IPAC2015 - List of Authors (Mueller, A.-S.)

Paper	Title	Page
MOPWA045	First Tests of a Beam Transport System from a Laser Wakefield Accelerator to a Transverse Gradient Undulator	216
	C. Widmann, V. Afonso Rodríguez, A. Bernhard, A.-S. Müller, R. Rossmanith, W. Werner KIT, Karlsruhe, Germany M. Kaluza, M. Nicolai, M.B. Schwab, A. Sävert IOQ, Jena, Germany M. Kaluza, S. Kuschel HIJ, Jena, Germany
	An experimental setup for the generation of monochromatic undulator radiation at the laser wakefield accelerator (LWFA) in Jena using a transverse gradient undulator (TGU) is planned. Proper matching of the betatron functions and the dispersion of the electron beam to the undulator is essential. Therefor a beam transport system with strong focusing magnets and chromatic correction of these magnets is required. As a first step, a linear beam transport system without chromatic correction was assembled at the LWFA. With this setup the electron beam’s dispersion and the beta function of one selected energy are matched to the required parameters at the TGU. This contribution presents the experimental results of these measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA045
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MOPHA023	Observation of Coherent Pulses in the Sub-THz Range at DELTA	823
	C. Mai, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Huck, M. Höner, S. Khan, A. Meyer auf der Heide, R. Molo, H. Rast, G. Shayeganrad, P. Ungelenk DELTA, Dortmund, Germany M. Brosi, B. Kehrer, A.-S. Müller, M.J. Nasse, P. Schönfeldt, P. Schütze, S. Walther KIT, Karlsruhe, Germany H. Huck DESY Zeuthen, Zeuthen, Germany
	Funding: Work supported by the BMBF (05K13PEC). Coherent ultrashort THz pulses induced by a laser-electron interaction are routinely produced and observed at DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University. The turn-by-turn evolution of the radiation spectrum is known to shift to the sub-THz regime after the initial laser-electron interaction. Recently, an ultrafast YBCO-based THz detector has been permanently installed and a Schottky diode has been tested at the THz beamline. Measurements with these detectors showing the temporal evolution of the coherent signals after several revolutions are presented. Furthermore, the concept of a recently designed Fourier-transform spectrometer optimized for the sub-THz region is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA023
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MOPHA037	Visible Light Diagnostics at the ANKA Storage Ring	866
	B. Kehrer, A. Borysenko, E. Hertle, N. Hiller, M. Holz, A.-S. Müller, P. Schönfeldt, P. Schütze KIT, Karlsruhe, Germany
	Synchrotron radiation in the visible light range is a versatile diagnostics tool for accelerator studies. At the ANKA storage ring of the Karlsruhe Institute of Technology (KIT), we have a dedicated visible light diagnostics beamline and two additional beam ports close to the radiation's source point. The visible light diagnostics beamline hosts a time-correlated single-photon-counting unit to measure the bunch filling pattern and a streak camera for longitudinal diagnostics. Recently, the beamline has been extended with a fast-gated intensified camera to study transverse instabilities. The synchrotron light monitor ports were previously used for direct source imaging. Due to the diffraction limit the vertical beam size could not be resolved. One of the two ports has recently been equipped with a double-slit to allow for interferometric measurements of the vertical beam size. In this paper we give an overview of the different setup modifications and present first results.
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MOPHA038	Studies for a Wakefield-Optimized Near-Field EO Setup at the ANKA Storage Ring	869
	P. Schönfeldt, A. Borysenko, N. Hiller, B. Kehrer, A.-S. Müller KIT, Karlsruhe, Germany
	Funding: This work is funded by the BMBF contract numbers 05K10VKC, and 05K13VKA. ANKA, the synchrotron light source of the Karlsruhe Institute of Technology (KIT), is the first storage ring with a near-field single-shot electro-optical (EO) bunch profile monitor inside its vacuum chamber. Using the method of electro-optical spectral decoding (EOSD), the current setup made it possible to study longitudinal beam dynamics (e.g. microbunching) occurring during ANKA's low-alpha-operation with sub-ps resolution (granularity). However, the setup induces strong wake-fields spanning the distance between consecutive bunches which cause heat load to the in-vacuum setup for high beam currents. This heat load in turn leads to a laser misalignment thus preventing measurements during multi-bunch operation. Fortunately, the EOSD setup also allows us to directly study these wake-fields so simulation results can be compared to measurement data. This paper reviews possible changes of the setup's geometry with respect to a reduction of the wakefield effects.
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MOPHA039	A Fast Gated Intensified Camera Setup for Transversal Beam Diagnostics at the ANKA Storage Ring	872
	P. Schütze, A. Borysenko, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, P. Schönfeldt KIT, Karlsruhe, Germany
	ANKA, the synchrotron light source at Karlsruhe Institute of Technology (KIT), can be operated in different modes including the short bunch operation with bunch lengths compressed to a few picoseconds. In this mode, coherent synchrotron radiation (CSR) is emitted leading to beam instabilities. For gaining further insight into those processes, a setup based on a fast gated intensified camera was installed recently at the visible light diagnostics beamline of the ANKA storage ring. The experimental layout consists of an optical setup, which magnifies the image of the beam in the horizontal and demagnifies it in the vertical plane to obtain a projection of the horizontal beam shape, the camera itself and a fast scanning galvanometric mirror that sweeps this image across the sensor. This allows the tracking of the horizontal bunch size and position over many turns. In this paper we present the setup and show first measurement results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA039
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MOPHA040	First Results of Energy Measurements with a Compact Compton Backscattering Setup at ANKA	876
	C. Chang, E. Bründermann, E. Hertle, N. Hiller, E. Huttel, A.-S. Müller, M.J. Nasse, M. Schuh, J.L. Steinmann KIT, Karlsruhe, Germany H.-W. Hübers, H. Richter DLR, Berlin, Germany
	Funding: This work is funded by the European Union under contract PITN-GA-2011-289191 An electron energy measurement setup based on the detection of Compton backscattered photons, generated by laser light scattered off the relativistic electron beam, has been proposed and developed for operation at the ANKA storage ring of the Karlsruhe Institute of Technology (KIT). In contrast to conventional methods based on head-on collisions, the setup at ANKA is, for the first time, realized in a transverse configuration where the laser beam hits the electron beam at an angle of ~90°. This makes it possible to achieve a relatively low-cost and very compact setup since it only requires a small side-port instead of a straight section. This development could benefit storage rings with restricted space or where no straight sections are available, for example due to interferences with existing beamlines. The setup and the first measurement results are presented in the paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA040
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MOPHA042	Online Studies of THz-radiation in the Bursting Regime at ANKA	882
	M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber KIT, Karlsruhe, Germany
	Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 The ANKA storage ring of the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and generates brilliant coherent synchrotron radiation in the THz range with a dedicated bunch length reducing optic. The producing of radiation in the so-called THz-gap is challenging, but this intense THz radiation is very attractive for certain user experiments. The high degree of compression in this so-called low-alpha optics leads to a complex longitudinal dynamics of the electron bunches. The resulting micro-bunching instability leads to time dependent fluctuations and strong bursts in the radiated THz power. The study of these fluctuations in the emitted THz radiation provides insight into the longitudinal beam dynamics. Fast THz detectors combined with KAPTURE, the dedicated KArlsruhe Pulstaking and Ultrafast Readout Electronics system developed at KIT, allow the simultaneous measurement of the radiated THz intensity for each bunch individually in a multi-bunch environment. This contribution gives an overview of the first experience gained using this setup as an online diagnostics tool.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA042
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MOPHA043	Properties of Transition- and Synchrotron Radiation at FLUTE	885
	M. Schwarz, A.-S. Müller KIT, Karlsruhe, Germany M.T. Schmelling MPI-K, Heidelberg, Germany
	FLUTE (Ferninfrarot Linac Und Test Experiment) is a 41 MeV linear accelerator currently under construction at KIT. It is aimed at accelerator physics and THz radiation research. For this reason the machine will cover a wide range of bunch charges (1 pC up to 3 nC) and lengths (1 fs to 300 fs). One aim of FLUTE is the study of different mechanisms for the generation of intense THz pulses, such as transition- (TR) or synchrotron radiation (SR). In this contribution, we calculate and compare various pulse properties, such as spectra, and electric fields, for both TR and SR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA043
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TUPWA039	Transverse Gradient Undulator-Based High-Gain-FELs - a Parameter Study	1502
	A. Bernhard, V. Afonso Rodríguez, E. Burkard, A.-S. Müller, C. Widmann KIT, Karlsruhe, Germany
	Transverse gradient undulators (TGU) have recently been discussed as sources for High Gain Free Electron Lasers (FEL) driven by electron beams with an elevated energy spread as for example generated in storage rings or wakefield accelerators. In this contribution we present the results of a parameter study based on the one-dimensional TGU-FEL theory making realistic assumptions on the key parameters achievable for the transverse gradient undulator. We show for which parameter areas LWFA-driven TGU-FELs are virtually technically feasible today and which technical improvements would be required to employ the concept for a laboratory-scale X-Ray FEL.
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TUPWA042	Status of the Accelerator Physics Test Facility FLUTE	1506
	M.J. Nasse, A. Bernhard, I. Birkel, A. Borysenko, A. Böhm, S. Hillenbrand, N. Hiller, S. Höninger, S. Marsching, A.-S. Müller, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, B. Smit, S. Walther, M. Weber, P. Wesolowski KIT, Karlsruhe, Germany R.W. Aßmann, M. Felber, K. Flöttmann, C. Gerth, M. Hoffmann, P. Peier, H. Schlarb, B. Steffen DESY, Hamburg, Germany R. Ischebeck, B. Keil, V. Schlott, L. Stingelin PSI, Villigen PSI, Switzerland
	A new compact versatile linear accelerator named FLUTE (Ferninfrarot Linac Und Test Experiment) is currently under construction at the Karlsruhe Institute of Technology (KIT). It will serve as an accelerator test facility and allow conducting a variety of accelerator physics studies. In addition, it will be used to generate intense, ultra-short THz pulses for photon science experiments. FLUTE consists of a ~7 MeV photo-injector gun, a ~41 MeV S-band linac and a D-shaped chicane to compress bunches to a few femtoseconds. This contribution presents an overview of the project status and the accompanying simulation studies.
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TUPWA043	Non-interferometric Spectral Analysis of Synchrotron Radiation in the THz regime at ANKA	1509
	J.L. Steinmann, M. Brosi, E. Bründermann, C.M. Caselle, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, M. Schuh, M. Schwarz, P. Schönfeldt, P. Schütze KIT, Karlsruhe, Germany J.L. Hesler Virginia Diodes Inc., Charlottesville, USA
	Interferometry is the quasi-standard for spectral measurements in the THz- and IR-range. The frequency resolution, however, is limited by the travel range of the interferometer mirrors. Therefore, a resolution in the low megahertz range would require interferometer arms of about 100 m. As an alternative, heterodyne measurements provide a resolution in the Hertz range, an improvement of 6 orders of magnitude. Here we present measurements done at ANKA with a VDI WR3.4SAX, a mixer that can be tuned to frequencies from 220 GHz to 330 GHz and we show how the bunch filling pattern influences the amplitude of specific frequencies.
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TUPJE042	Transverse Tunes Determination from Mixed BPM Data	1709
	P. Zisopoulos, F. Antoniou, Y. Papaphilippou CERN, Geneva, Switzerland E. Hertle, A.-S. Müller KIT, Eggenstein-Leopoldshafen, Germany
	Decoherence due to non-zero chromaticity and/or amplitude dependent tune-shift, but also damping mechanisms can affect the accurate tune determination by leaving a limited number of turns for frequency analysis of the turn by turn (TbT) position data. In order to by-pass these problems, Fourier analysis of mixed TBT data from all BPMs can be employed. The approach is applied in two different accelerators, a hadron collider as the LHC and a synchrotron light source as the ANKA storage ring. The impact in the accuracy of the method of missing BPM data is also discussed.
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WEPMA038	Compact In-vacuum Quadrupoles for a Beam Transport System at a Laser Wakefield Accelerator	2845
	A. Bernhard, V. Afonso Rodríguez, A.-S. Müller, J. Senger, W. Werner, C. Widmann KIT, Karlsruhe, Germany
	Funding: This work is partially funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and 05K10SJ2. For the transport and matching of electrons generated by a Laser Wakefield Accelerator (LWFA) a beam transport system with strong focusing magnets and a compact design is required. For the realization of such a beam transport system at the LWFA in Jena, Germany, two small series of inexpensive, modular quadrupoles were designed and built. The quadrupoles are iron-dominated electromagnets in order to keep the transport system adaptable to different energies and target parameters. To achieve the required field strength it was necessary to choose a small magnetic aperture. Therefore the magnets were designed for in-vacuum use with water-cooled coils. In this contribution the design, the realization and first field measurements of these quadrupoles are presented.
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WEPMA040	Magnet Studies for the Accelerator FLUTE at KIT	2849
	S. Hillenbrand, A. Bernhard, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Sauter, S. Schott, M. Schuh, S. Schulz, M. Weber, P. Wesolowski, C. Widmann KIT, Karlsruhe, Germany
	At KIT we are currently constructing the compact linear accelerator FLUTE (Ferninfrarot Linac Und Test Experiment). This 41 MeV machine is aimed at accelerator physics and synchrotron radiation research, using ultra-short electron bunches. The electrons are generated at a photo-cathode using picosecond long UV laser pulses. A magnetic chicane is used to compress the bunches longitudinally to a few femtoseconds. This contribution describes both the magnet design, in particular the optimization of the chicane dipoles based on finite element method (FEM) simulations, as well as the implementation of a magnet measurement system.
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Paper

Title

Page

First Tests of a Beam Transport System from a Laser Wakefield Accelerator to a Transverse Gradient Undulator

216

C. Widmann, V. Afonso Rodríguez, A. Bernhard, A.-S. Müller, R. Rossmanith, W. Werner
KIT, Karlsruhe, Germany
M. Kaluza, M. Nicolai, M.B. Schwab, A. Sävert
IOQ, Jena, Germany
M. Kaluza, S. Kuschel
HIJ, Jena, Germany

An experimental setup for the generation of monochromatic undulator radiation at the laser wakefield accelerator (LWFA) in Jena using a transverse gradient undulator (TGU) is planned. Proper matching of the betatron functions and the dispersion of the electron beam to the undulator is essential. Therefor a beam transport system with strong focusing magnets and chromatic correction of these magnets is required. As a first step, a linear beam transport system without chromatic correction was assembled at the LWFA. With this setup the electron beam’s dispersion and the beta function of one selected energy are matched to the required parameters at the TGU. This contribution presents the experimental results of these measurements.

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MOPHA023

Observation of Coherent Pulses in the Sub-THz Range at DELTA

823

C. Mai, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Huck, M. Höner, S. Khan, A. Meyer auf der Heide, R. Molo, H. Rast, G. Shayeganrad, P. Ungelenk
DELTA, Dortmund, Germany
M. Brosi, B. Kehrer, A.-S. Müller, M.J. Nasse, P. Schönfeldt, P. Schütze, S. Walther
KIT, Karlsruhe, Germany
H. Huck
DESY Zeuthen, Zeuthen, Germany

Funding: Work supported by the BMBF (05K13PEC).
Coherent ultrashort THz pulses induced by a laser-electron interaction are routinely produced and observed at DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University. The turn-by-turn evolution of the radiation spectrum is known to shift to the sub-THz regime after the initial laser-electron interaction. Recently, an ultrafast YBCO-based THz detector has been permanently installed and a Schottky diode has been tested at the THz beamline. Measurements with these detectors showing the temporal evolution of the coherent signals after several revolutions are presented. Furthermore, the concept of a recently designed Fourier-transform spectrometer optimized for the sub-THz region is shown.

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MOPHA037

Visible Light Diagnostics at the ANKA Storage Ring

866

B. Kehrer, A. Borysenko, E. Hertle, N. Hiller, M. Holz, A.-S. Müller, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany

Synchrotron radiation in the visible light range is a versatile diagnostics tool for accelerator studies. At the ANKA storage ring of the Karlsruhe Institute of Technology (KIT), we have a dedicated visible light diagnostics beamline and two additional beam ports close to the radiation's source point. The visible light diagnostics beamline hosts a time-correlated single-photon-counting unit to measure the bunch filling pattern and a streak camera for longitudinal diagnostics. Recently, the beamline has been extended with a fast-gated intensified camera to study transverse instabilities. The synchrotron light monitor ports were previously used for direct source imaging. Due to the diffraction limit the vertical beam size could not be resolved. One of the two ports has recently been equipped with a double-slit to allow for interferometric measurements of the vertical beam size. In this paper we give an overview of the different setup modifications and present first results.

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MOPHA038

Studies for a Wakefield-Optimized Near-Field EO Setup at the ANKA Storage Ring

869

P. Schönfeldt, A. Borysenko, N. Hiller, B. Kehrer, A.-S. Müller
KIT, Karlsruhe, Germany

Funding: This work is funded by the BMBF contract numbers 05K10VKC, and 05K13VKA.
ANKA, the synchrotron light source of the Karlsruhe Institute of Technology (KIT), is the first storage ring with a near-field single-shot electro-optical (EO) bunch profile monitor inside its vacuum chamber. Using the method of electro-optical spectral decoding (EOSD), the current setup made it possible to study longitudinal beam dynamics (e.g. microbunching) occurring during ANKA's low-alpha-operation with sub-ps resolution (granularity). However, the setup induces strong wake-fields spanning the distance between consecutive bunches which cause heat load to the in-vacuum setup for high beam currents. This heat load in turn leads to a laser misalignment thus preventing measurements during multi-bunch operation. Fortunately, the EOSD setup also allows us to directly study these wake-fields so simulation results can be compared to measurement data. This paper reviews possible changes of the setup's geometry with respect to a reduction of the wakefield effects.

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MOPHA039

A Fast Gated Intensified Camera Setup for Transversal Beam Diagnostics at the ANKA Storage Ring

872

P. Schütze, A. Borysenko, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, P. Schönfeldt
KIT, Karlsruhe, Germany

ANKA, the synchrotron light source at Karlsruhe Institute of Technology (KIT), can be operated in different modes including the short bunch operation with bunch lengths compressed to a few picoseconds. In this mode, coherent synchrotron radiation (CSR) is emitted leading to beam instabilities. For gaining further insight into those processes, a setup based on a fast gated intensified camera was installed recently at the visible light diagnostics beamline of the ANKA storage ring. The experimental layout consists of an optical setup, which magnifies the image of the beam in the horizontal and demagnifies it in the vertical plane to obtain a projection of the horizontal beam shape, the camera itself and a fast scanning galvanometric mirror that sweeps this image across the sensor. This allows the tracking of the horizontal bunch size and position over many turns. In this paper we present the setup and show first measurement results.

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MOPHA040

First Results of Energy Measurements with a Compact Compton Backscattering Setup at ANKA

876

C. Chang, E. Bründermann, E. Hertle, N. Hiller, E. Huttel, A.-S. Müller, M.J. Nasse, M. Schuh, J.L. Steinmann
KIT, Karlsruhe, Germany
H.-W. Hübers, H. Richter
DLR, Berlin, Germany

Funding: This work is funded by the European Union under contract PITN-GA-2011-289191
An electron energy measurement setup based on the detection of Compton backscattered photons, generated by laser light scattered off the relativistic electron beam, has been proposed and developed for operation at the ANKA storage ring of the Karlsruhe Institute of Technology (KIT). In contrast to conventional methods based on head-on collisions, the setup at ANKA is, for the first time, realized in a transverse configuration where the laser beam hits the electron beam at an angle of ~90°. This makes it possible to achieve a relatively low-cost and very compact setup since it only requires a small side-port instead of a straight section. This development could benefit storage rings with restricted space or where no straight sections are available, for example due to interferences with existing beamlines. The setup and the first measurement results are presented in the paper.

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MOPHA042

Online Studies of THz-radiation in the Bursting Regime at ANKA

882

M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber
KIT, Karlsruhe, Germany

Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320
The ANKA storage ring of the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and generates brilliant coherent synchrotron radiation in the THz range with a dedicated bunch length reducing optic. The producing of radiation in the so-called THz-gap is challenging, but this intense THz radiation is very attractive for certain user experiments. The high degree of compression in this so-called low-alpha optics leads to a complex longitudinal dynamics of the electron bunches. The resulting micro-bunching instability leads to time dependent fluctuations and strong bursts in the radiated THz power. The study of these fluctuations in the emitted THz radiation provides insight into the longitudinal beam dynamics. Fast THz detectors combined with KAPTURE, the dedicated KArlsruhe Pulstaking and Ultrafast Readout Electronics system developed at KIT, allow the simultaneous measurement of the radiated THz intensity for each bunch individually in a multi-bunch environment. This contribution gives an overview of the first experience gained using this setup as an online diagnostics tool.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA042

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MOPHA043

Properties of Transition- and Synchrotron Radiation at FLUTE

885

M. Schwarz, A.-S. Müller
KIT, Karlsruhe, Germany
M.T. Schmelling
MPI-K, Heidelberg, Germany

FLUTE (Ferninfrarot Linac Und Test Experiment) is a 41 MeV linear accelerator currently under construction at KIT. It is aimed at accelerator physics and THz radiation research. For this reason the machine will cover a wide range of bunch charges (1 pC up to 3 nC) and lengths (1 fs to 300 fs). One aim of FLUTE is the study of different mechanisms for the generation of intense THz pulses, such as transition- (TR) or synchrotron radiation (SR). In this contribution, we calculate and compare various pulse properties, such as spectra, and electric fields, for both TR and SR.

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TUPWA039

Transverse Gradient Undulator-Based High-Gain-FELs - a Parameter Study

1502

A. Bernhard, V. Afonso Rodríguez, E. Burkard, A.-S. Müller, C. Widmann
KIT, Karlsruhe, Germany

Transverse gradient undulators (TGU) have recently been discussed as sources for High Gain Free Electron Lasers (FEL) driven by electron beams with an elevated energy spread as for example generated in storage rings or wakefield accelerators. In this contribution we present the results of a parameter study based on the one-dimensional TGU-FEL theory making realistic assumptions on the key parameters achievable for the transverse gradient undulator. We show for which parameter areas LWFA-driven TGU-FELs are virtually technically feasible today and which technical improvements would be required to employ the concept for a laboratory-scale X-Ray FEL.

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TUPWA042

Status of the Accelerator Physics Test Facility FLUTE

1506

M.J. Nasse, A. Bernhard, I. Birkel, A. Borysenko, A. Böhm, S. Hillenbrand, N. Hiller, S. Höninger, S. Marsching, A.-S. Müller, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, B. Smit, S. Walther, M. Weber, P. Wesolowski
KIT, Karlsruhe, Germany
R.W. Aßmann, M. Felber, K. Flöttmann, C. Gerth, M. Hoffmann, P. Peier, H. Schlarb, B. Steffen
DESY, Hamburg, Germany
R. Ischebeck, B. Keil, V. Schlott, L. Stingelin
PSI, Villigen PSI, Switzerland

A new compact versatile linear accelerator named FLUTE (Ferninfrarot Linac Und Test Experiment) is currently under construction at the Karlsruhe Institute of Technology (KIT). It will serve as an accelerator test facility and allow conducting a variety of accelerator physics studies. In addition, it will be used to generate intense, ultra-short THz pulses for photon science experiments. FLUTE consists of a ~7 MeV photo-injector gun, a ~41 MeV S-band linac and a D-shaped chicane to compress bunches to a few femtoseconds. This contribution presents an overview of the project status and the accompanying simulation studies.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWA042

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TUPWA043

Non-interferometric Spectral Analysis of Synchrotron Radiation in the THz regime at ANKA

1509

J.L. Steinmann, M. Brosi, E. Bründermann, C.M. Caselle, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, M. Schuh, M. Schwarz, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany
J.L. Hesler
Virginia Diodes Inc., Charlottesville, USA

Interferometry is the quasi-standard for spectral measurements in the THz- and IR-range. The frequency resolution, however, is limited by the travel range of the interferometer mirrors. Therefore, a resolution in the low megahertz range would require interferometer arms of about 100 m. As an alternative, heterodyne measurements provide a resolution in the Hertz range, an improvement of 6 orders of magnitude. Here we present measurements done at ANKA with a VDI WR3.4SAX, a mixer that can be tuned to frequencies from 220 GHz to 330 GHz and we show how the bunch filling pattern influences the amplitude of specific frequencies.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWA043

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TUPJE042

Transverse Tunes Determination from Mixed BPM Data

1709

P. Zisopoulos, F. Antoniou, Y. Papaphilippou
CERN, Geneva, Switzerland
E. Hertle, A.-S. Müller
KIT, Eggenstein-Leopoldshafen, Germany

Decoherence due to non-zero chromaticity and/or amplitude dependent tune-shift, but also damping mechanisms can affect the accurate tune determination by leaving a limited number of turns for frequency analysis of the turn by turn (TbT) position data. In order to by-pass these problems, Fourier analysis of mixed TBT data from all BPMs can be employed. The approach is applied in two different accelerators, a hadron collider as the LHC and a synchrotron light source as the ANKA storage ring. The impact in the accuracy of the method of missing BPM data is also discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE042

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WEPMA038

Compact In-vacuum Quadrupoles for a Beam Transport System at a Laser Wakefield Accelerator

2845

A. Bernhard, V. Afonso Rodríguez, A.-S. Müller, J. Senger, W. Werner, C. Widmann
KIT, Karlsruhe, Germany

Funding: This work is partially funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and 05K10SJ2.
For the transport and matching of electrons generated by a Laser Wakefield Accelerator (LWFA) a beam transport system with strong focusing magnets and a compact design is required. For the realization of such a beam transport system at the LWFA in Jena, Germany, two small series of inexpensive, modular quadrupoles were designed and built. The quadrupoles are iron-dominated electromagnets in order to keep the transport system adaptable to different energies and target parameters. To achieve the required field strength it was necessary to choose a small magnetic aperture. Therefore the magnets were designed for in-vacuum use with water-cooled coils. In this contribution the design, the realization and first field measurements of these quadrupoles are presented.

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WEPMA040

Magnet Studies for the Accelerator FLUTE at KIT

2849

S. Hillenbrand, A. Bernhard, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Sauter, S. Schott, M. Schuh, S. Schulz, M. Weber, P. Wesolowski, C. Widmann
KIT, Karlsruhe, Germany

At KIT we are currently constructing the compact linear accelerator FLUTE (Ferninfrarot Linac Und Test Experiment). This 41 MeV machine is aimed at accelerator physics and synchrotron radiation research, using ultra-short electron bunches. The electrons are generated at a photo-cathode using picosecond long UV laser pulses. A magnetic chicane is used to compress the bunches longitudinally to a few femtoseconds. This contribution describes both the magnet design, in particular the optimization of the chicane dipoles based on finite element method (FEM) simulations, as well as the implementation of a magnet measurement system.

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