continuous passes of LEGRI through the SAA (7 times everyday) makes very difficult the background modelling. Long and short lived isotopes contribute in very different time scales to the proton-induced background component. The goal of this paper is to present a comparison between the long-lived background noise theoretical predictions and the experimental data. The results show an unexpected good agreement between the predicted and the observed counting rates.

The distribution of photosynthates in wheat plants was investigated using the 11C technique. Due to the short half-life (20.4 min) of the isotope and its penetrating radiation individual plants could be analysed several times. Wheat seedlings are known for a rapid export of freshly labelled photosynthates from leaves to roots. Early in the day up to 28 % of the 11C labeled compounds were transferred into the root system whereas in the afternoon only about 18 % of the photosynthetic products reached the roots. Wheat plants grown under 350 as well as 700 ppm CO2 responded immediately to ozone with a decline in transpiration. During 2 d of ozone treatment only little effect was observed on photosynthesis but plants under 350 ppm CO2 significantly reduced the carbon supply to the roots.

This article discusses whether the production of radioisotopes by high-intensity laser pulses is a breakthrough which will soon provide a cost-effective source of medically interesting nuclides or is merely a modest proof of principle without direct practical applications.

A program of simulation and optimization is developed for the case of cyclic activation analysis of short-lived isotopes with 14-MeV neutrons. The background line under the photopeaks of interest is simulated using Zikovsky’s model. The reliability of the program is checked on real conditions with a geological reference sample “Soil 5” provided by the IAEA. Optimum experimental conditions (timing parameters, number of cycles) are determined, and corresponding detection limits calculated. A systematic study of short-lived isotopes with half-lives lower than 5 min is done for Soil 5, and the results are discussed.

A survey of the target and ion-source techniques used at the ISOLDE (isotope separator on-line) facility for the production of short-lived mass-separated nuclei is given. The production of high-intensity beams of radioactive nuclei by bombardment of thick targets with 600-MeV protons or 910-MeV 3He is discussed. The release properties of various refractory target materials are presented, and the influence of reactive gases and the development of ion sources are considered. Results of on-line tests are given.

A rapid cost-effective instrumental neutron activation analysis method has been developed to characterize Egyptian ceramics. Using this approach, it is possible for one person to take representative samplings from 25 sherds, analyse them and tabulate the data within an 8 h working day. This in turn means that successive analytical samplings of available materials may be made on the basis of the suite of sherds already analysed. The efficacy of such an analytical procedure has been tested using a large number of sherds from the collection of the Egyptian Department of the Royal Ontario Museum. The results indicate that elements producing short-lived isotopes may be used to differentiate sherds made from Nile alluvium from sherds formed from chemically different clay sources and from mixtures of Nile alluvium and clays or other materials.

Cumulative yields of short-lived/barium isotopes139, 141, 142Ba have been determined in the spontaneous fission of252Cf, using fast radiochemical separation and gamma-ray spectrometry.142Ba yield is reported for the first time. The measured cumulative yields are converted to chain yields, assuming normal charge distribution systematics for comparision with the literature data.

The 228Th/228Ra activity ratio can provide a tool for age measurements of newly formed minerals, down to about 15 yr. A general discussion of the method is followed by an experimental check on an aphthitalite brine, crystallized from a geothermal well at Cesano (Rome) in July, 1978 (the real age is 85 ± 5 months). It yielded an age of 75 + 8/-5 months through alpha-spectrometry activity measurements, and 85 ± 3 months through gamma-spectrometry activity measurements. A residence time of the fluid in the rock ranging from 3 to 10 centuries has been estimated by comparing the Ra isotopic composition of the fluid with the U/Th ratio of the wall rocks, according to a model proposed by Cherdyntsev (1971).

A new technique for measuring local blood flow and distribution volume is proposed. The technique uses short-lived isotopes but is different from the equilibrium method in that no constant input is necessary, and no assumption about distribution volume is needed. The theoretical basis of the technique is developed, and the results of a computer-simulation study are presented to show the potential of the technique. The technique is expected to be easier to perform and to give more accurate flow values than the equilibrium method.

Recent developments in the technique of constant infusion and in emission computed tomography have provided a new method for quantitative regional flow measurements. This paper re-examines critically the theoretical relationship between flow and radioactivity during constant infusion of short-lived isotopes. Sensitivity analysis is used to assess the accuracy of the method. Criteria for the selection of an appropriate half-life to meet accuracy requirements are also discussed. A method for the determination of the distribution volume of the tracer is proposed.

Two relatively novel techniques that are utilized in the study of tissue distribution of drugs are discussed. The first technique, GC-MS fragmentography, provides an opportunity for the identification and quantification of several compounds and internal standards, in the same analysis, at picogram to nanogram amounts. The second technique utilizes short-lived radioisotopes and external scintigraphy. This approach can continuously monitor the tissue and organ distribution of an appropriately labeled compound. It produces quantifiable results and provides an opportunity for doing several experiments on the same animal in a noninvasive manner.

Presents a general formalism for evaluating dynamic parameters from equilibrium activity distributions of short-lived tracer. Specific examples for measuring CBF by using both constant and exponential infusions of tracer are worked out. Extension of the example to evaluating other dynamic parameters in the brain is also discussed.

Radio high pressure liquid chromatography (radio-HPLC) is the method of choice for quality control of radiopharmaceuticals labelled with short lived isotopes. Our preparations of “no carrier added”11C-labelled palmitic acid and L-methionine are both designed to end with a HPLC separation on either silica gel or C-18 reversed phase material. Since the crude reaction mixtures contain milligram amounts of inactive substrate materials, both separations must be carried out at preparative scale. Nevertheless they are performed in less than 10 min. The most critical factor for the separation of11C-palmitic acid from the main by-product pentadecane is the solvent composition: while the11C-L-methionine separation is especially sensitive to pH variations.

This brief description of cyclic activation analysis includes both a theoretical interpretation, by way of graphical representations and experimental considerations, for the determination of the concentration of elements by measurement of short-lived isotopes. Particular attention is given to the effect of sample transfer and the half-life of the background matrix. The use of a Ge(Li) detector and a low energy photon detector of intrinsic Ge, are also summarily discussed based on the experience of the authors' work in biological and environmental samples and the establishment of rapid, routine, multielemental and instrumental techniques.

The design and construction of an activation analysis system using an isotopic neutron source which allows the measurement of prompt and delay gamma-rays, in conventional activation and cyclic activation modes, is briefly described with emphasis laid on its flexibility, transportability and low cost. Photon spectra obtained from the irrdiation of large samples under prompt, delay and cyclic conditions using both NaI(Tl) and Ge(Li) detectors are presented and described with respect to ‘in-vivo’ neutron activation analysis and the measurement of N, O, Na, P, Cl and Cd. It is pointed out that, despite the attractive possiblity of measuring Se in liver, ‘in-vivo’, by cyclic activation analysis, the system may potentially prove a very useful tool for industrial and other non-medical applications.

A new type of activation analysis is reported for tungsten, gold, silver, selenium, hafnium, fluorine, and oxygen, making use of their 5- to 24- second isotopes for counting. The concept of the gamma -ray difference spectrum is applied to suppress longer-lived components in the gamma spectra of the activated samples. Analyses require less than 1/2 hour. As little as 1 ppm of hafnium can be detected. (auth)

For the angular correlation measurements on short-lived isotopes produced by (n, γ) reactions, a NaI(Tl)Ge(Li) angular correlation apparatus connected with on-line irradiation system has been developed. A counting-rate discriminator is used to get sources of the same initial strength and the amount of errors associated with this method is estimated. A multicounter goniometer has also been used in a similar on-line arrangement. Using these systems angular correlation measurements have been made on several short-lived isotopes. Details of the apparatus and some of the results obtained are presented.

An automatically controlled fast pneumatic transfer system is described using a rotating dual-sample irradiation assembly developed for use in activation analysis.