FP6 Design study "DIRAC secondary beams"

Project "NUSTAR":Experiments with stored radioactive beams

Super-FRS high-power production targethas to cover two totally different regimes:

1. Slow extraction: ≈ 1 second spills, P = 12 kW

2. Fast extraction: ≈ 50 ns spills, P = 12 kJ/50 ns = 240 GW!

Task 6: High-power production targets for fast-extracted beams

K.Sümmerer (GSI)

FP6 Design study "DIRACsecondary beams"Project "NUSTAR":Experiments with stored radioactive beamsTask 6: High-power production targets for fast-extracted beams

Delivrables:

•Conceptual design Target Wheel (month 24)•Conceptual design Liquid-Metall Target (month 36)•Prototype Liquid-Metall Target (month 36)

Goals of Task 6:

•"Research and development to handle the energy deposition of high-

intensity primary beams in the production target"

•"Design and prototype construction of a rotating target wheel"

•"Feasibility study and prototype construction of a liquid-metal target"

Super-FRS target for slow extraction

Facility Beam Total BeamEnergyE [kJ]

TargetThickness

[g cm-2]

DepositedEnergyΔE [kJ]

SpecificEnergy

ΔE/M [kJ/g]

PSI protons1x1016/s

1000 10.8 54 0.18

Super-FRS* all ions1x1012/s

40 1.0 – 8.0 12 0.17

* beam energy 1 A GeV, beam spot radius of 1 mm, target (rt = 15 cm) rotates with 60 rpm, beam hits target at rb = 14 cm.

PSI rotating graphite wheel is a suitable model for Super-FRS target for slow extraction!

Key parameters:

• radiation cooled (T = 1430 C)• 1 year continuous reliable operation (since 1990)• proven safe handling concepts (plug system, vertical access)

PSI target for slow extraction(G.Heidenreich, PSI)

PSI Target E Vertical plug handling concept at Super-FRS

Work plan for NUSTAR1 / Task 6

Rotating graphite wheel target:Explore theoretical concepts of energy deposition/transportEngineering design Calculate temperature response of realistic geometry Prototype for long-term/beam testingRadiation damage/annealingMedia connection, shielding, handling, repairs

GSI

Super-FRS targets for fast extraction

Key parameters:

•pulse length 50 ns ( beam interaction with nominal target thickness)•instantaneous power: 12 kJ/50 ns 240 GW•small beam spot & high power density solids not (always) feasible

Possible solutions:

1. graphite wheel as fall-back solution for low beam powers/larger beam spots

2. investigate windowless liquid-metal jet target (like ANL/RIA, ν-factories)

Liquid Li seems to be the most favorable metal!Open questions:damage due to shock waves?Li contamination of beam tube, diagnostic detectors etc.constancy of jetsafety issues

Response of liquid-Li jet to fast SIS pulses

2-dim. BIG-2 calculations by N. Tahir:Tmax on beam trajectory: 13 000 Kevaporated Li is ejected in/against beam direction with v0 = 10 km/sshock front travels with 1.5 km/s perpendicular to beam directionshock pressure still 2 GPa after 1 μs

to = 50 ns t1 = 1 μs

Work plan for NUSTAR1 / Task 6

Liquid-metal jet target:3-dim. hydro-dynamical calculations; comparison to

2-dim. calculationsDefine beam spot size where Li does not vaporizeFeasibility study (water model, Na model)Prototype Li loopTechnical (safety and vacuum) concept (incl.

handling)

FZK

Task 6 "NUSTAR1" Cost Table

NUSTAR1 GSI FZK

total EC Contr. total EC Contr.

Personnel 48 PM 24 PM 48 PM 24 PM

Consumables 140 k€ 70 k€

Total 462 k€ 231 k€ 492 k€ 246 k€