To enhance the quality of pulsed cold ion beams extracted from the two cryogenic stopping cells at FAIR (i.e., the one currently used in the FRS and the one under development for the Super-FRS at FAIR), we propose using a novel gas-dynamic ion beam extraction and bunching technique as an alternative to the radiofrequency quadrupole (RFQ) method. This technique allows for 100

In this article, we propose a new gas-dynamic ion beam cooler-buncher for the FAIR Laspec and MATS experiments. This very compact and having a simple design gas-dynamic cooler-buncher has a length of just 105 mm. It can convert continuous ion beams of various masses and with a transmission efficiency of around 100% into pulsed, high-quality ion beams. The special design of the supersonic nozzle and the RF-only funnel enables sufficient buffer gas (helium) thickness for effective ion beam cooling with an injection energy of up to several keV, without compromising the high vacuum in the other parts of the setup. The beams with a longitudinal emittance of down to 10 eV ns will be available. This emittance value is 20 times superior to the best current RFQ cooler-bunchers can deliver. We explored the operation of the proposed new gas-dynamic cooler-buncher by conducting detailed gas-dynamic and Monte Carlo ion-trajectory simulations. The results of these simulations are presented and discussed.

We have measured transition frequencies, isotope shifts, and hyperfine-structure splittings in the 3d2(3F)4s4FJ -> 3d2(3F)4p4GoJ+1 transitions in stable Ti+ ions for J = 32, 52, 72 using collinear laser spectroscopy. Ions were generated by laser ablation in a buffer-gas atmosphere and extracted into vacuum through a nozzle and a pair of radio-frequency funnels. The results obtained are of interest as reference values for on-line measurements of short-lived titanium isotopes and for astrophysical searches for temporal or spatial variations of the fine-structure constant alpha using quasar absorption spectra.

Neutrinoless double beta decay (0νββ) provides a way to probe physics beyond the Standard Model of particle physics. The upcoming nEXO experiment will search for 0νββ decay in ^136Xe with a projected half-life sensitivity exceeding 10^28 years at the 90% confidence level using a liquid xenon (LXe) Time Projection Chamber (TPC) filled with 5 tonnes of Xe enriched to ∼90% in the ββ-decaying isotope ^136Xe. In parallel, a potential future upgrade to nEXO is being investigated with the aim to further suppress radioactive backgrounds and to confirm ββ-decay events. This technique, known as Ba-tagging, comprises extracting and identifying the ββ-decay daughter ^136Ba ion. One tagging approach being pursued involves extracting a small volume of LXe in the vicinity of a potential ββ-decay using a capillary tube and facilitating a liquid-to-gas phase transition by heating the capillary exit. The Ba ion is then separated from the accompanying Xe gas using a radio-frequency (RF) carpet and RF funnel, conclusively identifying the ion as ^136Ba via laser-fluorescence spectroscopy and mass spectrometry. Simultaneously, an accelerator-driven Ba ion source is being developed to validate and optimize this technique. The motivation for the project, the development of the different aspects, along with the current status and results, are discussed here.

This study is a further development of our “Proposal of a new double-nozzle technique for in-gas-jet laser resonance ionization spectroscopy” paper published in the journal Atoms earlier this year. Here, we propose equipping the double-nozzle technique with the RF-only funnel and RF-buncher placed in a gas-jet chamber at a 70 mm distance downstream of the double-nozzle exit. It allows for highly effective extraction into vacuum heavy ion beams, produced in two-steps laser resonance ionization in the argon supersonic jet. We explored the operation of this new full version of the double-nozzle technique through detailed gas dynamic and Monte Carlo trajectory simulations, with the results presented and discussed. In particular, our calculations showed that more than 80% of all nobelium-254 neutral atoms, extracted by argon flow from the gas-stopping cell, can then be extracted into vacuum in a form of pulsed ion beam having low transverse and longitudinal emittance.

This paper reviews the development and present status of a novel gas dynamic RF-only funnel technique for low-energy ion beam extraction into vacuum. This simple and original technique allows for the production of high-quality continuous and pulsed ion beams in a wide range of masses, which have a very small transverse and longitudinal emittance.

This paper proposes a new double-nozzle technique for in-gas-jet laser resonance ionization spectroscopy. We explored the functionality of this new technique through detailed gas dynamic and Monte Carlo atom-trajectory simulations, in which results are presented and discussed. The results of similar computer simulations for JetRIS setup (as a typical representative of the conventional in-gas-jet technique nowadays) are also presented and discussed. The direct comparison of calculation results for the proposed new technique with the conventional one shows that the double-nozzle technique has many advantages compared with the one used in the JetRIS setup at GSI for future high-resolution laser spectroscopic study of heaviest elements. To fully implement the proposed new technique in all existing (or under construction) setups for in-gas-jet laser resonance ionization spectroscopy, it will be enough to replace the used supersonic nozzle with the miniature double-nozzle device described in the paper.

Here we propose a simple way in which one can considerably improve performance of the gas stripper setup at the GSI UNILAC. To do so, it will be enough to replace inside the main GSI stripper chamber the present nozzle and the short windowless storage gas cell (for pulsed gas-jet operation mode) by a simple conical diverging nozzle combined with a gas catcher tube placed on the axis of gas-jet at some distance downstream the nozzle exit. As a result, the background pressure in the main and differentially pumped adjacent vacuum chambers of the gas stripper at the GSI UNILAC will dramatically reduce, and it will make possible to achieve the required optimal thickness of gas targets. The pulsed gas stripper operation is simply realized by implementing a commercially available fast gas valve connected to the nozzle entrance. Moreover, the ion beam pulses repetition rate can be increased and it will allow for the considerably higher average intensity of the ion beams extracted from the GSI UNILAC. Performance of the proposed GSI UNILAC gas stripper modification we explored by means of detailed computer experiments, which give a realistic description of supersonic gas jets flowing out the nozzle into vacuum. Results of these computer experiments have presented and discussed.

PANDA (anti-Proton ANnihiliation at DArmstadt) is planned to be one of the four main experiments at the future international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is going to address fundamental questions of hadron physics and quantum chromodynamics using cooled antiproton beams with a high intensity and and momenta between 1.5 and 15 GeV/c. PANDA is designed to reach a maximum luminosity of 2x10^32 cm^2 s. Most of the physics programs require an excellent particle identification (PID). The PID of hadronic states at the forward endcap of the target spectrometer will be done by a fast and compact Cherenkov detector that uses the detection of internally reflected Cherenkov light (DIRC) principle. It is designed to cover the polar angle range from 5{\deg} to 22{\deg} and to provide a separation power for the separation of charged pions and kaons up to 3 standard deviations (s.d.) for particle momenta up to 4 GeV/c in order to cover the important particle phase space. This document describes the technical design and the expected performance of the novel PANDA Disc DIRC detector that has not been used in any other high energy physics experiment (HEP) before. The performance has been studied with Monte-Carlo simulations and various beam tests at DESY and CERN. The final design meets all PANDA requirements and guarantees suffcient safety margins.

AbstractThe antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: $${\bar{p}}p \rightarrow {\bar{\varLambda }}\varLambda $$ p ¯ p → Λ ¯ Λ and $${\bar{p}}p \rightarrow {\bar{\varXi }}^+\varXi ^-$$ p ¯ p → Ξ ¯ + Ξ - . The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N^* and spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N^* and spectra. The future antiproton experiment P ANDA will provide direct access to final states containing a pair, for which production cross sections up to μ b are expected in p̅ p reactions. With a luminosity of L=10^31 cm ^-2 s ^-1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼ 10^6 events /day . With a nearly 4π detector acceptance, P ANDA will thus be a hyperon factory. In this study, reactions of the type p̅ p → ^+ ^*- as well as p̅ p → ^*+ ^- with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5

The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: $${\bar{p}}p \rightarrow {\bar{\varLambda }}\varLambda $$ p ¯ p → Λ ¯ Λ and $${\bar{p}}p \rightarrow {\bar{\varXi }}^+\varXi ^-$$ p ¯ p → Ξ ¯ + Ξ - . The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or PANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton-nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper.

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards $$N^*$$ and $$\varDelta $$ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the $$N^*$$ and $$\varDelta $$ spectra. The future antiproton experiment $$\overline{\text{ P }}$$ ANDA will provide direct access to final states containing a $${\overline{\varXi }}\varXi $$ pair, for which production cross sections up to $$\mu \text{ b }$$ are expected in $$\bar{\text{ p }}$$ p reactions. With a luminosity of $$L=10^{31}$$ cm $$^{-2}$$ s $$^{-1}$$ in the first phase of the experiment, the expected cross sections correspond to a production rate of $$\sim 10^6\, \text{ events }/\text{day }$$ . With a nearly $$4\pi $$ detector acceptance, $$\overline{\text{ P }}$$ ANDA will thus be a hyperon factory. In this study, reactions of the type $$\bar{\text{ p }}$$ p $$\rightarrow $$ $${\overline{\varXi }}^{+}$$ $$\varXi ^{*-}$$ as well as $$\bar{\text{ p }}$$ p $$\rightarrow $$ $${\overline{\varXi }}^{*+}$$ $$\varXi ^{-}$$ with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.

The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: $${\bar{p}}p \rightarrow {\bar{\varLambda }}\varLambda $$ and $${\bar{p}}p \rightarrow {\bar{\varXi }}^+\varXi ^-$$ . The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.

A novel UniCell setup for studies of superheavy elements (SHE) was proposed recently. Here we deploy the concept of the so called "Fair-wind gas cell" and suggest a new buffer gas stopping cell, that may serve as an optional main part of the UniCell setup. Advantages of this new optional gas cell compared to the previous version for the UniCell setup consists in the use of an intense compulsory buffer gas flow, as a driving force for ion transport through the high-density gas stopping cell, combined with an RF-only funnel. This allows a fast and highly efficient extraction of ions from the gas stopping cell without application of traditional DC gradient fields. For the reduction of the pure buffer gas consumption the intense flow is recirculating in a loop. The functionality of the proposed new gas stopping cell was explored by detailed gas dynamic and Monte Carlo ion-trajectory simulations, the results of which are presented and discussed. They demonstrate the feasibility of the fair-wind gas stopping cell for the application in SHE research.

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, $$|G_{E}|$$ | G E | and $$|G_{M}|$$ | G M | , using the $$\bar{p} p \rightarrow \mu ^{+} \mu ^{-}$$ p ¯ p → μ + μ - reaction at $$\overline{\text {P}}\text {ANDA}$$ P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at $$\overline{\text {P}}\text {ANDA}$$ P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is $$\bar{p} p \rightarrow \pi ^{+} \pi ^{-}$$ p ¯ p → π + π - , due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N ∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N ∗ and Δ spectra. The future antiproton experiment PANDA will provide direct access to final states containing a ΞΞ pair, for which production cross sections up to μ b are expected in ¯ pp reactions. With a luminosity of L = 10 31 cm − 2 s − 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼ 10 6 events / day. With a nearly 4 π detector acceptance, PANDA will thus be a hyperon factory. In this study, reactions of the type ¯ pp → Ξ + Ξ ∗− as well as ¯ pp → Ξ ∗+ Ξ − with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, vertical bar G(E)vertical bar and vertical bar G(M)vertical bar, using the (p) over barp -> mu(+)mu(-) reaction at PANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at PANDA, using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is (p) over barp -> pi(+)pi(-), due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.

Laser ablation opens a material-independent method to produce ions from transition metals for laser spectroscopy. To overcome some drawbacks of this process, an ion source is under development at TU Darmstadt. A distinctive feature of this source is that ions are produced via laser ablation in presence of helium buffer gas where they stop and cool in the process of their collisions with the buffer gas atoms and are then extracted by the gas flow into low-pressure conditions through the supersonic nozzle. The compact RF-only funnel ion guide placed on the axis behind the nozzle exit allows for effective extraction of high-quality ion beams into a pressure region below 10 − 4 mbar. The extraction is realized by using the gas flow trough a supersonic nozzle and an RF-only funnel ion guide, followed by a second nozzle and an RF+DC funnel representing two differential pumping stages. The technical details of this laser ablation ion source are described and the results of the first tests with the RF-only funnel are presented.