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