1. Joint IR Studies: Operating Margins Nikolai Mokhov Fermilab bnl - fnal- lbnl - slac US LHC Accelerator Research Program LARP Collaboration Meeting SLAC October 17-19, 2007

2. LARP CM9 October 17-19, 2007 N. Mokhov, JIRS Operating Margins 2 Operating Margins: Sub-Tasks Sub-task 1 (with BNL and CERN). Estimate the operational performance margins for QA magnets installed in the LHC. Develop requirements for QA temperature margin studies in bench tests. Sub-task 2 (with JJ and CERN). Perform parametric studies of radiation dose and heat deposition in potential QB candidates (and other components), as a function of aperture, optics, layout and distance from IP, in a full upgrade scenario. Explore means to reduce the level of radiation and heat deposition in magnet coils using radial and longitudinal absorbers to the level consistent with magnet operation margin and lifetime requirements. Sub-task 3 (with BNL, CERN, ATLAS and CMS teams). Study radiation dose, dynamic and static heat deposition in “slim” IR dipoles and quadrupoles inside the LHC detectors. Evaluate operational margin and magnet life-time for “slim” magnets based on NbTi, Nb3Sn or HTS technologies.

3. LARP CM9 October 17-19, 2007 N. Mokhov, JIRS Operating Margins 3 QA Quadrupole Mission Statement: FY08 & FY09 1.Define and evaluate a short list of potential QA locations at CERN, based on clearly established criteria, in full communication with LARPs primary liaisons at CERN (L. Rossi and H. Schmickler) and others. These locations may include (but are not limited to) LHC Q1 or Q3 in a potential early “hybrid” upgrade, and quadrupoles vulnerable to accidental radiation in the collimation region. 2.Develop appropriately strict or relaxed specifications for the magnetic and accelerator-quality parameters of QA magnets – alignment, field quality, persistent current fluctuations, snap-back, power supply regulation et cetera – based on at least one of the potential locations. 3.Examine the possibility of using LQ or HQ-derived designs and tooling to build QA magnets. 4.Identify bench tests on QA or LQ or HQ magnets that would help explore and demonstrate accelerator quality performance (except radiation), to be performed within LARP Magnet Systems or at CERN.

4. LARP CM9 October 17-19, 2007 N. Mokhov, JIRS Operating Margins 4 Operating Margins Sub-task 1: FY08 Based on realistic energy deposition calculations, estimate the operational performance margins for Nb3Sn quadrupoles QA installed in the LHC and develop requirements for QA temperature margin studies in bench tests. This study will include: Building realistic model of a QA quadrupole for the MARS Monte Carlo code with detailed 3-D geometry and materials description and OPERA-calculated 2-D magnetic field map. Building a corresponding thermal model of QA. Energy deposition calculations and thermal analysis of performance of QA being a part of the LHC inner triplet. Estimate the operational performance margins for QA. Define and evaluate a list of potential locations of QA at the LHC (e.g., Q1 or Q3 in an early “hybrid” upgrade) or elsewhere at CERN or Fermilab, in circulating beam or in a beam line -> a dedicated irradiation test! The above, in full communication with the LARP primary liaisons at CERN and iterations with the Optics & Layout Task group.

5. LARP CM9 October 17-19, 2007 N. Mokhov, JIRS Operating Margins 5 Sub-task 1: FY08 Deliverables: - Report on energy deposition and thermal studies of QA quadrupoles in the LHC and operational performance margins for QA quadrupoles QA in the LHC and requirements for beam bench tests. Personnel: FNAL: N. Mokhov, V.V. Kashikhin, I. Rakhno, A. Zlobin CERN Contacts: J.P. Koutchouk, L. Rossi, E. Wildner

6. LARP CM9 October 17-19, 2007 N. Mokhov, JIRS Operating Margins 6 Slim Magnets Mission Statement: 1.List and evaluate “sample straw man” parameters (aperture, length, OD, field/gradient, field quality, alignment, etc.) and operation conditions (radiation deposition, forces and fields from detector magnet, dynamic and static heat load, etc.) for slim magnets located inside ATLAS and/or CMS. 2. Evaluate the usefulness of conventional NbTi technology, or of alternative magnet technologies (Nb3Sn or HTS) in terms of operational margin, magnet life-time, et cetera.

7. LARP CM9 October 17-19, 2007 N. Mokhov, JIRS Operating Margins 7 Slim Magnets: Operat. Margins FY08 Within a fruitful collaboration between JPK and NM groups 1.Complete FLUKA/MARS benchmarking and sensitivity analysis studies for the LHC IRs. 2.Agree on a slim magnet parameters and configuration of its implementation into a detector and IR layout. 3.Initiate detailed energy deposition simulations for the configuration agreed.