Status of Tertiary Collimator Studies

1
Status of Tertiary Collimator Studies
US LHC Accelerator Research Program
bnl - fnal- lbnl - slac

• Nikolai Mokhov
• (presented by Vladimir Shiltsev)

2
TERTIARY BEAM HALO LOSS
Primary 6 sigma Secondary 7
sigma Inner Triplets 8.5 sigma Arcs
30 sigma
3
MODELING WITH TWO COPPER TCTs
4
1.3.2.2 Tertiary Collimator Studies

• L3 Leader Nikolai Mokhov (FNAL)
• FY06 budget 30 k
• Goals
• Tertiary collimators in high-luminosity
  insertions are needed to protect of LBQuads and
  detectors. We will carry out full tracking
  with the STRUCT code - of secondary halo
  particles up to the limiting apertures in the IP1
  and IP5 insertions and farther to the CMS and
  ATLAS detector inner detectors followed by
  realistic energy deposition modeling with the
  MARS15 code with and without tertiary
  collimators.
• Minimization of machine-related backgrounds and
  protection of the final focus and collider
  detector components at normal operation and
  accidental beam losses is to be added to the
  collimation system specifications. The ultimate
  goal is a successful design for high efficient
  robust tertiary collimators in all the LHC
  experimental insertions. The design
  specifications are the primary deliverables.

5
TC IP1/IP5 MARS15 MODEL UPGRADE

• Conversion to LHC lattice ver. 6.5
• Update of layout, dimensions, magnetic field
  maps, beam screen in Q1, cylindrical D1-D2 pipe
• TAN standalone, with ZDC, with LHCf (if IP1)
• Implementation of collar shielding A and B, and
  TCT collimators TCL open and closed
• Upgrade of machine-detector interface (CMS beam
  pipe, blockhouse, its extension into the tunnel
  etc).
• Extension of the model into arcs (up to IP4IP6)
• Beam loss patterns from IP3/IP7 (Ralf Assmann),
  and beam-gas

6
IP5 TCT TERTIARY COLLIMATORS MARS15 STUDIES

1. Outgoing beam TCTs are pretty radioactive
(especially if made of tungsten) and
interfere with the TOTEM first station XRP1 at
146 m. 2. Incoming beam preliminary results for
beam-gas are encouraging. 3. On September 30,
2005, Ralph Assmann provided beam loss patterns
from IP7 betatron cleaning for BEAM1 its
contribution at IP5 is negligible. 4. Desperately
waiting for BEAM1 (momentum) and especially for
BEAM2 (momentum and betatron) Ralph says we
will get it this month. (!)
7
TertCollim Issues/Plans

• Need input from Ralph ASAP
• - its not the first time obviously a
  communication issue
• As soon as beam loss input files received ? 2
  mos to finish most work on TCT
• If no surprizes task can be closed 1/2 yr