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Title: DESIREE - A Double Electrostatic Storage Ring for Merged-Beam Experiments

Abstract

DESIREE is a double electrostatic storage ring cooled to cryogenic temperatures. It is built at the Manne Siegbahn Laboratory for merged-beam and single-beam experiments in atomic and molecular physics as well as biophysics. This paper describes the present status of the design of DESIREE.

Authors:
; ; ; ; ; ; ; ; ; ;  [1]; ; ; ; ;  [2]
  1. Manne Siegbahn Laboratory, Frescativaegen 28, S-104 05 Stockholm (Sweden)
  2. Department of Physics, Stockholm Universtity, S-106 91 Stockholm (Sweden)
Publication Date:
OSTI Identifier:
20798442
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 821; Journal Issue: 1; Conference: COOL05: International workshop on beam cooling and related topics, Galena, IL (United States), 18-23 Sep 2005; Other Information: DOI: 10.1063/1.2190153; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BEAM COOLING; BEAM DYNAMICS; CRYOGENICS; DESIGN; ELECTROSTATIC ACCELERATORS; PARTICLE BEAMS; STORAGE RINGS

Citation Formats

Danared, H., Liljeby, L., Andler, G., Bagge, L., Blom, M., Kaellberg, A., Leontein, S., Loefgren, P., Paal, A., Rensfelt, K.-G., Simonsson, A., Schmidt, H. T., Cederquist, H., Larsson, M., Rosen, S., and Schmidt, K. DESIREE - A Double Electrostatic Storage Ring for Merged-Beam Experiments. United States: N. p., 2006. Web. doi:10.1063/1.2190153.
Danared, H., Liljeby, L., Andler, G., Bagge, L., Blom, M., Kaellberg, A., Leontein, S., Loefgren, P., Paal, A., Rensfelt, K.-G., Simonsson, A., Schmidt, H. T., Cederquist, H., Larsson, M., Rosen, S., & Schmidt, K. DESIREE - A Double Electrostatic Storage Ring for Merged-Beam Experiments. United States. doi:10.1063/1.2190153.
Danared, H., Liljeby, L., Andler, G., Bagge, L., Blom, M., Kaellberg, A., Leontein, S., Loefgren, P., Paal, A., Rensfelt, K.-G., Simonsson, A., Schmidt, H. T., Cederquist, H., Larsson, M., Rosen, S., and Schmidt, K. Mon . "DESIREE - A Double Electrostatic Storage Ring for Merged-Beam Experiments". United States. doi:10.1063/1.2190153.
@article{osti_20798442,
title = {DESIREE - A Double Electrostatic Storage Ring for Merged-Beam Experiments},
author = {Danared, H. and Liljeby, L. and Andler, G. and Bagge, L. and Blom, M. and Kaellberg, A. and Leontein, S. and Loefgren, P. and Paal, A. and Rensfelt, K.-G. and Simonsson, A. and Schmidt, H. T. and Cederquist, H. and Larsson, M. and Rosen, S. and Schmidt, K.},
abstractNote = {DESIREE is a double electrostatic storage ring cooled to cryogenic temperatures. It is built at the Manne Siegbahn Laboratory for merged-beam and single-beam experiments in atomic and molecular physics as well as biophysics. This paper describes the present status of the design of DESIREE.},
doi = {10.1063/1.2190153},
journal = {AIP Conference Proceedings},
number = 1,
volume = 821,
place = {United States},
year = {Mon Mar 20 00:00:00 EST 2006},
month = {Mon Mar 20 00:00:00 EST 2006}
}
  • We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate ''rings'' and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven tomore » work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.« less
  • We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C{sub n}{sup -}, n= 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C{sub 2}{sup -} molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s {+-} 18 s with two independent detector systems.more » Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10{sup -14} mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.« less
  • We describe the design of and the first commissioning experiments with a newly constructed electrostatic storage ring named SAPHIRA (Storage Ring in Aarhus for PHoton-Ion Reaction Analysis). With an intense beam of Cu{sup −} at 4 keV, the storage ring is characterized in terms of the stored ion beam decay rate, the longitudinal spreading of an injected ion bunch, as well as the direct measurements of the transverse spatial distributions under different conditions of storage. The ion storage stability in SAPHIRA was investigated systematically in a selected region of its electrical configuration space.
  • A rotating dual-wire beam proile monitor based upon a modified National Electrostatics Corporation Model BPM80 beam profile monitor is described. The device can measure beam profiles in two perpendicular directions (horizontal and vertical) in each of two pseudoplanes that are situated along the beam axis and are separated by a distance of 6.0 cm. The output signal from the device is analyzed in real time to yield horizontal and vertical beam profiles and to calculate the divergence of a particle beam that traverses the device. This set-up is well-suited for merged-beams experiments where one beam is tuned to saved profilesmore » from a second beam in order to minimize the merge angle and beam divergences while maximizing the beam-beam overlaps.« less
  • We report the design, construction, and performance of a soft x-ray beam line with accessible photon energy 0.8--4.0 keV at the Synchrotron Radiation Center, University of Wisconsin--Madison. The beam line features an ultrahigh-vacuum (UHV) compatible high-precision double-crystal monochromator (DCM) covering Bragg angles 12{degree}--72{degree}, which was designed and built at the Physical Science Laboratory (PSL), University of Wisconsin--Madison. The monochromatic x rays are focused by a bent cylindrical mirror (Ni-coated fused silica, located 7.5 m from the source) into the experimental chamber (located 5.5 m from the mirror) down to a spot less than 1 mm(h){times}3 mm(v). During the initial runs,more » the DCM used a pair of InSb(111) crystals and covered photon energy 1.75--3.7 keV. At the silicon {ital K} edge (1840 eV), the beam line delivered about 4{times}10{sup 11} photons/s with stored electron beam at 100 mA at 1 Gev, among the most intense and stable sources currently available at this energy. The energy resolution is about 0.9 eV at the Si {ital K} edge.« less