MASHA De te c to r F ind ing the so urc e o f lo we r e ne rg - - PowerPoint PPT Presentation

MASHA De te c to r

F ind ing the so urc e o f lo we r e ne rg y alpha pa rtic le s in fo c al plane o f silic o n strip d e te c to r o n MASHA

Pa rtic ipa tio n a nd Affilia tio ns

Stude nts a nd Supe rviso rs 2012 Stude nt Pra c tic e

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Stude nts

• Bing wa Ndzo nde le lo

Wa lte r Sisulu Unive risty

• E

lsje Oppe rma n Ste lle nb o sc h Unive rsity

• F

iki Mme thi UNI SA

• Sitha ndile Ng xa ng xa

Wa lte r Sisulu Unive risty

• Zukiswa Mb a nde

Wa lte r Sisulu Unive risty

Supe r visor s

• Dr L

. K rupa F le ro v L a b o ra to ry o f Nuc le a r Re se a rc h (FL NR)

• I

va n Siva c e k F L NR

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T he Pro je c t

Ba c kg ro und T he o ry Aim Me tho d E xpe rime nta tio n Re sults Summa ry Co nc lusio n

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Ba c kg ro und

MASHA Ma ss Ana lyse r fo r Supe r He a vy Ato ms

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• Silic o n strips
• Width– 1.1mm
• 1 – fo c a l strips (3x64)
• 2, 3 – up & do wn side

strips 2x(2x32)

• 4 – le ft & rig ht side strips

2x(16)

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T he o ry

• T

he de te c to r re c o rds the ma ss o f fra g me nts/ iso to pe s, the e ne rg y a nd the inte nsity.

• Ca lib ra tio n Runs:

40Ar+ ySm→ y-xnHg+ xn 40Ar+ 166Er→206−xnRn+ xn

• Hg a nd Rn a re ra dio a c tive a nd α-de c a y
• Diffe re nt iso to pe s o f pro d uc ts de te c te d in diffe re nt

strips (ma ss se pa ra te d)

• I

so to pe s α-de c a y in de te c to r

• De c a ys’ spe c tra de te c te d

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Aim

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• Spe c trum c a n b e g a te d fo r

spe c ific re sults.

• E

ne rg y spe c trum fro m c a lib ra tio n runs sho ws ta ils o n lo w e ne rg y side o f pe a k, no t Ga ussia n distrib utio n.

• I

ndic a te s tha t the re is a de a d la ye r o n the de te c to r – a vo lume

• n the surfa c e o f e a c h strip in

whic h the c ha rg e is no t c o lle c te d.

• Aim: Is the de ad laye r

the sour c e

• f the tails on the pe aks of the

alpha pa r tic le spe c tr a?

60 80 100 120 140 160 180 200 4,5 5,0 5,5 6,0 6,5 7,0 185 184 183 182 180

(2.56 s)

181(3.6 s)

40Ar+

Sm t nat

catch=1600 С о

Energy, MeV

Alpha Co unt T a ils

L

• g a rithmic

sc a le sho wing c o unts o f a lpha pa rtic le s e mitte d a t 6700ke V fro m

202Rn.

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Me tho d

Me a suring e ne rg y spe c trum o f α- de c a y a t two po sitio ns will sho w shift in e ne rg y pe a ks. I ndic a te d thic kne ss o f de a d la ye r.

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Po sitio n 1 Po sitio n 2 De a d la ye r Ac tive la ye r

E xpe rime nta tio n

E xpe rime nta l se t up

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De te c to r

226Rn

So urc e Mo va b le pla te T

• DAQ

Ha ndle E va c ua te d Cha mb e r

Me tho d

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Simula tio n

T e c hnic a l diffic ultie s, simula t.e d da ta

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Re sults

Alpha spe c trum fro m full fo c a l pla ne . So urc e pla c e d in c e ntre o f de te c to r a nd to le ft o f de te c to r. Slig ht shift in e ne rg y pe a k, diffe re nc e in ta ils.

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Spe c trum fo r Sing le Strip

T

• p: So urc e in c e ntre

(le ft e nd strip, middle strip). Bo tto m: So urc e to le ft (le ft strip, middle strip).

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Summa ry

Pe a k e ne r g y/ KeV

So urc e in c e ntre So urc e to le ft Shift/ ke V Middle strip 4530 4453 77 L e ft strip 4452 4530

• 78

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Summa ry

So urc e o f e ne rg y diffe re nc e in the c e ntre strip.

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E

1 = 4453K

e V E

0 = 4784K

e V E

2 = 4530K

e V

θ

d

Co nc lusio n

De a d la ye r is a t le a st in pa rt re spo nsib le

fo r ta ils.

Ne e d mo re d a ta po ints fo r mo re

sta tistic ally a c c ura te re sult

I

n pra c tise ne e d c o llima to r to c re a te ‘ b e a m’ o f alpha s.

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Ac kno wle dg me nts

NRF

(Na tio nal re se a rc h F

• und a tio n)

JINR (Jo int Institute o f Nuc le a r Re se a rc h)

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