IBIC2013 - List of Keywords (undulator)

Paper	Title	Other Keywords	Page
MOPC10	Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector	DIAMOND, radiation, photon, beam-position	67
	P. Ilinski BNL, Upton, Long Island, New York, USA
	Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, conﬁguration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.

MOPC41	Engineering Design of the New LCLS X-band Transverse Deflecting Cavity	klystron, SLAC, LCLS, controls	167
	P. Krejcik, E.L. Bong, M. Boyes, S. Condamoor, J.P. Eichner, G.L. Gassner, A.A. Haase, B. Hong, B. Morris, J.J. Olsen, D.W. Sprehn, J.W. Wang SLAC, Menlo Park, California, USA
	Funding: This work was supported by Department of Energy Contract No. DE-AC0276SF00515 This paper describes the engineering design and installation of the new X-band transverse deflecting cavity installed downstream of the FEL undulator at the LCLS. This is a companion submission to the paper “Commissioning the New LCLS X-Band Transverse Deflecting Cavity with Femtosecond Resolution” also presented at this conference. The project dealt with the challenge of installing a new high-power RF system in the undulator tunnel of the LCLS, outside of the linac tunnel itself and its accelerator engineering infrastructure. A description of the system design, installation, alignment, cooling, controls, vacuum, waveguide, low level RF, klystron and modulator systems for the XTCAV is given, with emphasis on achieving the performance goals necessary to achieve femtosecond resolution.

MOPF08	Design and Performance of the Upgraded LHC Synchrotron Light Monitor	LHC, focusing, optics, dipole	220
	A. Goldblatt, E. Bravin, F. Roncarolo, G. Trad CERN, Geneva, Switzerland
	The LHC is equipped with two synchrotron radiation systems, one per beam, used to measure the transverse bunch distributions. The light emitted by a superconducting undulator and/or by a dipole magnet (depending on beam energy) is intercepted by an extraction mirror in vacuum and sent through a viewport to the imaging Beam Synchrotron Radiation Telescope (BSRT). The first version of the telescope, used from 2009 to mid 2012, was based on spherical focusing mirrors in order to minimize chromatic aberrations. However, this required a very complicated delay line in order to switch the focus between the two different light sources as a function of beam energy. A new system based on optical lenses was designed and installed in mid 2012 in order to simplify the optical line and thus reduce misalignment and focusing errors. The first results with LHC beam using this new system showed a significant reduction in the correction factor required to match the emittance as measured by wire scanners. This contribution discusses the performance of the new optical system, presenting the LHC results and comparing simulations with measurement performed in the laboratory using a BSRT replica.

MOPF10	Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics	radiation, CLIC, electron, transverse	228
	A. Jeff, T. Lefèvre CERN, Geneva, Switzerland A. Jeff, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Jeff, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 10¹⁵ electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMAX simulations using the CLIC Drive Beam parameters are shown.

TUAL2	Commissioning the New LCLS X-band Transverse Deflecting Cavity with Femtosecond Resolution	FEL, LCLS, electron, linac	308
	P. Krejcik, F.-J. Decker, Y. Ding, J.C. Frisch, Z. Huang, J.R. Lewandowski, H. Loos, J.L. Turner, J.W. Wang, M.-H. Wang, J.J. Welch SLAC, Menlo Park, California, USA C. Behrens DESY, Hamburg, Germany
	Funding: This work was supported by Department of Energy Contract No. DE-AC0276SF00515 The new X-band transverse deflecting cavity began operation in May 2013 and is installed downstream of the LCLS undulator. It is operated at the full 120 Hz beam rate without interfering with the normal FEL operation for the photon users. The deflected beam is observed on the electron beam dump profile monitor, which acts as an energy spectrometer in the vertical plane. We observe, on a pulse by pulse basis, the time resolved energy profile of the spent electron beam from the undulator. The structure is powered from a 50 MW X-band klystron, giving a 48 MV kick to the beam which yields a 1 fs rms time resolution on the screen. We have measured the longitudinal profile of the electron bunches both with the FEL operating and with the lasing suppressed, allowing reconstruction of both the longitudinal profile of the incoming electron beam and the time-resolved profile of the X-ray pulse generated in the FEL. We are immediately able to see whether the bunch is chirped and which parts of the bunch are lasing, giving us new insight into tuning the machine for peak performance. The performance of the system will be presented along with examples of measurements taken during LCLS operation.
	Slides TUAL2 [9.210 MB]

TUPC25	Design of the SwissFEL BPM System	BPM, pick-up, XFEL, linac	427
	B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, F. Marcellini, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer PSI, Villigen PSI, Switzerland
	SwissFEL is a Free Electron Laser (FEL) facility being constructed at PSI, based on a 5.8GeV normally conducting main linac. A photocathode gun will generate two bunches with 28ns spacing at 100Hz repetition rate, with a nominal charge range of 10-200pC. A fast beam distribution kicker will allow to distribute one bunch to a soft X-ray undulator line and the other bunch to a 0.1nm hard X-ray undulator line. The SwissFEL electron beam position monitor (BPM) system will employ three different types of dual-resonator cavity BPMs, since the accelerator has three different beam pipe apertures. In the injector and main linac (38mm and 16mm aperture), 3.3GHz cavity BPMs will be used, where a low Q of ~40 was chosen to minimize crosstalk of the two bunches. In the undulators that just have single bunches and 8mm BPM aperture, a higher Q will be chosen. This paper reports on the development status of the SwissFEL BPM system. Synergies as well as differences to the E-XFEL BPM system* will also be highlighted. * F. Marcellini et al., "Design of Cavity BPM Pickups For SwissFEL", Proc. IBIC'12, Tsukuba, Japan, 2012. ** B. Keil et al., "The European XFEL BPM System", Proc. IPAC'10, Kyoto, Japan, 2010.
	Poster TUPC25 [1.074 MB]

TUPC45	DOSFET-L02: An Advanced Online Dosimetry System for RADFET Sensors	radiation, monitoring, ELETTRA, controls	481
	L. Fröhlich, S. Grulja Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy F. Löhl PSI, Villigen PSI, Switzerland
	Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3. Radiation-sensing field-effect transistors (RADFETs) are integrating dosimeters that have found wide application in space and particle accelerator environments. We present a new system, the DOSFET-L02, for the readout of up to four RADFET sensors. The system features enhanced readout stability, support for long sensor cables, an adjustable exposure bias voltage of up to 30 V, and integrated temperature measurement. Recent measurements demonstrate the performance of the system with RADFETs at bias voltages of 9 V, 25 V, and under zero bias.

TUPF18	Vertical Undulator Emittance Measurement: A Statistical Approach	emittance, photon, electron, radiation	543
	K.P. Wootton, R.P. Rassool The University of Melbourne, Melbourne, Australia M.J. Boland, B.C.C. Cowie, R.T. Dowd SLSA, Clayton, Australia
	Direct measurement of low vertical emittance in storage rings is typically achieved via interferometric techniques. Proof of low vertical emittance is demonstrated by the measurement of a null radiation field, which is also the crux of the vertical undulator emittance measurement. Here we present strategies to improve the sensitivity to low vertical emittance beams. We move away from photon spectrum analysis to a statistical analysis of undulator radiation, showing the measured increase in signal-to-background. Reproducing simulations of previous work, we demonstrate that photon beam polarisation extends the linearity of the technique by several decades in emittance. These statistical and polarisation improvements to the signal-to-background allow realistic measurement of smallest vertical emittance.
	Poster TUPF18 [2.090 MB]

TUPF19	APPLE-II Undulator Magnetic Fields Characterised from Undulator Radiation	radiation, emittance, photon, insertion	546
	K.P. Wootton, R.P. Rassool The University of Melbourne, Melbourne, Australia M.J. Boland, B.C.C. Cowie SLSA, Clayton, Australia
	The spatial profile of APPLE-II undulator radiation has been measured at high undulator deflection parameter, high harmonic and very small emittance. Undulators are typically designed to operate with small deflection parameter to push the fundamental mode to high photon energies. This unusual choice of parameters is desirable for measurement of vertical emittance with a vertical undulator. We present 1-D and 2-D measured profiles of undulator radiation, and show that this is reproduced in numerical models using the measured magnetic field of the insertion device. Importantly these measurements confirm that for these parameters, the spatial intensity distribution departs significantly from usual Gaussian approximations, instead resembling a double-slit diffraction pattern. This could be an important consideration for photon beamlines of ultimate storage ring light sources.
	Poster TUPF19 [2.364 MB]

WEAL1	Large Aperture X-ray Monitors for Beam Profile Diagnostics	optics, photon, emittance, diagnostics	608
	C.A. Thomas, G. Rehm Diamond, Oxfordshire, United Kingdom F. Ewald ESRF, Grenoble, France J.W. Flanagan KEK, Ibaraki, Japan
	Emittance is one of the main characteristic properties of a beam of particles in an accelerator, and it is measured generally by means of the particle beam profile. In particular, when the beam of particles is emitting an X-ray photon beam, a non perturbative way of measuring the particle beam profile is to image it using the emitted X-ray photon beam. Over the years, numerous X-ray imaging methods have been developed, fulfilling the requirements imposed by a particle beam becoming smaller, and approaching micron size for electron beam machine with vertical emittance of the order of 1pm-rad. In this paper, we will first recall the properties of the X-ray photon as function of source and its properties. From this we will derive some natural definition of a large aperture X-ray imaging system. We will then use this selection criterion to select a number of X-ray imaging devices used as a beam profile diagnostics in an attempt to give an overview of what has been achieved and what is possible to achieve with the selected devices.
	Slides WEAL1 [7.499 MB]

WEPC24	Performance Measurements of the New X-Band Cavity BPM Receiver	BPM, LCLS, dipole, SLAC	735
	A. Young, J.E. Dusatko, S. L. Hoobler, J.J. Olsen, T. Straumann SLAC, Menlo Park, California, USA C. Kim PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515 SLAC is developing a new X-band Cavity BPM receiver for use in the LCLS-II. The Linac Coherent Light Source II (LCLS-II) will be a free electron laser (FEL) at SLAC producing coherent 0.5-77 Angstroms hard and soft x-rays. To achieve this level of performance precise, stable alignment of the electron beam in the undulator is required. The LCLS-II cavity BPM system will provide single shot resolution better than 50 nm resolution at 200 pC. The Cavity BPM heterodyne receiver is located in the tunnel close to the cavity BPM. The receiver will processes the TM010 monopole reference cavity signal and a TM110 dipole cavity signal at approximately 11 GHz using a heterodyne technique. The heterodyne receiver will be capable of detecting a multibunch beam with a 50ns fill pattern. A new LAN communication daughter board will allow the receiver to talk to an input-output-controller (IOC) over 100 meters to set gains, control the phase locked local oscillator, and monitor the status of the receiver. We will describe the design methodology including noise analysis, Intermodulation Products analysis. Commissioning and Performance of LCLS Cavity BPMs, Stephen Smith, et al., Proc. of PAC 2009
	Poster WEPC24 [0.251 MB]

Paper

Title

Other Keywords

Page

MOPC10

Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector

DIAMOND, radiation, photon, beam-position

67

P. Ilinski
BNL, Upton, Long Island, New York, USA

Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, conﬁguration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.

MOPC41

Engineering Design of the New LCLS X-band Transverse Deflecting Cavity

klystron, SLAC, LCLS, controls

167

P. Krejcik, E.L. Bong, M. Boyes, S. Condamoor, J.P. Eichner, G.L. Gassner, A.A. Haase, B. Hong, B. Morris, J.J. Olsen, D.W. Sprehn, J.W. Wang
SLAC, Menlo Park, California, USA

Funding: This work was supported by Department of Energy Contract No. DE-AC0276SF00515
This paper describes the engineering design and installation of the new X-band transverse deflecting cavity installed downstream of the FEL undulator at the LCLS. This is a companion submission to the paper “Commissioning the New LCLS X-Band Transverse Deflecting Cavity with Femtosecond Resolution” also presented at this conference. The project dealt with the challenge of installing a new high-power RF system in the undulator tunnel of the LCLS, outside of the linac tunnel itself and its accelerator engineering infrastructure. A description of the system design, installation, alignment, cooling, controls, vacuum, waveguide, low level RF, klystron and modulator systems for the XTCAV is given, with emphasis on achieving the performance goals necessary to achieve femtosecond resolution.

MOPF08

Design and Performance of the Upgraded LHC Synchrotron Light Monitor

LHC, focusing, optics, dipole

220

A. Goldblatt, E. Bravin, F. Roncarolo, G. Trad
CERN, Geneva, Switzerland

The LHC is equipped with two synchrotron radiation systems, one per beam, used to measure the transverse bunch distributions. The light emitted by a superconducting undulator and/or by a dipole magnet (depending on beam energy) is intercepted by an extraction mirror in vacuum and sent through a viewport to the imaging Beam Synchrotron Radiation Telescope (BSRT). The first version of the telescope, used from 2009 to mid 2012, was based on spherical focusing mirrors in order to minimize chromatic aberrations. However, this required a very complicated delay line in order to switch the focus between the two different light sources as a function of beam energy. A new system based on optical lenses was designed and installed in mid 2012 in order to simplify the optical line and thus reduce misalignment and focusing errors. The first results with LHC beam using this new system showed a significant reduction in the correction factor required to match the emittance as measured by wire scanners. This contribution discusses the performance of the new optical system, presenting the LHC results and comparing simulations with measurement performed in the laboratory using a BSRT replica.

MOPF10

Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics

radiation, CLIC, electron, transverse

228

A. Jeff, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Jeff, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 10¹⁵ electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMAX simulations using the CLIC Drive Beam parameters are shown.

TUAL2

Commissioning the New LCLS X-band Transverse Deflecting Cavity with Femtosecond Resolution

FEL, LCLS, electron, linac

308

P. Krejcik, F.-J. Decker, Y. Ding, J.C. Frisch, Z. Huang, J.R. Lewandowski, H. Loos, J.L. Turner, J.W. Wang, M.-H. Wang, J.J. Welch
SLAC, Menlo Park, California, USA
C. Behrens
DESY, Hamburg, Germany

Funding: This work was supported by Department of Energy Contract No. DE-AC0276SF00515
The new X-band transverse deflecting cavity began operation in May 2013 and is installed downstream of the LCLS undulator. It is operated at the full 120 Hz beam rate without interfering with the normal FEL operation for the photon users. The deflected beam is observed on the electron beam dump profile monitor, which acts as an energy spectrometer in the vertical plane. We observe, on a pulse by pulse basis, the time resolved energy profile of the spent electron beam from the undulator. The structure is powered from a 50 MW X-band klystron, giving a 48 MV kick to the beam which yields a 1 fs rms time resolution on the screen. We have measured the longitudinal profile of the electron bunches both with the FEL operating and with the lasing suppressed, allowing reconstruction of both the longitudinal profile of the incoming electron beam and the time-resolved profile of the X-ray pulse generated in the FEL. We are immediately able to see whether the bunch is chirped and which parts of the bunch are lasing, giving us new insight into tuning the machine for peak performance. The performance of the system will be presented along with examples of measurements taken during LCLS operation.

Slides TUAL2 [9.210 MB]

TUPC25

Design of the SwissFEL BPM System

BPM, pick-up, XFEL, linac

427

B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, F. Marcellini, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer
PSI, Villigen PSI, Switzerland

SwissFEL is a Free Electron Laser (FEL) facility being constructed at PSI, based on a 5.8GeV normally conducting main linac. A photocathode gun will generate two bunches with 28ns spacing at 100Hz repetition rate, with a nominal charge range of 10-200pC. A fast beam distribution kicker will allow to distribute one bunch to a soft X-ray undulator line and the other bunch to a 0.1nm hard X-ray undulator line. The SwissFEL electron beam position monitor (BPM) system will employ three different types of dual-resonator cavity BPMs, since the accelerator has three different beam pipe apertures. In the injector and main linac (38mm and 16mm aperture), 3.3GHz cavity BPMs will be used, where a low Q of ~40 was chosen to minimize crosstalk of the two bunches*. In the undulators that just have single bunches and 8mm BPM aperture, a higher Q will be chosen. This paper reports on the development status of the SwissFEL BPM system. Synergies as well as differences to the E-XFEL BPM system** will also be highlighted.
* F. Marcellini et al., "Design of Cavity BPM Pickups For SwissFEL", Proc. IBIC'12, Tsukuba, Japan, 2012.
** B. Keil et al., "The European XFEL BPM System", Proc. IPAC'10, Kyoto, Japan, 2010.

Poster TUPC25 [1.074 MB]

TUPC45

DOSFET-L02: An Advanced Online Dosimetry System for RADFET Sensors

radiation, monitoring, ELETTRA, controls

481

L. Fröhlich, S. Grulja
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
F. Löhl
PSI, Villigen PSI, Switzerland

Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3.
Radiation-sensing field-effect transistors (RADFETs) are integrating dosimeters that have found wide application in space and particle accelerator environments. We present a new system, the DOSFET-L02, for the readout of up to four RADFET sensors. The system features enhanced readout stability, support for long sensor cables, an adjustable exposure bias voltage of up to 30 V, and integrated temperature measurement. Recent measurements demonstrate the performance of the system with RADFETs at bias voltages of 9 V, 25 V, and under zero bias.

TUPF18

Vertical Undulator Emittance Measurement: A Statistical Approach

emittance, photon, electron, radiation

543

K.P. Wootton, R.P. Rassool
The University of Melbourne, Melbourne, Australia
M.J. Boland, B.C.C. Cowie, R.T. Dowd
SLSA, Clayton, Australia

Direct measurement of low vertical emittance in storage rings is typically achieved via interferometric techniques. Proof of low vertical emittance is demonstrated by the measurement of a null radiation field, which is also the crux of the vertical undulator emittance measurement. Here we present strategies to improve the sensitivity to low vertical emittance beams. We move away from photon spectrum analysis to a statistical analysis of undulator radiation, showing the measured increase in signal-to-background. Reproducing simulations of previous work, we demonstrate that photon beam polarisation extends the linearity of the technique by several decades in emittance. These statistical and polarisation improvements to the signal-to-background allow realistic measurement of smallest vertical emittance.

Poster TUPF18 [2.090 MB]

TUPF19

APPLE-II Undulator Magnetic Fields Characterised from Undulator Radiation

radiation, emittance, photon, insertion

546

K.P. Wootton, R.P. Rassool
The University of Melbourne, Melbourne, Australia
M.J. Boland, B.C.C. Cowie
SLSA, Clayton, Australia

The spatial profile of APPLE-II undulator radiation has been measured at high undulator deflection parameter, high harmonic and very small emittance. Undulators are typically designed to operate with small deflection parameter to push the fundamental mode to high photon energies. This unusual choice of parameters is desirable for measurement of vertical emittance with a vertical undulator. We present 1-D and 2-D measured profiles of undulator radiation, and show that this is reproduced in numerical models using the measured magnetic field of the insertion device. Importantly these measurements confirm that for these parameters, the spatial intensity distribution departs significantly from usual Gaussian approximations, instead resembling a double-slit diffraction pattern. This could be an important consideration for photon beamlines of ultimate storage ring light sources.

Poster TUPF19 [2.364 MB]

WEAL1

Large Aperture X-ray Monitors for Beam Profile Diagnostics

optics, photon, emittance, diagnostics

608

C.A. Thomas, G. Rehm
Diamond, Oxfordshire, United Kingdom
F. Ewald
ESRF, Grenoble, France
J.W. Flanagan
KEK, Ibaraki, Japan

Emittance is one of the main characteristic properties of a beam of particles in an accelerator, and it is measured generally by means of the particle beam profile. In particular, when the beam of particles is emitting an X-ray photon beam, a non perturbative way of measuring the particle beam profile is to image it using the emitted X-ray photon beam. Over the years, numerous X-ray imaging methods have been developed, fulfilling the requirements imposed by a particle beam becoming smaller, and approaching micron size for electron beam machine with vertical emittance of the order of 1pm-rad. In this paper, we will first recall the properties of the X-ray photon as function of source and its properties. From this we will derive some natural definition of a large aperture X-ray imaging system. We will then use this selection criterion to select a number of X-ray imaging devices used as a beam profile diagnostics in an attempt to give an overview of what has been achieved and what is possible to achieve with the selected devices.

Slides WEAL1 [7.499 MB]

WEPC24

Performance Measurements of the New X-Band Cavity BPM Receiver

BPM, LCLS, dipole, SLAC

735

A. Young, J.E. Dusatko, S. L. Hoobler, J.J. Olsen, T. Straumann
SLAC, Menlo Park, California, USA
C. Kim
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515
SLAC is developing a new X-band Cavity BPM receiver for use in the LCLS-II. The Linac Coherent Light Source II (LCLS-II) will be a free electron laser (FEL) at SLAC producing coherent 0.5-77 Angstroms hard and soft x-rays. To achieve this level of performance precise, stable alignment of the electron beam in the undulator is required. The LCLS-II cavity BPM system will provide single shot resolution better than 50 nm resolution at 200 pC*. The Cavity BPM heterodyne receiver is located in the tunnel close to the cavity BPM. The receiver will processes the TM010 monopole reference cavity signal and a TM110 dipole cavity signal at approximately 11 GHz using a heterodyne technique. The heterodyne receiver will be capable of detecting a multibunch beam with a 50ns fill pattern. A new LAN communication daughter board will allow the receiver to talk to an input-output-controller (IOC) over 100 meters to set gains, control the phase locked local oscillator, and monitor the status of the receiver. We will describe the design methodology including noise analysis, Intermodulation Products analysis.
* Commissioning and Performance of LCLS Cavity BPMs, Stephen Smith, et al., Proc. of PAC 2009

Poster WEPC24 [0.251 MB]