Activation Calculation for the Robinson Wiggler at the Metrology - - PowerPoint PPT Presentation

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Activation Calculation for the Robinson Wiggler at the Metrology - - PowerPoint PPT Presentation

Nov 22, 2022 158 likes •342 views

Activation Calculation for the Robinson Wiggler at the Metrology Light Source Y. Bergmann, K. Ott Helmholtz- Zentrum Berlin yvonne.bergmann@helmholtz-berlin.de 9th Int. Workshop on Radiation Safety at Synchrotron Radiation Sources RADSYNCH

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  • Y. Bergmann, K. Ott

Helmholtz- Zentrum Berlin

yvonne.bergmann@helmholtz-berlin.de

Activation Calculation for the Robinson Wiggler at the Metrology Light Source

9th Int. Workshop on Radiation Safety at Synchrotron Radiation Sources RADSYNCH 2017, NSRRC Taiwan

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MAP OF THE AREA

RadSynch 2017, NSRRC, Taiwan

BESSY II MLS bERLinPro

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OUTLINE

  • Overview Metrology Light Source
  • Development of the Robinson Wiggler
  • Activation Calculation
  • Calculation with FLUKA
  • Summary and Outlook

RadSynch 2017, NSRRC, Taiwan

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OVERVIEW MLS

RadSynch 2017, NSRRC, Taiwan

Microtron Transfer line Undulator U125 Injection Septum Cavity

MLS – KEY FIGURES

Energy E [MeV] 50 to 629 Circumference [m] 48 Beam Current I [mA] 1e-9 to 200 Beam Lifetime (150 mA) [h] 6 Cavity Voltage [kV] 500 Horizontal Emittance [nm rad] 117 Magnetic Field B [T] 1.3 Bending Radius R [m] 1.5

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  • lifetime (Lt) fundamental for users of synchrotron radiation
  • 2012 Standard user optic at MLS: Lt = 3,5 h at 150 mA
  • 2014 change magnet optics  new user optics: Lt = 6 h at 150 mA
  • lifetime at MLS dominated by Touschek effect
  • to increase lifetime  improve Touschek lifetime
  • Touschek lifetime depends on bunch size and length
  • Redistributing damping partition of beam  incr. bunch length  incr. Lt
  • Solution for existing accelerator

 ID consisting of alternating combined function magnets

A ROBINSON WIGGLER FOR THE MLS

RadSynch 2017, NSRRC, Taiwan

Robinson Wiggler

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RadSynch 2017, NSRRC, Taiwan

  • normal conducting Robinson Wiggler will consist of twelve poles, incl. endpoles
  • to achieve necessary high field strengths use Cobalt-Iron steel (AFK502) for yoke
  • AFK502: compound of 49% Fe, 49% Co, and 2% V

A ROBINSON WIGGLER FOR THE MLS

  • 1 available straight section at MLS
  • section of 2.5 m lengths

Gray: ferromagnetic yoke, copper: coils Poles have hyperbolic shape in horizontal direction, giving rise to linear, horizontal field gradient

Robinson Wiggler max. 1.74 m

  • Design studies show:
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at electron accelerators Bremsstrahlung and electron losses induce gamma-radiation  leads to neutron radiation and activation

MOTIVATION – ACTIVATION AT ACCELERATORS

RadSynch 2017, NSRRC, Taiwan

Activation is a serious hazard since the radiation remains after switching off the accelerator. Consequences: Additional radiation exposition thermal neutrons  activation?

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MOTIVATION – CROSS SECTION

RadSynch 2017, NSRRC, Taiwan

Amount in yoke σ (n,γ) (25 meV) Fe 49% 2.6 barns Co 49% 37.2 barns V 2% 4.8 barns

High amount of Cobalt might get activated by beamloss

  • Neutron cross section express likelihood of interaction

between incident neutron and target

  • Thermal neutrons of great importance: cross section decrease by increasing kinetic energy
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Activation rate:

σ(EP): cross section EP: energy of photons Φ(EP, r).dEP: flux density of photons with energies between EP and EP+dE at r n=ρ.NL/A: number of nuclei per volume ρ: density of nuclei NA: avogadro constant = 6.022 E23 mol-1 A: mass number of nucleus

Activation Equation:

ν: number of irradiation periods λ = (ln2)/T1/2 (T1/2: half-life of nucleus) tB: irradtiation time tK: decay time

Activation rate can be calculated by FLUKA = 1 for one radiation period

(1) (2)

ACTIVATION CALCULATION

RadSynch 2017, NSRRC, Taiwan

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CALCULATION OF DOSE OF KNOWN REACTION 59Co + n  60Co*  60Co + γ

  • Assumption: cross section of Co predominantly for interaction with neutrons

N0 N(x) N0 = 1.6 E9 neutrons/year/yoke calculated by Fluka N ~ N0 N

RadSynch 2017, NSRRC, Taiwan

  • „method by hand“:
  • tB=1 year, tK= 0
  • N = 25 neutrons / sec
  • λ (60Co)=4.17 E-9 / sec

Activation (2) Av = 3.12 Bq / cm3

  • distance r of 10 cm
  • Γ(60Co) =

With

] [ ² 354 . GBq h m mSv  

With

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FLUKA CALCULATION: PRELIMINIARY CONSIDERATIONS

RadSynch 2017, NSRRC, Taiwan

  • 200 mA / injection
  • 1800 injections / year
  • revolution frequency 6.25 MHz
  • Injection efficiency ~ 20%

Loss of ~ 18 E14 electrons / year

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FLUKA CALCULATION: OUTPUT

RadSynch 2017, NSRRC, Taiwan

For every region of interest: generated resnucle-file Fluka Output in residual nuclei / pP code (aktiv2 by K. Ott) which identifies radionuclides (> 200) with A and Z and its activation Output: list of radionuklides and its activation

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RESULTS: RADIONUCLIDES AND ACTIVATION

RadSynch 2017, NSRRC, Taiwan

Nuklid NK A∞ A(t) T (1/2) 1 _ 1 H 2,59E-06 8,21E+00 8,21E+00 stabil 2 _ 1 H 2,45E-08 7,77E-02 7,77E-02 stabil 3_1H 2,94E-09 9,33E-03 5,10E-04 12.323 a 4 _ 2 He 3,34E-07 1,06E+00 1,06E+00 stabil 46 _ 20 Ca 3,05E-10 9,68E-04 9,68E-04 stabil 47 _ 21 Sc 6,11E-10 1,94E-03 1,94E-03 3.35 d 49 _ 21 Sc 3,05E-10 9,68E-04 9,68E-04 57.2 min 47 _ 22 Ti 3,05E-10 9,68E-04 9,68E-04 stabil 48 _ 22 Ti 9,16E-10 2,91E-03 2,91E-03 stabil 49 _ 22 Ti 1,22E-09 3,87E-03 3,87E-03 stabil 50 _ 22 Ti 4,28E-09 1,36E-02 1,36E-02 stabil 51 _ 22 Ti 3,05E-10 9,68E-04 9,68E-04 5.8 m 48 _ 23 V 6,11E-10 1,94E-03 1,94E-03 15.97 d 49 _ 23 V 4,88E-09 1,55E-02 8,29E-03 330 d 51 _ 23 V 5,49E-09 1,74E-02 1,74E-02 stabil 52 _ 23 V 1,53E-09 4,84E-03 4,84E-03 3.75 m 49 _ 24 Cr 3,05E-10 9,68E-04 9,68E-04 42 m 50 _ 24 Cr 4,01E-09 1,27E-02 1,27E-02 stabil 51 _ 24 Cr 2,59E-08 8,23E-02 8,23E-02 27.7 d 52 _ 24 Cr 5,02E-08 1,59E-01 1,59E-01 stabil 53 _ 24 Cr 1,13E-07 3,57E-01 3,57E-01 stabil 54 _ 24 Cr 5,24E-09 1,66E-02 1,66E-02 stabil 55 _ 24 Cr 6,11E-10 1,94E-03 1,94E-03 3.5 m 52 _ 25 Mn 6,71E-09 2,13E-02 2,13E-02 5.6 d 53 _ 25 Mn 6,14E-08 1,95E-01 3,65E-08 3.7e6 a 54 _ 25 Mn 5,82E-07 1,85E+00 1,03E+00 312.2 d 55 _ 25 Mn 2,00E-07 6,34E-01 6,34E-01 stabil 56 _ 25 Mn 3,13E-07 9,91E-01 9,91E-01 2.58 h 57 _ 25 Mn 3,09E-09 9,79E-03 9,79E-03 1.5 m 58 _ 25 Mn 3,05E-10 9,68E-04 9,68E-04 65.3 s 52 _ 26 Fe 3,05E-10 9,68E-04 9,68E-04 8.27 h 53 _ 26 Fe 7,23E-09 2,29E-02 2,29E-02 8.51 m 54 _ 26 Fe 2,50E-06 7,94E+00 7,94E+00 stabil 55 _ 26 Fe 7,93E-07 2,52E+00 5,64E-01 2.73 a 56 _ 26 Fe 6,96E-05 2,21E+02 2,21E+02 stabil 57 _ 26 Fe 9,07E-06 2,88E+01 2,88E+01 stabil 58 _ 26 Fe 6,66E-07 2,11E+00 2,11E+00 stabil 59 _ 26 Fe 2,42E-07 7,67E-01 7,64E-01 44.503 d 56 _ 27 Co 6,10E-09 1,93E-02 1,86E-02 77.26 d 57 _ 27 Co 1,19E-07 3,77E-01 3,63E-01 271.79 d 58 _ 27 Co 8,20E-07 2,60E+00 2,53E+00 70.86 d 59 _ 27 Co 7,64E-05 2,42E+02 2,42E+02 stabil 60 _ 27 Co 3,21E-05 1,02E+02 1,25E+01 5.272 a 61 _ 28 Ni 4,40E-10 1,39E-03 1,39E-03 stabil 62 _ 28 Ni 2,65E-09 8,40E-03 8,40E-03 stabil 63 _ 28 Ni 8,47E-09 2,68E-02 1,85E-04 100 a 64 _ 29 Cu 8,48E-10 2,69E-03 2,69E-03 12.7 h 65 _ 29 Cu 1,83E-09 5,81E-03 5,81E-03 stabil 66 _ 29 Cu 1,00E-08 3,18E-02 3,18E-02 5.1 m 64 _ 30 Zn 8,00E-09 2,54E-02 2,54E-02 stabil 65 _ 30 Zn 2,13E-08 6,75E-02 4,35E-02 244.3 d 66 _ 30 Zn 3,27E-06 1,04E+01 1,04E+01 stabil 67 _ 30 Zn 3,07E-07 9,72E-01 9,72E-01 stabil

Beam 1 year no decay time

Nuklid NK A∞ A(t) T (1/2) 1 _ 1 H 2,59E-06 8,21E+00 8,21E+00 stabil 2 _ 1 H 2,45E-08 7,77E-02 7,77E-02 stabil 3_1H 2,94E-09 9,33E-03 5,10E-04 12.323 a 4 _ 2 He 3,34E-07 1,06E+00 1,06E+00 stabil 46 _ 20 Ca 3,05E-10 9,68E-04 9,68E-04 stabil A∞ 55 _ 24 Cr 6,11E-10 1,94E-03 1,94E-03 3.5 m 52 _ 25 Mn 6,71E-09 2,13E-02 2,13E-02 5.6 d 53 _ 25 Mn 6,14E-08 1,95E-01 3,65E-08 3.7e6 a 54 _ 25 Mn 5,82E-07 1,85E+00 1,03E+00 312.2 d 55 _ 25 Mn 2,00E-07 6,34E-01 6,34E-01 stabil 56 _ 25 Mn 3,13E-07 9,91E-01 9,91E-01 2.58 h 57 _ 25 Mn 3,09E-09 9,79E-03 9,79E-03 1.5 m A∞ 57 _ 27 Co 1,19E-07 3,77E-01 3,63E-01 271.79 d 58 _ 27 Co 8,20E-07 2,60E+00 2,53E+00 70.86 d 59 _ 27 Co 7,64E-05 2,42E+02 2,42E+02 stabil 60 _ 27 Co 3,21E-05 1,02E+02 1,25E+01 5.272 a 61 _ 28 Ni 4,40E-10 1,39E-03 1,39E-03 stabil 62 _ 28 Ni 2,65E-09 8,40E-03 8,40E-03 stabil

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RESULTS: RADIONUCLIDES AND ACTIVATION

RadSynch 2017, NSRRC, Taiwan

Nuklid NK A∞ A(t) T (1/2) 1 _ 1 H 2,59E-06 8,21E+00 0,00E+00 stabil 2 _ 1 H 2,45E-08 7,77E-02 0,00E+00 stabil 3_1H 2,94E-09 9,33E-03 4,83E-04 12.323 a 4 _ 2 He 3,34E-07 1,06E+00 0,00E+00 stabil 46 _ 20 Ca 3,05E-10 9,68E-04 0,00E+00 stabil 47 _ 21 Sc 6,11E-10 1,94E-03 3,08E-36 3.35 d 49 _ 21 Sc 3,05E-10 9,68E-04 0,00E+00 57.2 min 47 _ 22 Ti 3,05E-10 9,68E-04 0,00E+00 stabil 48 _ 22 Ti 9,16E-10 2,91E-03 0,00E+00 stabil 49 _ 22 Ti 1,22E-09 3,87E-03 0,00E+00 stabil 50 _ 22 Ti 4,28E-09 1,36E-02 0,00E+00 stabil 51 _ 22 Ti 3,05E-10 9,68E-04 0,00E+00 5.8 m 48 _ 23 V 6,11E-10 1,94E-03 2,55E-10 15.97 d 49 _ 23 V 4,88E-09 1,55E-02 3,85E-03 330 d 51 _ 23 V 5,49E-09 1,74E-02 0,00E+00 stabil 52 _ 23 V 1,53E-09 4,84E-03 0,00E+00 3.75 m 49 _ 24 Cr 3,05E-10 9,68E-04 0,00E+00 42 m 50 _ 24 Cr 4,01E-09 1,27E-02 0,00E+00 stabil 51 _ 24 Cr 2,59E-08 8,23E-02 8,88E-06 27.7 d 52 _ 24 Cr 5,02E-08 1,59E-01 0,00E+00 stabil 53 _ 24 Cr 1,13E-07 3,57E-01 0,00E+00 stabil 54 _ 24 Cr 5,24E-09 1,66E-02 0,00E+00 stabil 55 _ 24 Cr 6,11E-10 1,94E-03 0,00E+00 3.5 m 52 _ 25 Mn 6,71E-09 2,13E-02 5,09E-22 5.6 d 53 _ 25 Mn 6,14E-08 1,95E-01 3,65E-08 3.7e6 a 54 _ 25 Mn 5,82E-07 1,85E+00 4,56E-01 312.2 d 55 _ 25 Mn 2,00E-07 6,34E-01 0,00E+00 stabil 56 _ 25 Mn 3,13E-07 9,91E-01 0,00E+00 2.58 h 57 _ 25 Mn 3,09E-09 9,79E-03 0,00E+00 1.5 m 58 _ 25 Mn 3,05E-10 9,68E-04 0,00E+00 65.3 s 52 _ 26 Fe 3,05E-10 9,68E-04 1,334E-322 8.27 h 53 _ 26 Fe 7,23E-09 2,29E-02 0,00E+00 8.51 m 54 _ 26 Fe 2,50E-06 7,94E+00 0,00E+00 stabil 55 _ 26 Fe 7,93E-07 2,52E+00 4,38E-01 2.73 a 56 _ 26 Fe 6,96E-05 2,21E+02 0,00E+00 stabil 57 _ 26 Fe 9,07E-06 2,88E+01 0,00E+00 stabil 58 _ 26 Fe 6,66E-07 2,11E+00 0,00E+00 stabil 59 _ 26 Fe 2,42E-07 7,67E-01 2,60E-03 44.503 d 56 _ 27 Co 6,10E-09 1,93E-02 7,04E-04 77.26 d 57 _ 27 Co 1,19E-07 3,77E-01 1,37E-02 271.79 d 58 _ 27 Co 8,20E-07 2,60E+00 7,11E-02 70.86 d 59 _ 27 Co 7,64E-05 2,42E+02 0,00E+00 stabil 60 _ 27 Co 3,21E-05 1,02E+02 1,10E+01 5.272 a 61 _ 28 Ni 4,40E-10 1,39E-03 0,00E+00 stabil 62 _ 28 Ni 2,65E-09 8,40E-03 0,00E+00 stabil 63 _ 28 Ni 8,47E-09 2,68E-02 1,84E-04 100 a 64 _ 29 Cu 8,48E-10 2,69E-03 6,17E-211 12.7 h 65 _ 29 Cu 1,83E-09 5,81E-03 0,00E+00 stabil 66 _ 29 Cu 1,00E-08 3,18E-02 0,00E+00 5.1 m 64 _ 30 Zn 8,00E-09 2,54E-02 0,00E+00 stabil 65 _ 30 Zn 2,13E-08 6,75E-02 1,55E-02 244.3 d 66 _ 30 Zn 3,27E-06 1,04E+01 0,00E+00 stabil 67 _ 30 Zn 3,07E-07 9,72E-01 0,00E+00 stabil

Nuklid NK A∞ A(t) T (1/2) 1 _ 1 H 2,59E-06 8,21E+00 0,00E+00 stabil 2 _ 1 H 2,45E-08 7,77E-02 0,00E+00 stabil 3_1H 2,94E-09 9,33E-03 4,83E-04 12.323 a 4 _ 2 He 3,34E-07 1,06E+00 0,00E+00 stabil 46 _ 20 Ca 3,05E-10 9,68E-04 0,00E+00 stabil A∞ 55 _ 24 Cr 6,11E-10 1,94E-03 0,00E+00 3.5 m 52 _ 25 Mn 6,71E-09 2,13E-02 5,09E-22 5.6 d 53 _ 25 Mn 6,14E-08 1,95E-01 3,65E-08 3.7e6 a 54 _ 25 Mn 5,82E-07 1,85E+00 4,56E-01 312.2 d 55 _ 25 Mn 2,00E-07 6,34E-01 0,00E+00 stabil 56 _ 25 Mn 3,13E-07 9,91E-01 0,00E+00 2.58 h 57 _ 25 Mn 3,09E-09 9,79E-03 0,00E+00 1.5 m A∞ 57 _ 27 Co 1,19E-07 3,77E-01 1,37E-02 271.79 d 58 _ 27 Co 8,20E-07 2,60E+00 7,11E-02 70.86 d 59 _ 27 Co 7,64E-05 2,42E+02 0,00E+00 stabil 60 _ 27 Co 3,21E-05 1,02E+02 1,10E+01 5.272 a 61 _ 28 Ni 4,40E-10 1,39E-03 0,00E+00 stabil 62 _ 28 Ni 2,65E-09 8,40E-03 0,00E+00 stabil

Beam 1 year 1 year decay time

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RESULTS: COMPARISON WITH RADIATION PROTECTION ORDINANCE

RadSynch 2017, NSRRC, Taiwan

To release the Wiggler for recycling after removal, the limitation in the Radiation Protection Ordinance have to be observed.

Wiggler could not be recycled as metal scrap after removal!

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FLUKA: EQUIVALENT DOSE

Equivalent dose after decay time 1 Equivalent dose after decay time 2 etc.

Irradiation Profile

RADDECAY requests simulation of radioactive decays and sets the corresponding biasing and transport conditions Scoring:

RadSynch 2017, NSRRC, Taiwan

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FLUKA: EQUIVALENT DOSE AND COMPARISON OF METHODS

RadSynch 2017, NSRRC, Taiwan

gamma dose rate (pSv/h) after one year of operation for different decay times:

1 second 1 day 3 month 1 year A (Bq/cm3) Dose (pSv/h) Calculation by Hand 3.12 0.11 Calculation by programm 12 0.1

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SUMMARY / OUTLOOK

Thank you for your attention!

Summary

RadSynch 2017, NSRRC, Taiwan

  • Design studie for the Robinson Wiggler almost completed
  • Lifetime improvement between 60% and 100% (depending on operation mode)
  • Activation is not critical for operation
  • Recycling after removal at the earliest after a waiting period of at least 6.5 years

Next steps

  • Design of the final hardware layout
  • order Robionson Wiggler until 2017
  • installation until 2018