Chain of Modules using 1cm wide Cu Tape between hybrids SP- SP+ M0 M1 M2 M3 Initial test used...
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Transcript of Chain of Modules using 1cm wide Cu Tape between hybrids SP- SP+ M0 M1 M2 M3 Initial test used...
Chain of Modules using 1cm wide Cu Tape between hybrids
SP-
SP+
M0
M1
M2
M3
Initial test used External shunt control (subsequently reverted)
Photo shows initial (inadequate) hookup wireswhich have been replaced by fatter ones.
Power feed is choked to reject external noise, with 1nF + 10uF thereafter to provide local HF bypass.
Link between modules is ~3mm wide Cu, no coils
H0 H1 H2 H3 H4 H5 H6 H7
Column
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ENC @ 2fC
664 620 640 689 642 617 636 678 655 623 655 708 663 637 636 677
ENC @ 1fC
656 617 632 678 633 610 629 669 645 615 649 692 651 625 626 658
DTN @1.0fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.75fC
0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0
DTN @0.5fC
91 108 0 5 345 148 4 32 361 463 13 23 745 934 16 169
Chain of Hybrids @ 5A (2144-3)
H0 H1 H2 H3 H4 H5 H6 H7
Column
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ENC @ 2fC
654 610 636 687 636 610 639 685 679 630 640 674 680 648 614 640
ENC @ 1fC
645 610 627 675 627 603 625 669 671 622 632 669 672 639 609 634
DTN @1.0fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.75fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.5fC
0 0 5 61 0 0 21 185 13 4 7 36 95 38 57 350
Chain of Modules @ 9A (2182-3) – M2 using external shunt control
DTN and ENC better on average, but not for every column
The Bigger Picture
Caps here
Choke on hookup wires(not to scale!)
M2 now uses internal shunt control
H0 H1 H2 H3 H4 H5 H6 H7
Column
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ENC @ 2fC
655 612 636 687 636 610 639 686 703 644 651 708 709 659 623 661
ENC @ 1fC
646 609 626 675 627 604 626 667 691 634 641 695 695 648 617 653
DTN @1.0fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.75fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.5fC
0 0 5 55 1 0 16 161 12 3 25 128 129 46 83 550
Chain of Modules @ 9A (2186-3) – M2 using internal shunt control
H0 H1 H2 H3 H4 H5 H6 H7
Column
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ENC @ 2fC
655 612 638 686 637 613 631 672 693 638 652 691 686 651 629 657
ENC @ 1fC
645 606 627 675 627 604 620 657 684 629 644 684 675 639 621 651
DTN @1.0fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.75fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.5fC
0 0 6 54 2 2 14 102 10 3 20 80 102 49 63 346
Chain of Modules @ 9A (2187-3) – M2 using internal shunt control, “column 3” shield ties added
Stavelet DTN @ 0.50fC
2187-11 : M0 at 0.5fC 2187-11 : M1 at 0.5fC
Sum(hits): simply sum the number of hits shown in each double trigger plot
0
0
6
54
2
2
14
102
5
131 slices, each slice 100 events, each column 1280 channels
Stavelet DTN @ 0.50fC
2187-11 : M2 at 0.5fC 2187-11 : M3 at 0.5fC
Sum(hits): simply sum the number of hits shown in each double trigger plot
10
3
20
80
102
49
63
346
6
H0 H1 H2 H3 H4 H5 H6 H7
Column
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ENC @ 2fC
ENC @ 1fC
647 610 627 675 630 605 621 655 682 628 654 691 678 641 625 655
DTN @1.0fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.75fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.5fC
0 0 4 58 0 0 13 107 7 1 11 63 99 31 58 347
Chain of Modules @ 9A (2188-19) – M2 SP+ link with 12nH inductor
H0 H1 H2 H3 H4 H5 H6 H7
Column
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ENC @ 2fC
ENC @ 1fC
644 610 626 674 626 603 619 657 696 640 652 693 680 641 625 658
DTN @1.0fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.75fC
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DTN @0.5fC
0 0 4 60 0 1 11 132 11 2 27 83 100 47 70 386
Chain of Modules @ 9A (2188-19) – M2 SP- link with 12nH inductor
Interpretation
• CofM gives better DTN than CofH– No surprises
• External shunt regulation of M2 gave better DTN and ENC results than internal regulation– Due to inductance of wired links between boards?– Due to location of regulation at power entry?– Due to higher Vdd?
• Addition of “column 3” shield ties had no effect– No surprises
• Adding 12nH inductor to SP+ inter-hybrid link improves DTN verys slightly– Same inductor in SP- inter-hybrid link does nothing
Ideas: what next?
• Try a star point geometry– Remove the existing inter-module ties and instead bridge the
current between modules using wires (or tape) soldered to the middle of the inter-hybrid copper tape links.
– Should reduce HF currents on “odd” numbered hybrids (which have worse DTN).
– If caps fitted at the star point, should also be better rejection of bus noise.
– Does this make any sense?• Reduce loop area of hookup• Caps (10uF + 1nF) from each module to common HF return
foil