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TOFP STATUSW.J. Llope, N. Adams, P. Sappenfield, E. Rareshide, S. Becker,
G. Eppley, G. Mutchler, and E. Platnerfor the STAR-TOFp group
11/18/98 TOFp Proposal released12/01/98 Review committee formed and charged12/15/98 VideoCon Review...01/06/99 ...more discussions with review committee
04/13/99 Committee report released andSysTest-I Proposal requested
04/22/99 SysTest-I Proposal released05/21/99 SysTest-I approved by spokesman
06/08/99 20 k$ located to begin SysTest-I (special thanks to Tim Hallman)
→ roughly five month pause....but now very much underway on Systest-I...
Appropriateness of Flat-Coax cablePerformance of CW basesPerformance of custom FEEPerformance overall inc. CAMAC readout
Manpower?The Start Detector we need...
On track for re-review in Sept 1999
Install during March 2000 Shutdown
Also on hand: Discriminators P/S 704 (4), 715 ... LRS 621BL and 623B ... Ortec 934cfd ... P/S 706 (∞)ADC/TDC LRS 2249A (4), 2228A (2), 2228 (3) ... P/S 7186 (2), P/S 7186H (3)Scopes HP Infinium (1.5 GHz, 8 GS/s) & Tektronix TDS640A (500 MHz, 2 GS/s)
SysTest-I Schematic
UV laser
Bicron BC420Hamamatsu
R3432
CW ver.3
(adjustablelengths)
FEEver.4
(Flat Coaxor RGxx)
Flat Coax(5ch x 250', 308ns)
Oven &Thermometer
Patch panel
Low VoltageSupplies
(2x)
GPIBInterface
HDLC Bus PC
CAMAC Crate
VME Crate
Radstone Board& MVME CPU
HDLCMother
(CW LV)
(Disc Threshold)
(PAW via//GSECT)
P/S 706 LE DiscLeCroy & P/S TDC
LeCroy ADCLEDisc
CFLogic
(PMTsignal)
(Log
ic S
igna
ls to
TD
Cs)
FEE ver.4
NIM Crate(laser start,self start,or pulser)
(Start as start)
(Start as stop)
(fans, gates, &coincidences)
(ADC gate)
(Ana
log
Sig
nals
to A
DC
s)
The Present Set-up...
dark box
VSL-337ND Laser& Optics/Splitting
NIM/CAMAC LVGPIB/PC/PAW
BC420(20x4x2)+R5946
8575 Ref PMT
CW v.2
not shown:Oven, HVSys cells
10-1
1
10
10 2
1 10 102
103
104
ω (MHz)
Atte
nuat
ion
(dB
/100
ft)
Coaxial Cable Attenuation SpecsRG58 (circles), RG58A/C (squares), LDF5-50A (triangles)
RG-58 (tabulation)RG-58A/C (tabulation)RG-58 (measured)FlatCoax (measured)FlatCoax (tabulation)
Series 22,25,28 -- P/S 706 Disc, RT=2ns, ∆=5,50,100ns
-800
-600
-400
-200
0
0 20
V (
mV
)
0 50 100 0 50 100 150t (ns)
Series 22,25,28 -- P/S 706 Disc, RT=2ns, ∆=5,50,100ns
-800
-600
-400
-200
0
-5 0 5 10
V (
mV
)
-5 0 5 10 15 0 10 20t (ns)
Comparison of Flat-Coax and RG58no discernable difference in cable rise times...both have τ~5ns per 250’
1
1.1
1.2
1.3
1.4
1.5
2.5 5 7.5 10 12.5 15 17.5 20ω (MHz)
Am
plitu
de R
atio
(/1
00ft)
Coaxial Cable AttenuationRG58 (circles), RG58A/C (squares), LDF5-50A (triangles)
RG-58 (tabulation)RG-58A/C (tabulation)RG-58 (measured)FlatCoax (measured)FlatCoax (tabulation)
good agreement withtabulations...
our resultstabulated
Sine wave attenuationRange 0.1 - 20 MHzMeasured
250ft RG58-AU250ft Flat Coax
Plot equiv. 100ft of cable
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0 50 100 150 200time (ns)
V (
%) Fit Results:N=11, χ2/N=3.47942E-06
τ =4.7233ns
FlatCoax, 250ft, pos. sq. pulse, ∆=50ns
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0 50 100 150 200time (ns)
V (
%)
Fit Results:N=9, χ2/N=2.73036E-06τ =4.79647ns
RG-58, 250ft, pos. sq. pulse, ∆=50ns • at 20 MHz, FlatCoax cable amplitude cross talkfor sine wave input is about 1%
• at same frequency, “RG58 pair”amplitude cross talka factor of 5-10 less.
but 1 to 20 MHz is only a fraction of the relevant frequencies..
In progress: amplitude C.T. for actual signals...L-L, L-A, A-L, A-A
timing C.T. using the Infinium...
Signal propagation simulations... Cross Talk...
1
10
10 2
2.5 5 7.5 10 12.5 15 17.5 20ω (MHz)
λ (d
B/1
00m
)
Nearest Neighbor C.T.(attenuation rel. to Vout)
Same channel attenuation
paired RG58AU, 250 ftFlatCoax, 250ft
250ft long “pair” of RG58...250ft long flat coax, 4 wide...
Preliminary
Voltage
TOFp proposal suggests Nick Adams’ (Rice) version III CW basessimpler than previous versions, and stableon original schedule, would have been best approach
the present schedule cannot afford this any more...
EMCO (declined to quote for our specs)Hamamatsu (don’t work in magnetic fields)HVSys Valery Astakhov et al.
http://www.tsl.uu.se/~sukhanov/HVSys/Astakhov/welcome.htm
• simple control via System Module 6U VME, connects only to PC & AC power• single bus for all cells in a tray only feedthrough is single 10 ch. ribbon• cells are small diameter 1.5”, length ~ 2”• power <0.5 W/cell, or <25 W/tray practical upper limit is 50 cells/tray• cost/cell ~80$, and can be produced quickly• System Module (2 k$) already in hand• for testing, simple DOS GUI to control cells
06/04/99: began discussions with Valery...06/09/99: agrees to make 6 cells on spec...06/19/99: design specs for TOFp finalized...07/04/99: TOFp cells complete...07/05/99: cells carried to Dallas by a friend...07/08/99: cells arrive at Rice...
presently testing: stability... confirm power draw... linearity/gain curves from diff. systems... performance magnetic field on vs. off...
FEE version IILE, 2ch, RT~750ps (commercially, RT~2.5 ns)
FEE version III (completed 7/22/99)CFD, 1ch→ RT ~ 610ps→ resolution ~11ps
Functional Description of TOFp FEE version IVWJL, 7/6/99 (revised 7/23/99)
History:v. I - 1ch, first breadboardv. II - 2ch LE, RT~0.75nsv. III - 1ch. first version of LE+CFv. IV - 5ch LE w/ 2ch CFD
→ 2 boards, each 5 channels (3 ch LE+width, 2 ch LE+CF+width).
Dimensions: Board width to bolt onto TOFp cooling rails. Minimize length.
I/O specs: LE thresholds individually adjustable from 50 mV to 1V output rise time < 1ns, and minimized. (v.III has RT~0.6 ns) output fixed flat-top voltage, NIM standard -800 mV output widths individually adjustable in range 20ns to 100ns dead time = 100ns (=widest adjustable gate, dec. in ver.V) provide board space and connections for input protection.
Connections: 5 lemo female take 5 PMT signals 10 lemo female give 5 logic & 5 PMT signals
Present Schedule: 1 week - design/construct/test v.III (complete 7/22/99) 1 week - artwork for version IV 2 days - PCB fab (shopped) 1 week - stuff/test
→ Completion of two (2) Version IV boards expected Aug 7, 1999.
Thr = Pot for LED thresholdTst = Thres test pointWid = Pot for logic width
8.0 inches7.0 inches
~2 in
TstThr
Wid
LED
CF
Width
TstThr
Wid
LED
CF
Width
TstThr
Wid
LED
Width
TstThr
Wid
LED
Width
TstThr
Wid
LED
Width
to ADC...to TDC...
Position Test and Comparison of TOFp FEE V4 and P/S 704
200
300
400
500600700800900
0 25 50 75 100 125 150 175 200 225 250
Z (mm)
AD
C (
ch)
exponential fit of Refpar(1) = 6.86E+00 +/- 1.00E+00par(2) = -2.13E-04 +/- 1.00E+00
exponential fit of Slatzpar(1) = 6.46E+00 +/- 3.17E-03zpar(2) = -1.16E-03 +/- 2.40E-05
600
650
700
750
800
850
900
0 50 100 150 200 250
Linear Fit of LE Disctpar(1) = 7.73E+02 +/- 1.19E+00tpar(2) = 1.24E-01 +/- 8.76E-03
Z (mm)
AV
G T
DC
(ch
)
Linear Fit of CFDcpar(1) = 8.64E+02 +/- 1.05E+00cpar(2) = 1.09E-01 +/- 7.69E-03
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
0 50 100 150 200 250Z (mm)
TD
C σ
(ch
)
CFDLED
41ps
36ps
vIII CFD
PS 704
PS 704
vIII CFD
• single discrimination to LRS TDC• short cables
Preliminary
4 TDC 16:15, July, 23, 1999
0
50
100
150
200
250
300
350
400
450
480 485 490 495 500 505 510
IDEntriesMeanRMS
105 1000
487.6 0.8818
1.088 / 4Constant 452.4Mean 487.6Sigma 0.8814
cables8.hbook
Conclusions on the SysTest so far:
• we still like sept. 99 for the next review...
~45 ps~36 ps w/ short cables
important coming tests: • Better control of Edep by Laser! (via filters) • Fake slewing... • FEE version IV + P/S 704 • FEE version IV + P/S 7106 • P/S 7186H TDC ... • Temperature dependence of timing...
sqrt(45**2-36**2) ~ 20 ps contributionfrom 250ft cables on both start and stop,→ ~14 ps contribution from a 250ft cable...
Results from the big full system
• large laser pulses...• BC420 20x4x2cm + Epotek 301 + R5946 + 2:1:...:1 CW base• First discrimination is Rice V.III• 250 feet cable between 1st and 2nd discrimination• Second discrimination is P/S 704• CAMAC digitization to LRS 2228A TDC (50ps/ch)• GPIB readout to PC and HBOOK/PAW
{Preliminary!
Central China Normal UniversityWuhan, China
Discussions began a few months ago amongst:Liu, Lianshou (Director, IOPP/CCNU),T. Hallman (BNL),myself and B. Bonner (Rice), andX.N. Wang (LBNL)...
possible major contributions to TOFp& TOF by IOPP group...
• Applying for CNNSF fundingpossible ~late 2000?
• Pursuing University funds for immediate use...“Expert” mtg, discussed and approvedApproved by CCNU President, ~7/25/99
The political arrangements are being discussed...The plan being discussed involves:- Support ~5 visitors to Rice & BNL...- Deliver ~25 R5946 PMTs...- Deliver DAQ/TRG interface...
Declan Keane reaffirms interest in significant KSU participationRice (~6), LBNL (~2), CMU (~1), MIT (~1) still active...
Time of Flight means starts and stops... time resolution is the quadrature sum of the two...
circa TOFp proposal, our understanding was the VPD would not exist in Year 1.we simulated TOFp-based corrections to ZDC (~250ps)
→ ~50ps resn. under favorable conditions, 91% efficientthis correction only works in highest mult collisions...in peripheral Au+Au, Si+Si, p+p, → ~200ps starts?
a simple <= ~16ch pVPD would solve the problem rather effectivelymost of the detector/electronics can be borrowed → conventional and very cheap
Recent interest/actual work towards a VPD or pVPD...Bellwied/Pandey et al. Bench tests of resolution of prop. electronicsKaplan/Russ et al. New simulationsJohn Mitchell Possible interest in significant participation...Crawford et al and TOFp...
What TOFp needs from a pVPD is not the full functionality of the well-known VPD.
TOFp wants Nch >> 2, up to Nch~16 (Nch/2 elements per side)TOFp only wants Nch analog signals with pVPD PMTs → TOFp ADCs...
Nch logic signals from disc close by → TOFp TDCs...CTB or equiv pretrigger as for RICH......then logic local to TOFp forms TOFp master starts
STARpVPD
4m
pVPD
8-16 Pb/Sci or Pb/Quartz + Fast PMT
bellwied/edwards/brown
8575PMT?
linearbase
linearfan
commercial disc.close to pVPD elements!
HV
µ-metal
Publicto TOFp ADCto TOFp disc+TDC
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