IBIC2014 - List of Keywords (experiment)

Paper	Title	Other Keywords	Page
TUCYB2	Pulsed Green Laser Wire System for Effective Inverse Compton Scattering	laser, electron, cavity, emittance	254
	A.A. Rawankar, N. Terunuma, J. Urakawa Sokendai, Ibaraki, Japan T. Akagi, A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan D. Jehanno LAL, Orsay, France K. Sakaue Waseda University, Tokyo, Japan
	Funding: This work has been supported by the Quantum Beam Technology Program of the Japanese Ministry of Education, Culture, Sports, Science,and Technology(MEXT). Laser-Compton scattering has become an important technique for beam diagnostics of the latest accelerators. In order to develop technologies for low emittance beams, an Accelerator Test facility (ATF) was built at KEK. It consists of an electron linac, a damping ring in which beam emittance is reduced, and an extraction line. For emittance measurement we are developing a new type of beam profile monitor which works on the principle of inverse Compton scattering between electron and laser light. In order to achieve effective collision of photon and electron, a pulsed and very thin size laser is required. Laser wire is one technique of measuring a small beam size. With green lasers, which are converted to second harmonics from IR pulsed laser, minimum beam waist is half of the beam waist obtained using infrared (IR) laser oscillator. Therefore, it is possible to obtain beam waist less than 5 μm using green laser pulse, which is required for effective photon-electron collision. First, pulsed IR seed laser is amplified with 1.5 meter long PCF based amplifier system. This pulsed IR laser is converted to second harmonics with a non-linear crystal. Pulsed green laser is injected inside four mirror optical cavity to obtain very small beam waist at interaction point (IP). Using a pulsed compact laser wire, we can measure 10 um electron beams in vertical directions. We report the development of the pulsed green laser and parameters of compact four mirror optical cavity for effective inverse Compton scattering.
	Slides TUCYB2 [2.632 MB]
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TUPF09	Calibration of OLYMPUS/DORIS Beam Position Monitors	electronics, positron, target, electron	324
	U. Schneekloth, N. Görrissen, G. Kube, J. Neugebauer, Ru. Neumann, F. Schmidt-Föhre DESY, Hamburg, Germany
	The goal of the OLYMPUS experiment is a precise measurement of the ratio of the positron-proton and electron-proton elastic scattering cross sections in order to quantify the effect of two-photon exchange. The experiment was performed using intense beams of electrons and positrons stored in the DORIS ring at Deutsches Elektronen Synchrotron in Hamburg, impinging on an un-polarized, internal, hydrogen gas target. An essential ingredient of the experiment is a precise determination of the luminosity, which requires a precise knowledge of the beam position of both beam species. During DORIS operation cylindrical button beam position monitors, read out by two independent electronics systems, were mounted up- and downstream of the target chamber. After the end of operation, the readout systems were cross-calibrated. The BPMs were then calibrated using a test-stand, consisting of a wire scanner assembly. The beam was simulated by applying an RF signal to the wire. This paper describes the calibration principles and test setup, together with the results compared to the expected BPM response.
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TUPD03	Terahertz and Optical Measurement Apparatus for the Fermilab ASTA Injector	radiation, dipole, laser, optics	403
	R.M. Thurman-Keup, A.H. Lumpkin, J.C.T. Thangaraj Fermilab, Batavia, Illinois, USA
	ASTA is a facility at Fermilab that, once completed, will consist of a photoinjector with two superconducting capture cavities, at least one superconducting ILC-style cryomodule, and a small ring for studying non-linear, integrable beam optics. This paper discusses the layout for the optical transport system that will provide THz radiation to a Martin-Puplett interferometer for bunch length measurements as well as optical radiation to an externally located streak camera, also for bunch length measurements. It will be able to accept radiation from two synchrotron radiation ports in the bunch compressor, a diffraction/transition radiation screen downstream of the compressor, and a transition radiation screen after the spectrometer magnet for measurements of energy-time correlations.
	Poster TUPD03 [3.202 MB]
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TUPD05	Optimization of Beam Induced Fluorescence Monitors for Profile Measurements of High Current Heavy Ion Beams at GSI	detector, ion, operation, background	412
	C. Andre, P. Forck, R. Haseitl, A. Reiter, R. Singh, B. Walasek-Höhne GSI, Darmstadt, Germany
	To cope with the demands of the Facility for Antiproton and Ion Research (FAIR) for high current operation at the GSI Heavy Ion Linear Accelerator UNILAC non intercepting methods for transverse beam profile measurement are required. In addition to intercepting diagnostics like Secondary Electron Emission Grid (SEM-Grid) or scintillating screens, the Beam Induced Fluorescence (BIF) Monitor, an optical measurement device based on the observation of fluorescent light emitted by excited nitrogen molecules, was brought to routine operation. Starting with the first installations in 2008 and consequent improvements, successively six monitors were set up in the UNILAC and in the transfer line (TK) towards the synchrotron SIS18. BIF is used as a standard diagnostic tool to observe the ion beam at kinetic energies between 1.4 and 11.4 MeV/u. Beside the standard operation mode where the gas pressure is varied, further detailed investigations were conducted. The BIF setups were tested with various beam parameters. Different settings of camera, optics and image intensification were applied to improve the image quality for data analysis. In parallel, the light yield from different setups was compared for various ions, charge states, beam energies and particle numbers.
	Poster TUPD05 [0.639 MB]
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WEPF08	Dosimetry of Pulsed Beams in Proton Therapy	proton, ion, high-voltage, electron	548
	J. van de Walle, Y. Claereboudt, G. Krier, D. Prieels IBA, Louvain-la-Neuve, Belgium G. Boissonnat, J. Colin, J.-M. Fontbonne LPC, Caen, France
	Ion Beam Applications (IBA) has developed in recent years the ProteusONE proton therapy system, which aims at reducing the cost and footprint of proton therapy systems, making them affordable and accessible to more patients worldwide. The heart of the ProteusONE system is a super conducting synchro-cyclotron (S2C2), which provides short (10 μs) proton bunches at 1 kHz. This is in contrast to the proton therapy systems including the IBA Cyclone230, which delivers a continuous beam. Nevertheless, the same average dose rates are provided by both systems. As a consequence, the instantaneous dose rates with the S2C2 are much higher and recombination losses in the large area beam diagnostics and dosimetry devices become non negligible. Since the proton charge which is send to a patient should be measured with high precision, these recombination losses have to be addressed carefully. In this work, a large area (30x30 cm²) and large gap (>3 mm) ionization chamber (IC) is presented which allows to quantify recombination losses in each beam pulse on-line. The principle is based on the introduction of two ionization volumes in series with slightly different gap sizes. The ratio of detected charges in both IC's is the basic observable which is used to recalculate the efficiency of each IC. The principle of this so-called "asymmetric ionization chamber" (AIC) was tested with beam from the S2C2 prototype. The results show that the efficiency can be re-calculated to 0.5% precision for voltages higher than 1000 V. Together with the experimental results, the theoretical background of the recombination losses will be discussed and it will be shown how this theory is applied in a robust and simple way to correct for these losses in the proton therapy system.
	Poster WEPF08 [0.999 MB]
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WEPF24	Development of Three-Dimensional Dose Verification System using a Fluorescent Screen in Ion Beam Therapy	ion, brightness, background, heavy-ion	601
	Y. Hara, T. Furukawa, K. Mizushima, K. Noda, N. S. Saotome, T. Shirai, E. Takeshita, R. Tansho NIRS, Chiba-shi, Japan Y. Saraya National Institute of Radiological Sciences, Chiba, Japan
	For quality assurance (QA) of therapeutic ion beams, QA tool having high spatial resolution and quick verification is required. The imaging system with a fluorescent screen is suitable for QA procedure. We developed a quick veriﬁcation system (NQA-SCN) using a ﬂuorescent screen with a charge-coupled device (CCD) camera for the sake of two dimensional dosimetry. In carbon-ion therapy, the ﬂuorescent light is decreased by suffering from quenching effect due to the increased linear energy transfer (LET) in the Bragg peak. For the use of three-dimensional dose verification, we performed a simple correction for quenching effect and several types of corrections for the optical artifact. In addition, NQA-SCN is attached with an accordion-type water phantom which makes it possible to easily change measurement depth. To evaluate the performance of NQA-SCN, we carried out experiments concerning QA procedures. In my presentation, we provide correction methods and detailed analysis of measured results.
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WEPD24	New Features and Measurements using the Upgraded Transverse Multibunch Feedback at Diamond	feedback, damping, betatron, FPGA	696
	G. Rehm, M.G. Abbott, A.F.D. Morgan DLS, Oxfordshire, United Kingdom
	A Transverse Multi-Bunch Feedback has been used in the Diamond Storage Ring for the stabilization of instabilities since 2007. Following a recent upgrade of the FPGA code and EPICS layer, a set of new features is now available to support operation and machine development: Firstly, a bunch by bunch choice of feedback filter allows for better stabilization of a single high charge bunch in a hybrid fill pattern. Secondly, complex grow-damp experiments are now possible using a sequencer of internal states allowing precise measurements of the damping rates on a mode by mode basis. Thirdly, a phase locked loop excitation and detection has been implemented to allow both extremely fast (kHz update rates) and extremely precise tracking of the betatron tune frequencies. Finally, short FIR filters on the ADC input and DAC output enable a fine tuning of the impulse response to provide maximum bunch to bunch isolation, as for instance required for efficient bunch cleaning.
	Poster WEPD24 [1.977 MB]
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THCXB2	Performance Evaluation of the Intra-Bunch Feedback System at J-PARC Main Ring	feedback, simulation, damping, betatron	727
	K.G. Nakamura Kyoto University, Kyoto, Japan Y.H. Chin, T. Koseki, H. Kuboki, M. Okada, M. Tobiyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Intra-bunch feedback system in J-PARC (Japan Proton Accelerator Complex) Main Ring(MR) has been developed for suppression of head-tail motion and reduction of beam loss. This system consists of mainly BPM, signal processing circuit (iGp12), power amplifiers, and stripline kickers. These components were fabricated and installed in April of 2014. This system succeeded in suppressing the internal bunch motion caused by injection kicker error in the 3GeV constant-energy operation, and showed shorter damping time compared to the bunch by bunch feedback system, which is currently working in the normal operation. In this paper, we will report the performance of the system by comparison with simulations.
	Slides THCXB2 [6.430 MB]
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Paper

Title

Other Keywords

Page

TUCYB2

Pulsed Green Laser Wire System for Effective Inverse Compton Scattering

laser, electron, cavity, emittance

254

A.A. Rawankar, N. Terunuma, J. Urakawa
Sokendai, Ibaraki, Japan
T. Akagi, A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
D. Jehanno
LAL, Orsay, France
K. Sakaue
Waseda University, Tokyo, Japan

Funding: This work has been supported by the Quantum Beam Technology Program of the Japanese Ministry of Education, Culture, Sports, Science,and Technology(MEXT).
Laser-Compton scattering has become an important technique for beam diagnostics of the latest accelerators. In order to develop technologies for low emittance beams, an Accelerator Test facility (ATF) was built at KEK. It consists of an electron linac, a damping ring in which beam emittance is reduced, and an extraction line. For emittance measurement we are developing a new type of beam profile monitor which works on the principle of inverse Compton scattering between electron and laser light. In order to achieve effective collision of photon and electron, a pulsed and very thin size laser is required. Laser wire is one technique of measuring a small beam size. With green lasers, which are converted to second harmonics from IR pulsed laser, minimum beam waist is half of the beam waist obtained using infrared (IR) laser oscillator. Therefore, it is possible to obtain beam waist less than 5 μm using green laser pulse, which is required for effective photon-electron collision. First, pulsed IR seed laser is amplified with 1.5 meter long PCF based amplifier system. This pulsed IR laser is converted to second harmonics with a non-linear crystal. Pulsed green laser is injected inside four mirror optical cavity to obtain very small beam waist at interaction point (IP). Using a pulsed compact laser wire, we can measure 10 um electron beams in vertical directions. We report the development of the pulsed green laser and parameters of compact four mirror optical cavity for effective inverse Compton scattering.

Slides TUCYB2 [2.632 MB]

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TUPF09

Calibration of OLYMPUS/DORIS Beam Position Monitors

electronics, positron, target, electron

324

U. Schneekloth, N. Görrissen, G. Kube, J. Neugebauer, Ru. Neumann, F. Schmidt-Föhre
DESY, Hamburg, Germany

The goal of the OLYMPUS experiment is a precise measurement of the ratio of the positron-proton and electron-proton elastic scattering cross sections in order to quantify the effect of two-photon exchange. The experiment was performed using intense beams of electrons and positrons stored in the DORIS ring at Deutsches Elektronen Synchrotron in Hamburg, impinging on an un-polarized, internal, hydrogen gas target. An essential ingredient of the experiment is a precise determination of the luminosity, which requires a precise knowledge of the beam position of both beam species. During DORIS operation cylindrical button beam position monitors, read out by two independent electronics systems, were mounted up- and downstream of the target chamber. After the end of operation, the readout systems were cross-calibrated. The BPMs were then calibrated using a test-stand, consisting of a wire scanner assembly. The beam was simulated by applying an RF signal to the wire. This paper describes the calibration principles and test setup, together with the results compared to the expected BPM response.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPD03

Terahertz and Optical Measurement Apparatus for the Fermilab ASTA Injector

radiation, dipole, laser, optics

403

R.M. Thurman-Keup, A.H. Lumpkin, J.C.T. Thangaraj
Fermilab, Batavia, Illinois, USA

ASTA is a facility at Fermilab that, once completed, will consist of a photoinjector with two superconducting capture cavities, at least one superconducting ILC-style cryomodule, and a small ring for studying non-linear, integrable beam optics. This paper discusses the layout for the optical transport system that will provide THz radiation to a Martin-Puplett interferometer for bunch length measurements as well as optical radiation to an externally located streak camera, also for bunch length measurements. It will be able to accept radiation from two synchrotron radiation ports in the bunch compressor, a diffraction/transition radiation screen downstream of the compressor, and a transition radiation screen after the spectrometer magnet for measurements of energy-time correlations.

Poster TUPD03 [3.202 MB]

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TUPD05

Optimization of Beam Induced Fluorescence Monitors for Profile Measurements of High Current Heavy Ion Beams at GSI

detector, ion, operation, background

412

C. Andre, P. Forck, R. Haseitl, A. Reiter, R. Singh, B. Walasek-Höhne
GSI, Darmstadt, Germany

To cope with the demands of the Facility for Antiproton and Ion Research (FAIR) for high current operation at the GSI Heavy Ion Linear Accelerator UNILAC non intercepting methods for transverse beam profile measurement are required. In addition to intercepting diagnostics like Secondary Electron Emission Grid (SEM-Grid) or scintillating screens, the Beam Induced Fluorescence (BIF) Monitor, an optical measurement device based on the observation of fluorescent light emitted by excited nitrogen molecules, was brought to routine operation. Starting with the first installations in 2008 and consequent improvements, successively six monitors were set up in the UNILAC and in the transfer line (TK) towards the synchrotron SIS18. BIF is used as a standard diagnostic tool to observe the ion beam at kinetic energies between 1.4 and 11.4 MeV/u. Beside the standard operation mode where the gas pressure is varied, further detailed investigations were conducted. The BIF setups were tested with various beam parameters. Different settings of camera, optics and image intensification were applied to improve the image quality for data analysis. In parallel, the light yield from different setups was compared for various ions, charge states, beam energies and particle numbers.

Poster TUPD05 [0.639 MB]

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WEPF08

Dosimetry of Pulsed Beams in Proton Therapy

proton, ion, high-voltage, electron

548

J. van de Walle, Y. Claereboudt, G. Krier, D. Prieels
IBA, Louvain-la-Neuve, Belgium
G. Boissonnat, J. Colin, J.-M. Fontbonne
LPC, Caen, France

Ion Beam Applications (IBA) has developed in recent years the ProteusONE proton therapy system, which aims at reducing the cost and footprint of proton therapy systems, making them affordable and accessible to more patients worldwide. The heart of the ProteusONE system is a super conducting synchro-cyclotron (S2C2), which provides short (10 μs) proton bunches at 1 kHz. This is in contrast to the proton therapy systems including the IBA Cyclone230, which delivers a continuous beam. Nevertheless, the same average dose rates are provided by both systems. As a consequence, the instantaneous dose rates with the S2C2 are much higher and recombination losses in the large area beam diagnostics and dosimetry devices become non negligible. Since the proton charge which is send to a patient should be measured with high precision, these recombination losses have to be addressed carefully. In this work, a large area (30x30 cm²) and large gap (>3 mm) ionization chamber (IC) is presented which allows to quantify recombination losses in each beam pulse on-line. The principle is based on the introduction of two ionization volumes in series with slightly different gap sizes. The ratio of detected charges in both IC's is the basic observable which is used to recalculate the efficiency of each IC. The principle of this so-called "asymmetric ionization chamber" (AIC) was tested with beam from the S2C2 prototype. The results show that the efficiency can be re-calculated to 0.5% precision for voltages higher than 1000 V. Together with the experimental results, the theoretical background of the recombination losses will be discussed and it will be shown how this theory is applied in a robust and simple way to correct for these losses in the proton therapy system.

Poster WEPF08 [0.999 MB]

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WEPF24

Development of Three-Dimensional Dose Verification System using a Fluorescent Screen in Ion Beam Therapy

ion, brightness, background, heavy-ion

601

Y. Hara, T. Furukawa, K. Mizushima, K. Noda, N. S. Saotome, T. Shirai, E. Takeshita, R. Tansho
NIRS, Chiba-shi, Japan
Y. Saraya
National Institute of Radiological Sciences, Chiba, Japan

For quality assurance (QA) of therapeutic ion beams, QA tool having high spatial resolution and quick verification is required. The imaging system with a fluorescent screen is suitable for QA procedure. We developed a quick veriﬁcation system (NQA-SCN) using a ﬂuorescent screen with a charge-coupled device (CCD) camera for the sake of two dimensional dosimetry. In carbon-ion therapy, the ﬂuorescent light is decreased by suffering from quenching effect due to the increased linear energy transfer (LET) in the Bragg peak. For the use of three-dimensional dose verification, we performed a simple correction for quenching effect and several types of corrections for the optical artifact. In addition, NQA-SCN is attached with an accordion-type water phantom which makes it possible to easily change measurement depth. To evaluate the performance of NQA-SCN, we carried out experiments concerning QA procedures. In my presentation, we provide correction methods and detailed analysis of measured results.

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WEPD24

New Features and Measurements using the Upgraded Transverse Multibunch Feedback at Diamond

feedback, damping, betatron, FPGA

696

G. Rehm, M.G. Abbott, A.F.D. Morgan
DLS, Oxfordshire, United Kingdom

A Transverse Multi-Bunch Feedback has been used in the Diamond Storage Ring for the stabilization of instabilities since 2007. Following a recent upgrade of the FPGA code and EPICS layer, a set of new features is now available to support operation and machine development: Firstly, a bunch by bunch choice of feedback filter allows for better stabilization of a single high charge bunch in a hybrid fill pattern. Secondly, complex grow-damp experiments are now possible using a sequencer of internal states allowing precise measurements of the damping rates on a mode by mode basis. Thirdly, a phase locked loop excitation and detection has been implemented to allow both extremely fast (kHz update rates) and extremely precise tracking of the betatron tune frequencies. Finally, short FIR filters on the ADC input and DAC output enable a fine tuning of the impulse response to provide maximum bunch to bunch isolation, as for instance required for efficient bunch cleaning.

Poster WEPD24 [1.977 MB]

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THCXB2

Performance Evaluation of the Intra-Bunch Feedback System at J-PARC Main Ring

feedback, simulation, damping, betatron

727

K.G. Nakamura
Kyoto University, Kyoto, Japan
Y.H. Chin, T. Koseki, H. Kuboki, M. Okada, M. Tobiyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Intra-bunch feedback system in J-PARC (Japan Proton Accelerator Complex) Main Ring(MR) has been developed for suppression of head-tail motion and reduction of beam loss. This system consists of mainly BPM, signal processing circuit (iGp12), power amplifiers, and stripline kickers. These components were fabricated and installed in April of 2014. This system succeeded in suppressing the internal bunch motion caused by injection kicker error in the 3GeV constant-energy operation, and showed shorter damping time compared to the bunch by bunch feedback system, which is currently working in the normal operation. In this paper, we will report the performance of the system by comparison with simulations.

Slides THCXB2 [6.430 MB]

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