1. Energy efficient technologies for accelerators - an EuCard-2 effort
Mike Seidel (PSI)
E.Jensen (CERN), R.Gehring (KIT), A.Lundmark (ESS), J.Stadlmann, P.Spiller (GSI)

2. Accelerator Efficiency - Outline
Introduction
goals of Eucard / EnEfficient
power flow in accelerator facilities
scope of Efficiency?
Examples of activities
heat recovery, efficient magnets, efficient RF generation, energy management
Outlook & Summary
p-driver efficiency workshop
next Eucard Program

3. Eucard-2 ?
EUCARD = Integrating Activity Project for coordinated Research and Development on Particle Accelerators, co-funded by European commission, 2013…2017
coordinator: Maurizio Vretenar, CERN
Networking Activities
WP2: Catalysing Innovation (INNovation)
WP3: Energy Efficiency (EnEfficient)
WP4: Accelerator Applications (AccApplic)
WP5: Extreme Beams (XBEAM)
WP6: Low Emittance Rings (LOW-e-RING)
WP7: Novel Accelerators (EuroNNAc2)
Transnational Access
WP8:
WP9: and
Joint Research Activities
WP10: Future Magnets (MAG)
WP11: Collimator Materials for fast High Density Energy Deposition (COMA-HDED)
WP12: Innovative Radio Frequency Technologies (RF)
WP13: Novel Acceleration Techniques (ANAC2)

4. networking EnEfficient, Eucard-2
EnEfficient: WP3, networking activity to stimulate developments, support accelerator projects, thesis studies etc.
task 1: energy recovery from cooling circuits, Th.Parker, A.Lundmark (ESS) task 2: higher electronic efficiency RF power generation, E.Jensen (CERN) task 3: short term energy storage systems, R.Gehring (KIT) task 4: virtual power plant, J.Stadlmann (GSI) task 5: beam transfer channels with low power consumption, P.Spiller (GSI)
links to all workshops on

5. Example: PSI Facility, 10MW
Muon production targets
Ring Cyclotron 590 MeV
loss  10-4
Power transfer through
4 amplifier chains
4 resonators 50MHz
beam: 2.2 mA /1.3 MW
SINQ
spallation source
50MHz resonator
dimensions:
120 x 220m2
proton therapie center [250MeV sc. cyclotron]

6. Example: PSI Facility, 10MW
n: per beamline:
10eV ≈ 20µW
public grid ca. 10MW
RF Systems 4.1MW
Beam on targets
1.3MW
neutrons
muons
+: per beamline
30MeV/c
≈ 300µW
Magnets
 2.6MW
aux.Systems
Instruments
 3.3MW
heat  to river, to air
cryogenics

7. Efficiency of an accelerator based science facility ?
How many experiments at a certain quality can be done per energy drawn from the grid?
[vs. primary beam intensity per grid power]
optimization includes not only the accelerator, but also
secondary radiation conversion efficiency
secondary radiation transport and brightness at experiment
signal to noise ratio
instrument efficiency
 thus an overall optimization should be done
applies to many facilities:
light source, FEL
n, µ,  source
particle collider
example: upgrade potential of the PSI Neutron source [U.Filges et al]
Accelerator
Target
Moderator
Guides
Shielding
Instruments
1.0 – 1.25
1.0 – 1.1
1.0 – 2
1.0 – 5
1.0 – 10
1.0 – 3
concrete example for particular instrument:
x x x x x = 10.4

8. Example: improved conversion efficiency Spallation Target [M
Example: improved conversion efficiency Spallation Target [M.Wohlmuther, PSI]
old
new
measure
gain
Zr cladding instead steel
12%
more compact rod bundle 5%
Pb reflector
10%
inverted entrance window
total gain factor
1.42
beam
beam
color code: neutron density on same scale
(MCNPX)

9. next: Examples from EnEfficient tasks…

10. Heat Recovery Workshop, Lund, March 2014 [Th.Parker, E.Lindström, ESS]
Participants (Experts) from
DESY, ALBA, SOLEIL, ESS, MAX-4, PSI, DAFNE, ISIS (institutes)
E.ON, Kraftringen, Lund municipality (industry, local authorities)
lab survey on consumption and heat recovery
heat recovery works for many facilities; high temperatures beneficial
local heat distribution system required
greenhouses present interesting application (non-linear scaling)
new facilities MAX-4 and ESS foresee heat recovery on large scale
talks:

11. Lab Survey: Energy Consumption & Heat [Master Thesis, J
Lab Survey: Energy Consumption & Heat [Master Thesis, J.Torberntsson, ESS]
workshop on cooling and heat recovery, Lund, April 2014, ESS and MAXLab

12. Efficient RF Generation and Beam Acceleration
RF generation efficiency is key for many accelerator applications, especially high intensity machines
topics at workshop:
klystron development
multi beam IOT (ESS)
magnetrons
high Q s.c. cavities
CPI: multi-beam IOT
E2V: magnetron
THALES: multi-beam klystron
workshop EnEfficient RF sources:
SIEMENS: solid state amplifier
THALES: TETRODE

13. Inductive Output Tubes – considered for ESS [Morten Jensen (ESS) @ EnEfficient RF sources, 2014]
IOT
MB-IOT
IOT’s don’t saturate.
Built-in headroom for feedback.
70%
Klystron/MBK
+6 dB
sat  65-68%
ESS ~ 45%
Short-pulse
excursions possible
back-off for feedback
Operating
Power Level
Long-pulse
excursions possible
Pout
High gain
Courtesy of CPI
Low Gain
Pin
Klystrons: Back-off for feedback, cost: 30%
IOTs: Operate close to max efficiency

14. Klystrons: Methods to get high efficiency [Ch. Lingwood, I
Klystrons: Methods to get high efficiency [Ch.Lingwood, I.Syratchev et al]
Bunching split into two distinct regimes:
non-monotonic: core of the bunch periodically contract and expand (in time) around center of the bunch
outsiders monotonically go to the center of the bunch
Core experiences higher space charge forces which naturally debunch
Outsiders have larger phase shift as space charge forces are small
long but efficient tubes result.
from simulations: 90% efficiency comes into reach ё
Phase
Traditional bunching
Core oscillations
Cavity
talk by I.Syratchev in session Ic
CEA Saclay, study planned for Eucard-3
Space

15. low power accelerator magnets
see also M.Modena, CERN, next talk
permanent magnets
Pro: no power required, reliable, compact
Con: tunability difficult, large aperture magnets limited, radiation damage
optimized electromagnet
Pro: low power, less cooling
Con: larger size, cost
pulsed magnet
Pro: low average power, less cooling, high fields
Con: complexity magnet and circuit, field errors
s.c. magnet
Pro: no ohmic losses, higher fields
Con: cost, complexity, cryo installation
high saturation materials
Pro: lower power, compactness and weight
Con: cost, gain is limited
Workshop on Special Compact and Low Consumption Magnet Design, November 2014, CERN; indico.cern.ch/event/321880/

16. Eucard sponsored study: systematic comparison of energy efficient beam transport systems, Ph. Gardlowski, GSI
concepts:
high current pulsed magnets (HPC, original GSI proposal)
normalconducting magnets (NC)
superconducting magnets (SC)
superferric magnets (SF)
permanent magnets (PM)
varied parameters:
aperture
repetition rate
magnetic rigidity
goals of study:
assess energy consuption, investment cost, operating cost
technology recommendation for different applications
cross section: superferric dipole, Halbach type PM

17. outcome of study best concept depends much on required parameters
pulsed magnets can present an advantage for pulsed beams at low frequency
superferric can be best for large aperture/strong magnets
PM magnets applicable for wide range, but aperture limited
example:
Fig. 4.6 consumption versus magnetic rigidity, p- beamline.
Parameters:
drift length = 10.0 m
emit. = 19.2 mm mrad
repetition rate = 0.33 Hz, aperture radius = 40 mm
[P.Gardlowski, GSI]

18. Pulsed Quadrupole Magnet
[P.Spiller et al, GSI]
Prototype Quadrupole
Gradient
80 T/m
Length
0.65 m
Pulse length
90 ms (beam 1 ms)
Peak current
400 kA (35 kA)
Peak voltage
17 kV (5 kV) kV
65 kJ (5.6 kJ)
Inductivity
535 nH
Capacitor
450 mF
Forces
200 kN
Engineering model of the prototype quadrupole magnet incl. support
low average power; energy recovery in capacitive storage possible for periodic operation
complexity added by pulsing circuit; field precision potentially challenging

19. Energy Management strong variations of supply by wind and sun energy
even today strong variation by varying load on grid
 consider „dynamic operation“ of accelerators, depending on supply situation (challenging, loss of efficiency)
 consider options to store energy on site (expensive, evolving technology)
 economy depends on supply volatility and cost of energy
Germany

20. Energy management example: CLIC Study on standby modes
Andrea Latina, CERN
CLIC project predicts large power for 3TeV case: 580MW
idea:
prepare standby modes for high consumption times during day; relatively fast luminosity recovery from standby (challenging)
model calculation includes standby power, startup times
result of model with 2 standbys during day:

21. Study on energy statistics of accelerator facilities
goal of study:
investigate fluctuation statistics of accelerator facilities, identify potential for variable consumption, depending on grid situation
TU Darmstadt, Institute „Electrical Power Systems“, group Prof. Jutta Hanson

22. outlook: workshop in Feb/16, PSI
Proton Drivers with high intensity
for Neutron, Muon, Neutrino production
workshop: comprehensive consideration of efficiency from Grid to secondary beam at experiment/application
topics:
beam intensity demand for particle physics, structure of matter physics
target efficiency, conversion to secondary radiation
accelerator concepts, RF sources + accelerating structures
typical aux. systems, cryogenics, conventional cooling

23. Summary
with scarcity of resources and climat change Energy Efficiency becomes important for accelerator projects
Eucard-2/EnEfficient studies heat recovery, RF systems, cavities, magnets, E management
a new Eucard program is planned for
links to all activities: