The FAIR Antiproton Target B. Franzke, V. Gostishchev, K. Knie, U. Kopf, P. Sievers, M. Steck...

The FAIR Antiproton TargetThe FAIR Antiproton Target

B. Franzke, V. Gostishchev,

K. Knie, U. Kopf, P. Sievers, M. Steck

• Production Target

• Magnetic Horn (Collector Lens)

• CR and RESR

• Radiation Protection

Creation of antiprotons (p or pbar) Creation of antiprotons (p or pbar)

p, > 1 GeVp, > 1 GeV

m = E / c²mp = mpbar 1 GeV / c²

p

p

pbar

p

p, > 6 GeV p at rest

m = E / c²

p

p

p

pbar

__

Creation of antiprotons (p or pbar) Creation of antiprotons (p or pbar) __

0

0.00001

0.00002

0.00003

0.00004

0.00005

0.00006

0.00007

0 2 4 6 8 10 12 14 16 18 20

p [GeV/c]

d(p

_bar

/p)/

dp

(ar

b.

un

its)

120 GeV (Fermilab)

90 GeV (SIS300)

70 GeV

50 GeV

29 GeV (SIS100)

20 GeV

10 GeV

p = 3.82 GeV / c, E = 3 GeV, Bρ = 13 Tm

FAIR / CERN / FNAL pbar SourcesFAIR / CERN / FNAL pbar Sources

CERN (AC+AA) FNAL

E(p), E(pbar) 25 GeV, 2.7 GeV 120 GeV, 8 GeV

acceptance 200 mm mrad 30 mm mrad

protons / pulse 1 - 2 × 1013 ≥ 5 × 1012

pulse length 5 bunches in 400 ns single bunch 1.6 µs

cycle time 4.8 s 1.5 s

FAIR / CERN / FNAL pbar SourcesFAIR / CERN / FNAL pbar Sources

cycle time 10 s (cooling time in the CR)overall pbar yield: 5 × 10-6 pbar/p (based on CERN data) → 1 × 107 pbar/s

Increases the pbar yield by 50 %

FAIR Collector ring will be operated at h = 1, CERN ring was operated at h = 6

Time needed for stochastic cooling in CR (AC), upgrade possible

FAIR CERN (AC+AA) FNAL

E(p), E(pbar) 29 GeV, 3 GeV 25 GeV, 2.7 GeV 120 GeV, 8 GeV

acceptance 240 mm mrad 200 mm mrad 30 mm mrad

protons / pulse ≥ 2 × 1013 1 - 2 × 1013 ≥ 5 × 1012

pulse length single bunch (50 ns) 5 bunches in 400 ns single bunch 1.6 µs

cycle time 10 s 4.8 s 1.5 s

pbar Distribution After the Targetpbar Distribution After the Target

R.P. Duperray et al., Phys. Rev. D 68, 094017 (2003)

ppbar = 3.82 GeV/c ± 3%

From ~ 2.5 × 10-4 pbar / (p cm target) ~ 5 × 10-6 (or 2 %) are "collectable"

z / cm

y / c

m Ep = 29 GeV

MARS Simulation of the pbar YieldsMARS Simulation of the pbar Yields

-150

-100

-50

0

50

100

150

-50 -40 -30 -20 -10 0 10 20 30 40 50

x [mm]

x' [

mra

d]

after target

acceptance of separator

p = 3.82 GeV/c Dp/p = ± 3%

reaction products

B 1/r

primary beam does not hit the horn

Collecting pbars: Magnetic HornCollecting pbars: Magnetic Horn

CERN ACOL Horn, I = 400 kA

Collecting pbars: Magnetic HornCollecting pbars: Magnetic Horn

target beam axis magnetic field area

Collecting pbars: Magnetic HornCollecting pbars: Magnetic Horn

MARS Simulation of the pbar YieldsMARS Simulation of the pbar Yields

-150

-100

-50

0

50

100

150

-50 -40 -30 -20 -10 0 10 20 30 40 50

x [mm]

x' [

mra

d]

after targetafter hornacceptance of separator

p = 3.82 GeV/c Dp/p = ± 3%

yield =pbars in the ellipse

primary protons

MARS Simulation of the pbar YieldsMARS Simulation of the pbar Yields

0.0E+00

2.0E-06

4.0E-06

6.0E-06

8.0E-06

1.0E-05

1.2E-05

1.4E-05

1.6E-05

1.8E-05

2.0E-05

2.2E-05

2.4E-05

2.6E-05

2.8E-05

3.0E-05

3.2E-05

3.4E-05

3.6E-05

3.8E-05

4.0E-05

4.2E-05

4 6 8 10 12 14 16 18 20

target length [cm]

yie

ld [

pb

ar/

p]

after target, dp/p<3%, theta<80mrad

Ir, d=3, rms=0.1

0.0E+00

2.0E-06

4.0E-06

6.0E-06

8.0E-06

1.0E-05

1.2E-05

1.4E-05

1.6E-05

1.8E-05

2.0E-05

2.2E-05

2.4E-05

2.6E-05

2.8E-05

3.0E-05

3.2E-05

3.4E-05

3.6E-05

3.8E-05

4.0E-05

4.2E-05

4 6 8 10 12 14 16 18 20

target length [cm]

yie

ld [

pb

ar/

p]

after target, dp/p<3%, theta<80mrad

Ni d=3, rms=0.62

Temperature Increase in the TargetTemperature Increase in the Target

100

1000

10000

0 0.5 1 1.5 2 2.5

beam width (s) [mm]

Max

imu

m T

emp

erat

ure

incr

ease

D

T [

K]

DT = 360 K × w-1.68

DT = 310 K × w-1.68

DT = 2100 K × w-1.35

IrCuNi

melting of Ir

melting of Ni

melting of Cu

Fluka simulation

2×1013 protons per pulseGaussian beam profile

29 GeV/c, r = 1 mm (s)

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6

z [cm]

(dE

/dm

) max

[Ge

V/(

pri

m g

)]

Ir Cu/Ni

cIr = 130 J kg-1 K-1

cCu = 385 J kg-1 K-1

cNi = 440 J kg-1 K-10.0E+00

2.0E-06

4.0E-06

6.0E-06

8.0E-06

1.0E-05

1.2E-05

1.4E-05

1.6E-05

1.8E-05

2.0E-05

2.2E-05

4 6 8 10 12 14 16 18 20

target length [cm]

yiel

d [

pb

ar/p

]Ni/Cu, d=3, rms=0.62

Ir, d=4.5, rms=1

CR: Bunch Rotation and CR: Bunch Rotation and Stochastic Pre-CoolingStochastic Pre-Cooling

E

t

bunch rotation

adiabatic debunching

stochastic cooling

DE/E = ± 3 % ± 0.75 % ± 0.5 % ± 0.1 %

50 ns

stack core stack tail

Cross section throught the vacuum chamber at the momentum pick-up

stochastic coolingfor stack core

RESR: Antiproton AccumulationRESR: Antiproton Accumulation

stack core stack tail

160 mm (p/p = 0.8 %)

stochastic coolingfor stack core

partial apertureinjection kicker

injected beamfrom CR

acceleration by HF

(not in resonance with stack)

Antiproton AccumulationAntiproton Accumulation

stack core stack tail

160 mm (p/p = 0.8 %)

stochastic coolingfor stack core

stochastic coolingfor beam deposit

(high amplification)

Antiproton AccumulationAntiproton Accumulation

stack core stack tail

160 mm (p/p = 0.8 %)

stochastic coolingfor stack core

Antiproton AccumulationAntiproton Accumulation

stack core

160 mm (p/p = 0.8 %)

deceleration by HF

Antiproton AccumulationAntiproton Accumulation

stack core

160 mm (p/p = 0.8 %)

extraction kicker

Antiproton AccumulationAntiproton Accumulation

FAIR / CERN / FNAL pbar SourcesFAIR / CERN / FNAL pbar Sources

cycle time 10 s (cooling time in the CR)overall pbar yield: 5 × 10-6 pbar/p (based on CERN data) → 1 × 107 pbar/s

Increases the pbar yield by 50 %

FAIR Collector ring will be operated at h = 1, CERN ring was operated at h = 6

Time needed for stochastic cooling in CR (AC), upgrade possible

FAIR CERN (AC+AA) FNAL

E(p), E(pbar) 29 GeV, 3 GeV 25 GeV, 2.7 GeV 120 GeV, 8 GeV

acceptance 240 mm mrad 200 mm mrad 30 mm mrad

protons / pulse ≥ 2 × 1013 1 - 2 × 1013 ≥ 5 × 1012

pulse length single bunch (50 ns) 5 bunches in 400 ns single bunch 1.6 µs

cycle time 10 s 4.8 s 1.5 s

cycle time 10 s (cooling time in the CR)overall pbar yield: 1 × 10-5 pbar/p (based on CERN data) → 2 × 107 pbar/s

Target StationTarget Station

Target Exchange (target on air!)Target Exchange (target on air!)

Target StationTarget Station

Dose rates around the pbar targetDose rates around the pbar target

170 m

Fluka input, top viewFluka input, top view

air concrete irongraphite vacuum

Super

NESR

FRS

SIS18

CRRESRatomic physics

targetfrom SIS 100

Equivalent dose rates during operationEquivalent dose rates during operation

Equivalent Dose rate [Sv/h],2 × 1013 protons per pulse, 0.1 Hz

Induced Activity after Shut-DownInduced Activity after Shut-Down

airplane at 12000 m

Induced Activity after Shut-DownInduced Activity after Shut-Down

vertical section 4 m downstream of target

air concrete iron

SummarySummary

• Yield (target / horn / separator): 11 cm Ni-target, copy of CERN horn ~ 2 × 10-5 pbar per primary proton (4 × 107 pbar / s)

• Yield (out of RESR): ~ 1 × 10-5 pbar per primary proton (2 × 107 pbar / s)

• No significant increase of this number can be expected with another type of collector like a Li-lens.

• time averaged, less than 1 kW is deposited in the target higher repetition rate should be no problem

• Radiation protection: no principal problems up to now