New divider floating vs. grounded

1. New divider floating vs. grounded Sasha Milov July 10, 2007 Sasha Milov HBD internal... July 10, 2007

2. New divider • Some other changes: • GEMS are not shown because they are made of 28 R/C and are huge. • No change in the results compare to the old scheme found • In the scheme on the left PS shorts to zero at a trip time. I used 1ms fall time and 1Meg residual resistance on the PS Rout. • Changing Rout to zero does not really change much, anyways. Bot Mid Top Mesh Sasha Milov HBD internal... July 10, 2007

3. Float vs Ground topGEM-mesh float ground across GEMs across transfer gaps Sasha Milov HBD internal... July 10, 2007

4. Float vs Ground • Ground scheme has advantages: • transients dV are smaller (even with Rout = 0 they are so) • GEM discharges faster • Transfer gaps flip sign “momentarily” so to prevent any affect on lower GEM. • Here is my understanding of Floating vs. Grounded PS: • In case of a trip one would like to drain energy form the divider. Regardless of the PS, the scheme must have such drainage system with matching R/C’s. We learned it a hard way. Floating PS leaves transient process fully at hands of that drainage system. Grounded PS provides one more sewer, which if all R/C match properly gives another factor in speed, thus safety. • Bob and me measured BERTAN yesterday found it floating with Rout = 150M (guess at Fluke’s limit…) Sasha Milov HBD internal... July 10, 2007

5. New vs Old dividers topGEM-mesh new (float) old (used) across GEMs across transfer gaps Sasha Milov HBD internal... July 10, 2007