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CLARO Requirements 30 April 2013 CERN g.pessina -1-

CLARO

Paolo Carniti INFN & University of Milano Bicocca

Lorenzo Cassina INFN & University of Milano Bicocca

Angelo Cotta Ramusino INFN and University of Ferrara

Massimiliano Fiorini INFN and University of Ferrara

Andrea Giachero INFN & University of Milano Bicocca

Claudio Gotti INFN & University of Milano Bicocca

Matteo Maino INFN & University of Milano Bicocca

Roberto Malaguti INFN and University of Ferrara

Gianluigi Pessina INFN & University of Milano Bicocca

CLARO supporters:

Marta Calvi INFN & University of Milano Bicocca

Clara Matteuzzi INFN & University of Milano Bicocca


Summary

• Requirements from the upgrade;

• Spillover;

• Cross-talk;

• CLARO vs MAROC3;

• CLARO vs NINO;

• Resources;

• Plans.


Requirements

1. Capability to work up to 25 ns bunch crossing rate with no spillover

(see next);

2. Gain tuning to the pixel spread (factor of 3 maximum);

3. Binary output with adjustable threshold;

4. Small power consumption (programmable as a function of the

occupancy, connected to 1. and se next);

5. Cross-talk threshold below 5% (see why next and Claudio talk);

6. RadHard proved up to 81013 n/cm2 (next week we will know and

see Angelo talk).


Spillover requirements (1)

From Sajan simulations the maximum occupancy is expected between

22% and 31%, but only in the central region of the detector.



According to statistics the level of occupancy foreseen asks for no spillover, or

a marginal amount of it.

In addition the larger part of the detector region has a very low level of

occupancy. Therefore there the requirements of speed can be relaxed and

power consumption can be adjusted accordingly.



CLARO recovery time is within 25 ns and spillover is not present at all.

Power dissipation can be set remotely (new feature) in low power mode and high

power mode.

In low power mode signal is recovered anyway 25 ns and can be applied in the

lower occupancy parts of the detector.

CLARO measured signals from a few

hundreds of PMT e- up to more than 3 Me-.


Cross-talk (1)

From the PMT characterization it

seems that triggering below 35-

40% of the single-photon peaking

falls into noise.

We face 2 scenarios.

We suppose to have single-photon hits. The photon signals extend up to about the

double of the peak. If we ask that these signals do not trigger the neighbor

channels by cross-talk they should stay within 35%, or 17% with respect to the

peak.

Add 5% of additional margin we arrive at 12% (take care: 12% is not statistical is

the fraction of charge lost in the nearby channel via stray capacitance).

But…


Cross-talk (2)

So we have to add a constraint. One possible choice is that the maximum signal

that can be lost must be less than 20%, which means that 5% is the maximum

acceptable cross-talk.

Concerning single photon only we could consider acceptable a maximum

cross-talk level of 5%, limited by 20% of signal loss.

Q(1-4)

Q

Cxt

Cxt

Cxt Cxt

Q from pixel

Q

Q

Q

The fraction of the signal, , in the nearby

channels is 4 times that of the single channel. If

we do not care about it, the risk is that neither of

the 5 channels will trigger at all. For instance,

12%4=48%>35% threshold set!

(this is true as far as the time scale of the cross-

talk signal is comparable to that of the shaping

time, example Ri=100 and Cxt=2 pF 8 ns).


Cross-talk (3)

According to Sajan simulation, an

occupancy of about 25% lead to a

probability of double hit of about 6%.

If we would like to avoid cross-talk from this situation we have to ask for a factor of

2 smaller threshold, from which subtract again 5% of margin obtaining 4% of

acceptable cross-talk.

In case of double-photon signal we could consider acceptable a maximum

cross-talk level of 4-5%, or ¼ of the threshold, whichever is smaller.


Cross-talk (4)

In summary:

So we could consider:

Maximum cross-talk: 5%

• Single photon 5% of maximum acceptable cross-talk

• Double-photon 4-5% of maximum acceptable cross-

talk


Summary of the characteristics

Power consumption in ‘low power’ mode 0.7 mW/ch a low rate, 1.9 mW/ch @ 10 MHz event rate

Power consumption in ‘timing’ mode 1.5 mW/ch at low rate, 2.3 mW/ch @ 10 MHz event rate

Power consumption Remotely settable in the new chip, hardwired settable in the present

Input noise @ Ci=3.3 pF 6 ke- RMS

Gain setting 3 bits

Threshold setting 5 bits

Programming interface SPI (addressable SPI in the new version, Angelo’s talk)

Threshold step at max gain 150 ke-

Peaking time


Competitor comparison: MAROC (1)

CLARO MAROC (*)

Power (save a factor of 5) 0.7 mW/ch 3.5 mW/ch

Input noise 6 ke- RMS 6.5 ke- RMS

Gain setting 3 bits 8 bits

Threshold setting 5 bits Common to all channels, 10 bit DAC.

Programming interface SPI (addressable SPI in the new version)

SPI standard

Threshold step at max gain 150 ke- Do not know

Pulse width (narrower pulse width, 4 to 5 times)

5 ns to 25 ns Peaking time from 20 to 25 ns for fast shaping, 100 ns to 125 ns pulse width, 30 ns to 150 ns, tunable, pulse width from 150n s to 600 ns

Crosstalk 0% on chip 0.25% on chip, slow shaper 1% on chip for fast shaper (2-3% measured on previous versions)

Rad Hard We will see next week Do not know, expected similar to the present CLARO design

Rad hard strategy Triple redundancy in the register, addressable SPI protocol which simplify the logic (see Angelo’s talk)

No strategy (as far we know)

Time over threshold Available Not Available

(*) Source of characteristics: MAROC3 datasheet


Competitor comparison: MAROC (2)

0 25 50 75 100 125 150 175 2000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

11

Time (ns)

Arb

. U

n.

MAROC3

CLARO

Effect of shaping time on signal:

spillover B

unch

-3

Bunch

-5

Bu

nch

-4

Bu

nch

-2

Bu

nch

-1

Bu

nch

-6

Bunch

-7


Competitor comparison: NINO (1)

CLARO NINO (*)

Power (50 times smaller) 0.7 mW/ch (0.18 W per module) 35 mW/ch (9 W per module)

Input noise 6 ke- RMS 5 ke- RMS

Gain setting 3 bits Fixed

Threshold setting 5 bits Only in hd, not programmable

Programming interface SPI (addressable SPI in the new version)

Not present

Threshold step at max gain 150 ke- Do not know

Pulse width 5 ns to 25 ns Do not know

Crosstalk 0% on chip Donot know

Rad Hard We will see next week Do not know, expected a bit better to the present CLARO design (0.25 vs 0.35 CMOS)

Rad hard strategy Triple redundancy in the register, addressable SPI protocol which simplify the logic (see Angelo’s talk)

No strategy (as far we know)

Time over threshold Available Available: the output is only digital, not proportional to the input charge in amplitude, but in wildness.

Jitter 10 ps RMS, single photon 10 ps RMS, single photon.

(*) Source of characteristics: NIMA 533, 183, 2004, IEEE TNS 51, 1974, 2004.


Common attribute

CLARO, MAROC3 and NINO have all the input impedance declared between

50 and 100 .

This means that the expected level of cross-talk is expected quite similar in all

cases.


Resources

Recently MIB and FE joined some resources in this project.

In the next years we can dedicate time to both the PMT and the electronics.

In addition Genova will contribute also to both items.

We will have a meeting after tomorrow about this.


Plans

• Module prototype with the present CLARO version (80 chips on the

way, 4 PMTs and spare);

• New 8 channels CLARO (Rad Hard, gain, threshold, etc.)

pessina gianlugi - claro meeting...claro requirements 30 april 2013 cern g.pessina -1- claro paolo...

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