3rd annual eurocircol collaboration meeting · 2018-10-02 · 3rd annual eurocircol collaboration...

3RD ANNUAL EUROCIRCOL

COLLABORATION MEETING

EuroCirCol-P3-WP1-M1.10

EDMS 1991652

Date: 02/10/2018

Grant Agreement 654305 PUBLIC 1 / 18

Grant Agreement No: 654305

EuroCirCol European Circular Energy-Frontier Collider Study

Horizon 2020 Research and Innovat ion Framework Programme, Research and Innovat ion Act ion

MILESTONE REPORT



Document identifier: EuroCirCol-P3-WP1-M1.10

EDMS 1991652

Due date: End of Month 39 (September 1, 2018)

Report release date: 02/10/2018

Work package: WP1 Management, coordination and implementation

Lead beneficiary: CERN

Document status: RELEASED (V1.0)

Abstract:

In the scope of the annual meeting report on progress, showstoppers and findings in the form of

selective workshop presentations. Management and governance bodies of the project review the

progress. The approved minutes of the bodies will be made available to the Consortium members and

appropriate news coverage will be performed via the channels identified in the communication plan.




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Copyright notice:

Copyright © EuroCirCol Consortium, 2015

For more information on EuroCirCol, its partners and contributors please see www.cern.ch/eurocircol.

The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding

from the European Union's Horizon 2020 research and innovation programme under grant No

654305. EuroCirCol began in June 2015 and will run for 4 years. The information herein only

reflects the views of its authors and the European Commission is not responsible for any use that

may be made of the information.

Delivery Slip

Name Partner Date

Authored by

Antoine Chancé

Panagiotis Charitos

Rogelio Tomas

Francis Perez

Davide Tommasini

CERN 18/06/18

Edited by Johannes Gutleber

Julie Hadre CERN 28/06/18

Reviewed by Michael Benedikt, Frank Zimmermann CERN 25/09/18

Approved by EuroCirCol Coordination Committee 02/10/18

http://www.cern.ch/eurocircol




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TABLE OF CONTENTS

1. WP1 MANAGEMENT SUMMARY ...................................................................................................................... 4

1.1. 4TH COLLABORATION BOARD .............................................................................................................................. 4 1.2. OUTREACH REPORT ............................................................................................................................................ 5

2. WP2 ARC DESIGN SUMMARY ......................................................................................................................... 11

3. WP3 EXPERIMENTAL INSERTION REGION DESIGN SUMMARY ......................................................... 13

4. WP4 CRYOGENIC BEAM VACUUM SYSTEM SUMMARY ........................................................................ 15

5. WP5 HIGH FIELD MAGNET SUMMARY ....................................................................................................... 16

ANNEX: GLOSSARY .................................................................................................................................................... 18




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1. WP1 MANAGEMENT SUMMARY

1.1. 4TH COLLABORATION BOARD

1.1.1. Milestones and deliverables

All the milestones and deliverables have been submitted in due time to the EC, except for WP5

milestone on ‘Specifications for conductors and proposed conductor configurations’, which required

further technical discussions during the FCC Week 2018.

One can access the reports on the EuroCirCol website (http://eurocircol.eu/ -> Project -> Dashboard).

Table 1 – Deliverables and Milestones

WP Product Title Due

Date

Lead

beneficiary

1 Milestone 2nd Annual EuroCirCol Collaboration Meeting 01-03-17 CERN

3 Milestone Requirements and constraints of EIR design options on

WP3, WP4, WP5

01-05-17 UOXF

5 Deliverable Identification of preferred dipole design options and cost

estimates

01-08-17 CERN

1 Deliverable Collider complex layout and parameters 01-09-17 CERN

2 Deliverable Requirements and constraints of arc design options on WP3,

WP4, WP5

01-09-17 CEA

1 Milestone Outreach package 01-10-17 CERN

4 Deliverable Measurements of vacuum chamber at light source 01-10-17 ALBA

3 Deliverable Preliminary EIR design baseline 01-11-17 UOXF

4 Deliverable Preliminary beam screen and beam pipe engineering design 01-11-17 ALBA

2 Deliverable Preliminary arc design baseline 01-02-18 CEA

1.1.2. Upcoming events

The Collaboration Board members have been informed about the organization of several events:

The 1st edition of the EASItrain School dedicated to applied superconductivity, at TU Vienna, Austria,

from 3 to 14 September 2018 (https://indico.cern.ch/event/663949/ ) ; A public event in German will

take place on 8 September ‘Forschung? Was geht mich das an?’(http://forschung.web.cern.ch/ ).

The presentation of the FCC Conceptual Design report (EuroCirCol deliverable D1.5) at the University

Paris La Sorbonne on 29 January 2019.

The EuroCirCol industry and outreach event (Milestone M1.12) at Liverpool in February 2019.

The FCC week 2019, which will be combined with the final EuroCirCol Collaboration meeting

(Milestone M1.13), probably in June 2019 in Brussels, Belgium.

1.1.3. Collaboration matters

The WP3 leader Andrei Seryi (JAI UOXF) has taken up a leading position at the Jefferson laboratory

in the US. Consequently, another work package leader had to be found within a short period of time.

The EuroCirCol coordination committee proposed R. Tomas (CERN), presently deputy leader for

WP3 to assume the leading position. The suggestion was rapidly ratified and also confirmed by the

International Collaboration Board. R. Tomas will so take over the role of WP leader as from 01 June

2018. Although the work package lead moved from UOXF to CERN, UOXF remains beneficiary with

key personnel that continues to perform research work in the frame of this project within WP3.

http://eurocircol.eu/

https://indico.cern.ch/event/663949/

http://forschung.web.cern.ch/




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1.2. OUTREACH REPORT

1.2.1. Posters

Two posters were produced by the University of Liverpool in collaboration with CERN’s FCC study

office to promote the study among the scientific community. The first one presents the three scenarios

of the FCC, introducing FCC-hh as a discovery machine, FCC-ee as a machine for precision, and FCC-

he as a machine for new opportunities (Figure 1). It also shows the base parameters of each of the

options and their comparison with previous colliders. The second poster addresses the opportunities

opened by the FCC-hh for physics, in particular: testing of the standard model, discovery of new

particles and new symmetries, investigations into dark matter, Higgs physics, heavy ion collisions, and

the unexpected. (Figure 2) The posters are distributed at scientific meetings, particularly during the

FCC weeks.

Figure 1 – FCC scenarios poster Figure 2 – FCC-hh physics opportunities

1.2.2. Article – CERN Courier

An extensive report of the FCC week 2018 was published in June’s issue of the CERN Courier entitled

“CERN’s Thinks Bigger”. (Figure 3) It should be mentioned that in the same issue there was also an

article on China’s future colliders “China’s bid for a circular electron-positron collider”.

Figure 3 – Extract from CERN courier article

A summary of the FCC week 2018 was also published in CERN’s website, in CERN’s Bulletin and in

the EPS newsletter.

The event has also been covered in major Dutch newspapers, including NRC and Volkskrant.

http://cerncourier.com/cws/article/cern/71536

http://cerncourier.com/cws/article/cern/71537

https://home.cern/cern-people/updates/2018/05/discussing-future-colliders-fcc-week-2018

https://home.cern/cern-people/updates/2018/05/discussing-future-colliders-fcc-week-2018

http://www.epsnews.eu/2018/05/fcc-week-report/

https://www.nrc.nl/nieuws/2018/04/16/deeltjesversneller-van-de-toekomst-a1599660

https://www.volkskrant.nl/wetenschap/een-nieuwe-superversneller-groter-dan-de-lhc-in-geneve-hoe-moet-die-eruit-zien-~b6452414/?utm_campaign=shared%20content&utm_medium=social&utm_source=twitter&utm_content=free




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1.2.3. Public event

Panel discussion took place on Tuesday, April 10, 2018 at 19:00, Beurs van Berlage, Amsterdam.

Representatives from funding agencies and research centres discussed about the big open questions in

modern physics and the latest developments from the Higgs discovery to gravitational waves. Speakers

also referred to future large-scale research infrastructures that will shed more light on these questions.

There were three main presentations:

Prof. Dr. Jo Van den Brand, Simone Raatz, VU University Amsterdam and Nikhef, “Had Einstein

gelijk? Zwaartekrachtsgolven van botsende zwarte gaten en neutronensterren”.

Prof. Dr. Ivo van Vulpen, University of Amsterdam and Nikhef, “De open mysteries in de

deeltjesfysica na de ontdekking van het higgsdeeltje”.

Prof. Dr. Stan Bentvelsen, Director General of Nikhef, “Inleiding: Het universum van deeltjes”

Figure 4 – Public event at FCC Week 2018




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1.2.4. Innovation awards

The third edition of the FCC Innovation Award, took place during the FCC week 2018 sponsored by

IEEE Council for Superconductivity and one of the FCC collaboration industrial partners, Carbolite

Gero. The award reflects the high-quality work of young researchers towards technological

advancements that guarantee the feasibility of a future high-performance high energy collider.

The FCC innovation awards acknowledge student’s achievements but also ensure more opportunities

for young members of the FCC collaboration to network, to share results and experiences and be part

of the international legacy of expertise in our field. The participation of young researchers in the life

of the FCC collaboration is key for the realization of a new large-scale research infrastructure.

Figure 5 – FCC innovation award winners

1.2.5. Regular coverage of the FCC week 2018

Storify was used again as the main blogging platform for covering this year’s annual meeting. 32

stories were published during the 5 days of the conference – a significant rise compared to the previous

FCC week (26 stories).

On Twitter we run 42 tweets – on a daily rate of 7 tweets while we increase the followers of the FCC

study from 1220 to 1712 while we reached a total of 55.000 impressions.

Figure 6 - Average daily reach on FB during the FCC week. A reach of 7000 people per day while on the 11th the impact

of paid campaigns is clearly indicated (yellow area)




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Figure 7 - Top tweets made during the FCC week 2018 (all organic reach - no promotional campaigns)

On FB we posted about 40 posts reaching about 36000 people and having 14.301 posts engagement.




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Figure 8 - The curve shows the total reach of FB posts during the FCC week 2018. Different colours indicate where

people read and interacted with the posts. Most of them in their newsfeed (light blue) and a significant number directly

by visiting FCC study FB page (dark blue)

Moreover, during the FCC week 2018 we noticed a good overlap between organic and paid reach

(following our decision not to spend any budget as a training test of FB’s algorithm for the FCC page).

Figure 9 - Total paid (dark yellow) vs. organic (light yellow) reach of FB posts during the FCC week 2018




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Finally, for the first time we tried to increase our activity on LinkedIn where we published 8 stories

during the FCC week all performing very well (average readership: 1200, average number of likes:

25).

Figure 10 – Some EuroCirCol members at FCC Week 2018 (Photography: Elodie Burrillon, HUCOPIX)




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2. WP2 ARC DESIGN SUMMARY

The design, operational considerations (including heavy ion), beam performances, beam stability and

the injector chain of the FCC-hh machine have been shown in 7 sessions with many talks and posters.

The parameters of the 99.75-kilometer-long FCC-hh machine have been given. A draft of the concise

CDR exists. Some improvements are still required but the writing of the CDR is under good tracks.

The efforts will be focused on ultimate parameters. The comprehensive CDR has started.

Different schemes for the injection to FCC-hh have been addressed. Pros and cons of each scheme

have been listed. Currently, dynamic aperture studies exclude injection from superconducting SPS.

New layout of transfer lines is done with protection considerations. The layout of the FCC-hh machine

has a bit changed since FCC week 2017: new high luminosity experimental insertions (L*=40 m and

1.4-kilomer-long), two other experiments combined with injection, shorter short arcs (site

requirements).

The arc cell design (Task 2.2) has been updated after iteration with the magnet team (WP5). The length

estimates are improved. The octupoles are integrated to the arc lattice. The strategy is now to shorten

dipoles to preserve cell length if more space is required for correctors or quadrupole. Full integrated

lattice exists. Specifications for magnets are almost complete. The aperture model has been updated

according to the beam screen progress within WP4. The bottleneck of aperture is at injection in the

dispersion suppressors: optimization of optics and refining aperture requirements should be performed.

An alternative 60° FODO lattice is under study: the main concern is the aperture reduction. Alignment

tolerances for the main magnet of the arcs have been agreed with alignment group. Orbit NbTi

correctors enable to keep the residual orbit and angle compatible with the synchrotron radiation

evacuation. Dedicated beta-beating, dispersion and coupling correction schemes and the full

integration of orbit correction inside experimental region are to be further studied.

A new extraction section is available and should be integrated to the full lattice soon. Main changes

are 150 extraction kickers (against 300 in 2017), larger beam size at protection absorber, and SuShi

septa instead of superferric Lambertson septa. The dump line has been updated. The dilution system

has been modified: a constant frequency is now used (instead of modulated frequency like in 2017). A

new sweep pattern has been developed, which reduces the load on the dump. Required dilution kickers

are still challenging. Some directions to reduce the requirements will be explored. Studies show that

dump functionality is not compromised in case of asynchronous dump.

Dynamic aperture (DA) studies (Task 2.3) show that, if the systematic b3 component of main dipole

is corrected by the sextupole correctors MCS (feasible in NbTi technology), the DA is above the target

value of 12 σ at injection energy of 3.3 TeV. To limit β-beating, the maximum allowed MCS alignment

error should be less than 0.1 mm or the systematic dipole sextupole component should be reduced. The

DA can dramatically decrease when a wrong phase advance between opposite points in the ring is

combined with a set of field errors in different magnets. DA study at collision without beam-beam has

been expanded to include further errors. Thanks to phase scan optimization, almost all studies show

good results, even without non-linear correctors. The compatibility of the phase advance between

collision points should be checked with beam-beam studies within WP3. The phase advance should be

optimized for different other stages of the operation cycle.

Status of the single beam instabilities has been shown (Task 2.4). A distribution of impedance sources

for different instabilities has been made. The beam screen related impedance dominates coupled-bunch

instability. The impedance sources coming from the different beam screen elements have also been

detailed. Resistive wall becomes problematic if aperture is reduced to 12.2 mm. Electron cloud surface

treatment is acceptable if amorphous carbon or TiN coating is used. Measurements at FRESCA will




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determine if laser treatment is acceptable. Contributions from pumping holes and interconnects are

acceptable. The feedback system, scaled from LHC, is a solid baseline system to damp instabilities.

Simulations show that other operation schemes are feasible (like 5 ns spacing). Progress in simulation

codes will enable to go further in the feedback study. To have more experimental data would be much

appreciated for validation and verification of the models. Feedback will damp the mode m=0 whereas

octupoles will be used to damp the mode m=1. A trade-off is to be found between positive impact of

negative octupole polarity when at flat top, and positive polarity when in collision, because of long-

range beam-beam effects in an electron lens as an alternative for Landau damping is to be studied.

The status of electron cloud studies has been presented (Task 2.5). The effect of beam screen geometry

(from WP4) on electron cloud build-up has been evaluated. The large slit increases multipacting

threshold in drifts. With full chamber and updated parameters, an amorphous carbon coating or surface

laser treatment should be sufficient to suppress build-up for the 25 ns beam. For the alternative bunch

spacing, stability asks for a challenging secondary electron yield (SEY) of 1 in quadrupoles and

possibly coating in field free regions. Estimated photoelectron fluxes are within stability limits.

Photoelectrons from saw-tooth increase density in drifts. The expected flux is to be confirmed with

WP4. Studies have been performed to get electron cloud scaling rules from LHC to FCC. The

conclusion is that SEY threshold depends a lot on the chosen model. Times are mature to use measured

data to tune simulations and refine models.

Considerations about collimation (design, efficiency, or machine protection) have been addressed

(Task 2.6). The next steps for the momentum collimation are to optimize the placement of secondary

collimators and to study the aperture, cleaning performance, and power deposition. A new MARS -

MAD-X/PTC interface has been recently completed. An alternative lattice has also been developed.

The betatron collimation section keeps the layout, design and material of HL-LHC collimators.

Collimators with highest loads are now made of CFC. The energy deposition into the collimators and

the loss distribution into the FCC-hh machine have been calculated. Power on the most loaded primary

collimator has been reduced by halving the primaries’ active length as well as removing the skew

primary. Secondary collimator jaws have been thickened to decrease the power load. Collimation

efficiency has been evaluated. Currently, cleaning at top energy is mostly good for both planes. At

injection, cleaning is less efficient but beam energy is lower too: injection quench limits will determine

if the current design is acceptable. Collimation efficiency has been addressed also in case of failure of

the extraction kicker or collimator imperfections. The misalignment impact is not negligible on global

cold losses. More imperfections should be studied in the future. Cleaning the halos with electron lens

should be developed.




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3. WP3 EXPERIMENTAL INSERTION REGION DESIGN SUMMARY

The work related to the experimental insertion region design has been reviewed in the morning session

on Tuesday April 10 as well as the collective effect session on Thursday afternoon.

The changes made to the interaction region lattice since the FCC week 2017 were presented. This

includes an L* shortened to 40 m as well as triplet magnets compatible with 15 m long cryostats. These

changes allowed to reduce the maximum beta functions in the triplet and to have fully matched optics

within a 1400 m long straight section. The strengths of the separation and recombination dipoles have

been reduced to 2 T allowing the use of normal conducting technology in this highly radiative

environment. Initial studies with crab cavities suggest a crab voltage of less than 18.5 MV is required

for full crabbing even beyond ultimate beta*. Accordingly 20 m of space were reserved for crab

cavities.

In case operation with crab cavities proves to be impossible, an alternative triplet has been developed.

It features flat beams thereby reducing the required crossing angle. The beat functions at the IP are

0.15 x 1.2 m. This setup reduces the pile-up by 30% but also decreases the integrated luminosity by

20%. Studies of the long range beam-beam effect for flat optics are still ongoing.

Dynamic aperture studies at collision energy showed a significant impact of the phase advance

between the main interaction regions on the dynamic aperture. Optimized phase advances improved

the dynamic aperture from 6 sigma to 16 sigma. However, beam-beam studies revealed that these

phase advances led to a lowered dynamic aperture when octupoles are used to compensate beam-beam

effects. In conclusion, a phase optimization for collision needs to include both magnet errors and beam-

beam effects and different phase advances are needed at different stages of the operational cycle.

Furthermore, the beam-beam studies showed the need to increase the crossing angle in order to

guarantee a dynamic aperture larger than the collimator setting even at high chromaticity operational

scenarios. Two beam stability studies concluded that a negative octupole polarity provides a larger

dynamic aperture. However, the octupole strength with negative polarity is not sufficient with high

chromaticity operation, so stronger octupoles or other compensation techniques are required.

Studies of the energy deposition from collision debris were updated to include the separation and

recombination dipoles as well as the TAN. The reduced L* and shortened triplet magnets led to a

decreased quadrupole aperture and possible shielding thickness, increasing the radiation load in the

new lattice. While the peak power density is still below the expected quench limit, the peak dose

increased to 70 MGy at 30 ab^-1 while the operational limit is only 30 MGy. However, these studies

did not include mitigation strategies like crossing polarity and plane alternation as well as the Q1 split,

both of which have been successfully tested in previous lattice versions. The expected dose with these

strategies is below 40 MGy per 30 ab1.

A total power of 45 kW will be collected in the shielding. One of the reviewers raised concern that the

required cooling capillary diameter might become too large to fit inside the triplet shielding. This issue

was discussed with cryogenics experts, leading to the conclusion that at 15 mm thick cooling channel

is required, which does fit inside the 35 mm thick shielding.

Furthermore the study concluded that the separation dipoles, while normal conducting, require

dedicated protection which should be possible with the given magnet design. In summary, from the

energy deposition point of view, operation with ultimate parameters appears to be possible but needs

further studies, including e.g. the increased crossing angle required due to beam-beam effects.




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The detector cross talk studies concluded that elastically scattered protons only lead to a small

emittance growth. Only negligible amounts of inelastically scattered proton reach next IP and

dedicated collimators in the dispersion suppressors can mitigate cold losses. Furthermore, the range

of muons in the bed rock material is not sufficient to reach adjacent detectors, so the detector cross

talk was determined to be negligible.




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4. WP4 CRYOGENIC BEAM VACUUM SYSTEM SUMMARY

During the FCC week 2018 the activities directly related to the WP4–Cryogenic Beam Vacuum System

Conception, of EuroCirCol were discussed in two oral sessions on Tuesday, April 10th, one at 8:30 and

the second one at 10:30, with a total of four oral presentations. In addition, eight posters were displayed

during the poster session.

In addition, a parallel Coordination Meeting of the WP4 team was held on the morning of Thursday,

April 12th, from 8:30 to 12:30.

During the sessions, the progress and status of the different tasks of the WP4 were reviewed, in

summary:

With respect to the Study of beam induced vacuum effects (Task 4.2) a complete simulation of the

vacuum performance of the designed vacuum chamber screen of a complete cell was presented, with

simulations linking the Synrad+ and the Molflow software results, giving a quantification of the

expected profile of the vacuum level along the arcs of FCC-hh. From this simulation, the allowed

averaged particle density of 1015 H2/m3 is achievable with a conditioning time of around three months.

Also, the simulations of the vacuum behavior of the prototypes installed in the KARA have been

compared with the real measurements done which has confirmed the reliability of the computations.

The analysis of Mitigation strategies to reduce the beam induced vacuum effects (Task 4.3) as well as

the Study of the vacuum stability at cryogenic temperatures (Task 4.4), which should give detailed

experimental results to be able to define the final input parameters of the previous described

simulations, are under way and have been presented. After the preparation and calibration of the

experimental setups first results on copper as well as in different laser treated samples have been

shown. Next step, it is to fully characterize the laser treated samples, which is the initial mitigation

method chosen. The production of laser treated samples with different laser parameters, power and

speed, is under way and will continue with characterization in the cryogenic set-ups.

The final Conceptual design for the cryogenic beam vacuum system (Task 4.5) was also presented in

one of the sessions, where an overview was given of the evolution of the design in the last years in

order to comply with all the requirements imposed by vacuum, cryogenics, thermal and mechanical

stress robustness, beam stability and construction feasibility. The final design will incorporate the saw-

tooth profile as the most efficient way to absorb the synchrotron radiation and reduce the secondary

effects. Two prototypes have been constructed and on third one is under way. All of them will be

measured in the KARA setup allowing the characterization of the behavior of the vacuum chamber

screen under real synchrotron irradiation conditions. Also, two new technologies used for the

construction of the prototype, 3D laser printing and plasma cool spray, were presented, with a large

potential to be used in large scale vacuum chamber construction.

Finally, the results of the measurements of two of the prototypes in the test setup at KARA were

presented, work which is part of the Task 4.6: Measurements on the cryogenic beam vacuum system

prototypes. Data of the measurements of photon secondary desorption (PSD), reflectivity, heat load

and photoelectron generation were presented, with relevant conclusions for the design of the final

vacuum screen. The third prototype will be installed in summer and will be measured until the end of

2018.

In conclusion, a full overview of the works performed along last year in the framework of the

EuroCirCol WP4 was presented.




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5. WP5 HIGH FIELD MAGNET SUMMARY

During the FCC week 2018 the activities directly related to the “WP5–High-Field Accelerator Magnet

Design” of EuroCirCol were discussed in one talk at the 08:30 oral session on Tuesday, April 10th,

four talks at the 15:30 oral session of the same day, and three talks at the 08:30 oral session of

Wednesday, April 11th.

During the sessions, the progress and status of the different tasks of the WP5 were reviewed and can

be summarized as follows.

Task 5.1: Work Package Coordination

This is presently focussed in directing the work towards the compilation of the FCC CDR. The status

and plan has been briefly shown in a talk given by D. Tommasini (CERN). At the time of the FCC

week a first version of the magnets chapter of the CDR was already available and was finalized for

review following the outcome of the FCC week.

Task 5.2: Study accelerator dipole magnet design option

Following the positive results of the creative approaches employed in exploring the three EuroCirCol

design options, cosine-theta, block-coils and common-coils, during the EuroCirCol annual meeting of

2017 it was decided to continue to carry on all the three studies, though having chosen the cosinetheta

design as baseline for the FCC.

All the three design options have been presented in three oral talks given by B. Caiffi (INFN),

E. Rochepault (CEA) and F. Toral (CIEMAT).

The progress in the design since the FCC week 2017 has been considerable, for both electromagnetic

and mechanical aspects. It has been shown that all designs seem feasible with a loadline margin of

14% on paper. However for the cosine-theta and the block-coil two issues have been identified: the

presence of an important magnetic cross-talk between the two magnet apertures, creating a b2

component of about 50 units, and a large effect of magnetization currents in the superconductor

creating a large variation of b3 between injection and collision energies. During the meeting a number

of options were discussed to mitigate these effects with a further development of the study.

For the common coil, the main issue concerns a difficulty in designing an adequate mechanical

structure, coming from the complexity and amplitude of the force distribution in this configuration.

Task 5.3: Develop dipole magnet cost model

The activity of this task has been presented by D. Schoerling (CERN). The talk has highlighted the

importance of the cost of the conductor in the total cost of the magnets, recalling that achieving the

target FCC cost for the conductor shall remain a priority.

Task 5.4: Develop Magnet Conceptual Design

The work is being performed in parallel to the finalization of the baseline design option (cosinetheta),

but was not specifically presented at the FCC week 2018 due to lack of time in the program.

Task 5.5: Conductor studies

The work has been presented in an oral talk given by B. Bordini (CERN) focusing on the electro-

mechanical performance of the conductor. It has been shown that the measurements of cables and

wires under transverse load at CERN, Twente and Geneva Universities correlate the reversible

reduction of the critical current to a decrease of the Bc2. At 1.9 K, assuming a Bc2 equal to 28 T, a




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reduction of the Bc2 by 10 % would produce a reduction of the Jc approximately equal to: 20 % at

12 T, 31 % at 16 T , 44 % at 19 T.

Task 5.6: Devise quench protection concept

The work has been presented in an oral talk given by T. Salmi (CERN), summarizing the approaches

and the results of quench protection studies for all the three EuroCirCol design options. It has been

shown that all design options can respect the temperature limit of 350 K in case the coils are

quenched within 40 ms from the initiation of a quench. This condition can be met either with CLIQ,

or with quench heaters, or using both quench protection systems.




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ANNEX: GLOSSARY

SI units and formatting according to standard ISO 80000-1 on quantities and units are used throughout

this document where applicable.

Acronym Definition

CDR Conceptual Design Report

CFC Carbon Fiber Composite

c.m. Centre of Mass

DA Dynamic Aperture

DIS Dispersion suppressor

EIR Experimental Insertion Region

FCC Future Circular Collider

FCC-hh Hadron Collider within the Future Circular Collider study

FCC-ee Lepton Collider within the Future Circular Collider study

FRESCA Test station facility at CERN

FODO Focusing and defocusing quadrupole lenses in alternating order

HE-LHC High Energy - Large Hadron Collider

HL-LHC High Luminosity – Large Hadron Collider

IBS Intra Beam Scattering

IP Interaction Point

IR Interaction Region

KARA Karlsruhe Research Accelerator

LHC Large Hadron Collider

Nb3Sn Niobium-tin, a metallic chemical

Nb-Ti Niobium-titanium, a superconducting alloy

PSD Photo Secondary Desorption

RF Radio Frequency

RMS Root Mean Square

σ RMS size

SEY Secondary Electron Yield

SPS Super Proton Synchrotron

SR Synchrotron Radiation

SSC Superconducting Super Collider

3rd annual eurocircol collaboration meeting · 2018-10-02 · 3rd annual eurocircol collaboration...

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