Vision from LHC to HL-LHC operation

The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.

Vision from LHC to HL-LHC operation

Lucio RossiFor the HL-LHC project

2LRossi@R2E Workshop 14Oct2014

LHC performance evolution (guess!)

0.75 1034 cm-2s-1

50 ns bunch high pile up 40

1.5 1034 cm-2s-1

25 ns bunch pile up 40

1.7-2.2 1034 cm-2s-1

25 ns bunch pile up 60

Technical limits (experiments,

too) like :

50 25 ns


Lumi evolution till 2035 (no learnimg…)

When learning curve is folded in (250f-1/y in 2028) need to plan eventually 300 fb-1/y, with 7-7.5 1034 cm-2s-1 . Design should also able to allow to 4000 fb-1, if needed.

5 1034 cm-2s-1 , levelling, 250 fb-1/y, 3000 fb-1


High lumi insertions: higher, larger...

LHC triplet70 mm8 T11 kA

HL LHC triplet> 12 T150 mm15-17 kA

20 30 40 50 60 70 80distance to IP (m)

Q1 Q3Q2a Q2b

MC

BX

MC

BX

MC

BX

CP D1

Q: 140 T/mMCBX: 2.1 T 2.5/4.5 T mD1: 5.2 T 35 T m

4.0 4.0 4.0 4.06.8 6.8 6.71.2 1.2 2.2

SM

20 30 40 50 60 70 80distance to IP (m)

Q1 Q3Q2a

MC

BX

D1M

CB

X

MC

BX

Q2b

Q: 200 T/mMCBX: 3.3 T 1.5 T mD1: 1.8 T 26 T m

DFB

Longer Quads; Shorter D1 (thanks to SC)

ATLASCMS

ATLASCMS

E. Todesco

5Lucio Rossi@LMC184 9July2014

The HL-LHC Nb-T imagnet zoo…D1 (KEK) Nested orbit corrector (CIEMAT) HO correctors: superferric (INFN)

D2 (INFN) Q4 (CEA) D2 corrSee WP3 webpageE. Todesco et al.

6

Effect of the crab cavities

• RF crab cavity deflects head and tail in opposite direction so that collision is effectively “head on” and then luminosity is maximized• This are COMPACT CC, completely new

design! Must work synchronized (0.001) on each side of the IP!

Lucio Rossi@ICHEP2014

7Lucio Rossi@ICHEP2014

Latest cavity designs toward accelerator

RF Dipole: Waveguide orwaveguide-coax couplers

Double ¼-wave: Coaxial couplers withhook-type antenna

4-rod: Coaxial couplers with different antenna types

Coupler concepts

Concentrate on two designs

Present baseline: 3 cavity /cyomodule4 cavity/cryomod is under study for Crab Kissing TEST in SPS under preparation (A. MacPherson)

8

P2 - DS collimators ions – 11 T (LS2 -2018)

Lucio Rossi@ICHEP2014

11 T Nb3Sn

FNAL - CERN

9

Low impedence collimators(LS2 & LS3)

Lucio Rossi@LMC184 9July2014

New material: MoGr

Reduce impedance by > 2)S. Redaelli et al.

Maybe already in LS2


LRBBW: an enabling tool that needs a definitive test

9.3

Test using an adapted collimatorTest is expensive!The final system cannot be an electric wire embedded in a jaw!Þ e-lens used as e-wireÞ However wee need > 200 Am!

NOT baseline (yet)

11

Controlling halo diffusion rate: hollow e-lens (synergy with LRBBCW)


Promises of hollow e-lens:1. Control the halo dynamics without affecting the beam core;2. Control the time-profile of beam losses (avoid loss spikes);3. Control the steady halo population (crucial in case of CC fast failures).Remarks: - very convincing experimental experience in other machines!- full potential can be exploited if appropriate halo monitoring is available.

NOT baseline (yet)


Crystal collimation: a new paradigme in collimation (DS – partially – and primary

NOT baseline (yet)


Eliminating Technical BottlenecksCryogenics P4- P1 –P5

IT IT

ITIT

IT

ITIT

IT

RF

RF

New Plant 6 kW in P4 IN LS2

Two new 18 kW Plants in P1 and P5


New IR Cryo-scheme (sepration IR-Arc)

L. TavianR. Van WeelderenS. Claudet

15

Displacing EPC and DFB in the adjacent TDZ tunnel ( 500 m away) via SC linksIt si also a TEST!

DQR IP7

Q4Q5D3Q6DFBMDFBAQ11, Q10…Q7

IP 6

D4

4.5 K

8.75 m 1 m Warm magnets (PCs in UJ 76)

RR 73RR 73



L = 20 m(252) 1 kA @ 25 K, LHC Link P7

Feb 2014: World record for HTS transport current (A. Ballarino)


ParameterNominal LHC

(design report)HL-LHC 25ns

(standard) HL-LHC 25 ns

(BCMS) HL-LHC 50ns

Beam energy in collision [TeV] 7 7 7 7Nb 1.15E+11 2.2E+11 2.2E11 3.5E+11nb 2808 27481 2604 1404

Number of collisions at IP1 and IP5 2808 2736 2592 1404Ntot 3.2E+14 6.0E+14 5.7E+14 4.9E+14beam current [A] 0.58 1.09 1.03 0.89x-ing angle [μrad] 285 590 590 590beam separation [σ] 9.4 12.5 12.5 11.4β* [m] 0.55 0.15 0.15 0.15εn [μm] 3.75 2.50 2.50 3εL [eVs] 2.50 2.50 2.50 2.50r.m.s. energy spread 1.13E-04 1.13E-04 1.13E-04 1.13E-04r.m.s. bunch length [m] 7.55E-02 7.55E-02 7.55E-02 7.55E-02IBS horizontal [h] 80 -> 106 18.5 18.5 17.2IBS longitudinal [h] 61 -> 60 20.4 20.4 16.1Piwinski angle 0.65 3.14 3.14 2.87Geometric loss factor R0 without crab-cavity 0.836 0.305 0.305 0.331Geometric loss factor R1 with crab-cavity (0.981) 0.829 0.829 0.838beam-beam / IP without Crab Cavity 3.1E-03 3.3E-03 3.3E-03 4.7E-03beam-beam / IP with Crab cavity 3.8E-03 1.1E-02 1.1E-02 1.4E-02Peak Luminosity without crab-cavity [cm-2 s-1] 1.00E+34 7.18E+34 6.80E+34 8.44E+34Virtual Luminosity with crab-cavity: Lpeak*R1/R0 [cm -2 s-1] (1.18E+34) 19.54E+34 18.52E+34 21.38E+34

Events / crossing without levelling w/o crab-cavity 27 198 198 454Levelled Luminosity [cm-2 s-1] - 5.00E+34 5.00E34 2.50E+34Events / crossing (with levelling and crab-cavities for HL-LHC) 27 138 146 135Peak line density of pile up event [evt/mm] (max over stable beam) 0.21 1.25 1.31 1.20Levelling time [h] (assuming no emittance growth) - 8.3 7.6 18.0

Baseline Parameters (last PLC)

ATS required

Colli

sion

val

ues


The Achromatic Telescopic Squeezing (ATS) scheme Small b* is limited by aperture but not only: optics matching & flexibility (round and flat optics), chromatic effects (not only Q’), spurious dispersion from X-angle,..

A novel optics scheme was developed to reach un-precedent b* w/o chromatic limit based on a kind of generalized squeeze involving 50% of the ring

ATS is not an option is critical for the upgrade; implementation in Run II or Run III is beneficial!

b*= 40 cm b*= 10 cm

The new IR is sort of 8 km long !

(S. Fartoukh)

Proof of principle demonstrated in the LHC down to a b* of 10-15 cm at IP1 and IP5


The ``crab-kissing’’ (CK) scheme (2/5)

0.2 0.1 0.1 0.2

0.2

0.4

0.6

0.8

1.0

1.2

[mm-1]

z [m] w.r.t. IP

HL-LHC w/o CK scheme: Plan A (solid) and Plan B(dotted)- 12.5 MV crabs in X-plane, round optics (15/15 cm), sz =7.5 cm (Plan A)- or bb wire, flat optics (50/10 cm), sz =10 cm (Plan B)

“HL-LHC+” with CK scheme and Gaussian bunch profile ..adding crab-cavities to Plan B in X and || planes (6 MV+7 MV)

“HL-LHC++” with CK scheme and rectangular bunch profile ... adding a new 800 MHz RF system (still keeping sz =10 cm)

A net gain by a factor 2 at each step.... at nearly constant integrated performance

(S. Fartoukh)@ECFA HL –LHCExper. Workshop, Aix-les-Bains7October 2013


Operation & Intensity• Levelling cycle

• Beam intensity limitation(s)• To be assessed in next LHC run• TDIS in LS2 (don’t like too small emittance beams!)• Heating of kickers (MKI): new high Tc ferrite and

coating for e-clouds (prototype installed in LS2).


Efficiency for Ldt• All our assumptions are based on forecast for

the operation cycle:

𝜼=𝑳𝒕𝒂𝒓𝒈𝒆𝒕

𝑳𝒇𝒊𝒍𝒍

𝑻 𝒂𝒓𝒐𝒖𝒏𝒅−𝒎𝒊𝒏+𝑻 𝒇𝒊𝒍𝒍

𝑻 𝒔𝒑𝒕×𝟏𝟎𝟎

50%

High reliability and availbility are key goalsR. DeMaria, RLIUP

Integral luminosity: the final goal of HL_LHC• The total number of particles created at collider (e.g. total number of

Higgs bosons) is proportional to the Integrated Luminosity (expressed in fb-1):

• In the past, the most efficient way of increasing was by increasing . This is why accelerator people usually refer to .

• There are many workshops and conferences around the world discussing how to increase …..

• HL-LHC is a game changer: for the first time, is limited (due to pile-up and other considerations), to a certain extend...

• The only free parameters is the integral: how long can HL-LHC sustain operation a?

• Directly related to the availabilty of HL-LHC – this is the motivation for this workshop.

M. Brugger

Global Workshop ObjectivesUnderstand availability limitations due to radiation effects (SEE, TID, DD) as well as other effects onto accelerator equipment and quantify the required equipment performance to reach the luminosity goals Run 2, Run 3, HL-LHC.

Identify what is required (tools, facilities, expertise) to quantify and mitigate radiation effects on equipment.

Identify appropriate mitigation measures: radiation tolerant developments (tunnel electronics, PC), displacement of sensitive equipment (superconducting links etc.) and other aspects.

Identify the long-term requirements for electronic systems.

Address IR3-IR7 life time issues linked to radiation and equipment maintenance planning.

Understand how development of electronics for radiation environment is addressed in the LHC experiments.

Aiming for high availability

Radiation effectsSingle Event Errors (SEEs)

LS1 focus on mitigationFrom MITIGATION to PREVENTION

Cumulative (long-term) damage (TID, DD)so far not encountered at LHC (experience from injectors!)

Equipment failures (focus on electronics components)experience, development needs, options

Components reaching the end of life with and without radiation

Workshop Goals

25

Concerns for what to do next, but also in view of 22 years of LHC: we need R&D NOW!

What needs to be doneup to LS2/LS3 and for HL-LHC

Radiation damage and intervention concerns in IR3/7Design/test choices and synergies to be exploitedRequirements to reach the HL-LHC target

AvailabilityExpertise & FacilitiesDevelopments & Qualification Needs

Workshop Goals

26

In view of the 4 Workshop Sessions

Session-1: Fundamentals of R2E and Availability Radiation Monitoring & Test Facilities:

improve/operate

R2E Expertise (LHC, Injectors, Experiments): keep & develop

Availability: fault tracking, impact analysis:improve/adopt

Needs and Goals

27


Session-2: Concerned Equipment: up to LS2/LS3/HL-LHC Development needs and R2E requirements:

R2E structure?

Maintenance and lifetime (with & w/o. rad.): What is known and what needs to be?

How to improve availability:What can and has to be done?

Needs and Goals

28


Session-3: IR3/7 Damage/Maintenance IssuesFailure risks due to radiation/environment:

is there any show-stopper?

Needs: monitoring, handling, testing: what is ok and what needs to be improved?

Maintenance, life-time & mitigation: what is the equipment requirement/strategy?

Needs and Goals

29


Session-4: Long-term strategyMitigation/Prevention strategy & needs:

are we on the right track?

SCL & rad-tol PC options/needs/roadmap: what is the (combined) best strategy?

Required developments & synergies: what are and can be common grounds?

Needs and Goals

30

31

SC links removal of EPCs, DFBs from tunnel to surface (or new gallery?)


2150 kA

1 pair 700 m 50 kA – LS24 pairs 300 m 150 kA (MS)– LS3 4 pairs 300 m 150 kA (IR) – LS3 tens of 6-18 kA CLs pairs in HTS

In particular: do we need to remove the Powering of the Arc magnets in IR1-IR5 ?

Past Present Future

33

Run 1:

HL-LHC:

HL-LHC:

160 days

25 fb-1

200 days

210 fb-1

260 fb-1

HL-LHC:200 days + 20% availability 300 fb-1

R2E LHC Long-TermR2E SEE Failure Analysis

~250 hDowntime

2008-2011Analyze and mitigate all safety relevant cases and limit global impact

2011-2012Focus on long downtimes and shielding

LS1 (2013/2014)Final relocation and shielding

LS1-LS2 (2015-2018)Tunnel equipment and power converters

-> LS3-HL-LHCTunnel Equipment (Injectors + LHC) + RRs

~400 hDowntime

LS1 – LS2 Aiming for

<0.5 dumps / fb-1

~12

dum

ps /

fb-1

~3 d

umps

/ fb

-1

HL-LHC: < 0.1 dumps / fb-1

34

Relocation& Shielding

Equipment Upgrades

35

R2E LHC Long-Term

The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.

Vision from LHC to HL-LHC operation

Documents

Transcript of Vision from LHC to HL-LHC operation