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Neutron induced reaction and neutron sources

Introduction to Nuclear Science

Simon Fraser UniversitySpring 2011

NUCS 342 — April 6, 2011

NUCS 342 (Lecture 29) April 6, 2011 1 / 29

Outline

1 Neutron-induced reactions

2 Radionuclide neutron sources

3 Accelerator neutron sources

4 The SIMON project at SFU


Neutron-induced reactions

Nuclear reactions on Earth

Chemical reaction are commonly observed in the Earth environment.

There are, however, very few nuclear reactions occurring on Earth.

There are two reasons accounting for that fact

Nuclear reactions between charged ions (for example proton-inducedreactions) need to overcome the Coulomb barrier. There is not enoughthermal energy at standard temperatures to achieve that.

Neutrons, which can penetrate into a nucleus without the Coulombbarrier at standard temperatures, have 614 s (∼ 10 min) half-life andare present in the environment with extremely low quantities.

Nuclear reactions induced by cosmic rays in the upper parts of theatmosphere are the source of radio nuclides (14C) in the environment.

Nuclear decays are commonly observed.


Neutron-induced reactions

Man-made sources of neutrons

The lack of Coulomb barrier makes neutrons very attractive tool fornuclear transmutation.

Short neutron lifetime prompted development of man made sourcesof neutrons.

These sources fall into four general categories:

Neutrons can be produced by nuclear reactions induced by α particlesfrom naturally occurring α emitters.

Neutrons can be produced by nuclear reaction induced by acceleratedbeams of light ions.

Neutrons can be produced from a spallation reaction.

Neutrons can be produced from fission.

These different categories provide sources of various characteristicsand can be selected and tuned for specific applications.


Radionuclide neutron sources

Pu-Be neutron source

Let us calculate the Coulomb barrier for the reaction of α particles onberyllium

VC = 1.442 · 4

1.2(3√9 +

3√4)= 2.6 [MeV] (1)

This implies that for most of naturally occurring α emitters the energyof α particles is high enough to induce nuclear transmutation ofberyllium.

Such mixtures are useful neutron sources since

9Be + α→13 C →12 C + n (2)

A popular source is a mixture of 241Pu with 9Be.

It produces 30 neutrons per million of emitted α particles.




Other radionuclide neutron sources are

Radionuclide T1/2 Neutron Yield [n/Ci]210Po 138 d 2.5×106

238Pu 87.8 y 2.2×106

241Am 433 y 2.2×106

242Cm 163 d 2.5×106

252Cf 2.65 y 4.3×109

The decay rate conversion is 1 Ci = 3.7 ×1010Bq = 37 billion decaysper second.

The emission of neutrons is isotropic, meaning has equal probabilityin any direction.


Accelerator neutron sources

Light ion reactions producing neutrons

A number of nuclear reaction producing neutrons in the final statehave been identified.

The most common are

d + d → n +3 He Q = 3.25 MeV

d + t → n + α Q = 17.60 MeV

p +7 Li→ n +7 Be Q = −1.65 MeV

d +9 Be → n +10 B Q = 3.79 MeV

The light ion beams are accelerated to the energies slightly above theCoulomb barrier by charged particle accelerators.

Reaction kinematics can be used to tune the outgoing neutron energybased on the energy of the incoming beam.



Van de Graaff accelerator



Tandem Van de Graaff accelerator



Reaction kinematics and neutron energy

Let us consider the reaction

p +7 Li→ n +7 Be Q = −1.65 MeV

For the neutrons emitted at zero degree

~pp = ~pn + ~p7Be

~p7Be = ~pn − ~pp

p27Be = p2

n + p2p − 2

√pppn

But the energy momentum relation gives

T =p2

2m=⇒ p2 = 2Tm (3)

Which leads t0

7T7Be = Tn + Tp − 2√

TpTn (4)



Reaction kinematics and neutron energy

The Q value definition gives

Q = T7Be + Tn − Tp (5)

Combining the above with

7T7Be = Tn + Tp − 2√

TpTn (6)

leads to

7(Q − Tn + Tp) = Tn + Tp − 2√

TpTn

8Tn − 6Tp − 2√

TpTn = 7Q = −11.52 MeV (7)

The solution of the above equation gives energy of themono-energetic neutron beam as a function of the incoming protonenergy.



Properties of neutrons from accelerator sources

Emission of neutrons from accelerator sources is anisotropic (notisotropic).

Reaction kinematics focuses neutrons in the direction of the incomingbeam.

On the top of that there is a correlation between the direction of aneutron and its energy, larger angles give smaller energy neutrons.

Neutron beams can be provided using collimation.

Neutron beam energies can be tuned using the energy of theincoming ions and energy-angle correlation.

Neutron beams are used for basic and applied research, in particular,studies of material properties.



The Spallation Neutron Source

The Spallation Neutron Source is an accelerator-based neutronsource that provides the most intense pulsed neutron beams in theworld for scientific and industrial research and development.

It is located in Oak Ridge Tennessee in US.

The accelerator is 1 GeV proton linear accelerator.

The beam is pulsed with the bunch time width of 1 µs.

The spallation target is liquid mercury.

20-30 neutrons are emitted per spallation.

Neutron beams are formed by slowing down in moderators and bycollimation.



Spallation Neutron Source Instruments



Sealed tube neutron generators

Sealed tube neutron generators are small accelerators whichgenerate neutrons via

d + d → n +3 He

d + t → n + α (8)



Sealed tube neutron generators

Sealed tube neutron generators are portable neutron sources.

They generate quasimonoenergetic beams of neutrons with 14.1 MeVenergy for the d/t and 2.5 MeV energy for the d/d.

Neutrons from the d/t generator are emitted isotropically, while for thed/d generator the emission is slightly focused towards the beamdirection.

Yields are on the order of 108 neutrons/s for the sealed tube d/tgenerators, a factor of 50-100 smaller for the d/d generators.

The use of radioactive tritium is a concern in application of d/tgenerators, this is a reason for the sealed tube solution.

Other technical implementations of d/t neutron generator can reachfluxes of 1011 particles per second.


The SIMON project at SFU

Nuclear Science facilities

The SFU’s Chemistry building is renovated as a part of the $50MChemistry building renovation funded by the provincial governmentand Industry Canada’s Knowledge Infrastructure Program.

Renovation will be completed in the spring of 2011, new laboratorieswill be operational in the summer of 2011.Nuclear Science facilities of ∼$750,000 value will include

A renovated underground radiation vault, ready to host a D/T or D/Dneutron generator.

A radio-chemistry laboratory above the vault, with a fume-hood,glove-box and other equipment set up for chemical reprocessing ofradioactive materials.

Conduits between the radiation vault and the radio-chemistry labdesigned to accommodate gas jet and a pneumatic system (a rabbit)for transportation of radioactive samples.

A separate laboratory for detector development and testing.



The radiation vault

F.E.

ELECTRICALC6063

12'-8"

25'-2"R.O.

10'-2"R.O.

25'-2"R.O.

18'-3"4'-10"10'-2"R.O.

169'-0"

33'-0" 18'-8" 18'-2"

75'-8"11'-0"

156'-6"

23'-3"

10'-0" 15'-2" 24'-6" 10'-8" 19'-4"

6'-8 3/4"

9'-4" 8'-8"

31'-1" 27'-10" 15'-7"

9'-3"

21'-3"

6'-0"CLEAR

6'-0"CLEAR

20'-4 3/4"

4'-2 1/2"TO NEW 6"DIA. HOLE

20'-4 3/4"

6'-0"CLEAR

FROM FACE OFEXISTING CONC.

2'-10"

2'-11"

4'-10"

4'-4 1/2"

7'-0"

3'-3"

10'-11"

W4.1

RWL

UP

EXISTINGNEUTRALIZATION

TANK

EXISTING LOCK BLOCKTO BE REMOVED

STAIR #6

W2.5

UP

C6072.1

SECURESTORAGE

NMRLOBBY

XRDSPEC-TRO-

SCOPY

EPR

MICROANALYSIS

OFFICE

EAD

NEUTRON LAB

STORAGE

MECHANICAL

FACILITIES/STORAGE

UP

C6070

C6072.1

C6072

C6076

C6078

C6079

C609

MASS SPECC6087C6082

C6087.2

C7078

C7078.1

C6065

CORRIDORC607

CORRIDORC606

STAIR #1C67 AIR WELL

GARBAGE/RECYCLING

C6074

MOSSBAUERC6061

8" CONC.CURB

RAMP

NIC

MSTECH

OFFICE

NMRTECH

OFFICE

C6087.1

SECUREMS LABC6087.3

CORRIDORC608

W6.1aW6.1 W6.1a W6.1 W6.1

3

W4.3

W4.5

6

6

6

W6.8

W6.8

W6.8

2A2.01

2A2.01

C607 C607A

C67

C608

C6084

C6087

C6087.1

C6087.2

C6065

C6065A

1A2.02

ELEVATOR #1

12

7

11

14 14 14

14

ELEVATORMACHINE

ROOMC6067

14

14

1311

17

ANNUNCIATOR

18

19 19

W3.2

W4.5

W2.5

W2.5

W2.2

W3.1

W3.2

W3.2

W3.2

W4.4 W2.5

W3.2

W2.2

W6.7W6.7

W3.2 W3.2 W3.2

W3.4 W3.4

W3.2

W2.1

W4.5

W1.2

W1.2W4.1

W6.7a

W6.7

W3.2

W3.2

W3.2

W4.3

W2.2

W3.2

W4.3

W4.5

W2.2

W2.5

W2.2

W2.2

W2.2

W2.2

W2.2

W2.2

W2.2

W4.3

W1.4

W2.5

W3.2

22 22

W6.7W6.8

FD

MECHANICALVENT ABOVE TO

COURTYARD

W4.4

14

C6085

IW1

IW2

IW2

IW2

IW2

IW3

W6.8

IW11

IW18

8" CONCRETECURB

26

27

D1.13

GATE

1A4.05

W6.2

W6.2

1

5

23

D1.02

D1.03

D2.27

IW19

SLAB SEPARATION (SHOWN DASHED); SEE D2.39

SLAB SEPARATION (SHOWN DASHED); SEE D2.39

3000 GALLONNITROGEN

TANK

VAPORIZER &REGULATOR

EXISTINGNEUTRALIZATION

TANK

W6.2

DOCKLIFT

(14" PIT) TRAFFICMEMBRANE

2

W6.8

W4.3

W4.3 W6.2

W3.4

W3.2

W4.3 W2.2

W2.1

1A4.01

W2.2

W4.5

W6.1

W4.3

NEW CONVEYOR BELT

JANITOR

W3.2

W4.4

D2.105

W6.11 W6.11W6.1 W6.1a

ZIP TUBE; SEE D5.01. STAIR #9

C76

1193

1190

18

STAIR #10DN7

8

A5.02 12

A5.04

1A5.04

2

35

W4.4 W4.4

W3.1ABOVE

W4.4 W3.4

W4.3 W4.3

W4.3

W4.3

3535

10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 6'-0" 6'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 5'-9" 10'-0" 10'-0" 10'-0" 10'-0"10'-0" 10'-0"

69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

10'-0

"10

'-0"

10' -0

"10

'-0"

10'-0

"10

'-0"

10'-0

"10

'-0"

10'-0

"10

'-0"

10' -0

"10

'-0"

Ga

Fa

Ea

Da

Ca

Ba

Aa

Z

Y

X

W

V

U

CHEMISTRY SOUTHSFU SHRUM RENEW

CHEMISTRY NORTH

MAR 5, 2010

CONSULTANT

DRAWING TITLE

JOB TITLE

DATE DRAWN

SCALE CHECKED

JOB NO.

ISSUED FOR COORDINATION OCT 29, 2009

Architects Urban Designers

HENRIQUEZ • PARTNERS

402 West Pender StreetVancouver, BC V6B 1T6

Tel: 604.687.5681Fax: 604.687.8530

2914

GH/RN

SHRUM SCIENCE CENTRECHEMISTRY RENOVATION

BUILDING 026-029

SFU

ISSUED FOR INFORMATION NOV 2, 2009

ISSUED FOR COORDINATION NOV 12, 2009

ISSUED FOR STRUCTURAL AND UNDERGROUNDTENDER REVIEW

NOV 13, 2009

ISSUED FOR CONSULTANT COORDINATION NOV 18, 2009

ISSUED FOR PRELIMINARY PLAN APPROVAL NOV 19, 2009

ISSUED FOR STRUCTURAL ANDUNDERGROUND TENDER NOV 20, 2009

ISSUED FOR PROGRESS NOV 27, 2009

ISSUED FOR TENDER DEC 4, 2009

ISSUED FOR BUILDING PERMIT DEC 15, 2009

ISSUED FOR ARCHITECTURAL TENDER DEC 21, 2009

ISSUED FOR PROGRESS FEB 3, 2010

ISSUED FOR CONSTRUCTION MAR 5, 2010

A1.01

LEVEL 6000

PW

1/8"=1'-0"

NOTES

1 NEW WINDOW OPENING IN EXISTING CONCRETE WALL.

2 6" DIAMETER HOLE THROUGH WALL; 20" ABOVE THE FLOOR.

3 RETAIN AND RE-ESTABLISH GUARDRAIL, PAINT AND MAKE GOOD.

4 DOOR OPENING IN CONCRETE WALL.

5 NEW CONCRETE AT EXISTING WALL OPENING. SEE DETAIL D2.18.

6SAWCUT PAVING TO ALLOW FOR EXCAVATION; REPAIR AND RECONSTITUTE TO MATCH EXISTING.

7 TACTILE WARNING

8 STAIRS WITH (NEW) RUBBER TREADS/RISERS

9 EXISTING ROOF TO BE REMOVED. SHOWN DASHED

10 EXISTING WALKWAY

11 EXISTING TO BE REMOVED.SHOWN DASHED.

12 RECESSED FLOOR GRILLE; SAWCUT CONCRETE TOPPING AND REMOVE CONCRETE. FINISH W/ TRAFFIC MEMBRANE.

13 PAINTED METAL HANDRAIL

14 S.S. CORNER GUARD; 4'-0" HEIGHT, TYPICAL.

15 EXISTING PIPE TRENCHES TO BE FILLED W/ CONCRETE. SHOWN DASHED.

16 NEW CONCRETE STAIR

17 MECHANICAL LOUVRE ON 8" CURB

18 ACCESSIBLE BUTTON FOR POWER OPERATED DOOR.

19 SUNSHADE ABOVE

20 METAL LADDER C/W HANDRAILS (UNO). SEE D3.61/62 - TO SUIT CHANGE IN ELEV.

21 POST SUPPORT FOR MECHANICAL ABOVE.SEE DETAIL D3.63

22 SAND PREP AND PAINT EXISTING METAL STAIRS AND HANDRAILS. TYPICAL.

23 SIAMESE CONNECTION; SEE DETAIL D2.31

24 SCUPPER; SEE D3.03.

25 GUARDRAIL; SEE DETAIL D1.10A

26 CODE BLUE STATION

27 SHELF

28PROJECTION SCREEN (O.F.O.I.) AND WHITEBOARD; PROVIDE PLYWOOD BACKING FOR CASE AT WALL AS REQUIRED. SEE DETAIL 6.10

29 PROVIDE 1HR FRR WALL (TYPE AS NOTED) IN VOID SPACE ABOVE CORRIDOR AROUND EXISTING DUCTS.

30 WHITEBOARD WITH ROLLER BLIND; SEE DETAIL D6.09

31 WHITEBOARD; DIMENSIONS AS INDICATED. SEE DETAIL D6.11

32 BENCH; SEE DETAIL D6.07A

33 OFFICE SHELVING; SEE DETAIL D6.05

34 OFFICE DESK; SEE DETAIL D6.03

35

36 DISPLAY CABINET; SEE DETAIL D4.72

37 BENCH; SEE DETAIL D6.07C

NOTICE BOARD; SEE DETAIL D4.73

EXISTING CONCRETE WALL

EXTENT OF SCOPE OF WORK

LEGEND

NEW CONCRETE WALL

GENERAL NOTES:1. ENTIRE SLAB OF LEVEL 6000 TO BE REPLACED EXCEPT FOR NEUTRON LAB C7078 AND STORAGE ROOM C7078.1.

2. ALIGN WALLS; ADJUST AIR SPACE AS REQUIRED AT FURRING WALLS UNLESS OTHERWISE NOTED ON DRAWINGS.



The Nuclear Science Laboratories

W2.1

WB - 48 x 96

F.E.

F.E.

WB - 48 x 72

WB - 48 x 72

DN UP

UPUP

25'-2"R.O.

4'-10" 10'-2"R.O.

20'-4 3/4" 25'-2"R.O.

4'-10"10'-2"R.O.

20'-4 3/4" 18'-2 1/2"

2'-5 1/2" 1'-8"R.O.

5'-0" 3'-4"R.O.

1'-6 1/2"

6'-5"

23'-3"

6'-0"CLEAR

23'-10" 6'-6" 8'-4" 11'-0" 19'-1" 10'-11"16'-0 1/8"

14'-9 7/8"14'-2 1/4" 28'-11 1/8"13'-3 5/8"36'-10 3/8"

6'-0"CLEAR

6'-7"5'-0 5/8"25'-8 3/8"3'-0 5/8"

10'-1"

168'-11 1/2"

2'-5"

3'-6 1/4"

14'-3 3/8"

6'-0"CLEAR

1'-2 5/8"

31'-7"

1'-4 3/8"

8'-5 1/4"CLEAR

7'-2" 11'-0"

14'-3"

2'-3 1/2"

2'-0"

1'-11 7/8"2'-5"

W5.6

PLANTING

FD

FD

FD

W3.1

W4.1

ALL 3 SIDESOF COLUMN

W4.3

WC

UP

UP

UP

UP

W6.2

C7089

MECHANICAL

TEACHING LAB

LINE OF BUILDINGBELOWDN

ANALYTICALPHYSICAL

PD/GSOFFICEC7082

C7085

ANALYTICALPHYSICAL

(WET)

PD/GSOFFICEC7089.1

CORRIDORC708

C7086 C7088

ANALYTICALPHYSICAL

CYLINDERSC7076.1

C7076

ANALYTICALPHYSICAL

PD/GSOFFICEC7076.2

C7079

TEACHING LABC7077

TEACHING LABC7071

LOUNGEC7090

CORRIDORC707

OFFICEC7071.1

DATAC7050

C7079.1

CORRIDORC705

CORRIDORC704

C77

FILE/STORAGE

DISPENSARYC7071.3

EXISTING LANDSCAPED COURTYARD

C7084

MEETINGROOMC7080

JANITORC7083

C7076.3

ANALYTICALPHYSICAL

W6.2

CORRIDORC709

OFFICEC7071.2

W6.2

W6.1W6.1 W6.1a W6.1a

C7089A

W6.2

W6.2

1

W6.2

W6.2

W6.2

W6.2

W6.2

W6.2

1

5 5

5

1

6

RAMP

UP

4

1A2.01

2A2.01

2A2.01

6

STAIR #1

1

W6.2

W6.2

1

1

W6.2

C7083

C7089.1

C7079 C7079A

C7079.1

C77

C707

C7071

C705

C704

C7076.4

C7076.4

ANALYTICALPHYSICAL

10

1A2.02

ELEVATOR #1

1

C7071A

C709012

FD

FD

FD

FD

FD

11

FD

14

14

11

14

C7077

1414 14 14

14

14

FD

FD

FD

NOTE: APPROXIMATELY 300 LFT OF PIPE TRENCHESTO BE FILLED WITH CONCRETE IN THIS AREA.

15

15

15

C7090B

11

11

11

5

18

C75STAIR #2

C74STAIR #3

19

19

LINE OFBUILDING

ABOVE

FD

W6.2

19

5A4.03

1

1

1

12

W2.5

W2.5

W2.5

W2.5

W2.5

W2.5

W3.2

W3.2

W4.4 W4.4

W2.1

W3.2

W3.4

W2.1

W2.3

W3.4

W4.4

W4.3 W3.4

W4.4

W4.4

W1.2

W1.1

W4.5

W2.2

W2.2a

W2.2

W4.4

W3.2

W2.2

W2.3

W3.2

W3.2

W3.2

C7076A

W2.1

W4.4

W3.5

W3.1 W3.1

W3.6W4.5

W3.1

W3.2 W3.2

W2.3

W3.3W2.1

W2.1

W3.1

W3.1

W3.4

W4.5

W2.3

LINE OF BUILDING ABOVE

RD

TRAFFICMEMBRANE

(AREA SHOWNSHADED)

N.I.C.

W6.9

W6.9

W6.9

22

CORRIDOR

STAIR #4

STAIR #5

UP

IW4

IW6b

IW1727

26

1515

28

W4.5

W4.5

W4.4W4.3

W4.5

W4.3

W4.3 W4.3

W4.5

W4.3

W4.3

W4.5

W4.3

W4.3

W4.5 W4.5

STAIR #6

11

METALGRATING

2A4.05

-D1.10A

-D1.10C

25

W4.6

D4.51

D4.50

D4.31

W6.1aW6.1D2.28

D3.01

TRAFFICMEMBRANE

(AREA SHOWNSHADED)

N.I.C.

DN

LINE OF ROOF ABOVE

W6.2

LINE OF ROOF ABOVE

UPFD

FD

W4.5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

14

14

WOMENSWC

C7072

MENS WCC7074

1A5.01

W4.2 W4.2

W4.2

W4.2

10A5.01

W2.6

14

C710

W3.2

W4.4W4.4

W3.2

W3.4

W3.1W3.1

W3.1

D4.58W2.1

W4.5

D4.61

W3.4

W3.1

W3.3

W5.1

W4.2

W4.2ALL 3 SIDESOF COLUMN


W4.4

W4.4

W4.2

W4.2

W2.1

W4.3

W4.4

W4.2

W4.2

W4.2

W4.3

W4.4

W4.4


W4.2

W2.1

W3.2

W5.1W5.1

W3.1

W5.1 W5.1

W5.1

W4.3

W4.3

W4.3 W4.3

W4.3

W4.3

W4.3 W4.3

W4.3

W4.3

W4.3

W4.2

W4.4

W4.2

W4.2

W4.2

W2.1

W4.3

W4.3

W4.3 W4.3

W4.3

W4.3

W4.3 W4.3

IW6a

W2.1W3.3

W3.2

W2.3

W2.2

W2.2

W4.4

W4.4

W4.4

W4.5

W4.4

W3.2

2A4.01

W4.3

W4.3

W4.3

W6.2

W4.1 W4.4

ALIGN

W4.3 W4.3

ALIGNALIGN ALIGN

ALIGN ALIGNALIGN ALIGN

ALL SIDESOF COLUMN

W3.1

1A4.63

W4.3

W3.1

W4.3

17

W3.2

1205

18

D4.51

30

30

30

30 30

30

30

D4.74

1A2.01

1A5.05

NEW SIDEWALK

37

IW3

32

32 32

33

34

34

3334

3334 34 33

A5.03

1

2

A5.02 12

A5.04

1

2

W4.5W4.5

W3.1ABOVE

W3.1ABOVE

D4.75

31

31

31

31

31

31

30

35

35

35

35

35

35

35

36

ASSIGNMENT DROP BOXES

D2.106

W3.4

TYP.

D1.01

D2.43

D2.44

W4.4

W4.4

W4.4W4.4

RATED SHAFT ON ALL SIDES OF MECH EXHAUST ABOVE

W5.1

W1.2

W4.6

W4.6

W4.4

STAIRC76

13

IW20

10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 6'-0" 6'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 5'-9" 10'-0" 10'-0" 10'-0" 10'-0"10'-0" 10'-0"

69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

10'-0

"10

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"10

'- 0"

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"1 0

'- 0"

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"1 0

'- 0"

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"1 0

'- 0"

10' -0

"1 0

'-0"

Ga

Fa

Ea

Da

Ca

Ba

Aa

Z

Y

X

W

V

U

T

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R

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O

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M

EXTENT OF SCOPEOF WORK

MAR 5, 2010

CONSULTANT

DRAWING TITLE

JOB TITLE

DATE DRAWN

SCALE CHECKED

JOB NO.

ISSUED FOR COORDINATION OCT 29, 2009

Architects Urban Designers

HENRIQUEZ • PARTNERS

402 West Pender StreetVancouver, BC V6B 1T6

Tel: 604.687.5681Fax: 604.687.8530

2914

GH/RN

SHRUM SCIENCE CENTRECHEMISTRY RENOVATION

BUILDING 026-029

SFU

ISSUED FOR INFORMATION NOV 2, 2009

ISSUED FOR COORDINATION NOV 12, 2009

ISSUED FOR STRUCTURAL AND UNDERGROUNDTENDER REVIEW

NOV 13, 2009

ISSUED FOR CONSULTANT COORDINATION NOV 18, 2009

ISSUED FOR PRELIMINARY PLAN APPROVAL NOV 19, 2009

ISSUED FOR STRUCTURAL ANDUNDERGROUND TENDER NOV 20, 2009

ISSUED FOR PROGRESS NOV 27, 2009

ISSUED FOR TENDER DEC 4, 2009

ISSUED FOR BUILDING PERMIT DEC 15, 2009

ISSUED FOR ARCHITECTURAL TENDER DEC 21, 2009

ISSUED FOR PROGRESS FEB 3, 2010

ISSUED FOR CONSTRUCTION MAR 5, 2010

A1.02

LEVEL 7000

1/8"=1'-0"

PW

CHEMISTRY SOUTHSFU SHRUM RENEW

CHEMISTRY NORTH

EXISTING CONCRETE WALL

EXTENT OF SCOPE OF WORK

LEGEND

NEW CONCRETE WALL

GENERAL NOTES:1. ENTIRE SLAB OF LEVEL 6000 TO BE REPLACED EXCEPT FOR NEUTRON LAB C7078 AND STORAGE ROOM C7078.1.

2. ALIGN WALLS; ADJUST AIR SPACE AS REQUIRED AT FURRING WALLS UNLESS OTHERWISE NOTED ON DRAWINGS.

NOTES

1 NEW WINDOW OPENING IN EXISTING CONCRETE WALL.

2 6" DIAMETER HOLE THROUGH WALL; 20" ABOVE THE FLOOR.

3 RETAIN AND RE-ESTABLISH GUARDRAIL, PAINT AND MAKE GOOD.

4 DOOR OPENING IN CONCRETE WALL.

5 NEW CONCRETE AT EXISTING WALL OPENING. SEE DETAIL D2.18.

6SAWCUT PAVING TO ALLOW FOR EXCAVATION; REPAIR AND RECONSTITUTE TO MATCH EXISTING.

7 TACTILE WARNING

8 STAIRS WITH (NEW) RUBBER TREADS/RISERS

9 EXISTING ROOF TO BE REMOVED. SHOWN DASHED

10 EXISTING WALKWAY

11 EXISTING TO BE REMOVED.SHOWN DASHED.

12 RECESSED FLOOR GRILLE; SAWCUT CONCRETE TOPPING AND REMOVE CONCRETE. FINISH W/ TRAFFIC MEMBRANE.

13 PAINTED METAL HANDRAIL

14 S.S. CORNER GUARD; 4'-0" HEIGHT, TYPICAL.

15 EXISTING PIPE TRENCHES TO BE FILLED W/ CONCRETE. SHOWN DASHED.

16 NEW CONCRETE STAIR

17 MECHANICAL LOUVRE ON 8" CURB

18 ACCESSIBLE BUTTON FOR POWER OPERATED DOOR.

19 SUNSHADE ABOVE

20 METAL LADDER C/W HANDRAILS (UNO). SEE D3.61/62 - TO SUIT CHANGE IN ELEV.

21 POST SUPPORT FOR MECHANICAL ABOVE.SEE DETAIL D3.63

22 SAND PREP AND PAINT EXISTING METAL STAIRS AND HANDRAILS. TYPICAL.

23 SIAMESE CONNECTION; SEE DETAIL D2.31

24 SCUPPER; SEE D3.03.

25 GUARDRAIL; SEE DETAIL D1.10A

26 CODE BLUE STATION

27 SHELF

28PROJECTION SCREEN (O.F.O.I.) AND WHITEBOARD; PROVIDE PLYWOOD BACKING FOR CASE AT WALL AS REQUIRED. SEE DETAIL 6.10

29 PROVIDE 1HR FRR WALL (TYPE AS NOTED) IN VOID SPACE ABOVE CORRIDOR AROUND EXISTING DUCTS.

30 WHITEBOARD WITH ROLLER BLIND; SEE DETAIL D6.09

31 WHITEBOARD; DIMENSIONS AS INDICATED. SEE DETAIL D6.11

32 BENCH; SEE DETAIL D6.07A

33 OFFICE SHELVING; SEE DETAIL D6.05

34 OFFICE DESK; SEE DETAIL D6.03

35

36 DISPLAY CABINET; SEE DETAIL D4.72

37 BENCH; SEE DETAIL D6.07C

NOTICE BOARD; SEE DETAIL D4.73



The current status



The SIMON project

The role of SIMON is to provide access to high intensity neutronbeams without a nuclear reactor or spallation source.

SIMON will comprise of

D/T or D/D generator of fast neutrons

Beryllium shroud multiplying fast neutrons through the (n,2n) reaction

a Heavy-Water moderator

low-enriched Uranium for multiplication of moderated neutrons throughthe neutron-induced fission.

The goal is to develop a medium-size device (less then 7 m long, 3 mdiameter), fitting the floor-plan of the radiation vault at SFU.

The achievable flux is being examined, the target is 1013 n/cm2/s.



The road map for SIMON: 2011

A $150K Canadian Foundation of Innovation/ British ColumbiaKnowledge Development Fund proposal for a commercial neutrongenerator has been awarded

GEANT4 Monte-Carlo simulation codes for the neutron moderatorand multipliers developed based on the high-precision modelsavailable from GEANT4 for E < 20 MeV neutrons.

Optimization of the moderator and multiplier geometry based on theGEANT4 simulations is currently pursued.

A 3×108 commercial generator will be acquired.

Licensing process for the renovated vault and a generator to beacquired will be initiated in early 2011.

Funds for construction of a test moderator will be sought.



Moderation of neutrons in GEANT4

(Left)Simulated random walk, (Right) Simulated time in the moderator.

Simulated average time in a heavy-water moderator is ∼4 [ms].



SIMON: back on the envelope estimates

The volume of 100 [cm] long moderator with 50 [cm] radius and abore for inserting the generator with 5 [cm] radius is

V = 100 ∗ π ∗ (502 − 52) [cm3] = 7.8 × 105 [cm3]

Number of neutrons in the moderator is equal to the generator outputf times the lifetime in the moderator τ

n = fτ = 3 × 108 [part./s] ∗ 4 × 10−3 [s] = 1.2 × 106 [part.]

Number density of the neutrons in the moderator is

N =nV

=1.2 × 106

7.8 × 105 = 1.5 [part./cm3]




Assuming thermal neutrons with energy 0.025 [eV] and speed v of2.2 [km/s]=2.2×105 [cm/s] the neutron flux in the moderator withoutany neutron multiplication is

φ = N ∗ v = 1.5 ∗ 2.2 × 105 [part./cm2/s] = 3.3 × 105 [part./cm2/s]

If there is a reaction in the moderator which contributes ∆n neutronsper second into the full moderator the number density in themoderator will grow in a unit time according to

N + ∆N = N +∆nτ

V= N(1 +

∆nτNV

) = N(1 + λ) with λ =∆nτNV

Growth in time is described by

N(t) = N(0)(1 + λ)t




Let us assume thermal neutron induced fission of natural Uranium asthe multiplication reaction.Number of thermal-neutron induced fission per second is

∆n = φκadν̄σρ

µNA = Nvκadν̄σ

ρ

µNA

withκ = 0.007 being 235U content in nat.U,a and d being nat.U target area and thickness, respectively, with thead = 60 [cm3] representing the volume of nat.U in the moderator in 0.5cm thick, 2 cm long bars, 10 cm from the centre,ν̄ = 2.5 being the average number of neutrons per 235U fission,σ = 600 [b]=6×10−22 [cm2] is the cross section for 0.025 [eV] thermalneutron capture on 235U,ρ = 19 [g/cm2] is the density of nat.U,µ = 239 [g/mol] is the molar mass of nat.U,NA = 6 × 1023 is the Avogadro number.




Combining above equations the multiplication factor for 800 kg ofheavy water and 1.2 kg of nat.U becomes

F(t) =N(t)N(0)

= (1 + λ)t with λ = κν̄adV

vτσρ

µNA = 5.7 × 10−3

0

1

2

3

4

10

10

10

10

10

0 400 800 1200 1600

Mul

tiplic

atio

n fa

ctor

Time [s]



The road map for SIMON: long-range

GEANT4 codes will be validated using results obtained with thelow-flux generator and the test moderator.

Working parameters for the final neutron generator and the moderatorwill be specified and the final design will be defined based on thevalidated calculation.

Nuclear engineering assistance will be sought in regard to shielding,design, manufacturing and operation of the final neutron generatorand moderator assembly.

Utility of the SIMON for fundamental and applied research programwill be examined.



The utility of SIMON

SIMON is a project with significant discovery potentialCan become a driver for production of rare isotopes with large neutronexcess via neutron-induced fission.Consequently, it can support state of the art nuclear research probingthe beginning of the Universe and answering key fundamental scientificquestions regarding nucleosynthesis and distribution of elements.

SIMON provides an ideal training opportunities for future generationof Highly Qualified Personnel in Nuclear Science.

SIMON may open a way to produce important radioisotopes formedical and commercial applications without use of reactors.

For material sciences SIMON will enable neutron activation analysisproviding information on elemental composition on aparticle-per-billion level in a non-destructive way.

SIMON may also become a tool for neutron scattering aiding researchin material sciences.


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