Turn-around%20after%20DR?%2020050825%20Kiyoshi%20Kubo

1
Turn-around after DR? 20050825 Kiyoshi Kubo

• Conclusion YES.
• Unless stable extraction from DR is guaranteed.
• Required Relative Kicker stability 7E-4
  (TESLA-TDR).
• Lengths of additional beam line and tunnel depend
  on DR layout. (see last two slides.)

2
Input from WG1

• It will help to reduce beam jitter by
  feed-forward
• In particular bunch-to-bunch jitter
• Strongly recommended

3
Additional Cost for turn-around
DR Layout DR Layout Tunnel Beam Line
Downstream of Linac Downstream of Linac 0 0
Dogbone, Upstream Dogbone, Upstream 0 1 km
Circular (6 km), Upstream A 1km 1 km
Circular (6 km), Upstream B 0 3.5 km DR length/2 0.5 km
4
Case B
Case A
Extraction arc from DR ( 3.5 km)
Signal line for feed-forward ( 2.5 km)
DR (6 km)
DR (6 km)