MKD stack upgrade

MKD generator meetingViliam Senaj23/06/2015

Effect of return rod displacement

RR displacement [mm] 0Present

situation

5 10 15 20

Inductance stack [nH] 132 141 149 157 165

Inductance MKD total [nH] 2.682 2.691 2.699 2.707 2.715

Voltage @ 7 TeV [kV] 29 29.06 29.1 29.14 29.19

Emax [MV/m] 2.9 2.53 1.91 1.59 1.4

Trise increase [ns] 0 +4 + 8 +12 + 15

Solution with return rods displaced by 20 mm

• Return rod displaced by 20 mm• Araldite insulation of RR• Modified top insulator – upper tube

included• Reduced diameter of 4 upper HV

deflectors and full insulation by araldite• HV contact insulated by araldite• Modified 4 top snubber capacitors –

araldite tube around instead of HV deflectors

Solution with return rods displaced by 20 mm

Time plan

• Drawing of machining plans ~ 2 weeks• Procurement of raw material for 3 switches ~ 2 months • Machinning ~ 4 weeks• Assembly ~ 3 days • Test of single stack in HV case up to 40 kV ~ 1 week• Test inside generator ~ 6 months

Magnet current @29 kV o vs 20 mm displacement (132 vs 165 nH)

Main dividers 2 x 100 MΩ

Main dividers 2 x 100 MΩ

Main dividers 2 x 100 MΩ - solution

Main dividers 2 x 100 MΩ - solution

HV divider 10 x 5 MΩ, top deflector

HV divider 10 x 5 MΩ – solution

HV contact region - today

HV contact region - solution

Final solution

MKD E/B2 freewheel signal

MKD schematics