The energy deposition profile for 238U ions with energies 500 and 950 MeV/u in iron and copper.

A.A.Golubev1, A.V.Kantsyrev1, V.E.Luckjashin1, A.D.Fertman1,1 Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia;

A.V.Kunin2, V.V.Vatulin2, Yu.V.Panova2, 2Russian Federal Nuclear Center - All-Russia Research Institute of

Experimental Physics (RFNC-VNIIEF), Sarov, Russia;

E.Mustafin3, D.Schardt3, K.Weyrich3, I.Hofmann3, 3 Gesellschaft fur Schwerionenforschung (GSI), Darmstadt, Germany;

N.M.Sobolevsky4, L.N.Latysheva4.4 Institute for Nuclear Research of Russian Academy of Sciences (INR RAS),

Moscow, Russia.

Introduction

We present the results of precision measurement of the energy deposition profile of the U ions of energy E=500 and 950 MeV/u in copper and stainless steel targets performed in GSI. Comparison of the measured data with the dE/dx calculations using the ATIMA, SRIM and SHIELD codes is discussed.

These data are important for the design of the SIS-100 and SIS-300 synchrotrons of the GSI FAIR Project, as well as in various fields of fundamental and applied science, in particular for studies of high density energy contribution in a matter produced by heavy ion beams.

I o n B e a m

d x

x

d E d x

The ‘thick target’ method and its advantages: 1) it provides a direct measurement of the energy deposition function, rather than its reconstruction from the differential energy deposition measurements using thin foils; 2) it eliminates the ‘edge effects’ as compared to the ‘thin foil’ approach; 3) it takes into account the beam straggling and fragmentation, secondary particles etc.

The target consists of two wedges, with precise control of the angle (50) and surfaces of optical quality. The gap between the two wedges is about ~100m. Manipulator consist of the linear motor actuator, the control unit and a PC with software. The axial resolution of the manipulator is about 50m. This allows to set the total thickness of the wedges with a precision of about 2 m.

Calorimeter-caseHeat-resistant panel

Body of thermostat

Thermoelectric modules

Cap

Thin-filmresistances

Receiving platform.

0 5 10 15 20 250

20

40

60

80

100

Triger Calorimeter#1-4 Al thick 150 µm

Am

plitu

de, µ

V

Time, sec.

The calorimeter measures the change of temperature in a thin layer of material (Receiving platform) due to heating by the ion beam. Two thermo-elements transform the temperature increment to the electrical signal. The foil thickness is less than 1% of the total stopping range. The calorimeter is enclosed in a metal case, thermo-modules are fixed in a massive thermostat. The size of the device is Ø50x11mm, the aperture is Ø15 mm, The error of deposited energy measurement is 7%.

The oscilloscope is used to record the signal from the calorimeter. The time of growth of the signal amplitude (~3 s) is defined by the rate of dissipation of absorbed thermal energy in the volume of the foil. Then the temperature of the foil starts to decrease exponentially. The time constant of the calorimeter (of signal decreasing e times) is ~10 s. The sensitivity is 5mV/J.

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

Depth, mm

Energy deposition of 238U+72ion beam in Cu

dE

/dx,

Ge

V/m

m 500 MeV/u

6 7 8 9 10 11 12 13 14 15 160

10

20

30

40

50

60

70

950 MeV/u

Depth, mm

dE/d

x, G

eV/m

m

Energy deposition of 238U+72ion beam in Cu

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

Energy deposition of 238U+72ion beam in stainless steel

Depth, mm

dE/d

x, G

eV/m

m

500 MeV/u

6 7 8 9 10 11 12 13 14 15 160

10

20

30

40

50

60

70

Energy deposition of 238U+72ion beam in stainless steel

Depth, mm

dE/d

x, G

eV/m

m

950 MeV/u

500

Me

V/u

950

Me

V/u

Copper Stainless steel

Energy deposition profile of U ions of energy E = 950 MeV/u in Cu target

0

10

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6 8 10 12 14 16

depth, mm

dE

/dx,

GeV

/mm

MeasurementATIMASRIMSHIELD 1SHIELD 2

Ti 30 m Al 100 m Al 250 m Al 1

00

mA

l 150

m

Cu Target

Variablethickness

IonBeam Monitor Calorimeter

foil

IonBeam

SHIELD 1

SHIELD 2

Cu cylinder

0 5 10 15 20 25 300,0

0,5

1,0

1,5

2,0

238U(950 MeV/u) in Copper

dE/d

X,

rel.u

nits

Depth, mm

Generations Total Primary Second Third Fourth

0 5 10 15 20 25 3010-3

10-2

10-1

100

101

238U(950 MeV/u) in Copper

dE/d

X,

rel.u

nits

Depth, mm

Generations Total Primary Second Third Fourth

Contribution to energy deposition from various generations of secondary particles and fragments in Copper target. Calculation with the SHIELD code.

Conclusion

1. Precision measurements of the energy deposition by 238U ions of E=500 MeV/u and 950 MeV/u in Copper and Stainless steel were performed at the GSI SIS18 facility.

2. Detailed comparison of the measurement with calculations using the ATIMA, SRIM and SHIELD codes for the case of 950 MeV/u U-ions in Copper was performed.

3. On the plateau the energy deposition calculated with the SHIELD code underestimates the measured values of about 20-30% while the ATIMA code agrees with the measurement well.

4. The height of the Bragg curve in the peak from ATIMA and SHIELD coincides with the measurement within experimental accuracy.

5. The stop range calculated by ATIMA agrees with the measured range within 3%. The discrepancy of the range calculated with SHIELD is about 10% and with SRIM is about 15%.

6. Calculation of the stopping power for heavy ions in the SHIELD code according to Bethe-Bloch equation should be updated.

4. Ionization loss, fluctuation of ionization loss and multiple Coulomb scattering of charged hadrons and nuclear fragments.

5. 2- and 3-particle modes of meson decay.

6. Modeling of hA- и AA-interactions in exclusive approach (MSDM-generator). 5

1. Transport of N, , K, N and arbitrary nuclei (A,Z) up to 1 TeV/u.

2. Extended target as a combination of bodies limited by second order.surfaces (CG-compatible)

3. Arbitrary chemical and isotope composition of materials in the target zones.

7. Memorizing of each hadron cascade tree during its simulation without loss of physical information.

8. Storing of sources of , e, e+ and of neutrons (En<14.5 MeV) during simulation of the hadron cascade.55

9. Neutron transport (En<14.5 MeV) on the basis of the28-groups ABBN neutron data library.

10. Analog and weighted simulation modes, open architecture of the code

Recent version of the SHIELD code

Modeling of inelastic hA- и AA-interactions (MSDM – Multi Stage Dynamical Model)

Fast, cascade stage of nuclear reaction:• DCM (Dubna Cascade Model ) [1]• Independent Quark-Gluon String Model (QGSM) [2,3]• Coalescence model [1]

Pre-equilibrium emission of nucleons and lightest nuclei [4]

Equilibrium deexitation of residual nucleus:• Fermi break up of light nuclei [5]• Evaporation/Fission [5,6]• Multifragmentation of higly excited nuclei (SMM) [7]

1. V.D.Toneev, K.K.Gudima, Nucl. Phys. A400 (1983) 173c.

2. N.S.Amelin, К.К.Gudima, V.D.Toneev. Yad.Fiz. 51 (1990) 1730 (in Russian). 3. N.S.Amelin, К.К.Gudima, S.Yu.Sivoklokov, V.D.Toneev. Yad.Fiz. 52 (1990) 272 (in Russian).4. K.K.Gudima, S.G.Mashnik, V.D. Toneev, Nucl. Phys. A401 (1983) 329. 5. A.S.Botvina, A.S.Iljinov, I.N.Mishustin et al., Nucl. Phys. A475 (1987) 663.6. G.D.Adeev, A.S.Botvina, A.S.Iljinov et al. Preprint INR, 816/93, Moscow, 1993. 7. Botvina, A.S. Iljinov and I.N. Mishustin, Nucl.Phys. A507 (1990) 649.

Cross sections of NA-, A- and AA-interactions: V.S.Barashenkov, A.Polanski. Electronic Guide for Nuclear Cross Sections. JINR E2‑94‑417, Dubna, 1994. Cross sections of KA- и NA-interactions: B.S.Sychev et al. Report ISTC, Project 187, 1999.

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H - 202 MeV/u

4He - 200 MeV/u

7Li - 234 MeV/u

11B - 329 MeV/u

12C - 391 MeV/u

dE/dz [MeV/cm/projectile]

Depth [cm]

SHIELD-HIT energy deposition

into water

Ion beam

2030 cm, step 1 mm

Water target

SHIELD-HIT (Heavy Ion Therapy): medical version of the SHIELD.

1.Fluctuations of energy loss and multiple Coulomb scattering are taken into account.

2.Stopping power calculation dE/dx according to ICRU49 (1993).

3.Detailed energy grids for more precise interpolation of particle ranges and cross sections.

Track length estimation of fluences of all particles in all target zones.

5.Possibility to «switch off» various physics processes etc.

2 3 4 5 6 7 8 9 100.0

0.1

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0.5

Ene

rgy

depo

sitio

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rmal

ized

to

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inte

gral

Depth, cm

Proton 111.3 MeV/u in water target

SHIELD-HIT exp TRIUMF

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0,01

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Projectiles12C, 14N, 16O670 MeV/u

in water target

SHIELD-12CSHIELD-14NSHIELD-16OGSI exp 12CGSI exp 14NGSI exp 16O

Fra

gm

ent

per

Pro

ject

ile

Depth (cm)

Seconday fragments Z = 5

0 4 8 12 16 20 24 2810-3

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10-1

100

12C in waterSHIELD-HIT vs EXPERIMENT

330 MeV/uexp GSI

290 MeV/uexp HIMAC

195 MeV/uexp GSI

Ene

rgy

depo

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nno

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ized

to

the

inte

gral

Depth, cm

Comparison with experiment

4 6 8 10 12 14 16 18 20 22 240.00

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ber

of P

ET

isot

opes

norm

aliz

ed t

o th

e in

tegr

al

Depth, cm

20Ne 406 MeV/u in PMMA

exp GSI SHIELD-HIT

SHIELD LAHET

Target 667 670

Blanket (total)Rod №1Rod №2Rod №13Rod №14

583 26.9 30.8 10.9 14.6

607 28.1 33.0 11.0 14.6

Whole assembly 1250 1280

Integral energy deposition (MeV/proton)

Energy deposition into lead-uranium assembly under irradiation by 1.5 GeV proton beam (The Project «Energy+Transmutation»)

Target – lead cylinder,size 8.87см50см,mass 35 кг

Blanket – 30 rods3.6см20.8см, NatUin aluminum envelop0.5 mm, mass 103 кг.

Proton energy 1.5 ГэВ

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Yie

ld, (

n/ s

r pr

ojec

tile)

Yield, (n/GeV sr projectile)

Neutron energy, GeV

=0o

Exp GSI Calc SHIELD

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ld, n

/(G

eV s

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ojec

tile)

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=7.5o

Exp GSI Calc SHIELD

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ld, n

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tile)

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Exp GSI Calc SHIELD

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ctile

)

Neutron energy, GeV

=30o

Exp GSI Calc SHIELD

10-3 10-2 10-1 10010-2

10-1

100

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Yie

ld, n

/(G

eV

sr

proj

ect

ile)

Neutron energy, GeV

=50o

Exp GSI Calc SHIELD

10-3 10-2 10-1 10010-2

10-1

100

101

102

103

Yie

ld, n

/(G

eV

sr

proj

ect

ile)

Neutron energy, GeV

=90o

Exp GSI Calc SHIELD

R=491.3 cm (R‘90=370.0 cm)

238U1GeV/u

r=4.575 cmS=65.76 cm2

n

n

Iron target101020 cm

Differential neutron yield from iron target (101020 см) under irradiation by 1 GeV/u 238U ion beam

3.3 м

X

Z

Z

Y

Детектор CsJ

Al-плита

Вакуум Штанга

Satellite Coronas

OS Mir

International Spase station (full configuration)

10-2 10-1 100 101 102 103 104 105

10-5

10-4

10-3

10-2

10-1

100

101

102

103

104

1/(m2 sr sec MeV)

Energy, MeV

OS MIR GCR-1996 Proton ("Spectr") Neutron ("Spectr")

10-2 10-1 100 101 102 103 10410-4

10-3

10-2

10-1

100

101

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104

Neutron/(m2 sr sec MeV)

Neutron energy, MeV

GCR-1996 Coronas MIR ("Crystall") ISS (Airlock)

10-2 10-1 100 101 102 10310-5

10-4

10-3

10-2

10-1

100

101

Neutron/(cm2 sec MeV)

Neutron energy, MeV

MIR, Solar max. (1990-92) Exp. onboard OS MIR SHIELD ("Spectr")

(Both behind 20 g/cm2 of Al)

Proton and neutron fluxes in the “Spectr” module of OA Mir under GCR 1996 irradiation

Neutron fluxes at Satellite “Coronas”, OS Mir (the “Cristall” module) and at Airlock of ISS under GCR 1996 irradiation.

Comparison of caculated and measured neutron fluxes at OS Mir behind 20 g/cm2 Al depth at solar max.