geant 4 detector simulation
TRANSCRIPT
05/02/23 Chun-Min Jen, Summer 09, May Syracuse Uni.
1
Uniform B-field
5 m
Supposed that “Everything” is composed of “Vacuum” …
1.5 m
detector # : 0 1 2 3 4 5 6 7
Chun-Min Jen, Summer 09, May Syracuse Uni.
205/02/23
Sample: Signal Criteria
Generate 6’000 & 60’000 events Etotal = 3 GeV – 7 GeV incident = 25º - 35º All e- (negatively charged, light particle) No interactions w/ any matter, for example,
the tracking chambers, medium and the target (point source).
Single hit per tracking chamber / detector “Purely” helix motion in an uniform B-field
Chun-Min Jen, Summer 09, May Syracuse Uni.
305/02/23
X’ (t)
Y’ (t)
Uniform B-field : Summary X (t) = a*cos(t+)-a*cosY (t) = a*sin(t+)-a*sinX (t) = C*cos*t
X (t) = a*cos(t)-aY (t) = a*sin(t) X (t) = -0.5*a*2*t2Y (t) = a**t X = X7-X4 = -0.5*a*2*(t7
2 – t42) ; X/t = -0.5*a*2*(t7
+ t4) ; X = (X/t)*t + X -(X/t)*t = 0.5*a*2*t7*t4 = 0.5*(C*P┴/e*B)*(e*B/P)2*(Z7*Z4/C2*cos2) ~ sin/ P*cos2tanrec ~ (Y7 - Y4)/(Z7 - Z4) = tanini
=X (t)
Y (t)
cossin
-sincos
Rotation Transformation
Physics Invariance = 0
t << 1 /
S1S2 Z
B = 1.5 T ( )Y
X
Chun-Min Jen, Summer 09, May Syracuse Uni.
405/02/23
3 GeV 25º 30º 35ºT (period) (sec) 1.40e-7R (m) 2.82 3.33 3.82 Z (per T) (m) 38.05 36.36 34.39 5 GeVT (period) (sec) 2.33e-7 R (m) 4.70 5.56 6.37 Z (per T) (m) 63.42 60.60 57.32 7 GeVT (period) (sec) 3.27e-7 R (m) 6.57 7.78 8.92 Z (per T) (m) 88.78 84.84 80.25
Chun-Min Jen, Summer 09, May Syracuse Uni.
505/02/23
|ini – rec|
|ini – rec| v.s.
|ini – rec| v.s. ini |ini – rec| v.s. Pini
|ini – rec| / ini = 0.0023
ini ~ rec --- (1)
|ini – rec| / Pini = 2.94
Based on the fitting results, we could roughly estimate that the relation is
= K * / P2 ~ 0,
where = |ini – rec|
|ini – rec| /
= 0.0004 ~ 0
Chun-Min Jen, Summer 09, May Syracuse Uni.
605/02/23
/ (sin / P*cos2Based on P.3
/ (/ P)Based on P.7
v.s. P
v.s. P
v.s. ini v.s. ini
Chun-Min Jen, Summer 09, May Syracuse Uni.
705/02/23
/ (/ P)Based on P.7
/ (sin / P*cos2Based on P.3K2 ~ 14 – 15
P (rec, )= K2*sinrec / *cos2rec
ini (rec, ) = rec
K1 / Pini
= 0.017
K1 ~ too small
K1 / ini
= 0.045
K1 abandoned!
K2 / Pini
= 14.1
K2 is more reliable
and stable!
K2 / ini
= 15.3
Chun-Min Jen, Summer 09, May Syracuse Uni.
805/02/23
S
S1 / Pini
= 9.13 S1 / ini
= 15.3
S v.s. Pini S v.s. ini
Chun-Min Jen, Summer 09, May Syracuse Uni.
905/02/23
(S1 / ) / Pini
= 0.05(S1 / ) is reliable!
(S1 / ) / ini0.009
= 0.05
/ (sin / P*cos2Based on P.3K2 ~ 14 – 15
P (rec, )= K2*sinrec / *cos2rec
ini (rec, ) = rec
(S1 / ) = 0.05S1 (P, ini) = 0.05*= 0.05* K2*sinrec / P*cos2rec
S / v.s. PiniS / v.s. ini
S /
Chun-Min Jen, Summer 09, May Syracuse Uni.
1005/02/23
To-Do List :
Figure out the problem which caused X and Y not equal to zero. (in P.5 – P.6)
Apply a non-uniform B-field and as realistic materials as what the proposal described to our G4 simulation.
Compare the outcome with that derived from the uniform B-field case. See how much it may change with the impact of a non-uniform B-field as well as interactions between negatively charged electrons and materials on G4 simulation.
Proceed to the multi-hit case. More sophisticated. Need more time Programming…