Investigation of FCC positionImpacts on Hadron Injectors

John Osborne, Charlie Cook, Yung Loo (ARUP)16/09/2014

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Contents• Preliminary findings: Investigation of FCC Hadron Injector (FHI)

& geo/tunnelling impacts for 83km/100km ring siting

• Geology/CE Studies Progress Flow

• 100km- Circle and Racetrack – optimised alignment options within

study area limits

• 83km- Circle and Racetrack – optimised alignment options within

study area limits

• Alternatives and FHI constraints

Geology - Definition of key variables and investigation boundaries

- Terrain, overburden- Broad Ground Conditions which have

engineering impact (Moraine, Molasse, Cretaceous, Faults)

- Hydrology (Lake, Rivers)

Preliminary Machine Requirements

- Tunnel Length- Tunnel Shape- Tunnel Depth- Tunnel Slope- Location of Experimental Halls/Access Shafts

• Updated aims and requirements• e.g. laser straight,

corrections for ellipsoid• Updates on data constraints• Key decision output choices• GIS Useability / Accessability /

Transfer of Knowledge

BIM

TO

OL

DE

CIS

ION

AID

• BRGM Cretaceous Seismics

• Bathymetry data• Tool functionality

• CE constructability • Tunnelling, Geotechnics, Programme

• Interfaces Requirements• FHI requirements• Experimental groups• Iterations of constraints/requirements

assessment of a most feasible solution• Performance Design Requirements / Design Basis

(offline data manipulation)• Excel• GIS

INIT

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PR

OJE

CT

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IAB

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MP

TIO

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BIM tool export Model UpdatesAssessments & Studies

FCC - Geology/CE Studies Progress Flow

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100km Circle: Study Boundary Limits - North

• To minimise connection distance of injection tunnel between LHC and FCC, beneficial to locate

ring further east but constrained by Chablais

• Potential alignment optimisation with tilt, but unlike with LHC slope (solely to reduce Jura

impact). FCC - A beneficial tilt in one direction would be a negative tilt in another:

- i.e. three main mtns, Jura, Saleve, Pre Alps Chablais (+Le Vuache)

- Any tilt is also constrained by The Rhone

FHI Impacts Geo/Tunnelling Impacts

Positives • Possibility of good near parallel injection tunnel length into LHC P3, P4, P5.

Negatives • 10km spacing of detector caverns/shafts not possible due to alignment spacing between Pre Alpes du Chablais crossing (1km deep shaft) and lake

• Lake bed deeper• Top of molasse deeper• NE of ring moves out of

Valee de L’Arve corridor into Chablais

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100km Circle: Study Boundary Limits - North- General Scenario of Crossing near P3-P5

Riverbed

Molasse Rockhead

370

mASL

280

150*

Azimuth SlopemASL at

LakeAv. mASL Rationale

mASL near crossover

P3-5, mASLP3-5/FCC distance

Scenario 1a 0 0 150 150 top of molasse under lake 150

Scenario 1b 0 0 280 280 Bottom of riverbed 280

Scenario 2 0 0.5 150 273top of molasse under lake, bottom of

the Rhone145 - 180

Scenario 3 95 0.4 150 193top of molasse under lake, bottom of the Rhone, tunnel depth low under

Jura145 - 180

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Scen

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Scen

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2

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Scen

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100km Racetrack: Study Boundary Limits - North• Same issues as 100km Circle. In addition:

- Northern Limit is constrained by southern extent of racetrack crossing into

Grand Saleve (no benefit of crossing further north into Saleve)

- At NW extent of investigation area , Jura outcrops back towards Lake. Need

to move ring further east into Pre Alpes du Chablais to avoid this.

- Western edge continuously skirts Jura – high interface risk. Likewise,

pushing ring further east enters Chablais.

• However potential advantageous straight parallel alignment into P3,P4

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100km Circle: Study Boundary Limits - South

• Savings in tilt but constrained by the Rhone and Les Usses

FHI Impacts Geo/Tunnelling

Positives • Ring will pass under LHC, with potential good connection for injection tunnel (FCC passes near perpendicular to Point 1(and P7)).

• Lake bed shallower• Top of molasse shallower• Completely avoids Jura*• Avoids Pre-Alpes du Chablais+

Negatives • *(enters Le Vuache)• +(lies in the foothills not Valee de L’Arve

corridor between Saleve and Pre Alpes)• Starts to skirt Bornes-Aravais mtns to SE

(current uncertainty in geological data) • Molasse tapers out as situated towards

extreme southern tip of basin – Ground becomes more heterogeneous and faulted, more uncertainty and risk for tunnelling and shaft sinking.

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100km Circle: Study Boundary Limits - South- General Scenario of Crossing near P1

Riverbed

Molasse Rockhead

370

mASL

320

210

Azimuth SlopemASL at

LakeAv. mASL Rationale

mASL near crossover

P1, mASLP1/FCC distance

Scenario 1a 0 0 210 210 top of molasse under lake 210 359 149m

Scenario 1b 0 0 320 320 Bottom of riverbed 320 359 39m

Scenario 2 0 0.23 210 290

top of molasse under lake,bottom of the Rhone, les ussesTilted into southern mountains

(Vuache, Bornes, Saleve)

215 359 144m

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Scen

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Scen

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100km Racetrack: Study Boundary Limits - South

A B

A

B

• Limited capacity for movement. • Bound strictly by Jura, Vuache, Bornes• Poor connection at Point 1, esp. option B

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83km Circular- General Scenario of Crossing at P1

Riverbed

Molasse Rockhead

370

mASL

340

210

Azimuth SlopemASL at

LakeAv. mASL Rationale

mASL near crossover

P1, mASLP1/FCC distance

Scenario 1a 0 0 270 270 top of molasse under lake 270 359 89m

Scenario 1b 0 0 330 330Non-inclined, Bottom of riverbed,

bottom of the Rhone330 359 29m

Scenario 2 -035 0.5 210 342

Sloping high point in Borne/Saleve. Limited by Les Usses. Goes through

moraine @Valee de l’Arve (connectivity of flow not as

influential as under lake)

230 359 129m

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83km Circular- General Scenario of Crossing at P1

• Circular – Current default plan position near optimum

• Well positioned directly beneath and inline with P1

• Positioned well at shallower southern end of lake

• Well positioned east away from Jura

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83km Racetrack- General Scenario of Crossing at P1

Riverbed

Molasse Rockhead

370

mASL

350

210

Azimuth SlopemASL at

LakeAv. mASL Rationale

mASL near crossover

P1, mASLP1/FCC distance

Scenario 1a(83km-R2)

22 0.2 | 0.3 295 340 Top of molasse under lake 260 359 101m

Scenario 1b(83km-R2)

22 0.2 | 0.3 335 380Bottom of riverbed, bottom of the

Rhone305 359 54m

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Scen

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FCC-LHC Hadron Injection Constraints (1)

- “Required injection straight length is a function of the vertical height difference between LHC and FCC at P1 and the magnet technology”

- “For 20 – 200 m height difference and reasonable magnet technologies get about 0.5 to 1.5 km injection straight length per beam”

• To achieve these tolerances:

• Possible with 100km option but higher engineering risk

• More feasible to achieve shallow (50-100m) height differences and shorter injection straight lengths with 83km option.

• Both racetrack and circular options can be preferentially tilted and orientated to achieve much more satisfactory crossover relationships.

• Need to consider non-molasse boring options

• Can be better constrained through understanding dipole designs/injection approach limits

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FCC-LHC Hadron Injection Constraints (2)

- First Version of the Geology Tool should be imported onto CERN database this week

- Working meeting with CE and Hadron experts to be arranged for coming weeks to study options in more detail. Who should be invited ?