Manne Siegbahn Laboratory

Stockholm, Sweden

Manne Siegbahn Laboratory

Stockholm, Sweden
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News Article | April 19, 2017
Site: www.eurekalert.org

Accelerated electrons have passed through the complete 2.1 kilometre length of the accelerator tunnel. In the next step, the energy of the electrons will be raised further, before they will be sent into a magnetic slalom section where the bright X-ray laser light will be generated. This first lasing is planned for May. DESY is the largest shareholder of the European XFEL and is responsible for the construction and operation of the superconducting linear accelerator. "The European XFEL's particle accelerator is the first superconducting linear accelerator of this size in the world to go into operation. With the commissioning of this complex machine, DESY and European XFEL scientists have placed the crown on their 20-year engagement in developing and building this large international project. The first experiments are within reach, and I am quite excited about the discoveries ahead of us", says Chairman of the DESY Board of Directors Helmut Dosch. "I am exceptionally happy about arriving at this milestone and congratulate all involved for the outstanding work and their great tenacity." Chairman of the European XFEL Management Board Robert Feidenhans'l says: "The successful commissioning of the accelerator is a very important step that brings us much closer to the start of user operation in the fall. Under the leadership of DESY, the Accelerator Consortium, comprising 17 research institutes, has done an excellent job in the last years. I thank all colleagues involved for their work, which entailed a great deal of know-how and precision but also much personal commitment. The accelerator is an outstanding example of successful global cooperation, encompassing research facilities, institutes, and universities alongside companies that produced certain components." The European XFEL is an X-ray laser of superlatives: The research facility will produce up to 27 000 X-ray laser flashes per second, each so short and intense that researchers can make pictures of structures and processes at the atomic level. The superconducting particle accelerator of the facility, which is now operational across its full length, is the key component of the 3.4 km long X-ray laser. The accelerator's superconducting TESLA technology, which was developed in an international collaboration led by DESY, is the basis for the unique high rate of X-ray laser flashes. Superconductivity means that the accelerator components have no electrical resistance. For this, they have to be cooled to extremely low temperatures. From December into January, the accelerator was cooled to its operating temperature of -271°C. The so-called electron injector and first section of the main accelerator then went into operation, comprising altogether 18 of 98 total accelerator modules. Within this section, the electron bunches were both accelerated and compressed three times, down to 10 micrometres (a thousandth of a millimetre). Finally, the team placed the third section of the accelerator into operation. Currently, the electrons reach an energy of 12 gigaelectronvolts (GeV), and in regular operation, an energy of up to 17.5 GeV is planned. "The energy and other properties of the electron bunches are already within the range where they will be during first user operation", says DESY physicist Winfried Decking, who leads the commissioning of the European XFEL accelerator. The coordination of the unique components of the accelerator and the control of the electron beam will now be intensively tested before the accelerated electrons are allowed into the following section: the up to 210 m long special magnetic structures called undulators. There, the ultrabright X-ray laser flashes will be generated. Scientific experiments should begin this fall. The superconducting particle accelerator of the European XFEL was built over the last seven years through an international consortium, under the leadership of DESY, composed of the following research institutes: CEA and CNRS in France; INFN in Italy; IFJ-PAN, NCBJ, and the Wroc?aw University of Technology in Poland; the Budker Institute, Institute for High Energy Physics, Institute for Nuclear Research, and NIIEFA in Russia; CIEMAT and Universidad Politécnica de Madrid in Spain; the Manne Siegbahn Laboratory, Stockholm University, and Uppsala University in Sweden; and the Paul Scherrer Institute in Switzerland.


Accelerated electrons have passed through the complete 2.1 kilometre length of the accelerator tunnel. In the next step, the energy of the electrons will be raised further, before they will be sent into a magnetic slalom section where the bright X-ray laser light will be generated. This first lasing is planned for May. DESY is the largest shareholder of the European XFEL and is responsible for the construction and operation of the superconducting linear accelerator. "The European XFEL's particle accelerator is the first superconducting linear accelerator of this size in the world to go into operation. With the commissioning of this complex machine, DESY and European XFEL scientists have placed the crown on their 20-year engagement in developing and building this large international project. The first experiments are within reach, and I am quite excited about the discoveries ahead of us", says Chairman of the DESY Board of Directors Helmut Dosch. "I am exceptionally happy about arriving at this milestone and congratulate all involved for the outstanding work and their great tenacity." Chairman of the European XFEL Management Board Robert Feidenhans'l says: "The successful commissioning of the accelerator is a very important step that brings us much closer to the start of user operation in the fall. Under the leadership of DESY, the Accelerator Consortium, comprising 17 research institutes, has done an excellent job in the last years. I thank all colleagues involved for their work, which entailed a great deal of know-how and precision but also much personal commitment. The accelerator is an outstanding example of successful global cooperation, encompassing research facilities, institutes, and universities alongside companies that produced certain components." The European XFEL is an X-ray laser of superlatives: The research facility will produce up to 27 000 X-ray laser flashes per second, each so short and intense that researchers can make pictures of structures and processes at the atomic level. The superconducting particle accelerator of the facility, which is now operational across its full length, is the key component of the 3.4 km long X-ray laser. The accelerator's superconducting TESLA technology, which was developed in an international collaboration led by DESY, is the basis for the unique high rate of X-ray laser flashes. Superconductivity means that the accelerator components have no electrical resistance. For this, they have to be cooled to extremely low temperatures. From December into January, the accelerator was cooled to its operating temperature of -271°C. The so-called electron injector and first section of the main accelerator then went into operation, comprising altogether 18 of 98 total accelerator modules. Within this section, the electron bunches were both accelerated and compressed three times, down to 10 micrometres (a thousandth of a millimetre). Finally, the team placed the third section of the accelerator into operation. Currently, the electrons reach an energy of 12 gigaelectronvolts (GeV), and in regular operation, an energy of up to 17.5 GeV is planned. "The energy and other properties of the electron bunches are already within the range where they will be during first user operation", says DESY physicist Winfried Decking, who leads the commissioning of the European XFEL accelerator. The coordination of the unique components of the accelerator and the control of the electron beam will now be intensively tested before the accelerated electrons are allowed into the following section: the up to 210 m long special magnetic structures called undulators. There, the ultrabright X-ray laser flashes will be generated. Scientific experiments should begin this fall. The superconducting particle accelerator of the European XFEL was built over the last seven years through an international consortium, under the leadership of DESY, composed of the following research institutes: CEA and CNRS in France; INFN in Italy; IFJ-PAN, NCBJ, and the Wroc?aw University of Technology in Poland; the Budker Institute, Institute for High Energy Physics, Institute for Nuclear Research, and NIIEFA in Russia; CIEMAT and Universidad Politécnica de Madrid in Spain; the Manne Siegbahn Laboratory, Stockholm University, and Uppsala University in Sweden; and the Paul Scherrer Institute in Switzerland. Explore further: Superconducting part of the European XFEL accelerator ready


Andersson P.U.,Gothenburg University | Ojekull J.,Gothenburg University | Pettersson J.B.C.,Gothenburg University | Markovic N.,Chalmers University of Technology | And 11 more authors.
Journal of Physical Chemistry Letters | Year: 2010

The internal energy distribution of ammonia formed in the dissociative recombination (DR) of NH4 + with electrons has been studied by an imaging technique at the ion storage ring CRYRING. The DR process resulted in the formation of NH3 + H (0.90 ± 0.01), with minor contributions from channels producing NH2 + H2 (0.05 ± 0.01) and NH2 + 2H (0.04 ± 0.02). The formed NH 3 molecules were highly internally excited, with a mean rovibrational energy of 3.3 ± 0.4 eV, which corresponds to 70% of the energy released in the neutralization process. The internal energy distribution was semiquantitatively reproduced by ab initio direct dynamics simulations, and the calculations suggested that the NH3 molecules are highly vibrationally excited while rotational excitation is limited. The high internal excitation and the translational energy of NH3 and H will influence their subsequent reactivity, an aspect that should be taken into account when developing detailed models of the interstellar medium and ammonia-containing plasmas. © 2010 American Chemical Society.


Hamberg M.,University of Stockholm | Zhaunerchyk V.,University of Stockholm | Zhaunerchyk V.,Radboud University Nijmegen | Vigren E.,University of Stockholm | And 13 more authors.
Astronomy and Astrophysics | Year: 2010

Aims. We determine branching fractions, cross sections and thermal rate constants for the dissociative recombination of CD3CDOD+ and CH3CH2OH2 + at the low relative kinetic energies encountered in the interstellar medium. Methods. The experiments were carried out by merging an ion and electron beam at the heavy ion storage ring CRYRING, Stockholm, Sweden. Results. Break-up of the CCO structure into three heavy fragments is not found for either of the ions. Instead the CCO structure is retained in 23 ± 3% of the DR reactions of CD3CDOD+ and 7 ± 3% in the DR of CH 3CH2OH2 +, whereas rupture into two heavy fragments occurs in 77 ± 3% and 93 ± 3% of the DR events of the respective ions. The measured cross sections were fitted between 1-200 meV yielding the following thermal rate constants and cross-section dependencies on the relative kinetic energy: σ(Ecm[eV]) = 1.7 ± 0.3 × 10-15 (Ecm[eV])-1.23 ± 0.02 cm2 and k(T) = 1.9 ± 0.4 × 10-6 (T/300) -0.73 ± 0.02 cm3 s-1 for CH 3CH2OH2 + as well as k(T) = 1.1 ± 0.4 × 10-6 (T/300)-0.74 ± 0.05 cm3 s-1 and σ(Ecm[eV]) = 9.2 ± 4 × 10-16 (Ecm[eV])-1.24 ± 0.05 cm2 for CD3CDOD+ © 2010 ESO.


Hamberg M.,University of Stockholm | Vigren E.,University of Stockholm | Thomas R.D.,University of Stockholm | Zhaunerchyk V.,Radboud University Nijmegen | And 11 more authors.
EAS Publications Series | Year: 2011

We have investigated the dissociative recombination (DR) of the C 6D6 + and C6D7 + ions using the CRYRING heavy-ion storage ring at Stockholm University, Sweden. The dissociative recombination branching ratios were determined at minimal collision energy, showing that the DR of both ions was dominated by pathways keeping the carbon atoms together in one product. The absolute reaction cross sections for the titular ions are best fitted by σ(Ecm [eV]) = 1.3 ± 0.4 × 10-15 (Ecm [eV]) -1.19 ± 0.02 cm2 (C6D6 +) and σ(Ecm [eV]) = 1.1 ± 0.3 × 10-15(Ecm [eV])-1.33 ± 0.02 cm 2 (C6D7 +}) in the intervals 3-300 meV and 3-200 meV respectively. The thermal rate constants of the titular reactions are best described by: k(T) = 1.3 ± 0.4 × 10 -6(T/300)-0.69 ± 0.02 cm3s-1 for C6D6 +} and k(T) = 2.0 ± 0.6 × 10-6 (T/300)-0.83 ± 0.02 cm3s -1 for C6D6 +}. These expressions correlates well with earlier flowing afterglow studies on the same process. © EAS, EDP Sciences 2011.


Hamberg M.,University of Stockholm | Osterdahl F.,University of Stockholm | Thomas R.D.,University of Stockholm | Zhaunerchyk V.,University of Stockholm | And 8 more authors.
Astronomy and Astrophysics | Year: 2010

Aims. Determination of branching fractions, cross sections and thermal rate coefficients for the dissociative recombination of CD3OCD 2 + (0-0.3 eV) and (CD3)2OD + (0-0.2 eV) at the low relative kinetic energies encountered in the interstellar medium. Methods. The measurements were carried out using merged electron and ion beams at the CRYRING storage ring, Stockholm, Sweden. Results. For (CD3)2OD+ we have experimentally determined the branching fraction for ejection of a single hydrogen atom in the DR process to be maximally 7% whereas 49% of the reactions involve the break up of the COC chain into two heavy fragments and 44% ruptures both C-O bonds. The DR of CD3OCD2 + is dominated by fragmentation of the COC chain into two heavy fragments. The measured thermal rate constants and cross sections are k(T) = 1.7 ± 0.5 × 10-6(T/300 -0.77pm0.01 cm3 s-1, σ = 1.2 ± 0.4 × 10-15(Ecm[eV])-1.27±0.01 cm2 and k(T) = 1.7 ± 0.6 × 10-6(T/300) -0.70pm,0.02 cm3 s-1, σ = 1.7 ± 0.6 × 10-15(Ecm[eV])-1.20±0.02 cm2 for CD3OCD2 + and (CD 3)2OD+, respectively. © ESO, 2010.

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