Status of the Project LHC IR Upgrade - Phase I SLHC-IRP1 1. - - PowerPoint PPT Presentation

• R. Ostojic, 15 April 2008

Status of the Project “LHC IR Upgrade - Phase I”

• 1. Elements of SLHC roadmap
• 2. Project goals and milestones
• 3. Review of IR systems: main findings
• 4. The emerging concept
• 5. Elements of project organization
• 6. Collaborations
• 7. Perspectives

SLHC-IRP1

SLHC Roadmap

LHC IR Upgrade - Phase I

Goal of the upgrade: Enable focusing of the beams to β*=0.25 m in IP1 and IP5, and reliable operation of the LHC at 2 1034 cm-2s-1 on the horizon of the physics run in 2013. Scope of the Project:

1. Upgrade of ATLAS and CMS interaction regions. The interfaces between the LHC and the experiments remain unchanged. 2. Replace the present triplets with wide aperture quadrupoles based on the LHC dipole cables (Nb-Ti) cooled at 1.9 K. 3. Upgrade the D1 separation dipole, TAS and other beam-line equipment so as to be compatible with the inner triplet aperture. 4. Modify matching sections (D2-Q4, Q5, Q6) to improve optics flexibility. Introduction of other equipment to the extent of available resources. 5. The cryogenic cooling capacity and other infrastructure in IR1 and IR5 remain unchanged and will be used to full capacity.

Project milestones

Project Approval Dec 2007 Conceptual Design Report June 2008 Model quadrupole end 2009 Technical Design Report mid 2009 Pre-series quadrupole end 2010 String test 2012 Installation shutdown 2013

Review of IR systems: main findings (1)

1. Cold vacuum

• Vacuum stability remains a driving issue irrespective of larger aperture

→ beam screens (continue to be) required.

• Mechanical stability during quench (~ r5), beam screen thickness → 2mm.
• Possibility of cooling the beam screen at 40-60 K level.
• Main concerns: gas load (beam screen transparency) and average gas

density (background).

2. Optics and aperture requirements

• Most promising solutions: “symmetric” and “low-beta-max” triplets.
• D1 dipole must match the aperture of the triplet.
• The apertures of the matching section (D2-Q4, Q5) limit the reach of the
• triplet. Modifications of the BS and magnet position may be needed.

3. Cryostats and interconnections

• Access and transport to IR1/5 require that the OD and length of the

vacuum vessels of the new triplets are similar to the LHC main dipole.

• Re-use of the main components and assembly procedures for cryostating

limits the cold mass OD to ~570 mm (MB).

• Estimated min interconnect length → 1.3 m (magnetic length).

Review of IR systems: main findings (2)

4. Collimation system and the triplet aperture

• The main concern is the collimation inefficiency in IR7.
• Larger triplet aperture opens the possibility of opening the jaws and

reducing the collimator impedance. However, the inefficiency of collimation increases.

• Reduction of β* drives aberrations, which may corrupt the collimation

hierarchy.

• Background! Long optimization of TCT with experiments.

5. Cryogenic limitations and heat extraction

• The present estimate of ultimate e-cloud loads at 4.5-20 K higher than the

capacity of the plants. New “ultimate” conditions compatible with available plant capacity to be defined after commissioning.

• RF in IP4 requires ~ 4 kW at 4.5-20K of the 23 kW available. The triplet

in 5L may have less cooling capacity available than the others.

• Replacement of triplets in IR1/5 requires at present warm-up of 4 sectors.
• Recent studies of polyimide insulation schemes demonstrated a large

potential for increasing the power extracted from the coil (a factor of ~5 higher than the nominal LHC insulation).

Review of IR systems: main findings (3)

6. Options for D1 magnets

• Several possibilities for D1 considered: NC, SC and superferric magnets.
• A large aperture 4 T SC dipole is the most cost effective, opens the possibility of

using the space in between D1-D2 for other equipment (crab cavities). Drawbacks: sharing of cryogenic power (1.9 K or 4.5 K) and need for a local power converter.

• The most appropriate NC solution seems to build new magnets, optimized to the

existing converters and cooling plant (located on surface). Price is ~ twice the SC dipole, but varies strongly with required strength (D1-D2 separation) and aperture.

7. Powering and protection

• Quench protection must be considered from the beginning as an integral part of

the string design. Due to considerably higher stored energy, the magnets should be decoupled and energy extraction included.

• All electronics equipment (including DFBX) must be located outside the tunnel.

Severe space constraints around IP1 and IP5.

• The favoured powering scheme consists of one 13 kA PC, 600 A bipolar PC for

each magnet, circuit branch protection with warm thyristors, cryo-link (LTS or HTS), DFBX (or its compact variant based on HTS link).

• Several very useful practical reminders (e.g. asymmetric voltage taps allowing

polarity checks, use thin wires {different colours!}, avoid “omegas” for QH, T- sensor in liquid He, helical loops instead of lyras …).

Review of IR systems: main findings (4)

8. Energy deposition

• The baseline parameters of the triplet, including the cold bore and beam

screen (~6 mm total), result in a modified longitudinal distribution of losses in the triplet: the critical area is the Q1-Q2 region.

• The protection of the Q2 and Q3 magnets is ensured with the baseline cold

bore and beam screen. Additional absorber in Q1 can effectively reduce the power density peaks in the Q1-Q2 region.

• The total deposited power is ~380 W (scales linearly with luminosity and

length of the triplet). Linear average power is ~10 W/m (localized peaks up to 30 W/m). BS/absorber catches 10-30% of the total (~3 W/m).

• The TAS protects the front face of Q1. The total expected power (300 W)

requires a cooling system. Backlash to the experiment seem acceptable.

9. TAS absorbers

• The replacement of the TAS vacuum chamber requires removal and

storage of the TAS and installation of a new TAS body.

• Very tight interfaces with the shielding, survey equipment and beam

instrumentation; no possibility of reducing L* (23 m).

The emerging concept

Optics

• Correction of chromatic aberrations in IR3, IR7 and the inner triplets requires re-phasing of

all arcs and insertions for β* < 0.5 m. The strength of the arc sextupoles limits β* to 0.25 m.

• D2, Q4 and Q5 in IR1/5 need to be moved by ~15 m towards the arc to improve the tuning

flexibility of the insertions.

Triplet:

• Composed of four cryo-quadrupoles of similar length (~ 8-9 m).
• Cold bore+beam-screen engineered as protection elements; beam screen cooled at 40-60 K.
• Interconnections (He-pipes, PIM and BS) identical in IR1 and IR5.
• Dipole and multipole correctors lumped in a separate cryo-unit in between D1 and Q3.

Powering

• Each magnet protected separately. Energy extraction included in the main circuit.
• All delicate equipment moved into shielded areas. DFBX connected to the triplet through an

SC link (HTS or LTS).

Low-beta quadrupoles

• Magnet aperture based on the ultimate parameters of β*=0.25 m and n1=7 (using definitions

for nominal LHC). This leads to a beam-stay-clear of ~95 mm and coil ID of ~ 110 mm.

• Final choice of the aperture and length to take into account optimal use of existing cable.

The emerging triplet layout

~9 m ~8 m

CP Q3 Q2B Q1 D1

DFBX

Q2A

~8 m ~9 m ~5 m

QRL

• DFBX, power converters, energy extraction and

protection electronics located in shielded areas

• utside the LHC tunnel.
• Quadrupoles powered in series at ~ 10 kA.
• All correctors are assembled in a separate cryo-

unit (CP).

~1.6 ~1.6 ~1.6 ~1.6

SC or NC

Issues for Nb-Ti quad design

Fixed parameters

• SC cable: LHC dipole cables
• Collar material:Nippon Steel YUS

130 (thickness 3 mm)

• Yoke material: Cockerill steel

(thickness 5.8 mm)

• Cold mass outer diameter: 570 mm

(iron yoke 550mm and shell thickness 10 mm).

Issues

• Optimal use of available cable

(width and length).

• New cable insulation scheme for

improved heat transfer.

• Design of the mechanical structure to

support high forces.

• Collar and yoke transparency to

improve coupling to the cold source.

• Integration of the internal heat

exchanger.

A possible corrector cryo-unit (CP)

Current Integrated strength (field) Aperture

(identical to quads)

MCBX +/- 600A ~ 6 Tm/ (~3 T) 110-130mm MQSX +/- 600A ~ 20 T (~40 T/m) 110-130mm MCSX +/- 100A ~ 0.01 Tm (~0.05T@17mm) 110-130mm

MQSX MCSTX MCBV

~2 m ~0.5 m ~2 m

MCBH

~0.5 m

WBS structure

WP Project Engineer 1 Project management

• R. Ostojic

2 Optics and beam performance

• S. Fartoukh

3 Layout and integration

• S. Chemli, H. Prin

3.1 Triplet interfaces

• H. Prin

3.2 Tunnel integration

• S. Chemli, Y. Muttoni

4 Low-beta quadrupoles and correctors

• P. Fessia, H. Prin

4.1 Design of the model quadrupole

• P. Fessia, H. Prin

4.2 Construction of the model quadrupole

• R. Maccaferri

4.3 Design and construction of prototype quadrupole

• P. Fessia, H. Prin

4.4 Design and production of correctors

• M. Karppinen

4.5 Production of quadrupole cold masses

• F. Savary

4.6 Cryostating and supports

• V. Parma

4.7 Interconnections J-P Tock 5 D1 separation dipoles

• D. Tommasini

6 Magnet testing

• A. Siemko, M. Buzio

7 Quench protection

• R. Denz

8 Cold powering

• A. Ballarino

9 Power convertors

• D. Nisbet

10 Absorbers and shielding

• E. Wildner, F. Cerruti

11 Vacuum equipment

• V. Baglin, N. Kos

12 Beam instrumentation

• R. Jones, Ch. Boccard

13 Alignment and internal metrology

• H. Mainaud-Durand

14 QRL modifications R van Weelderen 15 LSS magnet modifications 16 String test Title

Project Team

• S. Fartoukh
• P. Fessia, H. Prin
• D. Nisbet
• E. Wildner,

F.Cerutti

• H. Prin, S. Chemli

Optics and performance Magnet construction Powering and quench protection Absorbers and RP issues Integration Planning, installation, safety 1

Project management

2

Optics and beam performance

3

Layout and integration

4

Low-beta quadrupoles and correctors

5

D1 separation dipoles

6

Magnet testing

7

Quench protection

8

Cold powering

9

Power convertors

10 Absorbers and

shielding

11 Vacuum equipment 12 Beam

instrumentation

13

Support and alignment equipment

14 QRL modifications 15 LSS magnet

modifications

16 String test LHC Upgrades - L. Evans WP Title SLHC-IRP1 Project Management - R. Ostojic

Management and communication

The Project reports to the overall Project Leader for the LHC Upgrade Activities (L. Evans) and informs regularly the management of the AB and AT Departments. Project Team:

• Coordinates on a continuous basis the coherence of requirements and

work advance across WP.

• Informs hierarchy on the advance, resource needs and detailed planning.
• Identifies relevant priorities and prepares LIUWG meetings.
• Meets once a week.

LHC Insertions Upgrade WG (LIUWG):

• Formed in Sept 2007. Includes specialists form various groups mandated

to develop the conceptual and technical designs of the new IRs.

• In 2007, the WG made a review of the optics and all major hardware

systems.

• With the Project in place in Jan 2008, extended to all WP holders.
• Meets every 2-4 weeks.

Cost estimate (Feb 08)

CHF 4,600,000 CHF 1,800,000 CHF 1,620,000 CHF 5,000,000 CHF 3,570,000 CHF 1,000,000 CHF 4,387,000 CHF 510,000 CHF 3,000,000 CHF 500,000 CHF 19,035,000 CHF 2,000,000 Project management Low-beta quadrupoles and correctors D1 separation dipoles for IP1 and IP5 Magnet testing Quench protection Cold powering Power convertors Absorbers and shielding Vacuum equipment Beam instrumentation Alignment equipment QRL modifications LSS modifications String test

Total: Materials: 48.5 MCHF (including production manpower) CERN manpower: 11.4 MCHF

Planning (Feb 08)

WP Title

J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D

1 Project management * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 2 Optics and beam performance * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 3 Layout and integration 3.1 Triplet interfaces * * * * * * * * * * * * * * * * * * * * * * * * 3.2 Tunnel integration * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 4 Low-beta quadrupoles and correctors 4.1 Design and construction of model quadrupole * * * * * * * * * * * * * * * * * * * * * 4.2 Design and construction of prototype quadrupole * * * * * * * * * * * * * * * * * * * * * * * * * * * 4.3 Design and production of correctors * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 4.4 Production of quadrupole cold masses * * * * * * * * * * * * * * * * * * * * * * 4.5 Cryostating and supports * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 4.6 Interconnections * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 5 D1 separation dipoles * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 6 Magnet testing * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 7 Quench protection * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 8 Cold powering * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 9 Power convertors * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 10 Absorbers, shielding * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 11 Vacuum equipment * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 12 Beam instrumentation * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 13 Alignment and internal metrology * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 14 QRL modifications * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 15 LSS magnet modifications * * * * * * * * * * * * * * * * * * 16 String test * * * * * * * * * * * * * * * * * *

2012 2008 2009 2010 2011

Collaborations

LHC IR upgrade phase I

CERN EU-FP 7 SLHC-PP Special French contribution US-LAUC

Status of collaborations

• 1. In-kind contribution from France
• CEA interested in the design and coil manufacture for the model

quadrupole, procurement and follow-up of specific components for the series quadrupoles, and follow-up of correctors (all to CERN specification).

• CNRS interested in the design, procurement and follow-up of cryostat

components and tooling.

• 2. CNI SLHC-PP – WP6
• Collaboration between CERN-CEA-CNRS-STFC (RAL)-CIEMAT on

the design and quadrupole model and prototype construction, and on the design and qualification of the correctors.

Collaborations started 1April 2008. Final negotiations on details and implementation in progress.

• 3. US-LARP
• A first draft of the LAUC proposal received for discussion. Several

inconsistencies need to be resolved (e.g. the draft does not take into account the activities at CERN in 2008/09).

Possible involvement of US labs

1. In view of the past contribution to the LHC construction and existing set

• f skills, CERN has invited the US-labs to contribute significantly to the

Phase-I upgrade by delivering main magnetic elements and contributing to the systems design and integration. 2. The attention in recent months has been on the supply of the quadrupoles.

• CERN does not have a preference for a specific magnet technology per se

(Nb-Ti or Nb3Sn), as long as the magnets satisfy specifications and meet the planning.

• In view of the lead time given by the Project approval and available

components, the Nb-Ti quadrupole programme at CERN offers effective sharing of the design, components and risk between CERN and US-labs.

• In the case of Nb3Sn quadrupoles, CERN cannot offer risk sharing and the

production would have to be managed fully by the US labs.

3. CERN considers that other major items, in particular D1 dipoles, should be included as part of the US contribution. In addition, the existing US expertise in the domain of cryogenics, powering and quench protection should be used to the best for Phase-I upgrade.

Perspectives

The first round of discussions has allowed to identify the constraints and the main performance issues. The layout concept and magnet parameters are gradually emerging. Important issues for immediate future:

• Advance with the optics studies and layout options.
• Quadrupole design:
• Refine the coil cross-section taking into account the optimal use of cable.
• Understand the limits of the collar structure.
• Advance the thermal design (cable insulation and heat exchanger definition).
• Understand the technical choices and costs of some work packages that

yet have to be defined in more detail.

• Clarify how will the European and potential US collaborations participate

in the design and construction.

The Conceptual Design Report, with an updated budget estimate,

• n track for June 2008.