# Presentation: 492512

## PHASE I Collimator Activities 

**A. Drees**

##  The LHC Collimation Project

- What is the scope of the project and its mandate ?
- Who are the people involved at CERN?
- What could be done at RHIC?

- GRD - 08/2004

## LHC PHASE I Collimation  Project: Scope 

**Two warm LHC insertions dedicated to cleaning:**
- IR3	 Momentum cleaning
- IR7	 Betatron cleaning
- Building on collimation system design that started in 1992!
- Various collimators in experimental insertions IR1, IR2, IR5, IR8.

****** ****Four collimation systems: Momentum and betatron for two beams!**

- GRD - 08/2004

## LHC Collimation Project: Mandate

- Finalize the design of the LHC collimation system in IR3 and IR7, taking into account all relevant requirements concerning robustness, performance, fabrication, installation, maintenance, machine protection and beam operation.
- Produce prototype collimator tanks for TCP, TCS, and TCL type collimators and verify their performance.
- Supervise production and installation of the full system.
- Commission the system without and with beam. Support routine operation.

- GRD - 08/2004

## The Phased Approach & LARP/BNL

*** **_**PHASE 1:**_
- -- **Maximum robustness, minimum cost of the IR3/IR7 collimation system** (C based) for injection & ramping, commissioning, early physics (running at impedance limit)
- -- **“Tertiary” collimators in IR1, IR2, IR5, IR7**** **for local protection and cleaning at the triplets.
- -- Thin targets for **beam scraping**
- Benchmarking of simulation code (sixtrack & K2) with RHIC loss map, this might need additional beam experiment time during proton running depending on results when work starts (probably Dec. 04)
- Testing of steering algorythms (~ 70 collimators!), will need some testing time with beam in RHIC (this upcoming run)
*** **_**PHASE 2:**_
**-- Metallic “hybrid” secondary collimators in IR7** for nominal performance, used only at end of squeeze and stable physics.
- ->	Development of collimator prototype @ SLAC ?, ass. simulations

- (in red are the areas of potential collaboration with LARP and/or BNL)

- GRD - 08/2004

## Loss Maps

- Losses in the yellow ring (Au)

- Zoom into collimator area

- direction of beam

- Data taken in a “beam experiment” shift to tune simulation software.
- More data available at storage energy and various species (Au, d, p).

- GRD - 08/2004

## Compare RHIC data with simulation

- Ray Fliller

- Fill 4854
- 2-stage
- (axis swapped!)

- Fill 3254
- 1-stage

- Needs some more work!

- GRD - 08/2004

## Tools for scattering and collimation tracking

- So far, limited tools were used for efficiency studies:
- _COLLTRACK/K2:_ limited linear tracking code
- 			 no imperfections models, no chromatic effects
- 			 element-by-element tracking
- 			 large number of particles can be tracked
- Now go to best possible tracking tools:
- _SIXTRACK:_ **fast** complete tracking code, incl. non linear effects
- 		      full functionality of MADX error and correction models
- 		      element-by-element tracking
- 		      only 64 particles MAXIMUM can be tracked
- Collimators implemented quick-and-dirty into SIXTRACK in 2002 (R. Aßmann)
- => Now: proper implementation into standard SIXTRACK version of the V6.5 Collimation System Design with debugging and careful consistency checks

- G. Robert-Demolaize

- GRD - 08/2004

## colltrack is installed at BNL and ready to be used.

- G. Robert-Demolaize

- Anticipated time for data analysis: Dec. 04 or Jan. 05

- GRD - 08/2004

## Summary

- BNL just started a collaboration with the LHC collimation WG: colltrack code is installed and compiled at BNL
- There is a need for code benchmarking and comparison in the world of loss maps (more pp beam time?), data will be analyzed with the help of the LHC collimation WG (grad. student for 1-2 months)
- Multiple collimator steering will likely require some beam time at RHIC
- hiring process of LARP postdoc started (likely for both fields, collimation and EC)

- GRD - 08/2004