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Overview of Results from Electrical Stavelets. Peter W Phillips et al 13/07/2011. Serially Powered Stavelet. H0 H1 H2 H3 H4 H5 H6 H7 EoS. DC-DC Stavelet. 8 th July 2011. Serially Powered Stavelet.
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Overview of Resultsfrom Electrical Stavelets Peter W Phillips et al 13/07/2011
Serially Powered Stavelet H0 H1 H2 H3 H4 H5 H6 H7 EoS DC-DC Stavelet
8th July 2011 Serially Powered Stavelet Jan Stastny Current Source at 5A, 230V bias, ALL MODULES ON
8th July 2011 Serially Powered Stavelet Double Trigger Noise: Basic Metric 1722-7: Columns 0-3 at 0.75fC 1722-8: Columns 0-3 at 0.50fC Sum(hits): simply sum the number of hits shown in each double trigger plot 220052 599661 262759 630266 0 88 0 78
20th May 2011 Serially Powered Stavelet Double Trigger Noise: Basic Metric L1A over COM, no additional delay (run 1580) Sum(hits) SP- SP+ Hybrid
Serially Powered Stavelet SP Stavelet Summary • Good ENC noise performance • Can bypass individual hybrids under DCS control (PPB / 1-wire) • Excess noise occupancy correlated with readout, notably “even” hybrids Have explored lots of ideas with single SP modules and/or the stavelet • Extra decoupling (helps a bit) • Improved referencing • Second backplane connection • Alternate shunt control circuits • M shunt plugin, SPP-COB chip Studies with a single module show that the double trigger noise is reduced if both hybrids on a detector sit at the same DC potential (see Tony’s talk) • Proposal is to convert stavelet from a “chain of hybrids” to a “chain of modules” • Maybe just build a new one? • Likely to give us a Serially Powered stavelet which meets required noise targets • Not as efficient as a “chain of hybrids”, should continue to work toward that in parallel
DC-DC Stavelet 12thJuly 2011 Stavelet + 47uF: One hybrid at a time 12thJuly 2011 Stavelet + 47uF: Both hybrids at once Single Module Reference Result
12thJuly 2011 DC-DC Stavelet Double Trigger Noise: Basic Metric 1730-7: Columns 0-3 at 0.75fC 1730-8: Columns 0-3 at 0.50fC Sum(hits): simply sum the number of hits shown in each double trigger plot 15 2898 4 2442 0 9 0 85
DC-DC Stavelet DC-DC Stavelet Summary • BetterDouble Trigger Noise performance • Can disable/re-enable hybrids under DCS control (1-wire) • Performance of H0 not yet satisfactory • Contrary to an earlier successful test of a stavelet module powered by STV DC-DC converters, initial results on the stavelet were not encouraging • Explored B field mapping and extra shielding • Minimal effect • Explored improved ground referencing • Minimal effect (but maybe did not go far enough) • Explored frequency spectrum of noise on the DC-DC power bus • Artefacts from converters and peaks from other sources such as HSIO • Latest result achieved by the addition of capacitors to the power bus • Still investigating ways to recover the performance of H0
DC-DC Stavelet Probing the power bus: up to 2MHz Power ON H0 + H1 + H2 active Power ON H0 + H1 + H2 active 47uF held at location H4 These measurements were made using an 800 MHz bandwidth diff probe located at the position where “H3” would normally be connected
DC-DC Stavelet Naked Converters! Converter 06: BC0000000476043A Converter 14: 7C0000000455D23A