ral 27 april 2006the beta-beam task, eurisol1 status of the beta-beam study mats lindroos on behalf...

RAL 27 April 2006 The beta-beam task, EURISOL 1

Status of the beta-beam study

Mats Lindroos on behalf of the EURISOL beta-beam task

RAL 27 April 2006 The beta-beam task, EURISOLBeta-beam

requirements, 2

Outline

The beta-beam Progress on a conceptual design

EURISOL beta-beam facility Challenges for the beta-beam Conclusions


requirements, 3

The EURISOL beta-beam facility!


requirements, 4

Beta-beam R&D The EURISOL Project

Design of an ISOL type (nuclear physics) facility. Performance three orders of magnitude above existing facilities. A first feasibility / conceptual design study was done within FP5. Strong synergies with the low-energy part of the beta-beam:

Ion production (proton driver, high power targets). Beam preparation (cleaning, ionization, bunching). First stage acceleration (post accelerator ~100 MeV/u). Radiation protection and safety issues.

Subtasks within beta-beam task ST 1: Design of the low-energy ring(s). ST 2: Ion acceleration in PS/SPS and required upgrades of the existing machines

including new designs to eventually replace PS/SPS. ST 3: Design of the high-energy decay ring. Around 38 (13 from EU) man-years for beta-beam R&D over next 4 years (only within

beta-beam task, not including linked tasks).


requirements, 5

Design study objectives

Establish the limits of the first study based on existing CERN accelerators (PS and SPS)

Freeze target values for annual rate at the EURISOL beta-beam facility Close cooperation with neutrino physics community

Freeze a baseline for the EURISOL beta-beam facility

Produce a Conceptual Design Report (CDR) for the EURISOL beta-beam facility

Produce a first cost estimate for the facility


requirements, 6

Challenges for the study

Production Charge state distribution after ECR source The self-imposed requirement to re-use a maximum

of existing infrastructure Cycling time, aperture limitations etc.

The small duty factor The activation from decay losses The high intensity ion bunches in the accelerator

chain and decay ring


requirements, 7

Intensity distribution during acceleration

30% of first 6He bunch injected are reaching decay ring Overall only 50% (6He) and 80% (18Ne) reach decay ring

Normalization Single bunch intensity to maximum/bunch Total intensity to total number accumulated in RCS

Bunch20th

15th

10th

5th1st

total


requirements, 8

Power losses - comparison

Nucleon losses compared PS and SPS comparable for CNGS and bb operation PS exposed to highest power losses

Ploss/l [ions] Beta-beam

CNGS 6He 18Ne

RCS - 0.17 0.14

PS 3.3 2.2 2.8

SPS 0.25 0.4 0.25

Power loss per unit circumference of a machine

machinecycle

lossloss ncecircumferet

cycleElP

*

//


requirements, 9

Dynamic vacuum

Decay losses cause degradation of the vacuum due to desorption from the vacuum chamber

The current baseline includes the PS, which does not have an optimized lattice for unstable ion transport and has no collimation system The dynamic vacuum degrades to

10-5 Pa in steady state (6He)

An optimized lattice with collimation system improves the situation by two orders of magnitude

1.00E+08

1.00E+09

1.00E+10

0 5 10 15 20 25 30 35

s [m]

6L

i lo

ss

es

[/0

.1m

/6s

-cy

cle

]

P. Spiller et al., GSI


requirements, 10

Merging

Achieving >90% merging efficiency of injected particles

Some ions are already collimated before having been stacked for 15 (20) merging cycles

2 4 6 8 10 12 14

0.5

0.6

0.7

0.8

0.9

Ions

stor

ed/io

nsin

ject

ed

t [s]

5 10 15 20

0.4

0.5

0.6

0.7

0.8

0.9

Ions

stor

ed/io

nsin

ject

ed

t [s]

6He

18Ne

S. Hancock, CERN


requirements, 11

Inje

cted

/mer

ged

collimated

decayed

Decay ring - Momentum collimation

After 15 (20) merges 50% (70%) of the injected 6He (18Ne) ions are pushed outside the acceptance limits.

Momentum collimation required. Dispersion region; multi stage collimation system

Space required: placed in “unused” straight section

Collimation power corresponds to 150 kW average to MW peak level during the bunch compression process

compression process lasts a few hundred milliseconds

A. Chance et al., Saclay

He6 Ne18 LHC p+ LHC Pb

100 100 7461 2964

T/ion (GeV) 555 1660 7000 574000

τrepetition (s) 6 3.6 10h 10h

Number of stored ions 9.71 1013 7.4 1013 3.2 1014 4 1010

Stored beam energy (MJ) 8.8 19.7 2 x 362 2 x 3.81


requirements, 12

aperture [cm]

Pow

er lo

ss [W

/m]

Decay ring - Decay losses

Decay products originating1) from straight section2) in arcs

1) are extracted at the first dipole in the arc, sent to dump

2) Arc lattice optimized for absorption of decay products To accommodate either ion species, the half-aperture

has to be very large (~ 8cm for the SC dipoles).

Absorbers take major part of decay losses ion arcs. About 60 W each SC dipoles still have to stand <10 W/m.

A. Chance et al., Saclay

-0,1

0,0

0,1

0,2

0,3

2300 2350 2400

HorizontalVertical

s (m)

envelopes (m)

Fluorine extraction

Bρ(18F9+) ≈ 621 T.m


requirements, 13

Production

Major challenge for 18Ne Workshop at LLN for production, ionization

and bunching this summer New production method proposed by C.

Rubbia!


requirements, 14

Production ring with ionization cooling (C. Rubbia, A.Ferrari, Y.Kadi and V. Vlachoudis)


requirements, 15

Ionization cooling


requirements, 16

Using existing PS and SPS, version 2Space charge limitations at the “right flux”

Space charge tune shift Note that for LHC the corresponding values are -0.078 and -0.34

[μm] 6He 18Ne RCS inj 16.4, 8.8 16.4, 8.8 PS inj 6.6, 3.5 4.0, 2.1 SPS inj 0.8, 0.4 0.5, 0.3

6He 18Ne RCS inj -0.019 -0.078 PS inj -0.11 -0.20 SPS inj -0.090 -0.15

Transverse emittance normalized to PS acceptance at injection for an annual rate of 1018 (anti-) neutrinos


requirements, 17

The slow cycling time.What can we do?

Production

PS

SPS

Decay ring

Ramp time PS

Time (s)0 8

Wasted time?

Ramp time SPS

Reset time SPS


requirements, 18

Accumulation at 400 MeV/u

2 4 6 8 10

Accumulationtime

21018

41018

61018

81018

11019

1.2 1019

Annualrate 6HeT1/2=1.67 s

T1/2=17 s

T1/2=0.67 s


requirements, 19

Stacking

0.2 0.4 0.6 0.8 1

25000

50000

75000

100000

125000

150000

Multiturn injection with electron cooling

Half life [s] 0.1 1 10Tvacuum [s] 30 30 30Intensity ions [every 100 ms in 30 microsceonds] 104 5 105 5 105

Tcool[ms] 100 100 100Number of turns 10 10 10Final emittance [micrometer] 0.1 0.1 0.1Final number of particles in stack 3 104 3 107 3 108

2 4 6 8 10 12

Time [s]

0

2

4

6

8

Beam

Inte

nsity [

E8 ions]

beam lifetime : 6.5s

Linac III rep rate : 2.5 HzIon beam energy : 4.2 MeV/uElectron energy : 2.35 keVElectron current : 105 mA

Average accumulated intensity : 6E8 ionsPeak intensity : 7.1E8 ions


requirements, 20

150Dy

Partly stripped ions: The loss due to stripping smaller than 5% per minute in the decay ring

Possible to produce 1 1011 150Dy atoms/second (1+) with 50 microAmps proton beam with existing technology (TRIUMF)

An annual rate of 1018 decays along one straight section seems as a realistic target value for a design study

Beyond EURISOL DS: Who will do the design? Is 150Dy the best isotope?


requirements, 21

Long half life – high intensities

At a rate of 1018 neutrinos using the EURISOL beta-beam facility:


requirements, 22

Gamma and decay-ring size, 6He

Gamma Rigidity

[Tm]

Ring length

T=5 T

f=0.36

Dipole Field

rho=300 m

Length=6885m

100 938 4916 3.1

150 1404 6421 4.7

200 1867 7917 6.2

350 3277 12474 10.9

500 4678 17000 15.6

Civil engineering

Magnet R&D

New SPS


requirements, 23

In 2008 we should know

The EURISOL design study will with the very limited resources available give us: A feasibility study of the CERN-Frejus baseline A first idea of the total cost An idea of how we can go beyond the baseline

Resources and time required for R&D Focus of the R&D effort

Production, Magnets etc.

ral 27 april 2006the beta-beam task, eurisol1 status of the beta-beam study mats lindroos on behalf...

Documents

betabeam rd

eurisol betabeam requirements

betabeam progress

betabeam conclusions

eurisol betabeam task

betabeam task st

betabeam study mats

ionsbetabeam cngs