Monte-Carlo simulations of thermal neutron filter and

neutron guide system for REVERANS reflectometer

Peter Konik

Petersburg Nuclear Physics Institute, Gatchina, RussiaSaint-Petersburg State University, Saint-Petersburg, Russia

Our facilities

REVERANS reflectometer

Thermal neutron filter

Neutron guide

Current work

Conclusion

Contents

Our facilities

WWR-M

Operational since 195918 MWt3·1014 n/cm2·s

PIK

First critical 2011100 MWt4.5·1015 n/cm2·s3 cold neutron sources1 hot neutron source50 instruments

Vertical scattering plane Both free and interface surfaces Phase boundaries Liquids, solutions, suspensions, colloid

solutions of nanoparticles, liquid crystals

REVERANS reflectometer

REVERANS at WWR-M

+ more neutrons- direct view

Thermal neutron filter

MC simulations

Collimator and filter width 28 mm

Entry window height 80 mm

Exit window height 13.3 mm

Number of collimator channels

3

Entry collimator length 1.77 m

Exit collimator length 1.5 m

Mirror coating m = 2.25

Mirror width 0.38 mm

Critical wavelength 6 Å

PIK neutron guide hall

Guide simulations

-0.06 -0.04 -0.02 0 0.02 0.04 0.06

-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0.1

x [m]

[ReactorTubeXY] ReactorTube.XY: Intensity Position Position Monitor (Square) per bin I Ierr N=[1.03797 0.000341065 9.26192e+006]

Min=0; Max=4.23222e-005; Mean= 2.59492e-005; X0=2.77173e-006; dX=0.0346387; Y0=-7.0141e-006; dY=0.0576173;

y [m

]

0

0.5

1

1.5

2

2.5

3

3.5

4

x 10-5

-3 -2 -1 0 1 2 3-8

-6

-4

-2

0

2

4

6

8

[ReactorTubedXdY] ReactorTube.dXdY: Intensity Divergence Divergence Monitor (Square) per bin I Ierr N=[1.03797 0.000341065 9.26192e+006]

Min=0; Max=0.000176385; Mean= 2.59492e-005; X0=0.000416564; dX=0.975999; Y0=0.000104928; dY=2.4769;

Hor. Divergence [deg]

V

ert.

Div

erge

nce

[deg

]

2

4

6

8

10

12

14

16

x 10-5

-0.06 -0.04 -0.02 0 0.02 0.04 0.06

-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0.1

[Coll4XY] Coll4.XY: Intensity Position Position Monitor (Square) per bin I Ierr N=[0.0518884 7.10727e-005 1.00685e+006]

Min=0; Max=1.03948e-005; Mean= 1.29721e-006; X0=1.01155e-005; dX=0.00875294; Y0=0.000123982; dY=0.0570388;

x [m]

y [m

]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

x 10-5

Guide simulations

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

[Coll4dXdY] Coll4.dXdY: Intensity Divergence Divergence Monitor (Square) per bin I Ierr N=[0.0464921 6.87967e-005 729792]

Min=2.51253e-024; Max=4.66167e-006; Mean= 1.1623e-006; X0=-0.000604858; dX=0.437428; Y0=0.000314909; dY=0.601589;

Hor. Divergence [deg]

V

ert.

Div

erge

nce

[deg

]0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

x 10-6

Guide simulations

-0.02 -0.015 -0.01 -0.005 0 0.005 0.01 0.015 0.02-0.03

-0.02

-0.01

0

0.01

0.02

0.03

[BenderR1XY] BenderR1.XY: Intensity Position Position Monitor (Square) per bin I Ierr N=[0.00976103 3.02274e-005 223776]

Min=0; Max=1.60163e-006; Mean= 2.44026e-007; X0=0.000126811; dX=0.00898632; Y0=8.71252e-006; dY=0.0144685;

x [m]

y [m

]

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6x 10

-6

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

[BenderR1dXdY] BenderR1.dXdY: Intensity Divergence Divergence Monitor (Square) per bin I Ierr N=[0.00976103 3.02274e-005 221347]

Min=0; Max=2.99619e-006; Mean= 2.44026e-007; X0=-0.000615002; dX=0.451814; Y0=-0.00760648; dY=0.5982;

Hor. Divergence [deg]

Ver

t. D

iver

genc

e [d

eg]

0

0.5

1

1.5

2

2.5

x 10-6

Divergence!

Hyperbolic mirror (i)

Cassegrain reflector

Hyperbolic mirror (ii)

0 10 20 30 400

5

10

15

20

25

30

Angle between beam direction and axe, deg

e = 0.8

m valuedivergence increase

0 5 10 15 20 25 300

5

10

15

20

25

30

Angle between beam direction and axe, deg

e = 0.5

m valuedivergence increse

MC simulation allow to:

Find optimal parameters

Handle complex geometry guides

Simulate new optical elements

Conclusion

Dr. Evgeny Moskvin

Vladimir Zabenkin

Dr. Alexander Ioffe

Acknowledgement

Thank you for attention!