Mozaic trigger system for high transverse momentum physics
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Transcript of Mozaic trigger system for high transverse momentum physics
Mozaic trigger system for high transverse momentum physics
A.Fulop(ELTE), G.Vesztergombi (KFKI-RMKI)
CHEP
PragueMarch, 2009
Motivation for new measurements below = 20 GeVs
Practically no high or medium Pt data between Einc = 24 and 200 GeV
Mysterious transition around 80-90 GeV: convex versus concave spectra
Energy threshold for Jet-quenching?
Emergence of Cronin-effect in pA interactions is completely unknown
energy dependencecentrality dependenceparticle type dependenceparticle correlations
Production of Upsilon (9.5 GeV) particles near the threshold.
NA49 (CERN) results at 158FODS (IHEP) at 70 GeV
Beier (1978)
Special requirements for Y-> e+e- and high pT
Extremely high intensity - Pile-up
Segmented multi-target - Relaxed vertex precision
Straight tracks - High momentum tracks
DREAM: 109 interactions/sec
z [cm]
x,y
[cm
]
Px=Py = 1 GeV/c; Pz= 5 GeV/c
Px=Py= 3 GeV/c Pz = 10 GeV/c
High ( > 5 GeV/c ) momentum Straight track
MAPS vs Hybrid
Vertex resolution: dz = 1 mm, dx,dy= 0.05 mm
High intensity: radiation hard
Practical 4+ 2 + 3 = 9 planes ( 4 Hybrids + 5 strips)
Selectivity depends on the availability of TOF information
i
i+1
j
j+1
3 dimensional scheme
k=1
k=2
k=3
Mosaic cells in plane “k” : M(i,j,k)
(i,j) Corridor contains: M(i,j,k), M(i,j+1,k), M(i+1,j,k), M(i+1,j+1,k) k=1,2,3
s = sqrt(XX*XX+YY*YY) - delta
delta
Sagitta:
10-20 cm track sections are practically straight fractals
(XX,YY,ZZ)
4 hybrids 2 + 3 strips
2 4 6Basic planes
* * ***
* ** *
Silicon planes
Basic planes: #2 = (x2,y2,z2) pixel , #4 = (x4,y4,z4) pixel, #6 = (x6,z6) strip
Parallel processing: CORRIDOR # corNum
Straight tracking in #2 and #4 planes in space => (mx,bx) and (my,by) Approximation: starting direction is given by (mx,my)
Separate track matching in xand y for planes 5-9
Matching in #1 and #3 pixel planes in space
TUBE definition:
x-tube: xi = mx*(zi-z2) +bx +parabol(x6,z6,zi) +/- deltaxiy-tube: yi = my*(zi-z2) +by +/- deltayi
New algorithm
Mozaic DAQ systemTwo separate systems:
PRETRACKING network: Pixel [#2 , #4] + Strip [#6x]
TRACK-QUALITY TUBE network:Pixel [ #1, #3] + Strip[#5x, #5y, #6y, #7x, #7y, #8x, #8y, #9x, #9y]
In each network parallel CORRIDOR processors: CorID =corNUMNumber of CORRIDOR processors: ndx*ndy
Data select their routes according to plane number and corNUM
In plane „zi” track-hit „xi,yi” calculates its corridor address:
corNum = idx*ndy + idy
Corridor processorsOLD system: consecutive cycling on all „planes”
If only 2 points per plane: number of cycles = 2(4+2*5) = 214 = 16384
NEW system: cycling only on 3 „planes” (for pixels x and y has common cycle)
If only 2 points per plane: number of cycles = 2(2+1) = 23 = 8
The PRETRACKING is producing a list containing:
corNUM, x1,x3,x5,x7,x8,x9, y1,y3,y5,y6,y7,y8,y9
There is NO PROCESSING TIME in the TRACK-QUALITY TUBE network becauseIt is only an ASSOCIATIVE memory which provides YES/NO.
The gain in processing time (if only 2 points per plane): 211 = 2048-fold