Topical Workshop - Low energy facility design and optimization through diagnostics

5 Feb 2019, 18:00 → 7 Feb 2019, 17:00 Europe/Zurich

KBW lecture hall (GSI)

ESR magnet © GSI, A. Zschau

This two-day workshop on the design and optimization of low energy ion and antiproton facilities will focus on how cutting edge diagnostics help improve machine and experiment performance.

We will discuss the performance limits of the latest low energy diagnostics, as well as how their readout can be used for beam dynamics simulation purposes, as well as for an efficient control of the accelerator and experiments. 

This event will combine talks by research leaders, with opportunities for early stage researchers to present their work and panel discussions. 

This event is open to any researcher working in this field. Contributed talks of 15 or 30 minutes will be selected from all submitted contributions.

Registration deadline: 11th January 2019

Abstract submission deadline: 11th January 2019 

Payment deadline: 11th January 2019

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 721559.

 

Information AVA-TW-GSI-Practical-Information.pdf

Poster AVA Poster Topical Workshop.pdf

Tuesday 5 February

20:00 Reception

Wednesday 6 February

08:30 Registration - please collect visitor ID at GSI front gate

1 Welcome / admin & logistics

Speakers: Wolfgang Quint (GSI), Zuzana Oriou (University of Liverpool)

Session 1: Low energy facilities and their design optimization

2 Operational aspects of ELENA and AD commissioning

Speaker: Davide Gamba (CERN)

AVA-TopicalWorkshop-AD_ELENA.pptx

AVA-TopicalWorkshop-AD_ELENA-v0.pdf

10:30 Coffee Break

Session 1: Low energy facilities and their design optimization

3 The electrostatic cryogenic storage ring CSR

The cryogenic storage ring CSR is a fully electrostatic storage ring used to store atomic, molecular and cluster ion beams in the energy range of q·(20-300) keV, where q is the absolute value of the ion charge state. The entire storage ring can be cooled down to temperatures of only a few Kelvin. This very low temperature creates an extremely low residual gas density. The observations from first cryogenic operation indicate the residual gas densities below 100 molecules/cm^3. The cooling of all ion optics and the vacuum enclosure to 10 K temperature also provides the benefit of uniquely low level of blackbody radiation where the stored molecular ion beams reach their lowest quantum states. In March 2014 the functionality of CSR was demonstrated by storing a 50 keV 40Ar+ beam under room temperature conditions. Later, in 2015, the storage ring was cooled down to an average temperature below 10 K. At this temperature the storage time for singly charged ions achieved up to 2500 s. Electron cooling could be proven in the last two years with molecular ion beams (HeH+, HD+) with energies of 125 and 250 keV as well with an atomic ion beam F6+ (E=1.34 MeV). In the case of the molecular ion beams a transverse and longitudinal cooling time in the range of 1 to 3 s could be measured. In the talk an overview about the CSR will be given.

Speaker: Dr Manfred Grieser (Max-Planck-Institut für Kernphysik)

Grieser_Low_Energy facility_design_2019.pptx

4 DESIREE – a compact low energy double ring

Speaker: Ansgar Simonsson (Stockholm University)

Running DESIREE 2019 c.pptx

12:30 Lunch break

Vouchers provided

Session 2: Beam quality optimization – Beam cooling

5 Study of cold electron emission sources for a cold cathode electron gun

Speaker: Bruno Galante (CERN)

BrunoGalante - GSI Workshop.pptx

6 Kinematics of electron beam cooling and performance optimization

Speaker: Bianca Veglia (University of Liverpool (GB))

TW_BVeglia.pptx

7 Low-energy Electron Cooling and Detection Methods at the Cryogenic Storage Ring

In order to observe molecular reactions at the ambient temperatures of the interstellar medium, the Cryogenic Storage Ring (CSR) was built at the Max Planck Institute for Nuclear Physics. This low-energy electrostatic storage ring is designed for molecular ions up to 300 keV per charge unit, independently of ion mass. With internal wall temperatures of 6 K, CSR allows infrared active molecular ions to radiatively cool toward their rovibrational ground state and to perform molecular collision experiments under these conditions.
In CSR, two types of cryogenic detectors for collisional products are available. On the one hand, movable counting detectors can identify particles by their mass/charge ratio. On the other hand, a multi-coincidence imaging detector is used for detection of neutral reaction products resolved in space and time, providing 3D information about reaction kinematics. Moreover, a technically challenging, low-energy (1 eV - 1000 eV) electron cooler was recently implemented in CSR that allows to perform electron-ion merged beam experiments in a cryogenic environment. Here we report on its electron cooling capabilities as well as on diagnostic tools for observing and optimizing electron cooling in a low-energy storage ring.

Speaker: Mr Daniel Paul (Max Planck Institute for Nuclear Physics, Heidelberg, Germany)

Paul_AVA_2019.pdf

8 Embedding instrument read-out in online accelerator simulations

Speaker: Volodymyr Rodin (University of Liverpool)

Embedding instrument read-out in online accelerator simulationsV2.pptx

Discussion Session: Current experimental limitations, research challenges, opportunities for collaborative projects and funding opportunities

Poster Session with refreshments

Coffee and cake will be served during the session.

19:30 Workshop Dinner

Thursday 7 February

09:00 Coffee Break

Session 3: Optimization towards experiments

9 Measurement of recurrent fluorescence cooling rates of PAH cations and di-cations using a compact electrostatic storage ring, the Mini-Ring

Measurement of recurrent fluorescence cooling rates of PAH cations and di-cations using a compact electrostatic storage ring, the Mini-Ring
J. Bernard1, A. Al-Mogeeth1, C. Joblin2, and S. Martin1
1Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon,
69622 Villeurbanne cedex, France
2Universite de Toulouse, UPS-OMP, IRAP, Toulouse, France

Email: jerome.bernard@univ-lyon1.fr

A very compact electrostatic ion storage ring, so-called Mini-Ring, has been built in Lyon almost ten years ago1. The design uses the focusing properties of conical shaped electrostatic mirrors to reduce the total number of necessary electrodes to 10 only. Compared to other existing storage rings at that time of several meters of circumference, it deserved its name of Min-Ring because its size was restraint to fit on a single plate 400 mm×200 mm.
With this Mini-Ring, we have thoroughly studied and quantified the radiative cooling of PAH cations (Naphthalene, Anthracene, Pyrene) and di-cation (Anthracene only). We have evidenced a fast radiative cooling that cannot be attributed to infrared vibrational emissions only. This fast radiative cooling, referred now as recurrent fluorescence, involves a mechanism that had been predicted in the early 80s, i.e., the transient population of electronic excited states from high vibrational states of the ground state of “hot” PAH cations via the inverse process of internal conversion (IIC). This IIC process is rapidly followed by a visible photon emission taking away few eVs from the system at once. The previous studies on singly charged PAHs2,3 has been recently extended to di-cations of Anthracene. An average energy shift rate of about 50 eV/s has been measured for di-cation, two times less compared to cation.

References:
1. Bernard, J. et al. A “tabletop” electrostatic ion storage ring: Mini-Ring. Rev. Sci. Instrum. 79, 075109 (2008).
2. Martin, S. et al. Fast Radiative Cooling of Anthracene Observed in a Compact Electrostatic Storage Ring. Phys. Rev. Lett. 110, 063003 (2013).
3. Martin, S. et al. Fast radiative cooling of anthracene: Dependence on internal energy. Phys. Rev. A 92, 053425 (2015).

Speaker: jérôme BERNARD (Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne cedex, France)

2019-02-05-jerome BERNARD - Workshop-Darmstadt -for AVA records.pdf

10 Photo-dissociation of dimer cations of PAHs stored in a compact electrostatic ion storage ring

In our study of Polycyclic Aromatic Hydrocarbons (PAHs) dimer cations such as di-benzene, di-naphthalene and di-pyrene, we use a compact electrostatic ion storage ring, the Mini-Ring. Dimer cations of PAHs are produced by using an electron cyclotron resonance plasma ion source (ECR) with low HF power and high pressure. They are stored in the Mini-Ring up to 100 ms in order to characterize the dynamics of dissociation and of radiative relaxation. We performed a coincidence experiment between neutrals detected by the channeltron and ions detected by the PSD. We used the Mini-Ring for half a revolution setting C1 and D3 voltages to half of their nominal values and D4 to 0 V to drive the cationic monomer fragment to the PSD. The laser beam was deflected to cross the ion beam between D2 and C1 to enhance the number of dissociation events. To record their photo-dissociation spectrum they are stored for about 2ms reducing this the background counts resulting from dissociation of hot cations. The photo-dissociation spectra are recorded as a function of OPO laser wavelength in the range 300-1400 nm. Two bands appear in this region: the most intense in the near infrared region is attributed to the charge resonance transition (CR) and the other one in the visible range is attributed to the local excitation transition (LE). The CR band is much broader compared to previous experiments by Inokuchi et al1. due to the higher temperature of the stored dimer cations in our experiment. Indeed, the studies of the cooling dynamics show that radiative cooling can only be due to infrared emissions on a much longer time scale compared to our 2 ms storage time. We plan to perform experiments at DESIREE with very long storage times like up to 10 s to study the evolution of the broadening and the center positions of the CR and LE bands as a function of the temperature.

Reference:
1. Inokuchi, Y., Ohashi, K., Matsumoto, M. & Nishi, N. Photodissociation Spectrum of Naphthalene Dimer Cation. J. Phys. Chem. 99, 3416–3418 (1995).

Speaker: Mr Abdulaziz Al Mogeeth (Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon)

2019-02-05- Abdulaziz Al-Mogeeth - Workshop-Darmstadt -for AVA records.pdf

11 Analyzing the ion composition of a beam stored in the electrostatic Cryogenic Storage Ring (CSR)

New research opportunities in atomic, molecular, and cluster physics are available in form of cold ion beams stored in the electrostatic Cryogenic Storage Ring (CSR) at the Max-Planck-Institut für Kernphysik in Heidelberg. This mass-independent storage device operated at cryogenic temperatures has observation times of hours and allows studying even large biomolecular or cluster systems in the gas phase. In order to detect and suppress the manifold isobaric contaminations of heavy-mass molecular species analysis tools are essential. This becomes even more important for low-intensity beams of rare species below the detection threshold of standard current and Schottky pickup detection systems. Here, two alternative procedures to determine the revolution frequency and consequentially the mass of a stored ion beam are presented. Masses of a primary ion and of its contaminant can be distinguished and identified. In combination with a fragment analysis of the complex molecules the ion beam composition can be effectively determined. The methods itself as well as proof-of-principle experiments are presented and discussed.

Speaker: Viviane Charlotte Schmidt (Max-Plank-Institut für Kernphysik)

AVA_2019_Schmidt.pptx

Session 3: Optimization towards experiments

12 Roadmap towards integration of all diagnostics, experiments and rings in control system

Speaker: Adélaïde Grimaud ( Cosylab d.d.)

ControlSystem_GSI_AGrimaud.pptx

13 Antiproton beam profile measurement with thin scintillating fiber detector

Speaker: Dominika Alfs (Forschungszentrum Jülich GmbH)

AVA-TW2-DAlfs.pdf

14 Low energy antiprotons and positronium manipulation, detection and diagnostics for pulsed antihydrogen production

Speaker: Mattia Fani' (CERN, INFN Sezione di Genova and Universita Genova (IT))

MFani_TW-GSI.final.pdf

15 Optimized ion trap design for atomic physics experiments

Speaker: Jeffrey Klimes (GSI)

AVA TW2 Talk.key

AVA TW2 Talk.pdf

AVA TW2 Talk.pptx

12:30 Lunch break

Vouchers provided

Session 4: Beam Diagnostics for Transport Optimization

16 CRYRING@ESR

Speaker: Frank Herfurth (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

17 The Collector Ring @ FAIR

Speaker: Oleksii Gorda (GSI)

TheCollectorRing@FAIR_AVAworkshop_07.02.2019.pptx

18 Monitoring of beam transport: Prospects of ultra-thin diamond detectors

Speaker: Miha Cerv (Vienna University of Technology (AT))

Presentation_AVA_GSI.pdf

Presentation_AVA_GSI.pptx

19 Realistic simulation of EM fields in traps and beamlines

Speaker: Zhexi Guo (GSI)

20 Putting it all together / Discussion

Speaker: Carsten Peter Welsch (Cockcroft Institute / University of Liverpool)

Tour of GSI