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

2 11/ 10/ 2012 Pa rtic ipa tio n a nd Affilia tio ns Stude nts a nd Supe rviso rs 2012 Stude nt Pra c tic e

3 11/ 10/ 2012 Stude nts Supe r visor s Bing wa Ndzo nde le lo � Dr L . K rupa � Wa lte r Sisulu Unive risty F le ro v L a b o ra to ry o f E lsje Oppe rma n � Nuc le a r Re se a rc h Ste lle nb o sc h Unive rsity (FL NR) F iki Mme thi � I va n Siva c e k UNI SA � F L NR Sitha ndile Ng xa ng xa � Wa lte r Sisulu Unive risty Zukiswa Mb a nde � Wa lte r Sisulu Unive risty

4 11/ 10/ 2012 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

5 11/ 10/ 2012 Ba c kg ro und MASHA Ma ss Ana lyse r fo r Supe r He a vy Ato ms

6 11/ 10/ 2012 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)

7 11/ 10/ 2012 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: � 40 Ar+ y Sm → y-xn Hg+ x n 40 Ar+ 166 Er → 206 − x n Rn+ x n 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) so to pe s α -de c a y in de te c to r I � De c a ys’ spe c tra de te c te d �

8 11/ 10/ 2012 7,0 nat 40 Ar+ Sm 2 180 (2.56 s) о catch =1600 С t 6 6,5 181 (3.6 s) 10 Energy, MeV 182 183 185 Aim 184 14 18 6,0 22 26 30 5,5 34 38 42 5,0 Spe c trum c a n b e g a te d fo r 46 � 50 4,5 spe c ific re sults. 60 80 100 120 140 160 180 200 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 o 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 � of the tails on the pe aks of the alpha pa r tic le spe c tr a?

9 11/ 10/ 2012 Alpha Co unt T a ils L o 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 202 Rn.

10 11/ 10/ 2012 Po sitio n 1 Me tho d De a d la ye r Me a suring e ne rg y spe c trum o f α - de c a y a t two po sitio ns will Ac tive la ye r Po sitio n 2 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.

11 11/ 10/ 2012 E va c ua te d De te c to r E xpe rime nta tio n Cha mb e r E xpe rime nta l se t up T o 226 Rn DAQ So urc e Ha ndle Mo va b le pla te

12 11/ 10/ 2012 Me tho d

13 11/ 10/ 2012 Simula tio n T e c hnic a l diffic ultie s, simula t.e d da ta

14 11/ 10/ 2012 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.

15 11/ 10/ 2012 Spe c trum fo r Sing le Strip T o 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).

16 11/ 10/ 2012 Summa ry Pe a k e ne r g y/ KeV So urc e in So urc e to le ft Shift/ ke V c e ntre Middle strip 4530 4453 77 L e ft strip 4452 4530 -78

17 11/ 10/ 2012 E 0 = 4784K e V Summa ry θ So urc e o f e ne rg y diffe re nc e in the d c e ntre strip. E 1 = 4453K e V E 2 = 4530K e V

18 11/ 10/ 2012 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.

19 11/ 10/ 2012 Ac kno wle dg me nts � NRF (Na tio nal re se a rc h F o und a tio n) � JINR (Jo int Institute o f Nuc le a r Re se a rc h)