ICALEPCS2013 - List of Authors (Borburgh, J.)

Paper

Title

Page

A New Spark Detection System for the Electrostatic Septa of the SPS North (Experimental) Area

246

R.A. Barlow, B. Balhan, J. Borburgh, E. Carlier, C. Chanavat, T. Fowler, B. Pinget
CERN, Geneva, Switzerland

Electrostatic septa (ZS) are used in the extraction of the particle beams from the CERN SPS to the North Area experimental zone. These septa employ high electric fields, generated from a 300 kV power supply, and are particularly prone to internal sparking around the cathode structure. This sparking degrades the electric field quality, consequently affecting the extracted beam, vacuum and equipment performance. To mitigate these effects, a Spark Detection System (SDS) has been realised, which is based on an industrial SIEMENS S7-400 programmable logic controller and deported Boolean processors modules interfaced through a PROFINET fieldbus. The SDS interlock logic uses a moving average spark rate count to determine if the ZS performance is acceptable. Below a certain spark rate it is probable that the ZS septa tank vacuum can recover, thus avoiding transition into a state where rapid degradation would occur. Above this level an interlock is raised and the high voltage is switched off. Additionally, all spark signals acquired by the SDS are sent to a front-end computer to allow further analysis such as calculation of spark rates and production of statistical data.

Poster MOPPC064 [0.366 MB]

MOPPC068

Operational Experience with a PLC Based Positioning System for a LHC Extraction Protection Element

254

C. Boucly, J. Borburgh, C. Bracco, E. Carlier, N. Magnin, N. Voumard
CERN, Geneva, Switzerland

The LHC Beam Dumping System (LBDS) nominally dumps the beam synchronously with the passage of the particle free beam abort gap at the beam dump extraction kickers. In the case of an asynchronous beam dump, an absorber element protects the machine aperture. This is a single sided collimator (TCDQ), positioned close to the beam, which has to follow the beam position and beam size during the energy ramp. The TCDQ positioning control is implemented within a SIEMENS S7-300 Programmable Logic Controller (PLC). A positioning accuracy better than 30 μm is achieved through a PID based servo algorithm. Errors due to a wrong position of the absorber w.r.t. the beam energy and size generates interlock conditions to the LHC machine protection system. Additionally, the correct position of the TCDQ w.r.t. the beam position in the extraction region is cross-checked after each dump by the LBDS eXternal Post Operational Check (XPOC). This paper presents the experience gained during LHC Run 1 and describes improvements that will be applied during the LHC shutdown 2013 – 2014.

Poster MOPPC068 [3.381 MB]

Paper	Title	Page
MOPPC064	A New Spark Detection System for the Electrostatic Septa of the SPS North (Experimental) Area	246
	R.A. Barlow, B. Balhan, J. Borburgh, E. Carlier, C. Chanavat, T. Fowler, B. Pinget CERN, Geneva, Switzerland
	Electrostatic septa (ZS) are used in the extraction of the particle beams from the CERN SPS to the North Area experimental zone. These septa employ high electric fields, generated from a 300 kV power supply, and are particularly prone to internal sparking around the cathode structure. This sparking degrades the electric field quality, consequently affecting the extracted beam, vacuum and equipment performance. To mitigate these effects, a Spark Detection System (SDS) has been realised, which is based on an industrial SIEMENS S7-400 programmable logic controller and deported Boolean processors modules interfaced through a PROFINET fieldbus. The SDS interlock logic uses a moving average spark rate count to determine if the ZS performance is acceptable. Below a certain spark rate it is probable that the ZS septa tank vacuum can recover, thus avoiding transition into a state where rapid degradation would occur. Above this level an interlock is raised and the high voltage is switched off. Additionally, all spark signals acquired by the SDS are sent to a front-end computer to allow further analysis such as calculation of spark rates and production of statistical data.
	Poster MOPPC064 [0.366 MB]

MOPPC068	Operational Experience with a PLC Based Positioning System for a LHC Extraction Protection Element	254
	C. Boucly, J. Borburgh, C. Bracco, E. Carlier, N. Magnin, N. Voumard CERN, Geneva, Switzerland
	The LHC Beam Dumping System (LBDS) nominally dumps the beam synchronously with the passage of the particle free beam abort gap at the beam dump extraction kickers. In the case of an asynchronous beam dump, an absorber element protects the machine aperture. This is a single sided collimator (TCDQ), positioned close to the beam, which has to follow the beam position and beam size during the energy ramp. The TCDQ positioning control is implemented within a SIEMENS S7-300 Programmable Logic Controller (PLC). A positioning accuracy better than 30 μm is achieved through a PID based servo algorithm. Errors due to a wrong position of the absorber w.r.t. the beam energy and size generates interlock conditions to the LHC machine protection system. Additionally, the correct position of the TCDQ w.r.t. the beam position in the extraction region is cross-checked after each dump by the LBDS eXternal Post Operational Check (XPOC). This paper presents the experience gained during LHC Run 1 and describes improvements that will be applied during the LHC shutdown 2013 – 2014.
	Poster MOPPC068 [3.381 MB]