ICALEPCS2021 - List of Keywords (alignment)

Paper	Title	Other Keywords	Page
MOPV021	Upgrading the National Ignition Facility’s (NIF) Integrated Computer Control System to Support Optical Thompson Scattering (OTS) Diagnostic	controls, laser, database, operation	173
	A.I. Barnes, A.A.S. Awwal, L. Beaulac, B. Blackwell, G.K. Brunton, K. Burns, J.R. Castro Morales, M. Fedorov, R. Lacuata, R.R. Leach, D.G. Mathisen, V.J. Miller Kamm, S. Muralidhar, V. Pacheu, Y. Pan, S. Patankar, B.P. Patel, M. Paul, R. Rozenshteyn, R.J. Sanchez, S. Sauter, M. Taranowski, D. Tucker, K.C. Wilhelmsen, B.A. Wilson, H. Zhang LLNL, Livermore, California, USA
	Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. With the ability to deliver 2.1 MJ of 500 TW ultraviolet laser light to a target, the National Ignition Facility (NIF) is the world’s most energetic laser. This combination of energy and power allows the study of materials under conditions similar to the center of the sun. On fusion ignition experiments, plasma generated in the interior of the target shell can detrimentally impact the implosion symmetry and the resulting energy output. We are in the final stages of commissioning a significant new diagnostic system that will allow us to better understand the plasma conditions and improve our symmetry control techniques. This Optical Thompson Scattering (OTS) system consists of two major components: a probe laser beamline capable of delivering a world first 1 J of energy at 211 nm, and a diagnostic that both reflects the probe laser into the target and collects the scattered photons. Between these two components, the control system enhancements required integration of over 450 components into the existing automation suite. This talk will provide an overview of the system upgrade approach and the tools used to efficiently manage and test changes to both our data and software.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-MOPV021
About •	Received ※ 09 October 2021 Accepted ※ 10 February 2022 Issue date ※ 21 February 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPV001	The Mirror Systems Benches Kinematics Development for Sirius/LNLS	controls, interface, operation, MMI	358
	G.N. Kontogiorgos, A.Y. Horita, L. Martins dos Santos, M.A.L. Moraes, L.F. Segalla LNLS, Campinas, Brazil
	Funding: Ministry of Science, Technology and Innovation (MCTI) At Sirius, many of the optical elements such as mirror systems, monochromators, sample holders and detectors are attached to the ground with high stiffnesses to reduce disturbances at the beam during experiments. Granite benches were developed to couple the optical device to the floor and allow automatic movements, via com-manded setpoints on EPICS that runs an embedded kinematics, during base installation, alignment, commis-sioning and operation of the beamline. They are com-posed by stages and each application has its own geome-try, a set number of Degrees-of-Freedom (DoF) and mo-tors, all controlled by Omron Delta Tau Power Brick LV. In particular, the mirror system was the precursor motion control system for other benches. Since the me-chanical design aims on stiffness, the axes of mirror are not controlled directly, the actuators are along the granite bench. A geometric model was created to simplify the mirror operation, which turn the actuators motion trans-parent to the user and allow him to directly control the mirror axes.
	Poster TUPV001 [1.229 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-TUPV001
About •	Received ※ 10 October 2021 Revised ※ 18 October 2021 Accepted ※ 20 November 2021 Issue date ※ 22 January 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPV003	The Control System of the Four-Bounce Crystal Monochromators for SIRIUS/LNLS Beamlines	controls, feedback, operation, synchrotron	365
	L. Martins dos Santos, P.D. Aranha, L.M. Kofukuda, G.N. Kontogiorgos, M.A.L. Moraes, J.H. Řežende, M. Saveri Silva, H.C.N. Tolentino LNLS, Campinas, Brazil
	Funding: Ministry of Science, Technology, and Innovation (MCTI) CARNAÚBA (Coherent X-ray Nanoprobe) and CATERETÊ (Coherent and Time Resolved Scattering) are the longest beamlines in Sirius - the 4th generation light source at the Brazilian Synchrotron Light Laboratory (LNLS). They comprise Four-Bounce Crystal Monochromators (4CM) for energy selection with strict stability and performance requirements. The motion control architecture implemented for this class of instruments was based on Omron Delta Tau Power Brick LV, controller with PWM amplifier. The 4CM was in-house designed and consists of two channel-cut silicon crystals whose angular position is given by two direct-drive actuators. A linear actuator mounted between the crystals moves a diagnostic device and a mask used to obstruct spurious diffractions and reflections. The system is assembled in an ultra-high vacuum (UHV) chamber onto a motorized granite bench that permits the alignment and the operation with pink-beam. This work details the motion control approach for axes coordination and depicts how the implemented methods led to the achievement of the desired stability, considering the impact of current control, in addition to benchmarking with manufacturer solution.
	Poster TUPV003 [1.477 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-TUPV003
About •	Received ※ 10 October 2021 Revised ※ 20 October 2021 Accepted ※ 21 December 2021 Issue date ※ 30 December 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEAL01	Image Processing Alignment Algorithms for the Optical Thomson Scattering Laser at the National Ignition Facility	laser, target, optics, plasma	528
	A.A.S. Awwal, T.S. Budge, R.R. Leach, R.R. Lowe-Webb, V.J. Miller Kamm, S. Patankar, B.P. Patel, K.C. Wilhelmsen LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Understanding plasma performance in the world’s largest and most energetic laser facility, the National Ignition Facility (NIF), is an important step to achieving the goal of inertial confinement fusion in a laboratory setting. The optical Thompson scattering (OTS) laser has been developed to understand the target implosion physics, especially for under-dense plasma conditions. A 5w probe beams can be set up for diagnosing various plasma densities. Just as the NIF laser with 192 laser beams are precisely aligned, the OTS system also requires precision alignment using a series of automated closed loop control steps. CCD images from the OTS laser (OTSL) beams are analyzed using a suite of image processing algorithm. The algorithms provide beam position measurements that are used to control motorized mirrors that steer beams to their defined desired location. In this paper, several alignment algorithms will be discussed with details on how they take advantage of various types of fiducials such as diffraction rings, contrasting squares and circles, octagons and very faint 5w laser beams. This is released as LLNL-ABS-821809
	Slides WEAL01 [1.303 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-WEAL01
About •	Received ※ 08 October 2021 Revised ※ 18 October 2021 Accepted ※ 21 November 2021 Issue date ※ 14 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPV016	The Automatic LHC Collimator Beam-Based Alignment Software Package	software, controls, status, collimation	659
	G. Azzopardi, B. Salvachua CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The Large Hadron Collider (LHC) at CERN makes use of a complex collimation system to protect its sensitive equipment from unavoidable beam losses. The collimators are positioned around the beam respecting a strict transverse hierarchy. The position of each collimator is determined following a beam-based alignment technique which determines the required jaw settings for optimum performance. During the LHC Run 2 (2015-2018), a new automatic alignment software package was developed and used for collimator alignments throughout 2018. This paper discusses the usability and flexibility of this new package describing the implementation in detail, as well as the latest improvements and features in preparation for Run 3 starting in 2022. The automation has already successfully decreased the alignment time by 70% in 2018* and this paper explores how to further exploit this software package. Its implementation provides a solid foundation to automatically align any new collimation configurations in the future, as well as allows for further analysis and upgrade of its individual modules. G.Azzopardi, et al"Software Architecture for Automatic LHC Collimator Alignment using ML",ICALEPCS19. *G.Azzopardi, et al"Operational Results on the Fully-Automatic LHC Collimator Alignment",PRAB19.
	Poster WEPV016 [0.443 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-WEPV016
About •	Received ※ 07 October 2021 Revised ※ 22 October 2021 Accepted ※ 22 December 2021 Issue date ※ 26 December 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPV022	Sample Alignment in Neutron Scattering Experiments Using Deep Neural Network	neutron, network, experiment, scattering	686
	J.P. Edelen, K. Bruhwiler, A. Diaw, C.C. Hall RadiaSoft LLC, Boulder, Colorado, USA S. Calder ORNL RAD, Oak Ridge, Tennessee, USA C.M. Hoffmann ORNL, Oak Ridge, Tennessee, USA
	Funding: DOE Office of Science Office of Basic Energy Science SBIR award number DE-SC0021555 Access to neutron scattering centers, such as Oak Ridge National Laboratory (ORNL) and the NIST Center for Neutron Research, has provided beam energies to investigating a wide variety of applications such as particle physics, material science, and biology. In these experiments, the quality of collected data is very sensitive to sample and beam alignment, and stabilization of the experimental environment, requiring human intervention to tune the beam. While this procedure works, it is inefficient and time-consuming. In the work we present progress towards using machine learning to automate the alignment of a beamline in neutron scattering experiments. Our algorithm uses convolutional neural network to both learn a surrogate of the image data of the sample and to predict the sample contour using a u-net. We tested our algorithm on neutron camera images from the H2-BA powder diffractometer and the Topaz single crystal diffractometer beamlines of ORNL.
	Poster WEPV022 [4.472 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-WEPV022
About •	Received ※ 10 October 2021 Revised ※ 22 October 2021 Accepted ※ 21 December 2021 Issue date ※ 06 February 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPV012	LHC Collimation Controls System for Run III Operation	collimation, controls, operation, software	888
	G. Azzopardi, M. Di Castro, S. Redaelli, B. Salvachua, M. Solfaroli Camillocci CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The Large Hadron Collider (LHC) collimation system is designed to protect the machine against unavoidable beam losses. The collimation system for the LHC Run 3, starting in 2022, consists of more than 100 movable collimators located along the 27 km long ring and in the transfer lines. The cleaning performance and machine protection role of the system critically depend on the accurate positioning of the collimator jaws. The collimation control system in place enables remote control and appropriate diagnostics of the relevant parameters. This ensures that the collimators dynamically follow optimum settings in all phases of the LHC operational cycle. In this paper, an overview of the top-level software tools available for collimation control from the control room is given. These tools range from collimator alignment applications to generation tools for collimator settings, as well as collimator scans, settings checks and machine protection sequences. Amongst these tools the key upgrades and newly introduced tools for the Run 3 are presented.
	Poster THPV012 [5.521 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-THPV012
About •	Received ※ 07 October 2021 Revised ※ 25 October 2021 Accepted ※ 16 December 2021 Issue date ※ 01 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPV040	New Machine Learning Model Application for the Automatic LHC Collimator Beam-Based Alignment	injection, flattop, software, operation	953
	G. Azzopardi CERN, Geneva, Switzerland G. Ricci Sapienza University of Rome, Rome, Italy
	A collimation system is installed in the Large Hadron Collider (LHC) to protect its sensitive equipment from unavoidable beam losses. An alignment procedure determines the settings of each collimator, by moving the collimator jaws towards the beam until a characteristic loss pattern, consisting of a sharp rise followed by a slow decay, is observed in downstream beam loss monitors. This indicates that the collimator jaw intercepted the reference beam halo and is thus aligned to the beam. The latest alignment software introduced in 2018 relies on supervised machine learning (ML) to detect such spike patterns in real-time. This enables the automatic alignment of the collimators with a significant reduction in the alignment time. This paper analyses the first-use performance of this new software focusing on solutions to the identified bottleneck caused by waiting a fixed duration of time when detecting spikes. It is proposed to replace the supervised ML model with a Long-Short Term Memory model able to detect spikes in time windows of varying lengths, waiting for a variable duration of time determined by the spike itself. This will allow to further speed up the automatic alignment. G. Azzopardi et al., "Automatic spike detection in beam loss signals for LHC collimator alignment", NIMA 2019. **G. Azzopardi et al., "Operational Results of LHC collimator alignment using ML", IPAC’19.
	Poster THPV040 [0.894 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-THPV040
About •	Received ※ 08 October 2021 Accepted ※ 21 November 2021 Issue date ※ 10 December 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Upgrading the National Ignition Facility’s (NIF) Integrated Computer Control System to Support Optical Thompson Scattering (OTS) Diagnostic

controls, laser, database, operation

173

A.I. Barnes, A.A.S. Awwal, L. Beaulac, B. Blackwell, G.K. Brunton, K. Burns, J.R. Castro Morales, M. Fedorov, R. Lacuata, R.R. Leach, D.G. Mathisen, V.J. Miller Kamm, S. Muralidhar, V. Pacheu, Y. Pan, S. Patankar, B.P. Patel, M. Paul, R. Rozenshteyn, R.J. Sanchez, S. Sauter, M. Taranowski, D. Tucker, K.C. Wilhelmsen, B.A. Wilson, H. Zhang
LLNL, Livermore, California, USA

Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
With the ability to deliver 2.1 MJ of 500 TW ultraviolet laser light to a target, the National Ignition Facility (NIF) is the world’s most energetic laser. This combination of energy and power allows the study of materials under conditions similar to the center of the sun. On fusion ignition experiments, plasma generated in the interior of the target shell can detrimentally impact the implosion symmetry and the resulting energy output. We are in the final stages of commissioning a significant new diagnostic system that will allow us to better understand the plasma conditions and improve our symmetry control techniques. This Optical Thompson Scattering (OTS) system consists of two major components: a probe laser beamline capable of delivering a world first 1 J of energy at 211 nm, and a diagnostic that both reflects the probe laser into the target and collects the scattered photons. Between these two components, the control system enhancements required integration of over 450 components into the existing automation suite. This talk will provide an overview of the system upgrade approach and the tools used to efficiently manage and test changes to both our data and software.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-MOPV021

About •

Received ※ 09 October 2021 Accepted ※ 10 February 2022 Issue date ※ 21 February 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPV001

The Mirror Systems Benches Kinematics Development for Sirius/LNLS

controls, interface, operation, MMI

358

G.N. Kontogiorgos, A.Y. Horita, L. Martins dos Santos, M.A.L. Moraes, L.F. Segalla
LNLS, Campinas, Brazil

Funding: Ministry of Science, Technology and Innovation (MCTI)
At Sirius, many of the optical elements such as mirror systems, monochromators, sample holders and detectors are attached to the ground with high stiffnesses to reduce disturbances at the beam during experiments. Granite benches were developed to couple the optical device to the floor and allow automatic movements, via com-manded setpoints on EPICS that runs an embedded kinematics, during base installation, alignment, commis-sioning and operation of the beamline. They are com-posed by stages and each application has its own geome-try, a set number of Degrees-of-Freedom (DoF) and mo-tors, all controlled by Omron Delta Tau Power Brick LV. In particular, the mirror system was the precursor motion control system for other benches. Since the me-chanical design aims on stiffness, the axes of mirror are not controlled directly, the actuators are along the granite bench. A geometric model was created to simplify the mirror operation, which turn the actuators motion trans-parent to the user and allow him to directly control the mirror axes.

Poster TUPV001 [1.229 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-TUPV001

About •

Received ※ 10 October 2021 Revised ※ 18 October 2021 Accepted ※ 20 November 2021 Issue date ※ 22 January 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPV003

The Control System of the Four-Bounce Crystal Monochromators for SIRIUS/LNLS Beamlines

controls, feedback, operation, synchrotron

365

L. Martins dos Santos, P.D. Aranha, L.M. Kofukuda, G.N. Kontogiorgos, M.A.L. Moraes, J.H. Řežende, M. Saveri Silva, H.C.N. Tolentino
LNLS, Campinas, Brazil

Funding: Ministry of Science, Technology, and Innovation (MCTI)
CARNAÚBA (Coherent X-ray Nanoprobe) and CATERETÊ (Coherent and Time Resolved Scattering) are the longest beamlines in Sirius - the 4th generation light source at the Brazilian Synchrotron Light Laboratory (LNLS). They comprise Four-Bounce Crystal Monochromators (4CM) for energy selection with strict stability and performance requirements. The motion control architecture implemented for this class of instruments was based on Omron Delta Tau Power Brick LV, controller with PWM amplifier. The 4CM was in-house designed and consists of two channel-cut silicon crystals whose angular position is given by two direct-drive actuators. A linear actuator mounted between the crystals moves a diagnostic device and a mask used to obstruct spurious diffractions and reflections. The system is assembled in an ultra-high vacuum (UHV) chamber onto a motorized granite bench that permits the alignment and the operation with pink-beam. This work details the motion control approach for axes coordination and depicts how the implemented methods led to the achievement of the desired stability, considering the impact of current control, in addition to benchmarking with manufacturer solution.

Poster TUPV003 [1.477 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-TUPV003

About •

Received ※ 10 October 2021 Revised ※ 20 October 2021 Accepted ※ 21 December 2021 Issue date ※ 30 December 2021

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEAL01

Image Processing Alignment Algorithms for the Optical Thomson Scattering Laser at the National Ignition Facility

laser, target, optics, plasma

528

A.A.S. Awwal, T.S. Budge, R.R. Leach, R.R. Lowe-Webb, V.J. Miller Kamm, S. Patankar, B.P. Patel, K.C. Wilhelmsen
LLNL, Livermore, California, USA

Funding: *This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Understanding plasma performance in the world’s largest and most energetic laser facility, the National Ignition Facility (NIF), is an important step to achieving the goal of inertial confinement fusion in a laboratory setting. The optical Thompson scattering (OTS) laser has been developed to understand the target implosion physics, especially for under-dense plasma conditions. A 5w probe beams can be set up for diagnosing various plasma densities. Just as the NIF laser with 192 laser beams are precisely aligned, the OTS system also requires precision alignment using a series of automated closed loop control steps. CCD images from the OTS laser (OTSL) beams are analyzed using a suite of image processing algorithm. The algorithms provide beam position measurements that are used to control motorized mirrors that steer beams to their defined desired location. In this paper, several alignment algorithms will be discussed with details on how they take advantage of various types of fiducials such as diffraction rings, contrasting squares and circles, octagons and very faint 5w laser beams.
*This is released as LLNL-ABS-821809

Slides WEAL01 [1.303 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-WEAL01

About •

Received ※ 08 October 2021 Revised ※ 18 October 2021 Accepted ※ 21 November 2021 Issue date ※ 14 March 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPV016

The Automatic LHC Collimator Beam-Based Alignment Software Package

software, controls, status, collimation

659

G. Azzopardi, B. Salvachua
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The Large Hadron Collider (LHC) at CERN makes use of a complex collimation system to protect its sensitive equipment from unavoidable beam losses. The collimators are positioned around the beam respecting a strict transverse hierarchy. The position of each collimator is determined following a beam-based alignment technique which determines the required jaw settings for optimum performance. During the LHC Run 2 (2015-2018), a new automatic alignment software package was developed and used for collimator alignments throughout 2018*. This paper discusses the usability and flexibility of this new package describing the implementation in detail, as well as the latest improvements and features in preparation for Run 3 starting in 2022. The automation has already successfully decreased the alignment time by 70% in 2018** and this paper explores how to further exploit this software package. Its implementation provides a solid foundation to automatically align any new collimation configurations in the future, as well as allows for further analysis and upgrade of its individual modules.
*G.Azzopardi, et al"Software Architecture for Automatic LHC Collimator Alignment using ML",ICALEPCS19.
**G.Azzopardi, et al"Operational Results on the Fully-Automatic LHC Collimator Alignment",PRAB19.

Poster WEPV016 [0.443 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-WEPV016

About •

Received ※ 07 October 2021 Revised ※ 22 October 2021 Accepted ※ 22 December 2021 Issue date ※ 26 December 2021

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPV022

Sample Alignment in Neutron Scattering Experiments Using Deep Neural Network

neutron, network, experiment, scattering

686

J.P. Edelen, K. Bruhwiler, A. Diaw, C.C. Hall
RadiaSoft LLC, Boulder, Colorado, USA
S. Calder
ORNL RAD, Oak Ridge, Tennessee, USA
C.M. Hoffmann
ORNL, Oak Ridge, Tennessee, USA

Funding: DOE Office of Science Office of Basic Energy Science SBIR award number DE-SC0021555
Access to neutron scattering centers, such as Oak Ridge National Laboratory (ORNL) and the NIST Center for Neutron Research, has provided beam energies to investigating a wide variety of applications such as particle physics, material science, and biology. In these experiments, the quality of collected data is very sensitive to sample and beam alignment, and stabilization of the experimental environment, requiring human intervention to tune the beam. While this procedure works, it is inefficient and time-consuming. In the work we present progress towards using machine learning to automate the alignment of a beamline in neutron scattering experiments. Our algorithm uses convolutional neural network to both learn a surrogate of the image data of the sample and to predict the sample contour using a u-net. We tested our algorithm on neutron camera images from the H2-BA powder diffractometer and the Topaz single crystal diffractometer beamlines of ORNL.

Poster WEPV022 [4.472 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-WEPV022

About •

Received ※ 10 October 2021 Revised ※ 22 October 2021 Accepted ※ 21 December 2021 Issue date ※ 06 February 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPV012

LHC Collimation Controls System for Run III Operation

collimation, controls, operation, software

888

G. Azzopardi, M. Di Castro, S. Redaelli, B. Salvachua, M. Solfaroli Camillocci
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The Large Hadron Collider (LHC) collimation system is designed to protect the machine against unavoidable beam losses. The collimation system for the LHC Run 3, starting in 2022, consists of more than 100 movable collimators located along the 27 km long ring and in the transfer lines. The cleaning performance and machine protection role of the system critically depend on the accurate positioning of the collimator jaws. The collimation control system in place enables remote control and appropriate diagnostics of the relevant parameters. This ensures that the collimators dynamically follow optimum settings in all phases of the LHC operational cycle. In this paper, an overview of the top-level software tools available for collimation control from the control room is given. These tools range from collimator alignment applications to generation tools for collimator settings, as well as collimator scans, settings checks and machine protection sequences. Amongst these tools the key upgrades and newly introduced tools for the Run 3 are presented.

Poster THPV012 [5.521 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-THPV012

About •

Received ※ 07 October 2021 Revised ※ 25 October 2021 Accepted ※ 16 December 2021 Issue date ※ 01 March 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPV040

New Machine Learning Model Application for the Automatic LHC Collimator Beam-Based Alignment

injection, flattop, software, operation

953

G. Azzopardi
CERN, Geneva, Switzerland
G. Ricci
Sapienza University of Rome, Rome, Italy

A collimation system is installed in the Large Hadron Collider (LHC) to protect its sensitive equipment from unavoidable beam losses. An alignment procedure determines the settings of each collimator, by moving the collimator jaws towards the beam until a characteristic loss pattern, consisting of a sharp rise followed by a slow decay, is observed in downstream beam loss monitors. This indicates that the collimator jaw intercepted the reference beam halo and is thus aligned to the beam. The latest alignment software introduced in 2018 relies on supervised machine learning (ML) to detect such spike patterns in real-time*. This enables the automatic alignment of the collimators with a significant reduction in the alignment time**. This paper analyses the first-use performance of this new software focusing on solutions to the identified bottleneck caused by waiting a fixed duration of time when detecting spikes. It is proposed to replace the supervised ML model with a Long-Short Term Memory model able to detect spikes in time windows of varying lengths, waiting for a variable duration of time determined by the spike itself. This will allow to further speed up the automatic alignment.
*G. Azzopardi et al., "Automatic spike detection in beam loss signals for LHC collimator alignment", NIMA 2019.
**G. Azzopardi et al., "Operational Results of LHC collimator alignment using ML", IPAC’19.

Poster THPV040 [0.894 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2021-THPV040

About •

Received ※ 08 October 2021 Accepted ※ 21 November 2021 Issue date ※ 10 December 2021

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)