Mats Lindroos
Future R&D: beta-beam
Mats Lindroos
Mats Lindroos
Production
• Test of target prototypes at e.g. TRIUMF (ISAC facility).
• Prototyping of a ring with ionization cooling for production of beta-beam isotopes.– C. Rubbia et co-workers (NIM A, In press),
for production of radioactive ions and with long. and trans. cooling
– Proposal by Y. Mori, NIM A 562(2006)591, for neutrons (and RIB) with trans. cooling using an FFAG.
Mats Lindroos
Production ring with ionization cooling
Mats Lindroos
A new approach
Beam cooling with ionisation losses – C. Rubbia, A Ferrari, Y. Kadi and V. Vlachoudis in NIM A, In press
“Many other applications in a number of different fieldsmay also take profit of intense beams of radioactive ions.”
7Li(d,p)8Li6Li(3He,n)8B
7Li6Li
Missed opportunities
Mats Lindroos
Transverse cooling in paper by Carlo Rubbia et al.
“In these conditions, like in the similar case of the synchrotron radiation, the transverse emittance will converge to zero. In the case of ionisation cooling, a finite equilibrium emittance is due to the presence of the multiple Coulomb scattering.”
Mats Lindroos
Longitudinal cooling in paper by Carlo Rubbia et al.
“In order to introduce a change in the dU/dE term — making it positive in order to achieve longitudinal cooling — the gas target may be located in a point of the lattice with a chromatic dispersion. The thickness of the foil must be wedge-shaped in order to introduce an appropriate energy loss change, proportionally to the displacement from the equilibrium orbit position.”
Number of turns
1) Without wedge, dU/dE<0
2) Wedge with dU/dE=0, no longitudinal cooling
3) Wedge with dU/dE=0.0094
4) Electrons, cooling through synchrotron radiation
Mats Lindroos
Inverse kinematics production and ionisation parameters in paper by Carlo Rubbia et al.
7Li(d,p)8Li6Li(3He,n)8B
Mats Lindroos
Collection in paper by Carlo Rubbia et al.
“The technique of using very thin targets in order to produce secondary neutral beams has been in use for many years. Probably the best known and most successful source of radioactive beams is ISOLDE.”
Protons
+/- 8V500A
+/- 9V1000A
*
Mats Lindroos
Reactions of interest for our application
• 27Al(4He,n)30P ?– D.J.Frantsvog et al, PRC 25(1982)770: 8.8-15.8 MeV, 480(50) mb
• 14N(2H,n)15O ?– S.Takacs et al, NIM/B,211(2003) 169
• 24Mg(3He,2H)25Al ?– D.J.Frantsvog et al, PRC 25(1982)770: 7.2-15.3 MeV, 430(70) mb
Mats Lindroos
6He production from 9Be(n,)
• Converter technology preferred to direct irradiation (heat transfer and efficient cooling allows higher power compared to insulating BeO).
• 6He production rate is ~2x1013 ions/s (dc) for ~200 kW on target.
Converter technology: (J. Nolen, NPA 701 (2002) 312c)
20 March 2006 EURISOL – Task #3T. Stora, CERN
Conceptual design of the dual converter-BeO target
• Be (n,) 6He
Mats Lindroos
ISAC at TRIUMF: First high power ISOL facility!
Mats Lindroos
Ionization and Bunching
• Test of all concepts for efficient ionization and bunching.
Mats Lindroos
60 GHz « ECR Duoplasmatron » for gaseous RIB
Very high densitymagnetized plasma
ne ~ 1014 cm-3
2.0 – 3.0 T pulsed coils or SC coils
60-90 GHz / 10-100 KW10 –200 µs / = 6-3 mm
optical axial coupling
optical radial (or axial) coupling(if gas only)
1-3 mm100 KV
extractionUHF windowor « glass » chamber (?)
Target
Rapid pulsed valve ?
20 – 100 µs20 – 200 mA
1012 per bunchwith high efficiency
Small plasmachamber ~ 20 mm / L ~ 5 cm
Arbitrary distanceif gas
P.Sortais et al.
Mats Lindroos
cryogenictraptarget
largeplasma chamber
efficient pumping(minimize charge exchange)
+ 20 kV
multi electrodesystem
28 GHz+
37 GHz(15 kW)
5 T 2.5 T
Source scheme
D. Hitz, CEA
Mats Lindroos
injectionside extraction
side2 to 4 central coils
hexapolar radial field
or dodecapolar radial fieldfor a better emittance
several central coils for a good confinement nearby injection side and worse confinement at extraction side
Magnets
Mats Lindroos
Accumulation
• Design of accumulation ring
Mats Lindroos
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
Mats Lindroos
The annual rate
• The annual rate at the EURISOL beta-beam facility is a factor of two below the annual rate assumed in most calculation– Is it possible to re-gain this missing
factor of two within the present base-line?
Mats Lindroos
High gamma beta-beam
Gamma Rigidity[Tm]
Ring length T=5 Tf=0.36
Dipole Fieldrho=300 mLength=6885m
100 938 4916 3.1
150 1404 6421 4.7
200 1867 7917 6.2
350 3277 12474 10.9
500 4678 17000 15.6Civil engineering
Magnet R&D
New SPS
Mats Lindroos
Summary
Project Subjects Cost Other communities
Production •Production ring•Target tests
5-25 MEuro10-50 FTE
Nuclear Astrophysics, Hadron therapy
Ionization and bunching
•60 GHz ECR (2 types)•BNL EBIS?
5-10 MEuro5-10 FTE
Nuclear physics
Machine studies •HI acceleration•Accumulation•Higher gamma beta-beam
5-10 FTE Heavy ion physics, Nuclear physics
Mats Lindroos
Conclusions
– We need a larger beta-beam machine study community
– For a fair comparison with neutrino factories we need to study the limits of the concept starting at “study 1”.• Green field study
– Neutrino beams at CERN• Difficult to convince management that
they should invest NOW in a neutrino beam study
• Feeling that the decision is far away• Radiation safety aspects a concern