Alfred Priller

University of Vienna | UniWien · Fakultät für Physik

The detection of low abundances of $^{135}$Cs in environmental samples is of significant interest in different fields of environmental sciences, especially in combination with its shorter-lived sister isotope $^{137}$Cs. The method of Ion-Laser InterAction Mass Spectrometry (ILIAMS) for barium separation at the Vienna Environmental Research Acceler...

An advanced radio-frequency quadrupole (RFQ) ion cooler was developed for accelerator mass spectrometry to use element-selective laser photodetachment and ion-molecule reactions for isobar suppression. The system will be installed as a central part of the new Anion Laser Isobar Separator (ALIS) at the 6 MV AMS system of CologneAMS. The new RFQ desi...

Possible ion output enhancement for C⁻, C4⁻, Al⁻, AlO⁻, CaF3⁻ and SrF3⁻ by pulsed operation of an NEC-MC-SNICS II ion source under AMS-conditions has been investigated. The cathode voltage was switched periodically between −5.0 kV for regular sputtering and an idle value of −0.8 kV. With normal Cs-supply, all investigated species showed a peak ion...

Correction for ‘Novel ⁹⁰ Sr analysis of environmental samples by Ion-Laser InterAction Mass Spectrometry’ by Maki Honda et al. , Anal. Methods , 2022, 14 , 2732–2738, https://doi.org/10.1039/D2AY00604A.

The sensitive analysis of 90Sr with accelerator mass spectrometry (AMS) was developed to advance environmental radiology. One advantage of AMS is the ability to analyze environmental samples with 90Sr/88Sr atomic ratios of 10-14 in following a simple chemical separation. Three different IAEA samples with known 90Sr concentrations (moss-soil, animal...

A setup for ion-laser interaction was coupled to the state-of-the-art AMS facility VERA five years ago and its potential and applicability as a new means of isobar suppression in accelerator mass spectrometry (AMS) has since been explored. Laser photodetachment and molecular dissociation processes of anions provide unprecedented isobar suppression...

The reactions Li6,7+Al27 were compared with the reactions O17,18+O16 which form the same compound nuclei S33,34. Cross-section data for the reactions Li6,7+Al27 were derived from experimentally determined γ-ray production cross sections for transitions in several residual nuclei. For the reactions O17,18+O16 experimental results from the literature...

The method of Ion-Laser InterAction Mass Spectrometry (ILIAMS) offers new options for the determination of ²⁶Al by Accelerator Mass Spectrometry (AMS) and improves the sensitivity and efficiency for the detection of this isotope in artificial and environmental samples. In ILIAMS, a laser is overlapped with the ion beam during its passage through a...

The long-lived radioisotope ¹⁸² Hf (T 1/2 = 8.9 Ma) is of high astrophysical interest as its potential abundance in environmental archives would provide insight into recent r-process nucleosynthesis in the vicinity of our solar system. Despite substantial efforts, it could not be measured at natural abundances with conventional AMS so far due to st...

Interest in the long-lived radioisotope ²³⁶U (T1/2 = 23.4 million years) has significantly increased recently due to the emergence of environmental and earth science applications. Compared to the previous setup at VERA, which was based on oxygen stripping and a time-of-flight detector, we have improved the sensitivity of VERA by more than an order...

The experimental setup at the Vienna Environmental Research Accelerator (VERA) was extended with an ion beam cooler and a 18 W laser to perform Ion-Laser InterAction Mass Spectrometry (ILIAMS). Gas collisions of the decelerated negative ion beam with He buffer gas inside a radio-frequency quadrupole slow down the ions, which facilitates element sel...

Natural ¹⁰Be (t1/2 = 1.387 ± 0.012 Ma) is produced by cosmic rays and is present on Earth's surface only at ultratrace concentrations (typically 10⁴ to 10¹⁰ atoms/g). Its cosmogenic origin makes it an important tracer for many applications in Earth and environmental sciences. An improved accelerator mass spectrometry (AMS) method has been developed...

Selective laser photodetachment of anions is a novel technique for isobar suppression in Accelerator Mass Spectrometry (AMS). Ion-laser interaction times on the order of ms required for near-complete isobar suppression are achieved by retarding the ions in a gas-filled radio frequency quadrupole cooler. Inside this RFQ, the cooled anion beam is ove...

The neutron capture cross section of Be9 for stellar energies was measured via the activation technique using the Karlsruhe Van de Graaff accelerator in combination with accelerator mass spectrometry at the Vienna Environmental Research Accelerator. To characterize the energy region of interest for astrophysical applications, activations were perfo...

Accelerator mass spectrometry (AMS) represents a complementary approach for precise measurements of neutron capture cross sections, e.g., for nuclear astrophysics. This technique, completely independent of previous experimental methods, was applied for the measurement of the Fe54(n,γ)Fe55 reaction. Following a series of irradiations with neutrons f...

The Ion Laser InterAction Setup (ILIAS) project at the University of Vienna aims at the exploration of negative ion beam filtering by selective laser photodetachment for applications in accelerator mass spectrometry (AMS). A gas-filled radio frequency quadrupole (RFQ) is used to decelerate and cool negative atomic and molecular ion beams with inten...

The detection of long-lived radionuclides through ultra-sensitive single atom counting via accelerator mass spectrometry (AMS) offers opportunities for precise measurements of neutron capture cross sections, e.g. for nuclear astrophysics. The technique represents a truly complementary approach, completely independent of previous experimental method...

Very sensitive methods, presently mainly accelerator mass spectrometry (AMS) are necessary for analysis of cosmogenic 10Be in the environment. AMS is mainly limited by the stable isobar 10B, while the requirements for mass separation are the least stringent of all standard isotopes analyzed by AMS. We tested a possibility to measure 10Be using a sm...

Interest in the long-lived radioisotope 236U (t1/2 = 23.4 million years) has significantly increased recently, due to the emergence of environmental and earth science applications. Presently, only a few (AMS) accelerator mass spectrometry instruments are suited for this measurement. One major limitation is the relatively low total detection efficie...

93Zr with a half-life of 1.6 Ma is produced with high yield in nuclear fission, and thus should be present as a natural or anthropogenic trace isotope in all compartments of the general environment. Sensitive measurements of this isotope would immediately find numerous applications, however, its detection at sufficiently low levels has not yet been...

Laser photodetachment is the process when the extra electron of a negative ion is removed by means of laser radiation. This can happen only if the photon energy is larger than the electron affinity of the ion. The process can be used in mass spectrometry to selectively suppress unwanted isobars, provided that the electron affinity of the unwanted i...

Radioisotopes produced in natural or anthropogenic fission are widely used for tracer studies of environmental processes, in nuclear forensics, and are important for nuclear waste disposal. Besides the well-known 137Cs, the longer-lived sister isotope 135Cs (T1/2 = 2.3 Myr) is also produced, and the combined measurement of the two isotopes would al...

A Centre for Nuclear and Accelerator Technologies (CENTA) has been established at the Comenius University in Bratislava comprising of a tandem laboratory designed for Ion Beam Analysis (IBA), Ion Beam Modification (IBM) of materials and Accelerator Mass Spectrometry (AMS). The main equipment of the laboratory, i.e. Alphatross and MC-SNICS ion sourc...

The present article reports on the results and interpretation of a total of 235 radiocarbon dates from Alpine sites in the Ötztal region. Out of these, 88 age determinations were performed on equipment and artifacts associated with the Neolithic Iceman (discovered in 1991), and on a variety of plant and animal specimens collected at his discovery s...

The requirements of extracting minute amounts of organic carbon in solution with high yield and minimum background are a prerequisite for radiocarbon dating of microgram amounts of carbon. Samples for biomedical or environmental research often arrive at the accelerator mass spectrometry (AMS) lab as concentrates dissolved in 1 mL of water or less....

VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure (239)Pu, (240)Pu, (241)Pu, (242)Pu and (244)Pu on the same AMS spu...

Recent progress with compact ionization chambers has opened new possibilities for isobar suppression in accelerator mass spectrometry (AMS). Separation of 36Cl (t1/2 = 0.30 Ma) at natural isotopic levels from its stable isobar 36S became feasible at particle energies of 24 MeV, which are also accessible for medium-sized tandem accelerators with 3 M...

For 14C AMS measurements of samples at the microgram level, ion source related effects start to play a role, while generally the lower sample size limit is set by the carbon background introduced during chemical preparation procedures. Measurements of about 800 graphite targets in the mass range of 1–100 μg were performed within 25 AMS beam-times d...

Isobaric interference represents one of the major limitations in mass spectrometry. For a few cases in AMS with tandem accelerators, isobaric interference is completely excluded like the well-known major isotopes 14C, 26Al, 129I. Additional isotopes are 55Fe (t1/2 = 2.74 years), 68Ge (t1/2 = 270.9 days) and 202Pb (t1/2 = 52.5 kyr), with 68Ge and 20...

To unravel the mechanisms of ion formation in the Middleton type cesium sputter negative ion source, we have acquired and analyzed the spectrum of the light emitted from the source region during sputtering of three different cathode materials; carbon, aluminum and copper. All cathodes were analyzed under the same source settings but with different...

Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued pr...

Isobaric interference represents one of the major limitations in mass spectrometry. For a few cases in AMS with tandem accelerators, isobaric interference is completely excluded like the well-known major isotopes 14 C, 26 Al, 129 I. Additional isotopes are 55 Fe (t 1/2 = 2.74 years), 68 Ge (t 1/2 = 270.9 days) and 202 Pb (t 1/2 = 52.5 kyr), with 68...

The requirements of extracting minute amounts of organic carbon in solution with high yield and minimum background are a prerequisite for radiocarbon dating of microgram amounts of carbon. Samples for biomedical or environmental research often arrive at the accelerator mass spectrometry (AMS) lab as concentrates dissolved in 1 mL of water or less....

We summarize some recent cross-section measurements using accelerator mass spectrometry (AMS). AMS represents an ultra-sensitive technique for measuring a limited, but steadily increasing number of longer-lived radionuclides. This method implies a two-step procedure with sample activation and subsequent AMS measurement. Applications include nuclear...

Concentrations of gases and particulate matter have been proven to be affected by meteorological and geographical variables from urban locations to high mountain clean air sites. Following our previous research in Vienna, we summarize here new findings about concentration levels of iodine isotopes in aerosols collected at two Alpine meteorological...

New techniques for suppression of atomic isobars in negative ion beams are of great interest for accelerator mass spectrometry (AMS). Especially small and medium-sized facilities can significantly extend their measurement capabilities to new interesting isotopes with a technique independent of terminal voltage. In a new approach, the effect of cont...

Accelerator mass spectrometry (AMS) of 36Cl (t1/2=0.30Ma) at natural isotopic concentrations requires high particle energies for the separation from the stable isobar 36S and was so far the exclusive domain of tandem accelerators with at least 5MV terminal voltage. Using terminal foil stripping and a detection setup consisting of a split-anode ioni...

The radioisotope 182Hf (t1/2=8.9Ma) is of great interest for astrophysical applications as a chronometer for the early solar system or as possible live supernova remnant on earth. However, AMS measurements of 182Hf are seriously influenced by the presence of the stable isobar 182W, which cannot be separated at typical AMS energies. Previous studies...

The aim of our study is to determine excitation functions for the formation of different reaction products with light ions near the Coulomb barrier and to compare the results with computations according to different reaction mechanisms (compound reactions, direct reactions). In the present study results from experiments with a beam of 9Be on a thin...

Theoretical models of superheavy elements (SHEs) predict a region of increased stability around the proton and neutron shell closures of Z = 114 and N = 184. Therefore a sensitive search for nuclides in the mass range from A = 288 to A = 300 was performed in natural platinum, lead, and bismuth, covering long-lived isotopes of Eka-Pt (Ds, Z = 110),...

A sensitive search for isotopes of a superheavy element (SHE) in natural gold materials has been performed with accelerator mass spectrometry at the Vienna Environmental Research Accelerator, which is based on a 3-MV tandem accelerator. Because the most likely SHE in gold is roentgenium (Rg, Z = 111), the search concentrated on Rg isotopes. Two dif...

The possibility of detecting 36Cl for geological exposure dating has been explored for several years at VERA (the Vienna Environmental Research Accelerator). First results on real samples were obtained with an ionization chamber (developed at the ETH/PSI, Zürich, Switzerland) with two anodes. To improve the suppression of 36S, we equipped the ioniz...

A growing number of AMS laboratories are pursuing applications of actinides. We discuss the basic requirements of the AMS technique of heavy (i.e., above ∼150 amu) isotopes, present the setup at the Vienna Environmental Research Accelerator (VERA) which is especially well suited for the isotope 236U, and give a comparison with other AMS facilities....

In the search for long-lived superheavy elements (SHEs) in nature the claim for the detection of a SHE species with A = 292 in a commercially available thorium solution at an abundance of (1-10) x 10(-12) relative to (232)Th using ICP-SFMS has been raised very recently by Marinov et al. The same group also claimed the finding of four long-lived iso...

VERA has been operated for 12 years with one 40-cathode SNICS ion source. Since the number of isotopes investigated at VERA increased steadily, we decided to install a second ion source. Due to space restrictions, a new injection line had to be built and merged into the existing one. The major task was to build an electrostatic analyzer assembly to...

(36)Cl AMS measurements at natural isotopic concentrations have yet been performed only at tandem accelerators with 5 MV terminal voltage or beyond. We have developed a method to detect (36)Cl at natural terrestrial isotopic concentrations with a 3-MV system, operated above specifications at 3.5 MV. An effective separation was obtained with an opti...

Recent improvements in isobaric suppression for medium-mass isotopes, e.g. 41Ca, offer new possibilities for tandem accelerators with terminal voltages of 3MV or lower; i.e. when dealing with particle energies ⩽1MeV/amu. In particular, detection of 41Ca requires sufficient discrimination of the stable isobar 41K. We explored the limits of 41Ca dete...

Efforts to extract weak geomagnetic excursion signals from Chinese loess-paleosol 10Be have generally been unsuccessful due to the complexities of its accumulation, because the geomagnetic and climate (precipitation and dust) sig-nals contained in loess-paleosol sequence are tightly overprinted. Here, we present a reconstruction of geomagnetic rela...

The measurement of cross sections relevant to nuclear astrophysics has become one main research topic at the VERA (Vienna Environmental Research Accelerator) facility. The technique applied, accelerator mass spectrometry (AMS), offers excellent sensitivity for the detection of long-lived radionuclides through ultra-low isotope ratio measurements. W...

Recent improvements in isobaric suppression for medium-mass isotopes, e.g. (41)Ca, offer new possibilities for tandem accelerators with terminal voltages of 3 MV or lower; i.e. when dealing with particle energies <= 1 MeV/amu. In particular, detection of (41)Ca requires sufficient discrimination of the stable isobar (41)K. We explored the limits of...

Efforts to extract weak geomagnetic excursion signals from Chinese loess-paleosol 10 Be have generally been unsuccessful due to the complexities of its accumulation, because the geomagnetic and climate (precipitation and dust) signals contained in loess-paleosol sequence are tightly overprinted. Here, we present a reconstruction of geomagnetic rela...

Chinese loess is well-known archive for the paleogeomagnetic and paleoclimatic studies [Zhou et al., 1990; An et al., 1990; Zhu et al., 2007]. However, earlier efforts to extract weak geomagnetic excursion signals from Chinese loess 10Be were always unsuccessful due to the complexities of loess 10Be, which results in the fact that loess 10Be was on...

The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E=0.1–1 MeV / amu , commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T∼1.5 K . They were irradia...

Cosmogenic radionuclides in the one-million-year half-life range offer unique possibilities for age determinations in geophysics. In measurements where the radioactive decay is being utilized as a clock, uncertainties in age determinations may be reduced if the ratio of two radioisotopes with different half-lives can be used as a chronometer. In th...

The stellar (n,gamma) cross section of Ca-40 at kT=25 keV has been measured with a combination of the activation technique and accelerator mass spectrometry (AMS). This combination is required when direct off-line counting of the produced activity is compromised by the long half-life and/or missing gamma-ray transitions. The neutron activations wer...

We are investigating the possibility of using laser photodetachment of negative atomic and molecular ions as an additional isobaric selection filter in accelerator mass spectrometry. The aim of this study is to find a possibility to further improve the detection limit for long-lived heavy radionuclides at AMS facilities. We will focus on the astrop...

The small doubly-charged molecular anion SiF62− was studied by two distinct approaches, one experimental the other theoretical. The dianion was produced in the gas phase by sputtering a Li2SiF6 specimen with Cs+ ions and was detected by means of accelerator mass spectrometry. The identification was via the 29Si19F62− isotopomer; it has an odd total...

Silverpoint drawings from the Renaissance are among the most precious and rarest treasures of graphical art. Our research group is particularly interested in the analysis of silverpoint drawings by Albrecht Dürer (1471–1528). A very sensitive and non-destructive analytical method, either spatially resolved synchrotron-radiation induced X-ray fluore...

The interaction of thermal neutrons with 235U results in fission with a probability of ∼85% and in the formation of 236U (t1/2 = 2.3 × 107 yr) with a probability of ∼15%. While anthropogenic 236U is, therefore, present in spent nuclear fuel at levels of 236U/U up to 10−2, the expected natural ratios in the pre-anthropogenic environment range from 1...

The increasing demand for measuring long-lived radionuclides with small AMS machines at energies below 1 MeV per nucleon raises the need for compact detectors which still have a decent energy resolution and allow for a clear identification of the incident particles. Based on a design by the AMS group at the ETH Zurich a compact gas ionization chamb...

We started a series of experiments, aiming at obtaining neutron-capture cross sections from measurements of the production of both long-lived nuclides (10)Be and (14)C, in the energy region of interest for astrophysical applications. Neutronrich scenarios lead to the production of the long-lived radionuclides (10)Be (t(1/2) = 1.51 Myr) and (14)C(t(...

Xinzhai is an important archaeological site discovered 40 yr ago and recently re-excavated in the Henan Prov- ince, China. It is believed that the cultural characteristics of the Xinzhai site correspond to the Xia dynasty, the first ancient dynasty of China. Radiocarbon measurements on bone samples from this site were performed at the Peking Univer...

We started a series of experiments, aiming at obtaining neutron-capture cross sections from measurements of the production of both long-lived nuclides 10Be and 14C, in the energy region of interest for astrophysical applications. Neutron-rich scenarios lead to the production of the long-lived radionuclides 10Be (t1/2 = 1.51 Myr) and 14C (t1/2 = 573...

We demonstrate a new method to derive quantitative paleo-rainfall estimates for continental interior regions using 10Be in loess. We apply this technique to derive an 80,000 year long rainfall record from the Chinese Loess Plateau. The key steps in this technique are to account for variations in 10Be flux that are due to magnetic field modulation o...

“The techniques and equipment developed for AMS studies are well suited for identifying exotic negative ions”. With this sentence begins a pioneering paper by Roy Middleton and Jeff Klein (M&K) on small doubly-charged negative carbon clusters [Nucl. Instr. and Meth. B 123 (1997) 532]. M&K were the first to utilize Accelerator Mass Spectrometry to p...

The potential for measuring the radionuclides 41Ca and 55Fe was investigated with the 3 MV tandem accelerator at VERA. Interestingly, up to now, no applications have been published for 55Fe using the technique of AMS. This is in strong contrast to 41Ca, which is routinely measured by medium and large tandem accelerators in various applications. Usi...

The measurement of the paired cosmogenic radionuclides 26Al and 10Be in environmental samples has potential applications in atmospheric and climate research. For this study, we report the first measurements of the 26Al/10Be atomic ratio in tropospheric aerosol samples from sites in Europe and Antarctica performed at the Vienna Environmental Researc...

This paper describes various modifications implemented at the 40-samples MC-SNICS Cs sputter source used at VERA. The pneumatic sample changer was replaced with a stepper motor drive, and also the adjustment collar for the vertical target wheel position was motorized. These two modifications allow now an automatic scanning of the target position wi...

Equipment for automated phase–space measurements was developed at the VERA Lab. The measurement of the beam’s intensity distribution, as well as its relative position with respect to the reference orbit is performed at two locations along the beam line. The device basically consists of moveable slits and a beam profile monitor, which are both coord...

The cosmogenic radionuclide 10 Be is produced by cosmic-ray spallation in Earth's atmosphere. Its production rate is regulated by the geomagnetic field intensity, so that its accumulation rate in aeolian sediments can, in principle, be used to derive high-resolution records of geomagnetic field changes. However, 10 Be atmospheric fallout rate also...

Well-established data on production-rates of long-lived radionuclides are important for the understanding and calculation of various nucleosynthesis processes. However, lack of information exists for a list of nuclides as pointed out by nuclear-data requests. In addition, the search for supernova (SN)-produced radionuclides will give an improved in...

With the Vienna Environmental Research Accelerator (VERA, based on a 3-MV tandem accelerator) we have systematically explored the limitations due to terminal voltage, both by modelling and by experiments. If no stable atomic isobars exist, e.g. for 236U or 244Pu, the same detection limits as for large machines have been achieved. In cases where iso...

The use of tandem accelerators for accelerator mass spectrometry (AMS) allows to literally "analyze" molecules. When a molecular ion with mass M and charge Q is injected at the low-energy side, it is efficiently broken up into its atomic constituents during the stripping process in the terminal. At the high-energy side the positively charged atomic...

The ΔTOF detector is a new approach for isobar separation at energies below 1MeV/amu. The specific energy loss after a degrader foil can be measured very precisely with time-of-flight (TOF). Small differences in the specific energy loss between isobars lead to clear separation even at low energies. The resolution is not deteriorated by angular scat...

A novel method to determine small cross-sections of nuclear reactions of astrophysical interest was implemented at the Vienna Environmental Research Accelerator laboratory (VERA). This method combines inverse-kinematics reactions taking place inside the stripper of a tandem accelerator with the identification of the recoil products using the accele...

(182)Hf is a so-called "extinct" radionuclide interesting for both geophysical and astrophysical studies. The discovery of live (182)Hf in the early solar system through isotopic anomalies of stable (182)W in meteorites opened up an important application as a chronometer for the formation of the Earth and Moon. In addition, (182)Hf plays an importa...

182Hf is a so-called "extinct" radionuclide interesting for both geophysical and astrophysical studies. The discovery of live 182Hf in the early solar system through isotopic anomalies of stable 182W in meteorites opened up an important application as a chronometer for the formation of the Earth and Moon. In addition, 182Hf plays an important role...

The existence of (metastable) molecular hydrogen anions H2(-), D2(-), and H3(-) is demonstrated. These anion species were produced by sputtering of TiH2 and TiD2 targets with Cs+ ions and were identified by accelerator mass spectrometry. From the respective flight times through the spectrometer, lifetimes for H2(-) and D2(-) of at least 3 micros an...

Accelerator mass spectrometry (AMS) represents a powerful technique for the detection of long-lived radionuclides through ultra-low isotope ratio measurements. In many cases, counting atoms rather than decays yields much higher sensitivities. The potential of AMS will be demonstrated on typical radionuclides of interest with half-lives between some...

A novel method to determine small cross-sections of nuclear reactions of astrophysical interest was implemented at the Vienna Environmental Research Accelerator laboratory (VERA). This method combines inverse-kinematics reactions taking place inside the stripper of a tandem accelerator with the identification of the recoil products using the accele...

In the framework EU Project STACCATO (Influence of Stratosphere–Troposphere Exchange in A Changing Climate on Atmospheric Transport and Oxidation Capacity), the first long-term, simultaneous monitoring of the two cosmogenic radionuclides 7Be and 10Be was performed. Emphasis was paid to a high-resolution record of the data, too. A comprehensive data...

The neutron-rich isotope 182Hf with its half-life of 9 ± 2 million years was alive in the early solar system and has been used to study the early development of the Earth and the Moon through isotopic anomalies of its stable decay product 182W. In addition, 182Hf may also complement a few other radionuclides in the million-year half-life range to t...