SPES -Thin target calculations:isotope production and

power deposition (ENEA-INFN Legnaro)

Carlo Petrovich

(ENEA, Bologna)

INFN – Legnaro, 24th January 2006

C. Petrovich - ENEA

Content:

- Description of the target configuration- Some evaluations for accuracy of the

MCNPX code- Simulations (by MCNPX) for:

1. power deposition

2. fission rates

3. fragmentation distribution

4. activation (FISPACT code)

C. Petrovich - ENEA

0

10

20

30

40

50

60

70

80

2 6 10 14 18 22 26 30 34 38 42 46 50Proton energy (MeV)

Sto

pp

ing

po

we

r (M

eV

cm

2 g

-1)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0F

iss

ion

cro

ss

-se

ctio

n (b

arn

)Stopping power

Fission cross-section

Stopping power & Fission cross-section for protons on UCx

For lower power deposition in uranium keeping high fission rates:

High energy p+ in the UCx and low energy p+ towards a dump.

C. Petrovich - ENEA

Comparison MCNPX vs. experim. for 238U proton fiss.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

5 10 15 20 25 30 35 40 45 50 55

Proton energy (MeV)

cro

ss-s

ecti

on

(b

arn

)

MCNPX - BERTINI

MCNPX - CEM2k

Stevenson et al.

Baba et al.

Discrepancies for the fission cross-section lie in the range 10%-30%

C. Petrovich - ENEA

Caesium

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

130 132 134 136 138 140 142 144 146 148 150

A (mass number)

cros

s-se

ctio

n (m

b)

exp. Tracy et al.

RAL model

ORNL model

Comparison MCNPX vs. experim. for 40 MeV

C. Petrovich - ENEA

Rubidium

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102

A (mass number)

cros

s-se

ctio

n (m

b)

exp. Tracy et al.

RAL model

ORNL model

Comparison MCNPX vs. experim. for 40 MeV

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~580 Watt / UCx disk

7.6·1012 fissions/s 1.5 ·1013 atoms/s

Carbon Window

proton

UCx disks Carbon Dump

1-step thin target configuration

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Data to be confirmed: radius? densities?

Beam proton energy 40 MeV

Beam current 0.2 mA

Beam profile Uniform circle with r=3 cm

Window Carbon, 1.75 g/cm3, 400 m

Target material UCx (U:C=1:4) , 2.5 g/cm3

Target disks 7 disks, r=3 cm, thickness=1.2-1.4 mm

Dump material Carbon, 1.75 g/cm3

Dump disks 3 disks, r=3 cm, thickness=0.8-1 mm

External box Carbon, 1.75 g/cm3

C. Petrovich - ENEA

1.E+09

1.E+10

1.E+11

1.E+12

60 70 80 90 100 110 120 130 140 150 160 170

Mass number (A)

Ato

m p

rodu

ctio

n pe

r sec

ond

(s-1

)Mass distribution (in-target)

MCNPX-ORNL (Oak-Ridge National Laboratory) model

C. Petrovich - ENEA

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

104 108 112 116 120 124 128 132 136 140 144 148

A (mass number)

Isot

ope

per s

econ

d pr

oduc

ed (s

-1)

Ag

Sn

Cs

Mass distribution (in-target)MCNPX-ORNL (Oak-Ridge National Laboratory) model

132Sn produced: ~109 s-1

C. Petrovich - ENEA

0.0E+00

2.0E+12

4.0E+12

6.0E+12

8.0E+12

1.0E+13

1.2E+13

1.4E+13

1.6E+13

1.8E+13

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Irradiation time (days)

Ac

tiv

ity

(B

q)

Induced target ACTIVITY during a full irradiation time of 1 month (warning: 30% of the atoms/sec not included in the code. No tritium)

after 1 hour: ~8·1012 Bq (= 2·1014 Bq/kg)

after 1 month: ~1·1013 Bq. (= 4·1014 Bq/kg), ~1016 H3 atoms, ~2·10-4 gr.of Pu

C. Petrovich - ENEA

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+13

1.E+14

1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02

Cooling time (years)

Ac

tiv

ity

(B

q)

ACTIVITY of the UCx discs during cooling(after irradiation of 1 month)