Experimental part:

• Measurement the energy deposition profile for U ions with energies E=100 MeV/u - 1 GeV/u in iron and copper.

• Measurement the residual activation doses induced by U ions of energies E=100MeV/u - 1 GeV/u in iron and copper targets.

A.Golubev

Project MeetingGSI

01.06.04.

INTAS Ref. # 03-54-3588 Experimental and Theoretical Study of Energy Deposition and Residual

Activation Induced by Uranium Ions to Model the Beam Loss Hazards in the GSI Future Facility

GSI, Darmstadt - GermanyITEP, Moscow - RussiaVNIIEF, Sarov - Russia

INR RAS, Troizk - RussiaSUT, Bratislava - Slovakia

"Thick target" approach for precise measurement of energy deposition profile dE/dx and total stopping range

• This method using thick targets of variable thickness, determined with high precision and registration of the energy deposition along the total ion stopping range by thin calorimeters detectors

• The precision of the method is determined by the detector parameters (energy resolution, registration efficiency, detection threshold, etc. depending on a detector type) the precision of the target thickness measurement.

I o n B e a m

d x

x

d E d x

This method has been developed in collaboration between ITEP, VNIIEF and GSI. GSI experiment S249.

Why need to use ‘thick target’ approach for measurement of total ion energy deposition ranges in solids

Because: it provides direct measurement of the energy deposition range, rather than its reconstruction from measured differential energy loss; it enables to eliminate the ‘edge effects’, as compared to ‘thin foil’ approach; it takes account of the beam straggling and fragmentation, secondary particles etc.

Scheme of the experimental setup

Cave A experimental area

Calorimeter-caseHeat-resistant panel

Body of thermostat

Thermoelectric modules

Cap

Thin-filmresistances

Receiving platform.

Calorimeter

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 due to its heating by the passing ion beam. The calorimeter is enclosed in a metal case and consists of a receiving platform made of a foil attached to thermo-modules, which are fixed on a massive thermostat. The size of the device is Ø50x11mm. The aperture of the calorimeter is Ø15 mm. The detector sensitivity is 5mV/J. The total stopping range is thus measured with the error less than 3%. The error of the specific deposited energy measurement is 7%.

6 8 10 12 14 160

10

20

30

40

50

60 950 MeV/u

Lenght, mm

dE/d

x, G

eV/m

mEnergy deposition of 238U+72ion beam in Cu

0 5 100

10

20

30

40

50

60

70

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

Lenght, mm

dE

/dx,

Ge

V/m

m

500 MeV/u

0 2 4 6 80

20

40

60

Energy deposition of 238U+72ion beam in Cu

dE

/dx,

Gev

/mm

Length, mm

500 MeV/u

5 10 150

10

20

30

40

50

60

70

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

Lenght, mm

dE

/dx,

Ge

V/m

m

950 MeV/u

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

0

10

20

30

40

50

60

70

80

6 8 10 12 14 16

depth, mm

dE

/dx, G

eV

/mm

MeasurementATIMASRIMSHIELD 1SHIELD 2

Measurement & Codes

Range, mm

Fe, 500 Cu, 500 Fe, 950 Cu 950

Measurement 5.9±0.2 5.3±0.2 14.3±0.4 12.8±0.4

ATIMA 6.1 (1.6%) 5.4 13.2 (7.7%) 13.4 (4.7%)

SRIM 6.5 (8.3%) 5.9 (9.4%) 16.1 (12.6%) 15.2 (18.6%)

SHIELD 5.9 5.4 15.1 (5.6%) 14.1 (10%)

0 500 1000 15000

20000

40000

60000

Me

V/m

m

Length, mm

U238 200 MeV/u in cupper foils target

• characterization of residual activity of selected components of the beam line (copper and stainless steel):

• dose rate measurements • radioactive nuclides identification for the thick copper and stainless steel targets irradiated by the U beam with 100 – 1000 MeV/u energies range;

• long time prediction of radioactive inventory around the beam transport system

Main topics of this research

Experimental investigation of the radioactivity of the solid matter induced by heavy ion beam irradiation

Experimental setup for the measurements of induced radioactivity after irradiation with heavy ion beams

N Material and configuration Initial energy of 238U ions and calculated range*

Target thickness, mm

Total dose on the target (ions) **

1 Fe – set of disks mm: 0.1, 0.5, 0.5

120 MeV/u –570.68 m (SRIM)

1.1 2.04*1011

2 Cu – set of 11 disks of 0.1 mm 120 MeV/u – 526.2 m (SRIM); 563 m (ATIMA)

1.1 3.32*1011

3 Fe – set of 35 disks mm: 0.1, 0.5, 0.1, 0.5, 0.5 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.1, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1.

500 MeV/u –6.28 mm (TRIM) 

11.9 ~2*1011

4 Cu – set of 34 disks mm: 0.1, 0.5, 0.1, 1, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.1, 0.1, 0.1, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1, 0.5, 0.5, 0.1

500 MeV/u –5.34 mm (ATIMA), 5.79 mm (SRIM)

11 ~2*1011

*Ranges were calculated with taking into account the energy losses in SEETRAM, 100 m Al window, and in 65 cm air; ** Preliminary estimated results

Results of calibration of beam current detector by different ion beams

Air

Al100 m

Secondaryelectron monitor

Ionizationchamber

600 mmTarget

“front“ surface (foil 0)

Vacuum

Ar Beam

50 mm

Targets for the Argon beam irradiation

Cu target set of disks mm:

Energy of 40Ar ions* and SRIM ranges

Target thickness

Total dose on the target (ions)

1,7, 1, 7, 1, 5, 1, 1, 1, 5, 1, 5, 1, 5, 1, 3, 1

500MeV/u 23.6 mm

47 mm 4.8*1011

1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 5, 1, 1, 1, 7, 1, 7, 1, 7, 1, 5, 1, 5, 1, 5, 1, 5, 1

800MeV/u 

47.74 mm

97 mm 1.2*1011

1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 5, 1

300MeV/u 10.64 mm

22 mm 3*1011

The one-millimeter foils were inserted after each thick disk, which allowed to obtained the spatial distribution of the activation rates in the copper target along the range. Besides that, the radionuclide spectra measurements were carried out for assembling. Based on these experimental data the predictions of the induced radioactivity of the accelerator equipment will made for continuous irradiation during normal operation.

Spatial distribution of activation rates of different nuclides in the copper target after 40Ar E0=800MeV/u irradiation.

0 20 40 60 80 1001E-11

2E-11

4E-11

6E-118E-111E-10

2E-10

4E-10

6E-108E-101E-9

2E-9

4E-9

6E-98E-9

TRIM tableAct

ivat

ion

rate

, (nu

clid

e)/(

initi

al io

n)

Depth in copper target, mm

7Be 46Sc

51Cr 54Mn

56Co 57Co

58Co

0

2

4

6

8

10

12

14

Energy loss, M

eV/(m

g/cm2)

Conclusion.

• Measurement the energy deposition profile for U ions with energiesE=100 MeV/u - 1 GeV/u in iron and copper are finished and the stage of processing data now

• Measurement the residual activation doses induced by U ions of energies E=100MeV/u - 1 GeV/u in iron and copper targets are started.