Slide 1

ISRM project

DFBXs Splice measurements

Richard Mompo on behalf of ELQA team

1TE/MPE-MS 10/05/2012, Richard Mompo1ISRM on DFBXsThere are 8 DFBXs in the LHC. 4 of them have an additional D1 magnet connected.

2 measuring set-up were prepared in order to measure 2 DFBXs at a time The measurements took place at the end of the Xmas break during the powering phase.

The DAQ was based on a PXI crate equipped with 7 or 9 high precision DVMs.Same principle as already applied for ISRM on IPDs, IPQs with QPM software.

We measured each DFBXs from the tunnel side.To avoid long cables and because of availability of additional diagnostic connectors (that are not routed to QPS controllers which are standing in the UAs/Ujs).

Circuits RQX/RTQX2 were powered together with a Mexican pyramid.Use of standard power cycle PNO.D11 with 3 current plateaus reduced to 10 min. each (instead of 1h).

D1 magnets were measured separately. Use of standard cycle power PNO.c2TE/MPE-MS 10/05/2012, Richard Mompo

DFBX Layout in LHC During PNO.D11, RTQX1 power converter is OFF.TE/MPE-MS 10/05/2012, Richard Mompo3Current plateaus for each DFBX4Current plateau 1 [A]Current plateau 2 [A]Current plateau 3 [A]Current plateau 4 [A]Current plateau 5 [A]RD1.L2200350100020003500RD1.L8200350100020003500RD1.R2200350100020003500RD1.R8200350100020003000RQX.L1200040005800RTQX2.L1130026003900RQX.L2200040005800RTQX2.L2130026003900RQX.L5200040005800RTQX2.L5130026003900RQX.R1120624143500RTQX2.R180016002400RQX.R5200040005800RTQX2.R5130026003900RQX.R8200040005800RTQX2.R8130026003900RQX.L8200040005800RTQX2.L8130026003900RQX.R2200040005800RTQX2.R2130026003900DFBX in R1: Current levels for are much lower? Why?TE/MPE-MS 10/05/2012, Richard MompoPNO.D11 cycle with voltage measurements5

Q2 is seeing 9700 Amps!TE/MPE-MS 10/05/2012, Richard Mompo6

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11D1 splices belong to another family and should be compared to other IPDsTE/MPE-MS 10/05/2012, Richard Mompo

12We have more noise on DVM 1, 4, 5 and 7!

Probably because we are mixing a current lead voltage tap with a magnet voltage tap Means there are not routed the same way up to the DFBXTE/MPE-MS 10/05/2012, Richard Mompo

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14I made the assumption that all splices are identical!DVM3 and DVM7 of DFBXB.R1 are slightly outside of the Gaussian curve TE/MPE-MS 10/05/2012, Richard MompoConclusionsWe managed to measure all 8 DFBXs during 2011-2012 Xmas break.We did not measure all Q1, Q2a, Q2b and Q3 internal splices (splices between poles)!From a statistic point of view, it looks like the nominal resistance value for the 2 groups of splices are:Around 0.5 E-09 Ohms for Q1, Q2 and Q3 splices Around 1 E-09 Ohms for D1 splices (comparable with other IPDs magnets) .All splices measured are below 5 E-09 Ohms so there is nothing worrying!An internal note will follow similar to the one written for IPDs and IPQs:EDMS 1172291

15TE/MPE-MS 10/05/2012, Richard Mompo15Thank you for your attention!16TE/MPE-MS 10/05/2012, Richard MompoSpare slidesTechnical drawings17TE/MPE-MS 10/05/2012, Richard MompoQ3 to DFBX splices18

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TE/MPE-MS 10/05/2012, Richard MompoQ3 to Q2 splices21

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TE/MPE-MS 10/05/2012, Richard MompoQ2 to Q1 splices24

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