US LHC Accelerator Research Program bnl fnal lbnl

US LHC Accelerator Research Program bnl - fnal- lbnl - slac Status of Tertiary Collimator Studies Nikolai Mokhov (presented by Vladimir Shiltsev) LARP, LBNL, April 2006 Tertiary Collimators - N. Mokhov

TERTIARY BEAM HALO LOSS Primary Secondary Inner Triplets Arcs LARP, LBNL, April 2006 6 sigma 7 sigma 8. 5 sigma 30 sigma Tertiary Collimators - N. Mokhov 2

MODELING WITH TWO COPPER TCTs LARP, LBNL, April 2006 Tertiary Collimators - N. Mokhov 3

1. 3. 2. 2 Tertiary Collimator Studies L 3 Leader: Nikolai Mokhov (FNAL) FY 06 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 IP 1 and IP 5 insertions and farther to the CMS and ATLAS detector inner detectors followed by realistic energy deposition modeling with the MARS 15 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. LARP, LBNL, April 2006 Tertiary Collimators - N. Mokhov 4

TC: IP 1/IP 5 MARS 15 MODEL UPGRADE ØConversion to LHC lattice ver. 6. 5 ØUpdate of layout, dimensions, magnetic field maps, beam screen in Q 1, cylindrical D 1 -D 2 pipe ØTAN: standalone, with ZDC, with LHCf (if IP 1) ØImplementation of collar shielding A and B, and TCT collimators; TCL open and closed ØUpgrade of machine-detector interface (CMS beam pipe, blockhouse, its extension into the tunnel etc). ØExtension of the model into arcs (up to IP 4&IP 6) ØBeam loss patterns from IP 3/IP 7 (Ralf Assmann), and beam-gas LARP, LBNL, April 2006 Tertiary Collimators - N. Mokhov 5

IP 5 TCT TERTIARY COLLIMATORS MARS 15 STUDIES 1. Outgoing beam: TCTs are pretty radioactive (especially if made of tungsten) and interfere with the TOTEM first station XRP 1 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 IP 7 betatron cleaning for BEAM 1: its contribution at IP 5 is negligible. 4. Desperately waiting for BEAM 1 (momentum) and especially for BEAM 2 (momentum and betatron): Ralph says we will get it this month. (!) LARP, LBNL, April 2006 Tertiary Collimators - N. Mokhov 6

Tert. Collim: Issues/Plans ØNeed input from Ralph ASAP - it’s not the first time – obviously a communication issue ØAs soon as beam loss input files received ~2 mos to finish most work on TCT Ø If no surprizes – task can be closed ~1/2 yr LARP, LBNL, April 2006 Tertiary Collimators - N. Mokhov 7