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Photo shows initial (inadequate) hookup wireswhich have been replaced by fatter ones.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