CEA Saclay Experience

Pierre Védrine, CEA Saclay, Irfu

EUCARD-2 WP3: Energy Efficiency

(EnEfficient)

Workshop on

Compact and Low Consumption Magnet Design

for Future Linear and Circular Colliders

INSTITUTE OF RESEARCH INTO THE FUNDAMENTAL

LAWS OF UNIVERSE

2

Irfu/SACM is developing and realizing particle accelerators, cryogenic systems and superconducting magnets for the scientific programs of Irfu and more widely of CEA.

Irfu/SACM is involved in large scale projects in Europe and in Japan.

Particle Physics

Nuclear Physics

Astrophysics

Space technologies

Accelerators,

Supra. Magnets

Systems engineering

Detectors, electronic,

computing

Institute of Research into the Fundamental laws of Universe

3

PAST EXPERIENCES

MAGNETS FOR PARTICLE PHYSICS

ATLAS Toroid magnet

CMS solenoid magnet

LHC quadrupole magnet

SUPERCONDUCTING MAGNETS

BACKGROUND

| PAGE 4

ATLAS and CMS: largest magnets Design and follow-up manufacturing

LARGE magnets Construction

For physics GLAD (GSI) For neuroscience ISEULT

Testing For fusion W7X & JT60SA

R&D Nb3Sn and HTS magnets Cryogenic systems Multi-scale simulations

LHC Upgrades Q4 NbTi Quadrupole for HL LHC 16 T Nb3Sn Dipole for FCC

5

(COMPACT AND LOW CONSUMPTION)

ATLAS EXPERIMENT

ATLAS IN COPPER CONDUCTOR !

Electrical Power > 100 MW

Winding size > 2-3 m

Weight > 5000 t of conductor

Reduced space for the detectors

MAGNET DESIGN FOR FUTURE PROJECTS

Efficient choice of conductor

Efficient magnet design

Efficient cryogeny for magnets

Save space for applications (detector, sample, …)

Reduce size, weight and cost …

Save helium, electrical consumption,

| PAGE 7

Magnets for HEP detectors High Field Magnets Cooling Schemes

FUTURE CIRCULAR COLLIDER-HH

LHC

27 km, 8.33 T

14 TeV (c.o.m.)

FCC-hh

80 km, 20 T 100 TeV (c.o.m.)

FCC-hh

100 km, 16 T 100 TeV (c.o.m.)

HE-LHC

27 km, 20 T 33 TeV (c.o.m.)

Geneva

PS

SPS

LHC

FCC / 100 TEV PROTON-PROTON DETECTOR MAGNET

100 TEV proton-proton collider needs a giant solenoid with followings design drivers

(extracted from H. ten Kate slides presented at FCC Workshop @ CERN, 27 May 2014)

26 NOVEMBRE 2014 | PAGE 9

FCC / 100 TEV PROTON-PROTON COLLIDER DETECTOR

A preliminary magnetic design has been performed at Saclay (G. Aubert) with

two driven hypothesis:

- Overall density to limit at 200MPa the hoop stress: ~7A/mm²

- Active shielding (120 000 t of iron required if passive shielding)

26 NOVEMBRE 2014 | PAGE 10

FCC Solenoid

22 GJ

24 m length

10 m diameter

CMS Solenoid

2.7 GJ

12.4 m length

6.6 m diameter

WHY NOT FCC DETECTOR MAGNET WITH MGB2?

In order to work at 10K

Today Jc MgB2 @10K/5T # 20 A/mm² but progress on-going

Jc in very large solenoid is limited by the stress (7A/mm² -> 200MPa)

| PAGE 11

WHY NOT FCC COLLIDER SOLENOID AT 10K?

To decrease the liquefier electrical power

From 4.2K to 10K, the efficiency increase is about 2.5 (Carnot based)

It could be possible to use the CMS liquefier (around 800 W at 4.45K & 4500 W at

50 K)

The actual CMS heat load at 4.4K is 200W

- 60% from radiative load

- 40% from supports load

Scaling assumption from CMS to FCC

- Radiative load is proportionnal to the surface

- Support load is proportionnal to the volume(=mass)

The FCC solenoid load at 4.4 K would be 1600W.

If a power equivalent to CMS refrigerator is « adapted » at 10K, the available power

could be about 2000W.

MGB2 R&D AT SACLAY: MULTIPURPOSE TEST FACILITY

13/32

Conduction cooled facility:

- Background field 3T (can be increased up to 5T)

- Temperature from 4K up to 40K

- Sample current up to 600A

- Sample diameter 300 mm

- Necessary for Wind&React MgB2 wire

13/21

MGB2 R&D AT SACLAY: PANCAKE WINDING

14/21

Double Pancake winding

DP impregnation

DP cross section

1 T / 2km wire solenoid under

manufacturing to be tested under 3T

background field

MGB2 R&D AT SACLAY: PARTNERSHIP AND PROJECTS

15/21

Industrial partnership:

- Winding technology development with SigmaPhi

- Wire material exchange agreement with Columbus

- Cryogen-free and MgB2 development support by Bpi France

Future:

- French ANR proposal “EcoChamp” for high field MgB2 solenoid

(LNCMI, SigamPhi, Columbus)

- FCC support for large MgB2 cable development ?

HIGH FIELD MAGNETS FOR RESEARCH

Magnetic fields serve as a powerful experimental probe

in physics, chemistry and in biology,

Numerous studies in physics, chemistry and biology require high

magnetic fields, homogeneous in space and stable in time.

Currently, magnetic fields above 23 T can only be generated by

resistive magnets, consisting of large water-cooled copper-based

coils in which large currents circulate.

Large electrical power consumption (typically 20 MW) and very

high operating costs, and only a few of such installations exist in the

world, giving access to all-resistive fields up to 38 T, and to hybrid

LTS-resistive fields up to 45 T.

This access is however very limited and very costly. 26 NOVEMBRE 2014 | PAGE 16

The 8.5 T Superconducting magnet

for the 43 T LNCMI hybride magnet.

Cryogenics design: Pressurized Superfluid Helium bath at 1.8 K &

1200 hPa

Goal: To offer a 43 Tesla static field platform

to the scientific community.

Superconduction coil Specifications:

Ri : 0.55 m - Re : 0.9 m - L : 1.4 m - W : 17 t

37 Double pancakes – 7100 A – 3 H – 76 MJ

Hybride Specifications:

43 T in 34 mm warm bore

Collaboration between CNRS and the CEA

34 TESLA RESISTIVE MAGNET

25 T 5 à 15 kA

400 V 2 x 6 MW

9 T 30 kA

400 V 12 MW

Bitter

PolyHelix

A ROBUST 8.5 TESLA SUPERCONDUCTING

MAGNET

8,5 T 7,1 kA 76 MJ

700 kW Liquefier and

pumps included

13 mm

18

mm

RUTHERFORD CABLE ON CONDUIT CONDUCTOR

The superfluid helium in the channel gives the

temperature margin for the coil. He II is 8 times more

energetics than cupper in the same volume.

A SUPERFLUID HELIUM INFRASTRUCTURE

HIGH PERFORMANCE CRYO-MECHANICAL

SUPPORT FERRULES

0.3 W @ 1.8 K

9.2 W @ 4.9 K

0.95 MN

1.2 m - 316 LN

37 W @ 30 K

237 W @ 77 K

3.98 MN

0.25 m - TA6V

SC Coil

Eddy current shield

To reduce the heat load

HIGH FIELD

SUPRECONDUCTING MAGNET OPTION

| PAGE 22

ENVIRONMENTAL AND SOCIO-ECONOMIC IMPACT

By developing all-superconducting magnets for fields beyond 30 Tesla,

running costs would be considerably reduced,

with negligible electricity and moderate cooling costs.

This is a very important development for the financial sustainability of

the research in, and technical applications of, very high magnetic fields

in a context of rising electricity costs, particularly for high field NMR.

The operation of a resistive magnet demands the entire power of the

installation, and requires efficient cooling to remove this dissipated

energy.

The environmental impact is also to be taken into account when we

consider that currently only a minor fraction of this energy can be

recovered.

30T + FULLY SUPERCONDUCTING MAGNET

The aim of this project is to make a design of an

all-superconducting user magnet that will go significantly above

what is currently available, and to test critical components in a

prototype.

The design target chosen is a 30+ Tesla

(30 T minimum and more if possible) solenoid magnet.

A possible design that was suggested consists of a commercial

large-bore 19 T NbTi-Nb3Sn outer coil with an 11 T inner coil

made from HTS conductors, with an inner bore of 30 mm for sample.

| PAGE 24

TASUM H2020 Design study proposal

Helium entrance

Cryocooler

cold head

+

Condenser

Heat

exchanger

Fluid flow

34 cm

19,5 cm

COMPACT COOLING METHODS |

COUPLING TO CRYO-COOLER

Closed natural circulation loop

- Flow is created by the weight

unbalance between the two branches (density change)

- No pumps or pressurization system

- Vapor is re-condensed in the reservoir

Autonomous loop

- Auto-tuned mass flow rate (cooling)

- Independence from a refrigeration unit

Different temperature ranges

ThermAutonome project, CEA Saclay

– Perfect for 100 W compact class system located far from a refrigeration unit

Helium Ø4 mm circulation loop around 4.2 K h~5000 W/m2K

qc=500 W/m2

Y. Song et al., Nucleate boiling heat transfer in a helium natural circulation

loop coupled with a cryocooler, International Journal of Heat and Mass

Transfer, Volume 66, November 2013, Pages 64-71

COMPACT COOLING METHODS |

COUPLING TO CRYO-COOLER

• Pulsating heat pipe

– Pressure change due to volume expansion and contraction at

phase transition

– Oscillation of liquid slugs and vapor bubbles

– High heat transfer due to phase change and convection

– No gravity dependency

– Easy to implement (Any geometry possible)

– Autonomous thermal links

• Self sustained oscillations (cooling)

• Independence from a refrigeration unit

– Different temperature ranges

ThermAutonome project, CEA Saclay

PHP Adiabatic part

PHP Condenser

Cryocooler

170 W @ 77 K

PHP evaporator part

SR2S project, CEA Saclay

36 tubes PHP LN2 100 W class PHP

– Perfect for 100 W compact class system located far from a refrigeration unit without

any geometry dependency

K. Natsume, Heat transfer performance of cryogenic oscillating heat pipes for effective cooling of superconducting

magnets, Cryogenics, Volume 51, Issue 6, June 2011, Pages 309-314

SAVE THE ENERGY….

26 NOVEMBRE 2014 FAILURE (Pong ! ) or POWER (Bingo !)