ICALEPCS2011 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOPKS015	Diagnostics Control Requirements and Applications at NSLS-II	controls, diagnostics, feedback, emittance	192
	Y. Hu, L.R. Dalesio, K. Ha, O. Singh BNL, Upton, Long Island, New York, USA
	To measure various beam parameters such as beam position, beam size, circulating current, beam emittance, etc., a variety of diagnostic monitors will be deployed at NSLS-II. The Diagnostics Group and the Controls Group are working together on control requirements for the beam monitors. The requirements are originated from and determined by accelerator physics. An attempt of analyzing and translating physics needs into control requirements is made. The basic functionalities and applications of diagnostics controls are also presented.
	Poster MOPKS015 [0.142 MB]

MOPMN027	The LHC Sequencer	database, GUI, controls, operation	300
	R. Alemany-Fernandez, V. Baggiolini, R. Gorbonosov, D. Khasbulatov, M. Lamont, P. Le Roux, C. Roderick CERN, Geneva, Switzerland
	The Large Hadron Collider (LHC) at CERN is a highly complex system made of many different sub-systems whose operation implies the execution of many tasks with stringent constraints on the order and duration of the execution. To be able to operate such a system in the most efficient and reliable way the operators in the CERN control room use a high level control system: the LHC Sequencer. The LHC Sequencer system is composed of several components, including an Oracle database where operational sequences are configured, a core server that orchestrates the execution of the sequences, and two graphical user interfaces: one for sequence edition, and another for sequence execution. This paper describes the architecture of the LHC Sequencer system, and how the sequences are prepared and used for LHC operation.
	Poster MOPMN027 [2.163 MB]

WEPMS013	Timing System of the Taiwan Photon Source	timing, controls, gun, EPICS	999
	C.Y. Wu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, D. Lee, C.Y. Liao NSRRC, Hsinchu, Taiwan
	The timing system of the Taiwan Photon Source provides synchronization for electron gun, modulators of linac, pulse magnet power supplies, booster power supply ramp, bucket addressing of storage ring, diagnostic equipments, beamline gating signal for top-up injection. The system is based on an event distribution system that broadcasts the timing events over a optic fiber network, and decodes and processes them at the timing event receivers. The system supports uplink functionality which will be used for the fast interlock system to distribute signals like beam dump and post-mortem trigger with 10 μsec response time. The hardware of the event system is a new design that is based on 6U CompactPCI form factor. This paper describes the technical solution, the functionality of the system and some applications that are based on the timing system.

WEPMS015	NSLS-II Booster Timing System	booster, timing, extraction, storage-ring	1003
	P.B. Cheblakov, S.E. Karnaev BINP SB RAS, Novosibirsk, Russia J.H. De Long BNL, Upton, Long Island, New York, USA
	The NSLS-II light source includes the main storage ring with beam lines and injection part consisting of 200 MeV linac, 3 GeV booster synchrotron and two transport lines. The booster timing system is a part of NSLS-II timing system which is based on Event Generator (EVG) and Event Receivers (EVRs) fromμResearch Finland. The booster timing is based on the external events coming from NSLS-II EVG: "Pre-Injection", "Injection", "Pre-Extraction", "Extraction". These events are referenced to the specified bunch of the Storage Ring and correspond to the first bunch of the booster. EVRs provide two scales for triggering both of the injection and the extraction pulse devices. The first scale provides triggering of the pulsed septums and the bump magnets in the range of milliseconds and uses TTL outputs of EVR, the second scale provides triggering of the kickers in the range of microseconds and uses CML outputs. EVRs also provide the timing of a booster cycle operation and events for cycle-to-cycle updates of pulsed and ramping parameters, and the booster beam instrumentation synchronization. This paper describes the final design of the booster timing system. The timing system functional and block diagrams are presented.
	Poster WEPMS015 [0.799 MB]

WEPMS020	NSLS-II Booster Power Supplies Control	booster, controls, operation, extraction	1018
	P.B. Cheblakov, S.E. Karnaev, S.S. Serednyakov BINP SB RAS, Novosibirsk, Russia W. Louie, Y. Tian BNL, Upton, Long Island, New York, USA
	The NSLS-II booster Power Supplies (PSs) [1] are divided into two groups: ramping PSs providing passage of the beam during the beam ramp in the booster from 200 MeV up to 3 GeV at 300 ms time interval, and pulsed PSs providing beam injection from the linac and extraction to the Storage Ring. A special set of devices was developed at BNL for the NSLS-II magnetic system PSs control: Power Supply Controller (PSC) and Power Supply Interface (PSI). The PSI has one or two precision 18-bit DACs, nine channels of ADC for each DAC and digital input/outputs. It is capable of detecting the status change sequence of digital inputs with 10 ns resolution. The PSI is placed close to current regulators and is connected to the PSC via fiber-optic 50 Mbps data link. The PSC communicates with EPICS IOC through a 100 Mbps Ethernet port. The main function of IOC includes ramp curve upload, ADC waveform data download, and various process variable control. The 256 Mb DDR2 memory on PSC provides large storage for up to 16 ramping tables for the both DACs, and 20 second waveform recorder for all the ADC channels. The 100 Mbps Ethernet port enables real time display for 4 ADC waveforms. This paper describes a project of the NSLS-II booster PSs control. Characteristic features of the ramping magnets control and pulsed magnets control in a double-injection mode of operation are considered in the paper. First results of the control at PS testing stands are presented. [1] Power Supply Control System of NSLS-II, Y. Tian, W. Louie, J. Ricciardelli, L.R. Dalesio, G. Ganetis, ICALEPCS2009, Japan
	Poster WEPMS020 [1.818 MB]

WEPMS022	The Controller Design for Kicker Magnet Adjustment Mechanism in SSRF	controls, software, feedback, kicker	1021
	R. Wang, R. Chen, Z.H. Chen, M. Gu SINAP, Shanghai, People's Republic of China
	The kicker magnet adjustment mechanism controller in SSRF is to improve the efficiency of injection by changing the magnet real-time, especially in the top-up mode. The controller mainly consists of Programmable Logic Controller (PLC), stepper motor, reducer, worm and mechanism. PLC controls the stepper motors for adjusting the azimuth of the magnet, monitors and regulates the magnet with inclinometer sensor. It also monitors the interlock. In addition, the controller is provided with local and remote working mode. This paper mainly introduces related hardware and software designs for this device.
	Poster WEPMS022 [0.173 MB]

WEPMS028	Online Evaluation of New DBPM Processors at SINAP	betatron, electronics, feedback, hardware	1041
	Y.B. Leng, G.Q. Huang, L.W. Lai, Y.B. Yan, X. Yi SSRF, Shanghai, People's Republic of China
	In this paper, we report our online evaluation results for new digital BPM signal processors, which are developed for the SSRF and the new Shanghai SXFEL facility. Two major prototypes have been evaluated. The first algorithm evaluation prototype is built using commercial development toolkits modules in order to test various digital processing blocks. The second prototype is designed and fabricated from chips level in order to evaluate the hardware performances of different functional modules and assembled processor.
	Poster WEPMS028 [0.546 MB]

WEPMU008	Access Safety Systems – New Concepts from the LHC Experience	controls, operation, site, hardware	1066
	T. Ladzinski, Ch. Delamare, S. Di Luca, T. Hakulinen, L. Hammouti, F. Havart, J.-F. Juget, P. Ninin, R. Nunes, T.R. Riesco, E. Sanchez-Corral Mena, F. Valentini CERN, Geneva, Switzerland
	The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hardwired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and the access control includes a state of the art biometry check. Building on the LHC experience, new projects targeting the refurbishment of the existing access safety infrastructure in the injector chain have started. This paper summarises the new concepts introduced in the LHC access control and safety systems, discusses the return of experience and outlines the main guiding principles for the renewal stage of the personnel protection systems in the LHC injector chain in a homogeneous manner.
	Poster WEPMU008 [1.039 MB]

WEPMU011	Automatic Injection Quality Checks for the LHC	kicker, GUI, timing, software	1077
	L.N. Drosdal, B. Goddard, R. Gorbonosov, S. Jackson, D. Jacquet, V. Kain, D. Khasbulatov, M. Misiowiec, J. Wenninger, C. Zamantzas CERN, Geneva, Switzerland
	Twelve injections per beam are required to fill the LHC with the nominal filling scheme. The injected beam needs to fulfill a number of requirements to provide useful physics for the experiments when they take data at collisions later on in the LHC cycle. These requirements are checked by a dedicated software system, called the LHC injection quality check. At each injection, this system receives data about beam characteristics from key equipment in the LHC and analyzes it online to determine the quality of the injected beam after each injection. If the quality is insufficient, the automatic injection process is stopped, and the operator has to take corrective measures. This paper will describe the software architecture of the LHC injection quality check and the interplay with other systems. A set of tools for self-monitoring of the injection quality checks to achieve optimum performance will be discussed as well. Results obtained during the LHC commissioning year 2010 and the LHC run 2011 will finally be presented.
	Poster WEPMU011 [0.358 MB]

WEPMU012	First Experiences of Beam Presence Detection Based on Dedicated Beam Position Monitors	operation, pick-up, extraction, instrumentation	1081
	A. Jalal, S. Gabourin, M. Gasior, B. Todd CERN, Geneva, Switzerland
	High intensity particle beam injection into the LHC is only permitted when a low intensity pilot beam is already circulating in the LHC. This requirement addresses some of the risks associated with high intensity injection, and is enforced by a so-called Beam Presence Flag (BPF) system which is part of the interlock chain between the LHC and its injector complex. For the 2010 LHC run, the detection of the presence of this pilot beam was implemented using the LHC Fast Beam Current Transformer (FBCT) system. However, the primary function of the FBCTs, that is reliable measurement of beam currents, did not allow the BPF system to satisfy all quality requirements of the LHC Machine Protection System (MPS). Safety requirements associated with high intensity injections triggered the development of a dedicated system, based on Beam Position Monitors (BPM). This system was meant to work first in parallel with the FBCT BPF system and eventually replace it. At the end of 2010 and in 2011, this new BPF implementation based on BPMs was designed, built, tested and deployed. This paper reviews both the FBCT and BPM implementation of the BPF system, outlining the changes during the transition period. The paper briefly describes the testing methods, focuses on the results obtained from the tests performed during the end of 2010 LHC run and shows the changes made for the BPM BPF system deployment in LHC in 2011.

WEPMU016	Pre-Operation, During Operation and Post-Operational Verification of Protection Systems	operation, controls, software, database	1090
	I. Romera, M. Audrain CERN, Geneva, Switzerland
	This paper will provide an overview of the software checks performed on the Beam Interlock System ensuring that the system is functioning to specification. Critical protection functions are implemented in hardware, at the same time software tools play an important role in guaranteeing the correct configuration and operation of the system during all phases of operation. This paper will describe tests carried out pre-, during- and post- operation, if protection system integrity is not sure, subsequent injections of beam into the LHC will be inhibited.

WEPMU020	LHC Collimator Controls for a Safe LHC Operation	controls, FPGA, survey, operation	1104
	S. Redaelli, R.W. Assmann, M. Donzé, R. Losito, A. Masi CERN, Geneva, Switzerland
	The beam stored energy at the Large Hadron Collider (LHC) will be up to 360 MJ, to be compared with the quench limit of super-conducting magnets of a few mJ per cm³ and with the damage limit of metal of a few hundreds kJ. The LHC collimation system is designed to protect the machine against beam losses and consists of 108 collimators, 100 of which are movable, located along the 27 km long ring and in the transfer lines. Each collimator has two jaws controlled by four stepping motors to precisely adjust collimator position and angle with respect to the beam. Stepping motors have been used to ensure high position reproducibility. LVDT and resolvers have been installed to monitor in real-time at 100 Hz the jaw positions and the collimator gaps. The cleaning performance and machine protection role of the system depend critically on the accurate jaw positioning. A fully redundant survey system has been developed to ensure that the collimators dynamically follow optimum settings in all phases of the LHC operational cycle. Jaw positions and collimator gaps are interlocked against dump limits defined redundantly as functions of the time, of the beam energy and of the beta* functions that describes the focusing property of the beams. In this paper, the architectural choices that guarantee a safe LHC operation are presented. Hardware and software implementations that ensure the required reliability are described. The operational experience accumulated so far is reviewed and a detailed failure analysis that show the fulfillment of the machine protection specifications is presented.

WEPMU023	External Post-Operational Checks for the LHC Beam Dumping System	controls, kicker, operation, extraction	1111
	N. Magnin, V. Baggiolini, E. Carlier, B. Goddard, R. Gorbonosov, D. Khasbulatov, J.A. Uythoven, M. Zerlauth CERN, Geneva, Switzerland
	The LHC Beam Dumping System (LBDS) is a critical part of the LHC machine protection system. After every LHC beam dump action the various signals and transient data recordings of the beam dumping control systems and beam instrumentation measurements are automatically analysed by the eXternal Post-Operational Checks (XPOC) system to verify the correct execution of the dump action and the integrity of the related equipment. This software system complements the LHC machine protection hardware, and has to ascertain that the beam dumping system is ‘as good as new’ before the start of the next operational cycle. This is the only way by which the stringent reliability requirements can be met. The XPOC system has been developed within the framework of the LHC “Post-Mortem” system, allowing highly dependable data acquisition, data archiving, live analysis of acquired data and replay of previously recorded events. It is composed of various analysis modules, each one dedicated to the analysis of measurements coming from specific equipment. This paper describes the global architecture of the XPOC system and gives examples of the analyses performed by some of the most important analysis modules. It explains the integration of the XPOC into the LHC control infrastructure along with its integration into the decision chain to allow proceeding with beam operation. Finally, it discusses the operational experience with the XPOC system acquired during the first years of LHC operation, and illustrates examples of internal system faults or abnormal beam dump executions which it has detected.
	Poster WEPMU023 [1.768 MB]

WEPMU026	Protecting Detectors in ALICE	detector, experiment, controls, monitoring	1122
	M. Lechman, A. Augustinus, P.Ch. Chochula, G. De Cataldo, A. Di Mauro, L.S. Jirdén, A.N. Kurepin, P. Rosinský, H. Schindler CERN, Geneva, Switzerland A. Moreno Universidad Politécnica de Madrid, E.T.S.I Industriales, Madrid, Spain O. Pinazza INFN-Bologna, Bologna, Italy
	ALICE is one of the big LHC experiments at CERN in Geneva. It is composed of many sophisticated and complex detectors mounted very compactly around the beam pipe. Each detector is a unique masterpiece of design, engineering and construction and any damage to it could stop the experiment for months or even for years. It is therefore essential that the detectors are protected from any danger and this is one very important role of the Detector Control System (DCS). One of the main dangers for the detectors is the particle beam itself. Since the detectors are designed to be extremely sensitive to particles they are also vulnerable to any excess of beam conditions provided by the LHC accelerator. The beam protection consists of a combination of hardware interlocks and control software and this paper will describe how this is implemented and handled in ALICE. Tools have also been developed to support operators and shift leaders in the decision making related to beam safety. The gained experiences and conclusions from the individual safety projects are also presented.
	Poster WEPMU026 [1.561 MB]

Paper

Title

Other Keywords

Page

MOPKS015

Diagnostics Control Requirements and Applications at NSLS-II

controls, diagnostics, feedback, emittance

192

Y. Hu, L.R. Dalesio, K. Ha, O. Singh
BNL, Upton, Long Island, New York, USA

To measure various beam parameters such as beam position, beam size, circulating current, beam emittance, etc., a variety of diagnostic monitors will be deployed at NSLS-II. The Diagnostics Group and the Controls Group are working together on control requirements for the beam monitors. The requirements are originated from and determined by accelerator physics. An attempt of analyzing and translating physics needs into control requirements is made. The basic functionalities and applications of diagnostics controls are also presented.

Poster MOPKS015 [0.142 MB]

MOPMN027

The LHC Sequencer

database, GUI, controls, operation

300

R. Alemany-Fernandez, V. Baggiolini, R. Gorbonosov, D. Khasbulatov, M. Lamont, P. Le Roux, C. Roderick
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) at CERN is a highly complex system made of many different sub-systems whose operation implies the execution of many tasks with stringent constraints on the order and duration of the execution. To be able to operate such a system in the most efficient and reliable way the operators in the CERN control room use a high level control system: the LHC Sequencer. The LHC Sequencer system is composed of several components, including an Oracle database where operational sequences are configured, a core server that orchestrates the execution of the sequences, and two graphical user interfaces: one for sequence edition, and another for sequence execution. This paper describes the architecture of the LHC Sequencer system, and how the sequences are prepared and used for LHC operation.

Poster MOPMN027 [2.163 MB]

WEPMS013

Timing System of the Taiwan Photon Source

timing, controls, gun, EPICS

999

C.Y. Wu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, D. Lee, C.Y. Liao
NSRRC, Hsinchu, Taiwan

The timing system of the Taiwan Photon Source provides synchronization for electron gun, modulators of linac, pulse magnet power supplies, booster power supply ramp, bucket addressing of storage ring, diagnostic equipments, beamline gating signal for top-up injection. The system is based on an event distribution system that broadcasts the timing events over a optic fiber network, and decodes and processes them at the timing event receivers. The system supports uplink functionality which will be used for the fast interlock system to distribute signals like beam dump and post-mortem trigger with 10 μsec response time. The hardware of the event system is a new design that is based on 6U CompactPCI form factor. This paper describes the technical solution, the functionality of the system and some applications that are based on the timing system.

WEPMS015

NSLS-II Booster Timing System

booster, timing, extraction, storage-ring

1003

P.B. Cheblakov, S.E. Karnaev
BINP SB RAS, Novosibirsk, Russia
J.H. De Long
BNL, Upton, Long Island, New York, USA

The NSLS-II light source includes the main storage ring with beam lines and injection part consisting of 200 MeV linac, 3 GeV booster synchrotron and two transport lines. The booster timing system is a part of NSLS-II timing system which is based on Event Generator (EVG) and Event Receivers (EVRs) fromμResearch Finland. The booster timing is based on the external events coming from NSLS-II EVG: "Pre-Injection", "Injection", "Pre-Extraction", "Extraction". These events are referenced to the specified bunch of the Storage Ring and correspond to the first bunch of the booster. EVRs provide two scales for triggering both of the injection and the extraction pulse devices. The first scale provides triggering of the pulsed septums and the bump magnets in the range of milliseconds and uses TTL outputs of EVR, the second scale provides triggering of the kickers in the range of microseconds and uses CML outputs. EVRs also provide the timing of a booster cycle operation and events for cycle-to-cycle updates of pulsed and ramping parameters, and the booster beam instrumentation synchronization. This paper describes the final design of the booster timing system. The timing system functional and block diagrams are presented.

Poster WEPMS015 [0.799 MB]

WEPMS020

NSLS-II Booster Power Supplies Control

booster, controls, operation, extraction

1018

P.B. Cheblakov, S.E. Karnaev, S.S. Serednyakov
BINP SB RAS, Novosibirsk, Russia
W. Louie, Y. Tian
BNL, Upton, Long Island, New York, USA

The NSLS-II booster Power Supplies (PSs) [1] are divided into two groups: ramping PSs providing passage of the beam during the beam ramp in the booster from 200 MeV up to 3 GeV at 300 ms time interval, and pulsed PSs providing beam injection from the linac and extraction to the Storage Ring. A special set of devices was developed at BNL for the NSLS-II magnetic system PSs control: Power Supply Controller (PSC) and Power Supply Interface (PSI). The PSI has one or two precision 18-bit DACs, nine channels of ADC for each DAC and digital input/outputs. It is capable of detecting the status change sequence of digital inputs with 10 ns resolution. The PSI is placed close to current regulators and is connected to the PSC via fiber-optic 50 Mbps data link. The PSC communicates with EPICS IOC through a 100 Mbps Ethernet port. The main function of IOC includes ramp curve upload, ADC waveform data download, and various process variable control. The 256 Mb DDR2 memory on PSC provides large storage for up to 16 ramping tables for the both DACs, and 20 second waveform recorder for all the ADC channels. The 100 Mbps Ethernet port enables real time display for 4 ADC waveforms. This paper describes a project of the NSLS-II booster PSs control. Characteristic features of the ramping magnets control and pulsed magnets control in a double-injection mode of operation are considered in the paper. First results of the control at PS testing stands are presented.
[1] Power Supply Control System of NSLS-II, Y. Tian, W. Louie, J. Ricciardelli, L.R. Dalesio, G. Ganetis, ICALEPCS2009, Japan

Poster WEPMS020 [1.818 MB]

WEPMS022

The Controller Design for Kicker Magnet Adjustment Mechanism in SSRF

controls, software, feedback, kicker

1021

R. Wang, R. Chen, Z.H. Chen, M. Gu
SINAP, Shanghai, People's Republic of China

The kicker magnet adjustment mechanism controller in SSRF is to improve the efficiency of injection by changing the magnet real-time, especially in the top-up mode. The controller mainly consists of Programmable Logic Controller (PLC), stepper motor, reducer, worm and mechanism. PLC controls the stepper motors for adjusting the azimuth of the magnet, monitors and regulates the magnet with inclinometer sensor. It also monitors the interlock. In addition, the controller is provided with local and remote working mode. This paper mainly introduces related hardware and software designs for this device.

Poster WEPMS022 [0.173 MB]

WEPMS028

Online Evaluation of New DBPM Processors at SINAP

betatron, electronics, feedback, hardware

1041

Y.B. Leng, G.Q. Huang, L.W. Lai, Y.B. Yan, X. Yi
SSRF, Shanghai, People's Republic of China

In this paper, we report our online evaluation results for new digital BPM signal processors, which are developed for the SSRF and the new Shanghai SXFEL facility. Two major prototypes have been evaluated. The first algorithm evaluation prototype is built using commercial development toolkits modules in order to test various digital processing blocks. The second prototype is designed and fabricated from chips level in order to evaluate the hardware performances of different functional modules and assembled processor.

Poster WEPMS028 [0.546 MB]

WEPMU008

Access Safety Systems – New Concepts from the LHC Experience

controls, operation, site, hardware

1066

T. Ladzinski, Ch. Delamare, S. Di Luca, T. Hakulinen, L. Hammouti, F. Havart, J.-F. Juget, P. Ninin, R. Nunes, T.R. Riesco, E. Sanchez-Corral Mena, F. Valentini
CERN, Geneva, Switzerland

The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hardwired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and the access control includes a state of the art biometry check. Building on the LHC experience, new projects targeting the refurbishment of the existing access safety infrastructure in the injector chain have started. This paper summarises the new concepts introduced in the LHC access control and safety systems, discusses the return of experience and outlines the main guiding principles for the renewal stage of the personnel protection systems in the LHC injector chain in a homogeneous manner.

Poster WEPMU008 [1.039 MB]

WEPMU011

Automatic Injection Quality Checks for the LHC

kicker, GUI, timing, software

1077

L.N. Drosdal, B. Goddard, R. Gorbonosov, S. Jackson, D. Jacquet, V. Kain, D. Khasbulatov, M. Misiowiec, J. Wenninger, C. Zamantzas
CERN, Geneva, Switzerland

Twelve injections per beam are required to fill the LHC with the nominal filling scheme. The injected beam needs to fulfill a number of requirements to provide useful physics for the experiments when they take data at collisions later on in the LHC cycle. These requirements are checked by a dedicated software system, called the LHC injection quality check. At each injection, this system receives data about beam characteristics from key equipment in the LHC and analyzes it online to determine the quality of the injected beam after each injection. If the quality is insufficient, the automatic injection process is stopped, and the operator has to take corrective measures. This paper will describe the software architecture of the LHC injection quality check and the interplay with other systems. A set of tools for self-monitoring of the injection quality checks to achieve optimum performance will be discussed as well. Results obtained during the LHC commissioning year 2010 and the LHC run 2011 will finally be presented.

Poster WEPMU011 [0.358 MB]

WEPMU012

First Experiences of Beam Presence Detection Based on Dedicated Beam Position Monitors

operation, pick-up, extraction, instrumentation

1081

A. Jalal, S. Gabourin, M. Gasior, B. Todd
CERN, Geneva, Switzerland

High intensity particle beam injection into the LHC is only permitted when a low intensity pilot beam is already circulating in the LHC. This requirement addresses some of the risks associated with high intensity injection, and is enforced by a so-called Beam Presence Flag (BPF) system which is part of the interlock chain between the LHC and its injector complex. For the 2010 LHC run, the detection of the presence of this pilot beam was implemented using the LHC Fast Beam Current Transformer (FBCT) system. However, the primary function of the FBCTs, that is reliable measurement of beam currents, did not allow the BPF system to satisfy all quality requirements of the LHC Machine Protection System (MPS). Safety requirements associated with high intensity injections triggered the development of a dedicated system, based on Beam Position Monitors (BPM). This system was meant to work first in parallel with the FBCT BPF system and eventually replace it. At the end of 2010 and in 2011, this new BPF implementation based on BPMs was designed, built, tested and deployed. This paper reviews both the FBCT and BPM implementation of the BPF system, outlining the changes during the transition period. The paper briefly describes the testing methods, focuses on the results obtained from the tests performed during the end of 2010 LHC run and shows the changes made for the BPM BPF system deployment in LHC in 2011.

WEPMU016

Pre-Operation, During Operation and Post-Operational Verification of Protection Systems

operation, controls, software, database

1090

I. Romera, M. Audrain
CERN, Geneva, Switzerland

This paper will provide an overview of the software checks performed on the Beam Interlock System ensuring that the system is functioning to specification. Critical protection functions are implemented in hardware, at the same time software tools play an important role in guaranteeing the correct configuration and operation of the system during all phases of operation. This paper will describe tests carried out pre-, during- and post- operation, if protection system integrity is not sure, subsequent injections of beam into the LHC will be inhibited.

WEPMU020

LHC Collimator Controls for a Safe LHC Operation

controls, FPGA, survey, operation

1104

S. Redaelli, R.W. Assmann, M. Donzé, R. Losito, A. Masi
CERN, Geneva, Switzerland

The beam stored energy at the Large Hadron Collider (LHC) will be up to 360 MJ, to be compared with the quench limit of super-conducting magnets of a few mJ per cm³ and with the damage limit of metal of a few hundreds kJ. The LHC collimation system is designed to protect the machine against beam losses and consists of 108 collimators, 100 of which are movable, located along the 27 km long ring and in the transfer lines. Each collimator has two jaws controlled by four stepping motors to precisely adjust collimator position and angle with respect to the beam. Stepping motors have been used to ensure high position reproducibility. LVDT and resolvers have been installed to monitor in real-time at 100 Hz the jaw positions and the collimator gaps. The cleaning performance and machine protection role of the system depend critically on the accurate jaw positioning. A fully redundant survey system has been developed to ensure that the collimators dynamically follow optimum settings in all phases of the LHC operational cycle. Jaw positions and collimator gaps are interlocked against dump limits defined redundantly as functions of the time, of the beam energy and of the beta* functions that describes the focusing property of the beams. In this paper, the architectural choices that guarantee a safe LHC operation are presented. Hardware and software implementations that ensure the required reliability are described. The operational experience accumulated so far is reviewed and a detailed failure analysis that show the fulfillment of the machine protection specifications is presented.

WEPMU023

External Post-Operational Checks for the LHC Beam Dumping System

controls, kicker, operation, extraction

1111

N. Magnin, V. Baggiolini, E. Carlier, B. Goddard, R. Gorbonosov, D. Khasbulatov, J.A. Uythoven, M. Zerlauth
CERN, Geneva, Switzerland

The LHC Beam Dumping System (LBDS) is a critical part of the LHC machine protection system. After every LHC beam dump action the various signals and transient data recordings of the beam dumping control systems and beam instrumentation measurements are automatically analysed by the eXternal Post-Operational Checks (XPOC) system to verify the correct execution of the dump action and the integrity of the related equipment. This software system complements the LHC machine protection hardware, and has to ascertain that the beam dumping system is ‘as good as new’ before the start of the next operational cycle. This is the only way by which the stringent reliability requirements can be met. The XPOC system has been developed within the framework of the LHC “Post-Mortem” system, allowing highly dependable data acquisition, data archiving, live analysis of acquired data and replay of previously recorded events. It is composed of various analysis modules, each one dedicated to the analysis of measurements coming from specific equipment. This paper describes the global architecture of the XPOC system and gives examples of the analyses performed by some of the most important analysis modules. It explains the integration of the XPOC into the LHC control infrastructure along with its integration into the decision chain to allow proceeding with beam operation. Finally, it discusses the operational experience with the XPOC system acquired during the first years of LHC operation, and illustrates examples of internal system faults or abnormal beam dump executions which it has detected.

Poster WEPMU023 [1.768 MB]

WEPMU026

Protecting Detectors in ALICE

detector, experiment, controls, monitoring

1122

M. Lechman, A. Augustinus, P.Ch. Chochula, G. De Cataldo, A. Di Mauro, L.S. Jirdén, A.N. Kurepin, P. Rosinský, H. Schindler
CERN, Geneva, Switzerland
A. Moreno
Universidad Politécnica de Madrid, E.T.S.I Industriales, Madrid, Spain
O. Pinazza
INFN-Bologna, Bologna, Italy

ALICE is one of the big LHC experiments at CERN in Geneva. It is composed of many sophisticated and complex detectors mounted very compactly around the beam pipe. Each detector is a unique masterpiece of design, engineering and construction and any damage to it could stop the experiment for months or even for years. It is therefore essential that the detectors are protected from any danger and this is one very important role of the Detector Control System (DCS). One of the main dangers for the detectors is the particle beam itself. Since the detectors are designed to be extremely sensitive to particles they are also vulnerable to any excess of beam conditions provided by the LHC accelerator. The beam protection consists of a combination of hardware interlocks and control software and this paper will describe how this is implemented and handled in ALICE. Tools have also been developed to support operators and shift leaders in the decision making related to beam safety. The gained experiences and conclusions from the individual safety projects are also presented.

Poster WEPMU026 [1.561 MB]