IBIC2013 - List of Keywords (background)

Paper	Title	Other Keywords	Page
MOCL2	Design of a Novel Cherenkov Detector System for Machine Induced Background Monitoring in the CMS Cavern	LHC, simulation, radiation, shielding	33
	S. Orfanelli, A.E. Dabrowski, M. Giunta CERN, Geneva, Switzerland M.J. Ambrose, A. Finkel, R. Rusack University of Minnesota, Minneapolis, Minnesota, USA D.P. Stickland PU, Princeton, New Jersey, USA
	A novel detector system has been designed for an efficient online measurement of the machine induced background in the CMS experimental cavern. The suppression of the CMS cavern background originating from pp collision products and the 25 ns bunch spacing have set the requirements for the detector design. Each detector unit will be a radiation hard, cylindrical Cherenkov radiator optically coupled to an ultra-fast UV-sensitive photomultiplier tube, providing a prompt, directionally sensitive measurement. Simulation and test beam measurements have shown the achievability of the goals that have driven the baseline design. The system will consist of 20 azimuthally distributed detectors per end, installed at a radius of r ~ 180 cm and a distance 20.6 m away from the CMS interaction region. The detector units will enable a measurement of the transverse distribution of the bunch-by-bunch machine induced background flux. This will provide important feedback from the CMS on the beam conditions during the LHC machine setup and comparisons to expectations based on FLUKA simulations.
	Slides MOCL2 [14.094 MB]

MOPC46	Beam Loss Monitor System for Low-Energy Heavy-Ion FRIB Accelerators	ion, radiation, beam-losses, heavy-ion	186
	Z. Liu, T. Russo, R.C. Webber, Y. Yamazaki, Y. Zhang FRIB, East Lansing, Michigan, USA
	Funding: Work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Radiation transport simulations reveal shortcomings in the use of ion chambers for the detection of beam losses in low-energy, heavy-ion accelerators like FRIB. Radiation cross-talk effects due to the specific FRIB paper-clip geometry complicate locating specific points of beam loss. We describe an economical and robust solution that complements ionization chambers. A specifically designed device, the halo monitor ring (HMR), is implemented upstream of each cryomodule to detect beam loss directly. Together with fast response neutron scintillators, the new integrated BLM system satisfies both machine protection and sensitivity requirements.
	Poster MOPC46 [1.014 MB]

MOPF19	Injection Efficiency Monitoring System at the Australian Synchrotron	injection, booster, synchrotron, extraction	248
	E.D. van Garderen, S.A. Griffiths, G. LeBlanc, S. Murphy, A. Rhyder, A. C. Starritt ASCo, Clayton, Victoria, Australia M.J. Boland SLSA, Clayton, Australia
	The Australian Synchrotron upgraded its user mode from decay mode to top-up mode in May 2012. To monitor the beam charge passing through the accelerator systems at key transfer points the transmission efficiency system has been upgraded. The original system could only measure the efficiency of the booster to storage ring injection. The new one calculates intermediate efficiencies between six points along the injection system, from the electron gun to the booster-to-storage ring transfer line. This is helpful to diagnose in real-time shot-to-shot the performance of the pulsed magnets, ramped magnets and ramped RF systems and their associated triggers. A software-based injection efficiency interlock has also been introduced, that can inhibit the gun when the machine settings are not optimal. This article details the architecture of the injection efficiency system and lists the improvements on the machine that have been carried out to obtain high quality data.

TUAL3	Absolute Bunch Length Measurements at Fermi@ELETTRA FEL	electron, radiation, ELETTRA, instrumentation	312
	R. Appio MAX-lab, Lund, Sweden P. Craievich, G. Penco, M. Veronese Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy P. Craievich PSI, Villigen PSI, Switzerland
	Electron bunch length measurements are of crucial importance for many types of accelerators, including storage rings, energy recovery linacs, free electron lasers. Many devices and instrumentation have been developed to measure and control the electron bunch length. A very powerful class of diagnostic tools is based on the coherent radiation power emitted by the electron bunch, that allows a non-destructive shot by shot measurement, well suitable for bunch length control feedback implementation. However they usually provide measurements of the bunch length relative variation, and external instrumentation like a transverse RF deflecting cavity is usually needed to calibrate them and to obtain absolute bunch length estimations. In this paper we present a novel experimental methodology to self-calibrate a device based on diffraction radiation from a ceramic gap. We indeed demonstrate the possibility to use coherent radiation based diagnostic to provide absolute measurements of the electron bunch length. We present the theoretical basis of the proposed approach and validate it through a detailed campaign of measurements that have been carried on in the FERMI@Elettra FEL linac.
	Slides TUAL3 [1.126 MB]

TUPC38	Longitudinal Profile Monitor Using Smith-Purcell Radiation: Recent Results from the E-203 Collaboration	radiation, longitudinal, electron, SLAC	464
	N. Delerue, J. Barros, S. Le Corre, M. Vieille Grosjean LAL, Orsay, France H.L. Andrews LANL, Los Alamos, New Mexico, USA F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S. Stevenson JAI, Oxford, United Kingdom V. Bharadwaj, C.I. Clarke SLAC, Menlo Park, California, USA N. Fuster Martinez IFIC, Valencia, Spain M. Labat SOLEIL, Gif-sur-Yvette, France
	Funding: Financial support from the John Adams Institute, the Fell Fund (University of Oxford), the Université Paris-Sud (programme 'Attractivité') and the French ANR (contract ANR-12-JS05-0003-01). We report on recent measurements made at FACET by the E-203 collaboration to test a longitudinal bunch profile monitor based on Coherent Smith-Purcell radiation. The capacity of this monitor to resolve sub-picosecond bunches will be shown as well as a comparison of profile reconstructed for different beam compression settings. We will also present recent electromagnetic simulations of the interactions between the beam and the grating as well as the expected resolution of such monitor. Comparison between Coherent Smith-Purcell radiation measurement and those made with other techniques will also be discussed. Finally future upgrades of the experiment and steps toward the construction of a single shot longitudinal profile monitor will be presented.

TUPF20	Low Noise and High Dynamic Range Optical Interferometer Beamsize Measurements	emittance, coupling, synchrotron, storage-ring	550
	M.J. Boland SLSA, Clayton, Australia T.M. Mitsuhashi KEK, Ibaraki, Japan K.P. Wootton The University of Melbourne, Melbourne, Australia
	The technique of optical interferometry to measure beam sizes requires a low noise and high dynamic range digitisation system to push the performance to ultra low emittance on storage rings. The next generation of camera sensor Scientific CMOS (sCMOS) promises to provide the technology to improve optical interferometry. A series of measurements was performed on the Australian Synchrotron storage ring using a sCMOS and a intensity imbalance optical interferometer. The coupling in the storage ring was varied from maximum to minimum using the skew quadrupoles and the beam size at the optical diagnostic beamline was varied from over 100 microns to around 1 micron. A comparison is made between interferometer measurements using the sCMOS with and without an intensity imbalance and with previous measurements using a CCD system.

WEPC35	Progress Report of the Spectral Decoding Based EOS with Organic Pockels EO Crystals	electron, laser, radiation, LEFT	765
	Y. Okayasu, S. Matsubara, H. Tomizawa JASRI/SPring-8, Hyogo-ken, Japan T. Matsukawa, H. Minamide RIKEN ASI, Sendai, Miyagi, Japan K. Ogawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	Funding: Grant-in-Aid for Scientific Research (Japan Society for the Promotion of Science, Grants No. 20612024 and No. 23360045) So far, the temporal structure of ultrashort electron bunches has been extensively investigated by various kinds of electro-optic sampling (EOS) techniques, such as temporal, spectral and spatial decoding method, at several FEL accelerator facilities since early 2000’s. Inorganic Pockels EO crystals, i.e., GaP and ZnTe, have been generally utilized for the EOS. On the other hand, since mid-1980’s, organic nonlinear optical materials have been extensively investigated and DAST, which has fast temporal response in the EO effect, was developed in 1986. DAST is transparent in visible near to IR wavelength range and absorbent in 0.8-1.3 THz. We introduced the DAST crystal into the EOS and successfully demonstrated the first observation of the bunch charge distribution at the EUV-FEL accelerator, SPring-8 on February 2012*. Through the previous experiment, it is found that the EO signal intensity was gradually decreased. On March and April 2013, we prepared DAST crystals with variety of thickness and succeeded to compare EO signal intensities with different bunch charges. Recent results of both optical and structural analysis will be reported in addition to experimental results. 4-N, N-dimethylamino-4’-N’-methyl stilbazolium tosylate S. Okada et al., Japan Patent Application 61-192404 (1986) *Y. Okayasu et al., Phys. Rev. ST Accel. Beams 16, 052801 (2013)

WEPC46	Beam Delivery Simulation (BDSIM): A Geant4 Based Toolkit for Diagnostics and Loss Simulation	LHC, CLIC, simulation, lattice	799
	S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom S.T. Boogert, S.M. Gibson, R. Kwee-Hinzmann, L.J. Nevay, J. Snuverink JAI, Egham, Surrey, United Kingdom L.C. Deacon CERN, Geneva, Switzerland
	BDSIM is a Geant4 and C++ based particle tracking code which seamlessly tracks particles in accelerators and particle detectors, including the full range of particle interaction physics processes in Geant4. The code has been used to model the backgrounds in the International Linear Collider (ILC), Compact Linear Collider (CLIC), Accelerator Test Facility 2 (ATF2) and more recently the Large Hadron Collider (LHC). This paper outlines the current code and possible example applications and presents a roadmap for future developments.

Paper

Title

Other Keywords

Page

MOCL2

Design of a Novel Cherenkov Detector System for Machine Induced Background Monitoring in the CMS Cavern

LHC, simulation, radiation, shielding

33

S. Orfanelli, A.E. Dabrowski, M. Giunta
CERN, Geneva, Switzerland
M.J. Ambrose, A. Finkel, R. Rusack
University of Minnesota, Minneapolis, Minnesota, USA
D.P. Stickland
PU, Princeton, New Jersey, USA

A novel detector system has been designed for an efficient online measurement of the machine induced background in the CMS experimental cavern. The suppression of the CMS cavern background originating from pp collision products and the 25 ns bunch spacing have set the requirements for the detector design. Each detector unit will be a radiation hard, cylindrical Cherenkov radiator optically coupled to an ultra-fast UV-sensitive photomultiplier tube, providing a prompt, directionally sensitive measurement. Simulation and test beam measurements have shown the achievability of the goals that have driven the baseline design. The system will consist of 20 azimuthally distributed detectors per end, installed at a radius of r ~ 180 cm and a distance 20.6 m away from the CMS interaction region. The detector units will enable a measurement of the transverse distribution of the bunch-by-bunch machine induced background flux. This will provide important feedback from the CMS on the beam conditions during the LHC machine setup and comparisons to expectations based on FLUKA simulations.

Slides MOCL2 [14.094 MB]

MOPC46

Beam Loss Monitor System for Low-Energy Heavy-Ion FRIB Accelerators

ion, radiation, beam-losses, heavy-ion

186

Z. Liu, T. Russo, R.C. Webber, Y. Yamazaki, Y. Zhang
FRIB, East Lansing, Michigan, USA

Funding: Work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Radiation transport simulations reveal shortcomings in the use of ion chambers for the detection of beam losses in low-energy, heavy-ion accelerators like FRIB. Radiation cross-talk effects due to the specific FRIB paper-clip geometry complicate locating specific points of beam loss. We describe an economical and robust solution that complements ionization chambers. A specifically designed device, the halo monitor ring (HMR), is implemented upstream of each cryomodule to detect beam loss directly. Together with fast response neutron scintillators, the new integrated BLM system satisfies both machine protection and sensitivity requirements.

Poster MOPC46 [1.014 MB]

MOPF19

Injection Efficiency Monitoring System at the Australian Synchrotron

injection, booster, synchrotron, extraction

248

E.D. van Garderen, S.A. Griffiths, G. LeBlanc, S. Murphy, A. Rhyder, A. C. Starritt
ASCo, Clayton, Victoria, Australia
M.J. Boland
SLSA, Clayton, Australia

The Australian Synchrotron upgraded its user mode from decay mode to top-up mode in May 2012. To monitor the beam charge passing through the accelerator systems at key transfer points the transmission efficiency system has been upgraded. The original system could only measure the efficiency of the booster to storage ring injection. The new one calculates intermediate efficiencies between six points along the injection system, from the electron gun to the booster-to-storage ring transfer line. This is helpful to diagnose in real-time shot-to-shot the performance of the pulsed magnets, ramped magnets and ramped RF systems and their associated triggers. A software-based injection efficiency interlock has also been introduced, that can inhibit the gun when the machine settings are not optimal. This article details the architecture of the injection efficiency system and lists the improvements on the machine that have been carried out to obtain high quality data.

TUAL3

Absolute Bunch Length Measurements at Fermi@ELETTRA FEL

electron, radiation, ELETTRA, instrumentation

312

R. Appio
MAX-lab, Lund, Sweden
P. Craievich, G. Penco, M. Veronese
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
P. Craievich
PSI, Villigen PSI, Switzerland

Electron bunch length measurements are of crucial importance for many types of accelerators, including storage rings, energy recovery linacs, free electron lasers. Many devices and instrumentation have been developed to measure and control the electron bunch length. A very powerful class of diagnostic tools is based on the coherent radiation power emitted by the electron bunch, that allows a non-destructive shot by shot measurement, well suitable for bunch length control feedback implementation. However they usually provide measurements of the bunch length relative variation, and external instrumentation like a transverse RF deflecting cavity is usually needed to calibrate them and to obtain absolute bunch length estimations. In this paper we present a novel experimental methodology to self-calibrate a device based on diffraction radiation from a ceramic gap. We indeed demonstrate the possibility to use coherent radiation based diagnostic to provide absolute measurements of the electron bunch length. We present the theoretical basis of the proposed approach and validate it through a detailed campaign of measurements that have been carried on in the FERMI@Elettra FEL linac.

Slides TUAL3 [1.126 MB]

TUPC38

Longitudinal Profile Monitor Using Smith-Purcell Radiation: Recent Results from the E-203 Collaboration

radiation, longitudinal, electron, SLAC

464

N. Delerue, J. Barros, S. Le Corre, M. Vieille Grosjean
LAL, Orsay, France
H.L. Andrews
LANL, Los Alamos, New Mexico, USA
F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S. Stevenson
JAI, Oxford, United Kingdom
V. Bharadwaj, C.I. Clarke
SLAC, Menlo Park, California, USA
N. Fuster Martinez
IFIC, Valencia, Spain
M. Labat
SOLEIL, Gif-sur-Yvette, France

Funding: Financial support from the John Adams Institute, the Fell Fund (University of Oxford), the Université Paris-Sud (programme 'Attractivité') and the French ANR (contract ANR-12-JS05-0003-01).
We report on recent measurements made at FACET by the E-203 collaboration to test a longitudinal bunch profile monitor based on Coherent Smith-Purcell radiation. The capacity of this monitor to resolve sub-picosecond bunches will be shown as well as a comparison of profile reconstructed for different beam compression settings. We will also present recent electromagnetic simulations of the interactions between the beam and the grating as well as the expected resolution of such monitor. Comparison between Coherent Smith-Purcell radiation measurement and those made with other techniques will also be discussed. Finally future upgrades of the experiment and steps toward the construction of a single shot longitudinal profile monitor will be presented.

TUPF20

Low Noise and High Dynamic Range Optical Interferometer Beamsize Measurements

emittance, coupling, synchrotron, storage-ring

550

M.J. Boland
SLSA, Clayton, Australia
T.M. Mitsuhashi
KEK, Ibaraki, Japan
K.P. Wootton
The University of Melbourne, Melbourne, Australia

The technique of optical interferometry to measure beam sizes requires a low noise and high dynamic range digitisation system to push the performance to ultra low emittance on storage rings. The next generation of camera sensor Scientific CMOS (sCMOS) promises to provide the technology to improve optical interferometry. A series of measurements was performed on the Australian Synchrotron storage ring using a sCMOS and a intensity imbalance optical interferometer. The coupling in the storage ring was varied from maximum to minimum using the skew quadrupoles and the beam size at the optical diagnostic beamline was varied from over 100 microns to around 1 micron. A comparison is made between interferometer measurements using the sCMOS with and without an intensity imbalance and with previous measurements using a CCD system.

WEPC35

Progress Report of the Spectral Decoding Based EOS with Organic Pockels EO Crystals

electron, laser, radiation, LEFT

765

Y. Okayasu, S. Matsubara, H. Tomizawa
JASRI/SPring-8, Hyogo-ken, Japan
T. Matsukawa, H. Minamide
RIKEN ASI, Sendai, Miyagi, Japan
K. Ogawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

Funding: Grant-in-Aid for Scientific Research (Japan Society for the Promotion of Science, Grants No. 20612024 and No. 23360045)
So far, the temporal structure of ultrashort electron bunches has been extensively investigated by various kinds of electro-optic sampling (EOS) techniques, such as temporal, spectral and spatial decoding method, at several FEL accelerator facilities since early 2000’s. Inorganic Pockels EO crystals, i.e., GaP and ZnTe, have been generally utilized for the EOS. On the other hand, since mid-1980’s, organic nonlinear optical materials have been extensively investigated and DAST*, which has fast temporal response in the EO effect, was developed in 1986**. DAST is transparent in visible near to IR wavelength range and absorbent in 0.8-1.3 THz. We introduced the DAST crystal into the EOS and successfully demonstrated the first observation of the bunch charge distribution at the EUV-FEL accelerator, SPring-8 on February 2012***. Through the previous experiment, it is found that the EO signal intensity was gradually decreased. On March and April 2013, we prepared DAST crystals with variety of thickness and succeeded to compare EO signal intensities with different bunch charges. Recent results of both optical and structural analysis will be reported in addition to experimental results.
*4-N, N-dimethylamino-4’-N’-methyl stilbazolium tosylate
**S. Okada et al., Japan Patent Application 61-192404 (1986)
***Y. Okayasu et al., Phys. Rev. ST Accel. Beams 16, 052801 (2013)

WEPC46

Beam Delivery Simulation (BDSIM): A Geant4 Based Toolkit for Diagnostics and Loss Simulation

LHC, CLIC, simulation, lattice

799

S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom
S.T. Boogert, S.M. Gibson, R. Kwee-Hinzmann, L.J. Nevay, J. Snuverink
JAI, Egham, Surrey, United Kingdom
L.C. Deacon
CERN, Geneva, Switzerland

BDSIM is a Geant4 and C++ based particle tracking code which seamlessly tracks particles in accelerators and particle detectors, including the full range of particle interaction physics processes in Geant4. The code has been used to model the backgrounds in the International Linear Collider (ILC), Compact Linear Collider (CLIC), Accelerator Test Facility 2 (ATF2) and more recently the Large Hadron Collider (LHC). This paper outlines the current code and possible example applications and presents a roadmap for future developments.