T.H. Pacey, D. Angal-Kalinin, A.R. Bainbridge, J. Henderson, J.K. Jones, N.Y. Joshi, S.L. Mathisen, A.E. Pollard, Y.M. Saveliev, E.W. Snedden, C. Tollervey, D.A. Walsh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D. Angal-Kalinin, A.R. Bainbridge, J.K. Jones, T.J. Overton, Y.M. Saveliev, C. Swain, J. Wolfenden
Cockcroft Institute, Warrington, Cheshire, United Kingdom
J. Henderson
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
N.Y. Joshi
UMAN, Manchester, United Kingdom
T.J. Overton
The University of Manchester, Manchester, United Kingdom
C. Swain, J. Wolfenden
The University of Liverpool, Liverpool, United Kingdom
The FEBE beamline at the CLARA facility will combine a 250 MeV FEL quality electron beam with a 100 TW class laser. One area of research FEBE will support is novel acceleration schemes; both structure and plasma based. There are stringent diagnostic requirements for measuring the input electron beam and challenges in characterisation of the accelerated beams produced by these novel schemes. Several of these challenges include measurement of: micrometer scale transverse profiles, 10 fs scale bunch lengths, single shot emittance, broadband energy spectra at high resolution, and laser-electron time of arrival jitter. Furthermore, novel shot-by-shot non-invasive diagnostics are required for machine learning driven optimisation and feedback systems. This paper presents an overview of R&D activities in support of developing a 6D diagnostics suite to meet these challenges.
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F. Fienga, G. Breglio, A. Irace, V.R. Marrazzo, L. Sito
University of Napoli Federico II, Napoli, Italy
N. Beni, G. Breglio, S. Buontempo, F. Carra, F. Fienga, F. Giordano, V.R. Marrazzo, B. Salvant, L. Sito, Z. Szillasi
CERN, Meyrin, Switzerland
N. Beni, Z. Szillasi
Atomki, Debrecen, Hungary
S. Buontempo
INFN-Napoli, Napoli, Italy
The passage of a high-intensity particle beam inside accelerator components generates heating, potentially leading to degradation of the accelerator performance or damage to the component itself. It is therefore essential to monitor such beam-induced heating in accelerators. This paper showcases the capabilities of iPipe, which is a set of Fiber Bragg Grating sensors stuck on the inner beam pipe of the Compact Muon Solenoid (CMS) experiment installed in the CERN Large Hadron Collider (LHC). In this study, the wavelength shift, linked directly to the temperature shift, is measured and is compared with the computed dissipated power for a set of LHC fills. Electromagnetic and thermal simulations were also coupled to predict the beam-induced temperature increase along the beam pipe. These results further validate the sensing system and the methods used to design accelerator components to mitigate beam-induced heating.
D. Lipka, M. Holz, S. Vilcins
DESY, Hamburg, Germany
The SINBAD facility (Short and INnovative Bunches and Accelerators at DESY) hosts various experiments in the field of production of ultra-short electron bunches and novel high gradient acceleration techniques. The SINBAD facility, also called ARES (Accelerator Research Experiment at SINBAD), is a conventional S-band linear RF accelerator allowing the production of low charge ultra-short electron bunches within a range between 0.5 pC and 1000 pC. The positions of the low charge bunches will be detected by cavity beam position monitors. The principal design is based on the experience from the EU-XFEL cavity beam position monitors. It consists of a 316 LN stainless steel body with a design loaded quality factor of 70, a resonance frequency of 3.3 GHz and a relative wide gap of 15 mm to reach a high peak position sensitivity of 4.25 V/(nC mm). This poster covered, the manufacture of the individual mechanical parts, as well as presents the special features in the manufacture of customer designed UHV feedthroughs.
K. Tian, W.J. Corbett, J. Kim, J.A. Safranek
SLAC, Menlo Park, California, USA
The Transverse Resonance Island Buckets have been studied at SPEAR3 as an option for timing experiment mode operation of this third generation synchrotron radiation facility. In this mode, with proper optics setting, the electron beam is populated to island orbits with the excitation from a kicker. In this paper, we will report the experimental observation of the beam dynamics with turn by turn beam position monitors and a fast gated camera. The results are also compared with tracking simulations.
R.L. Hermann, M. Galonska, Th. Haberer, A. Peters
HIT, Heidelberg, Germany
T. Gehrke
German Cancer Research Center (DKFZ), Heidelberg, Germany
B. Leverington
Universität Heidelberg, Heidelberg, Germany
Funding:Funded by Deutsche Forschungsgemeinschaft (DFG), project number 426970603. The Heidelberg Ion-Beam Therapy Center (HIT) pro-vides proton, helium, and carbon-ion beams with differ-ent energies and intensities for cancer treatment and oxy-gen-ion beams for experimentation. Below the intensities used for therapy, low-intensity ion beams (below 1·105 ions/s) are available for various experiments via manual-ly degrading of the beam. Since there is no built-in beam profile instrumentation device for this intensity region, the development of a transverse ion beam profile monitor for these intensities is therefore of interest. The principle of operation is based on scintillating fibres, particularly those with enhanced radiation hardness. The fibres transform the deposited energy of a traversing ion into photons, which are then converted and amplified via silicon pho-tomultipliers (SiPMs) into electric pulses. These pulses are recorded and processed by a novel and dedicated readout electronics: the front-end readout system (FERS) A5200 by CAEN. A prototype set-up consisting of all the above-mentioned parts was tested in beam and has proven to record the transverse beam profile successfully from intensities of 1·107 ions/s down to 1·102 ions/s.
N. Vitoratou, L. Bobb
DLS, Oxfordshire, United Kingdom
A. Last
KIT, Eggenstein-Leopoldshafen, Germany
G. Rehm
HZB, Berlin, Germany
X-ray pinhole cameras are employed to provide the transverse profile of the electron beam from which the emittance, coupling and energy spread are calculated in the storage ring of Diamond Light Source. Tungsten blades separated by shims are commonly used to form the pinhole aperture. However, this approach introduces uncertainties regarding the aperture size. X-ray lithography, electroplating and moulding, known as LIGA, has been used to provide thin screens with well-defined and high aspect ratio pinhole apertures. Thus, the optimal aperture size given the beam spectrum can be used to improve the spatial resolution of the pinhole camera. Experimental results using a LIGA screen of different aperture sizes have been compared to SRW-Python simulations over the 15-35 keV photon energy range. Good agreement has been demonstrated between the experimental and the simulation data. Challenges and considerations for this method are also presented.
M.U. Urbaniak, Y. Balkova, S.K. Kowalski, S. Puławski, K.W. Wójcik
University of Silesia in Katowice, Katowice, Poland
NA61/SHINE is a fixed-target experiment located at CERN Super Proton Synchrotron. The development of new beam position detectors is part of the ongoing upgrade of the detector system. Two types of detectors have been manufactured and tested. The first one is a scintillating fibers detector with photomultiplier as a readout. The scintillating fibers detector consists of two ribbons, which are arranged perpendicularly to each other. Each ribbon is made of two layers of 250 µm diameter fibers. The grouping method was used, which allows using of a single multichannel photomultiplier for one detector. The second type of detector is based on the single-sided silicon strip detector (SSD). In this project, Si strips produced by Hamamatsu (S13804) were used, where the pitch has a width equal to 190 um. The developed detectors must meet several requirements: should work efficiently with proton and lead beams with beam intensity on the level of 100 kHz, the detector’s material on the beamline should be minimized, the detectors should be able to determine the position of X and Y hit of each beam particle with maximum possible accuracy. During my speech I will present the results of our work.
N. Aftab, Z. Aboulbanine, P. Boonpornprasert, G.Z. Georgiev, J. Good, M. Groß, A. Hoffmann, M. Krasilnikov, X.-K. Li, A. Lueangaramwong, R. Niemczyk, A. Oppelt, H.J. Qian, C.J. Richard, F. Stephan, G. Vashchenko
DESY Zeuthen, Zeuthen, Germany
W. Hillert
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
A.J. Reader
KCL, London, United Kingdom
Methodical studies to improve the longitudinal phase space (LPS) tomography of space-charge dominated electron beams were carried out at the Photo Injector Test facility at DESY in Zeuthen (PITZ). An analytical model was developed to quantify mean momentum, RMS energy spread, bunch length and phase advance. Phase advance analysis determined the booster phase scan range and step size to be used for obtaining momentum projections. A slit was introduced before the booster to truncate the beam in transverse plane to strongly reduce the space charge effects. The signal resolution of this truncated beam was improved by careful beta function control at the reference screen of the momentum measurements. The reconstruction algorithm was changed from Algebraic Reconstruction Technique (ART) to Image Space Reconstruction Algorithm (ISRA) owing to its assurance of non-negative solutions. In addition, the initial physically justified assumption of LPS, based on low-energy section measurements, was established to clear out noise-like artefacts. This paper will highlight the improvements made in the LPS tomography and compare the simulated and experimental results.
S.L. Mathisen, T.H. Pacey, R.J. Smith
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
As part of the development of the CLARA electron accelerator at Daresbury Laboratory, a new analog front end for bunch charge measurement has been developed to provide accurate measurements across a wide range of operating charges with repetition rates of up to 400 Hz. The qualification tests of the front end are presented. These include tests of the online calibration system, compared to a bench Faraday cup test setup; online beam test data with a Faraday cup from 1 to 200 pC; online beam test data with a wall current monitor from 1 to 200 pC, and tests using signal processing such as singular value decomposition. This is demonstrated to enable the measurement of bunch charges in the order of 100 fC using both Faraday Cups and Wall Current Monitors.
S. Brandenburg, M.J. Goethem
PARTREC, Groningen, The Netherlands
T. Delaviere, L. Dupuy, F. Stulle
BERGOZ Instrumentation, Saint Genis Pouilly, France
In conventional proton therapy (PT) typical beam currents are of the order of 1 nA. At these currents dose monitoring is reliably achieved with an ionization chamber. However, at the very high dose rates used in FLASH irradiations (employing beam currents >100 nA) ionization chambers will exhibit large intensity dependent recombination effects and cannot be used. A possible solution is a current transformer. Here we report on the performance of the LC-CWCT (Bergoz Instrumentation, France) which has been developed to push noise floor of such non-destructive current measurement systems into the nano-ampere range. We present first beam current measurements at the PARTREC cyclotron (Netherlands). Beam currents measured by the LC-CWCT and a Faraday Cup were shown to linearly correlate up to the maximum intensity of 400 nA used in the measurements. For pulsed beams, charge measured by the LC-CWCT linearly correlated with pulse length over the measurement range from 50 to 1000 µs. Measurement noise as low as 2.8 nA was achieved. The results confirm that the LC-CWCT has the potential to be applied in FLASH PT for accurate determination of beam current and macro pulse charge.
S. Mazzoni, W. Andreazza, E. Balci, D. Belohrad, E. Bravin, N.S. Chritin, J.C. Esteban Felipe, T. Lefèvre, M. Martin Nieto, M. Palm
CERN, Meyrin, Switzerland
The Beam Rate of Neutrals (BRAN) is a monitor that provides a relative luminosity measurement for the four LHC experiments. BRANs are used during operations as a tool to find and optimise collision and to cross-check experiments luminosity monitors. While each LHC experiments is equipped with BRANs, in this contribution we will focus on the new monitors installed for ATLAS and CMS that will replace the current ageing gas chambers during LHC run 3. These will also serve as as prototypes for the future High Luminosity LHC monitors that will need to sustain an even higher collision rate. A description of the BRAN as well as the first results obtained during the LHC Run 3 start-up will be presented.
S. Takano, T. Fujita, K. Fukami, H. Maesaka, M. Masaki, K. Soutome, M. Takao, T. Watanabe
JASRI, Hyogo, Japan
K. Fukami, T. Hiraiwa, H. Maesaka, K. Soutome, S. Takano, H. Tanaka, T. Watanabe
RIKEN SPring-8 Center, Hyogo, Japan
K. Ueshima
QST, Sendai, Miyagi, Japan
The alignment of sextupole magnets is one of the critical issues for the upcoming 4th generation light sources and future colliders. The alignment error of magnets and the beam offsets in sextupoles should be within a few 10 µm rms to ensure enough dynamic aperture for stable operation and minimize deterioration of beam quality. Considering that the quadrupole field in a sextupole is proportional to the displacement (normal Q for horizontal and skew Q for vertical), we propose a beam-based calibration (BBC) method to measure the sextupole centers by observing the betatron tune shift. The magnetic center is the point where the tune does not change regardless of the sextupole field strength. The key is increasing the XY coupling to obtain a tune shift large enough for the vertical calibration. We studied experimentally the feasibility of the sextupole BBC at SPring-8 and successfully demonstrated the principle for both horizontal and vertical calibration. The tune shift was monitored by bunch-by-bunch feedback electronics with approximately 1e-5 resolution. The measurement resolution of the sextupole center was approximately 10 µm std., which was sufficient for our requirement.
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A.I. Novokshonov, G. Kube, S. Strokov
DESY, Hamburg, Germany
Z. Aboulbanine, G.D. Adhikari, N. Aftab, P. Boonpornprasert, G.Z. Georgiev, J. Good, M. Groß, C. Koschitzki, M. Krasilnikov, X. Li, O. Lishilin, A. Lueangaramwong, D. Melkumyan, F. Mueller, A. Oppelt, H.J. Qian, F. Stephan, G. Vashchenko, T. Weilbach
DESY Zeuthen, Zeuthen, Germany
A standard technique to measure beam profiles in linear accelerators are screen monitors using scintillating screens. This technique is used e.g. at the European XFEL in order to overcome coherence effects in case of OTR usage [*]. During the XFEL commissioning it was found out that screens based on LYSO:Ce as scintillating material revealed a nonproportional light output [**]. Reason for it is the high particle beam density. As consequence it was decided to exchange LYSO:Ce by GAGG:Ce scintillators because the excitation carriers can rapidly transfer their energy to excited states of gadolinium, and a rapid migration of this energy among the Gd sub-lattice is expected. Driven by the observations at XFEL a series of measurements was started to investigate the properties of various scintillator materials (LYSO:Ce, YAP:Ce, YAG:Ce, LuAG:Ce and GAGG:Ce). The last measurement campaign was carried out at PITZ which allows to operate at higher beam charge and lower electron energy compared to the XFEL. The present work summarizes the results of these measurements. * S.Wesch and B.Schmidt, in Proc. DIPAC’11, Hamburg, WEOA01, pp. 539-543. ** G.Kube, A.Novokshonov, S.Liu, M.Scholz, in Proc. FEL’19, Hamburg, WEB01, pp. 301-306.
C. Salgado-López, A. Curcio, G. Gatti, J.L. Henares, J. Imanol Apiñaniz, J.A.P. Pérez-Hernández, L. Volpe, D. de Luis
CLPU, Villamayor, Spain
Funding:LASERLAB-EUROPE V (Grant Agreement No. 871124, EU Horizon 2020). IMPULSE (Grant Agreement No. 871161, EU Horizon 2020). Equipment Grant No. EQC2018-005230-P, Junta de CyL (Grant No. CLP263P20). Laser-plasma driven accelerators have become reliable sources of low-emittance, broadband and multi-species ion sources, with cut-off energies above the MeV-level*. We report on the development, construction, and experimental test of an angle resolved Thomson parabola spectrometer for laser-accelerated multi-MeV ion beams able to distinguish between ionic species with different q/m ratio. The angular resolving power, which is achieved due to an array of entrance pinholes, can be simply adjusted by modifying the geometry of the experiment and/or the pinhole array itself. The analysis procedure allows for different ion traces to cross on the detector plane, which greatly enhances the flexibility and capabilities of the detector. A full characterization of the TP magnetic field has been implemented into a relativistic code developed for the trajectory calculation of each beamlet. High repetition rate compatibility is guaranteed by the use of a MCP as active particle detector. We describe the first test of the spectrometer at the 1PW VEGA 3 laser facility at CLPU, Salamanca (Spain), where up to 15MeV protons and carbon ions from a 3-micron laser-irradiated metallic foil are detected**. *A. Macchi et. al., Rev. Mod. Phys. 85, 751 (2013) **C. Salgado et. al., Sensors 22, 3239 (2022).
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D.S. Levin, C. Ferretti, A. Kaipainen, N.A. Ristow
University of Michigan, Ann Arbor, Michigan, USA
P.S. Friedman
Integrated Sensors, LLC, Ottawa Hills, Ohio, USA
T.N. Ginter
NSCL, East Lansing, Michigan, USA
Funding:This work is funded by SBIR Phase-II Award No. DE-SC0019597, DOE Office of Science to Integrated Sensors, LLC. A high performance Scintillator Ion Beam Monitor (SBM)provides diagnostics across a range of isotopes, energies, and intensities. It uses a machine-vision camera and a magazine of thin scintillators, movable into the beam without breaking vacuum. Two proprietary scintillators are used: a semicrystalline polymer material (PM) tested over a thickness range of ~1 to 190 µm. The PM yields stronger signals than other commercial plastic scintillators tested and is radiation damage resistant; a 100-400 µm opaque wafer consisting of inorganic crystals in a polymer hybrid matrix (HM). Both PM and HM are non-hygroscopic and produce minimal secondary reflections. HM produces significantly larger signals than CsI with excellent radiation damage resistance. The SBM was staged at the FRIB (East Lansing) ion beam, demonstrating real-time beam profile and rate analysis spanning more than five orders-of-magnitude including visualization of single ion signals with ~10-20 µm spatial resolution. It is superior to and may replace the reference detectors: Faraday cup, silicon strips and a CCD camera beam imager. A proton test beam extended the dynamic range by four orders-of-magnitude.
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N. Samadi, G. Lovric, C. Ozkan Loch
PSI, Villigen PSI, Switzerland
X. Shi
ANL, Lemont, Illinois, USA
The advance in low-emittance x-ray sources urges the development of novel diagnostic techniques. Existing systems either have limited resolution or rely heavily on the quality of the optical system. An x-ray beam property analyzer based on a multi-crystal diffraction geometry was recently introduced. By measuring the transmitted beam profile of a dispersive Laue crystal downstream of a double-crystal monochromator, the system can provide a high-sensitivity characterization of spatial source properties, namely, size, divergence, position, and angle in the diffraction plane of the system at a single location in a beamline. In this work, we present the experimental validation at a super-bending magnet beamline at the Swiss Light Source and refine the method to allow for time-resolved characterization of the beam. Simulations are then carried out to show that the system is feasible to characterize source properties at undulator beamlines for fourth-generation light sources.
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M. Masaki, H. Dewa, T. Fujita, H. Maesaka, K. Soutome, T. Sugimoto, S. Takano, M.T. Takeuchi, T. Watanabe
JASRI, Hyogo, Japan
T. Fukui, H. Maesaka
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
K. Kubota
SES, Hyogo-pref., Japan
K. Soutome, T. Sugimoto, S. Takano, H. Tanaka, T. Watanabe
RIKEN SPring-8 Center, Hyogo, Japan
We developed a new correction algorithm for closed orbit distortion (COD) based on adaptive feedforward control (AFC). The AFC system effectively works for the suppression of the fast COD due to known error sources with repetitive patterns such as helicity-switching undulators. The scheme aims to counteract error sources by feedforward correctors at the position or in the vicinity of error sources so that a potential risk of unwanted local orbit bumps, which is known to exist for the global orbit feedback, can be eliminated in a reliable and accurate manner. This option is especially advantageous when an error source causes an angular distortion of photon beams such as a fast orbit distortion near undulators. Thus, the AFC provides a complementary capability to a so-called fast global orbit feedback (FOFB) for coming next-generation light sources where ultimate light source stability is essentially demanded. In this talk, introduction to the AFC, its theoretical aspect and advantages, the system overview, the experimental results for the effects of AFC will be presented. M. Masaki, et al., J. Synchrotron Rad. 28, 1758-1768 (2021).
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R. Hill
University of Huddersfield, Huddersfield, United Kingdom
Standard beam position monitors (BPM) are intrinsically insensitive to beams with no temporal structure, so-called DC beams, which many CERN experiments rely on. We therefore propose a novel detection technique in which the usual BPM electrodes are replaced with electro-optic (EO) crystals. When exposed to an electric field, such crystals change their optical properties. This can be exploited to encode the electric field magnitude onto the polarisation state of a laser beam crossing the crystal. An additional EO crystal, placed outside the vacuum chamber, can be used to control the system’s working point and to introduce a sinusoidal modulation, allowing DC measurements to be performed in the frequency domain. This contribution presents the working principle of this measurement technique, its known limitations, and possible solutions to further increase the system’s performance. Analytical results and simulations for a double-crystal optical chain are benchmarked against the experimental data taken on a laboratory test bench.
C. Bloomer, L. Bobb
DLS, Oxfordshire, United Kingdom
W. Freund, J. Grünert, J. Liu
EuXFEL, Schenefeld, Germany
M.E. Newton
University of Warwick, Coventry, United Kingdom
The European XFEL can generate extremely intense, ultra-short X-ray pulses at MHz repetition rates. Single-crystal CVD diamond detectors have been used to transparently measure the photon beam position and pulse intensity. The diamond itself can withstand the power of the beam, but the surface electrodes can be damaged since a single pulse can already exceed the damage threshold of the electrode material. Presented in this work are pulse intensity and position measurements obtained at the European XFEL using a new type of all-carbon single-crystal diamond detector developed at Diamond Light Source. Instead of traditional surface metallisation, the detector uses laser-written graphitic electrodes buried within the bulk diamond. There is no metallisation in the XFEL X-ray beam path that could be damaged by the beam. The results obtained from a prototype detector are presented, capable of measuring the intensity and 1-dimensional X-ray beam position of individual XFEL pulses. These successful measurements demonstrate the feasibility of all-carbon diagnostic detectors for XFEL use.
U. Iriso, A.A. Nosych, M. Zeus
ALBA-CELLS, Cerdanyola del Vallès, Spain
A.C. Cazorla
ICMAB, Bellatera, Spain
I. Mases Solé
CERN, Meyrin, Switzerland
ALBA is currently equipped with two x-ray pinhole cameras for continuous beam size monitoring using the synchrotron radiation from two different bending magnets. The first pinhole was installed in day-1 and it is working properly since 2012 as the work-horse for the ALBA emittance measurements, while the second one has been commissioned in beginning 2021 for redundancy purposes. This paper summarizes the exercises to characterize the Point Spread Function (PSF) of both pinhole cameras using analytical calculations, SRW simulations, and experimental measurements using the beam lifetime.
J. Herranz
Proactive Research and Development, Sabadell, Spain
I. Bustinduy, .A. Rodríguez Páramo
ESS Bilbao, Zamudio, Spain
P. Forck, T. Sieber
GSI, Darmstadt, Germany
A. Navarro Fernandez
CERN, Meyrin, Switzerland
New SEM-Grid has been developed for FAIR Proton Linac, the instrument consists of 2 harps fixed together in an orthogonal way. This SEM-Grid will provide higher resolution and accuracy measurements as each harp consists of 64 tungsten wires 100 micro-meter in diameter and 0.5 mm pitch. Each wire is fixed to a ceramic PCB with an innovative dynamic stretching system, this system assures wire straightness under typical thermal expansion due to beam heat deposition. Electric field distribution has been performed, 3 main parameters have been optimized, wires distribution, quantity of polarization electrodes and distance between electrodes and wires. The design and production of the SEM-Grids have been performed by the company Proactive R&D that has count on the expertise of ESS-Bilbao to define safe operation limits and signal estimation by means of a code developed specifically for this type of calculations. Preliminary validations of the first prototypes shown good values of electric field behaviour signal. After additional beam test validations to be performed on June 2022, final series of the SEM-Grid will be produced and installed on FAIR proton LINAC.
A. Navarro Fernandez, M. Martin Nieto, F. Roncarolo
CERN, Meyrin, Switzerland
The operation of wire grids and wire scanners as beam profile monitors can be heavily affected, both in terms of measurement accuracy and wire integrity, by the thermal response of the wires to the energy deposited by the charged particles. Accurate measurements of material emissivity are crucial, as Radiative Cooling represent the most relevant cooling process. In this work, we present a method for emissivity measurements of gold-coated tungsten wires based on calorimetric techniques. The dedicated electrical setup allowed allowed transient and steady state measurements for temperatures up to 2000 K. A theoretical description of the measurement technique will be followed up by the electrical set up description and a detailed discussion about the measured results and uncertainties.
L. Parsons França, M. Duraffourg, F. Roncarolo, F.M. Velotti
CERN, Meyrin, Switzerland
E. Kukstas, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
Funding:This work was supported by CERN and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. The CERN fixed target experimental areas have recently acquired new importance thanks to newly proposed experiments, such as those linked to Physics Beyond Colliders (PBC) activities. Secondary Emission Monitors (SEMs) are the instruments currently used for measuring beam current, position and size in these areas. Guaranteeing their reliability, resistance to radiation and measurement precision is challenging. This paper presents the studies being conducted to understand ageing effects on SEM devices, to calibrate and optimise the SEM design for future use in these beamlines. These include feasibility studies for the application of machine learning techniques, with the objective of expanding the range of tools available for data analysis.
S.J. Martens
University of Saskatchewan, Saskatoon, Canada
T. Batten, D. Bertwistle, M.J. Boland
CLS, Saskatoon, Saskatchewan, Canada
A transverse bunch-by-bunch feedback system has been installed in the storage ring at the Canadian Light Source (CLS) to counteract beam instabilities. The 2.9 GeV electron storage ring is 171~m in circumference with 13 insertion devices currently installed, each contributing to the impedance of the ring and lowering the instability threshold. The new Transverse Feedback System (TFBS) provides improved bunch isolation, higher bandwidth amplification and diagnostics to study, understand and damp these instabilities. This paper will show and overview of the system setup, examples of operational performance and results of the diagnostic capabilities, including tune feedback, grow/damp measurements and excite/damp measurements.
S.E. Engel
University of Essex, Physics Centre, Colchester, United Kingdom
P. Boutachkov, R. Singh
GSI, Darmstadt, Germany
An exploration into the application of three machine learning (ML) approaches to identify and separate events in the detectors used for particle counting at the GSI Helmholtz Centre for Heavy Ion Research. A convolutional neural network (CNN), a shape-based template matching algorithm (STMF) and Peak Property-based Counting Algorithm (PPCA) were developed to accurately count the number of particles without domain-specific knowledge required to run the currently used algorithm. The three domain-agnostic ML algorithms are based on data from scintillation counters commonly used in beam instrumentation and represent proof-of-work for an automated particle counting system. The algorithms were trained on a labelled set of over 150 000 experimental particle data. The results of the three classification approaches were compared to find a solution that best mitigates the effects of particle pile-ups. The two best-achieving algorithms were the CNN and PPCA, achieving an accuracy of 99.8\%. This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under GA No 101004730.
P. Boutachkov, M. Saifulin, C. Trautmann, B. Walasek-Höhne
GSI, Darmstadt, Germany
E.I. Gorokhova
GOI, St Petersburg, Russia
P. Rodnyi, I.D. Venevtsev
SPbPU, St. Petersburg, Russia
Novel radiation-hard scintillators were developed in the last years based on indium-doped ZnO ceramic with an extremely short decay time below a ns. Fast counting detectors and fast screens were considered as potential beam diagnostic applications of this material. At the GSI/FAIR facility, scintillation detectors are commonly used for measuring the intensity and detailed time structure of relativistic heavy ion beams. The scintillating material is inserted directly into the beam path. Signals from individual ions are counted, providing systematic-error-free beam intensity information. Standard scintillators require frequent maintenance due to radiation damage. To address this limitation, a large area ZnO radiation-hard detector was developed. The prototype detector operates at orders of magnitude higher irradiation levels, at higher counting rates and has better time resolution compared to a plastic scintillator. In addition, the novel detector material opens the possibilities for applications in other beam diagnostic systems, for example, scintillation screens for transverse profile measurements. Therefore, ZnO scintillation ceramics are of general interest for beam diagnostics.
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A. Mariet, B. Moser, R. Veness
CERN, Meyrin, Switzerland
M. Devel, J.E. Groetz
UFC, Besançon, France
A. Mikhalchan, J.J. Vilatela
IMDEA, Madrid, Spain
With the planned increase of luminosity at CERN for HL-LHC and FCC, instruments for beam quality control must meet new challenges. The current wires, made up of plain carbon fibers and gold-plated tungsten would be damaged due to their interactions with the higher luminosity beams. We are currently testing a new and innovative material, with improved performance: carbon nanotube fibers (CNTF). The HiRadMat (High Radiation for Material) experimental line at the output of the SPS is a user facility which can irradiate fix targets up to 440 GeV/c. CNTF with various diameters were irradiated in HiRadMat with different intensities, later imaged with a SEM microscope and tested for their mechanical properties. In addition, simulations have been carried out with the FLUKA particle physics Monte-Carlo code, in order to better understand the mechanisms and assess the energy deposition from protons at 440 GeV/c in those CNTF wires, depending mainly on their diameters and densities. This could lead to a good estimation of the CNTF temperature during irradiation. In this contribution, we first present the HiRadMat experimental setup and then we discuss the results of our FLUKA simulations.
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C. Szwaj, S. Bielawski, C. Evain, E. Roussel
PhLAM/CERLA, Villeneuve d’Ascq, France
C. Gerth, B. Steffen
DESY, Hamburg, Germany
B. Jalali
UCLA, Los Angeles, California, USA
Funding:ULTRASYNC ANR-DFG project, CPER Photonics for Society, CEMPI LABEX Recording electric field evolutions in single-shot and with sub-picosecond resolution is required in electron bunch diagnostics, and THz applications. A popular strategy consists of transferring the unknown electric field shape onto a chirped laser pulse, which is eventually analyzed. The technique has been investigated and/or been used as routine diagnostics at FELIX, DESY, PSI, Eu-XFEL, KARA, SOLEIL, etc. However fundamental time-resolution limitations have been strongly limiting the potential of these methods. We review recent results on a strategy designed for overcoming this limit: DEOS [1] (Diversity Electro-Optic Sampling). A special experimental design enables to reconstruct numerically the input electric signal with unprecedented temporal resolution. As a result, 200 fs temporal resolution over more than 10 ps recording length could be obtained at European XFEL - a performance that could not be realized using classical spectrally-decoded electro-optic detection. Although DEOS uses a radically novel conceptual approach, its implementation requires few hardware modifications of currently operating chirped pulse electro-optic detection systems. [1] E. Roussel, C. Szwaj, C. Evain, B. Steffen, C. Gerth, B. Jalali and S. Bielawski, Light: Science & Applications 11, 14 (2022). https://www.nature.com/articles/s41377-021-00696-2
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