[Halld-cal] Pulsing of Fcal and Bcal monitoring systems

[Fernando J Barbosa]

Hi Elton,

There are 4 distribution boxes upstream and 4 downstream; each 
distribution box services 12 BCAL sectors for preamp power (+5V & -5V), 
SiPM biases, RTDs (12 connectors) and monitor control boards (12 
connectors) - a total of 24 connectors feeding the 12 sectors - plus the 
input power and SiPM bias connectors from the power supplies. I could 
probably add another connector per box for the LED control board power 
and bias (we would have 6 LED bias and one LED power per box). We would 
then need 12 additional connectors for the LED control signals (12 
cables) coming from some rack(s). Because we are talking about two 
distinct functions, and given the number of all these connectors, I 
suggest we have the monitoring functionality in a separate box: a 
power/bias/RTD distribution box and a monitor distribution box.

The CAEN 1495 w/ three A395D provides for 24 separate triggers. So, we 
will need two of this per distribution box or 16 in total. We wil also 
need the corresponding CL2 cables (55 ft).

My total estimates are as follows:
Monitoring distribution boxes - 8 ($8k)
LED Power and bias supplies - 8 + 1 chassis ($36k)
CAEN 1495 w/ three A395D - 16 + 1 VME chassis ($58k)
Cables - 24 ($2k)
Total = $104k

Adding the FCAL and splitting these functions between the N and S 
platforms will get this total to $150k. As for schedules, we should be 
able to handle these tasks by late summer or early fall as resources are 
very tight.

Claus needs to submit the ETC to DOE by 11/13/12 so I need to have this 
into the ETC within the next few days.

Best regards,
Fernando






On 11/2/2012 10:15 AM, Elton Smith wrote:
> Dear collaborators,
>
> The cabling connections are being finalized and to complete design of
> distribution boxes and purchase necessary hardware we need to finalize
> some decisions regarding granularity of the pulsing and the bias supplies.
>
> A quick reminder of what we have: The Bcal and Fcal LED biases, +5V
> power, and trigger signals are supplied externally to the control
> boards. Each trigger signal will pulse 10 LEDs at a time. For testing of
> the mini-Bcal, we have been providing the bias the Bcal monitoring
> strings with a single bias, single +5V and a single trigger signal to
> pulse one string at a time. The trigger pulse was generated using NIM
> logic to produce TTL pulses. The bias and power for the boards will be
> provided by the same modular supplies we are using for the SiPMs, but we
> need to decide on the granularity (i.e. how may strings do we power from
> a single channel). The pulse generator should be programmable, so we
> need to make a decision about which electronics to purchase, and also
> how many strings should be pulsed at the same time (i.e. how many
> independent trigger signals do we need for the entire detector). One
> possibility is to use the VME 1495 with A395D boards for TT output,
> which can be programmed via VME.
>
> One final note about cabling distribution. For the Bcal, the voltages
> and triggers will be routed through distribution boxes, each box
> servicing one sector upstream or downstream. Therefore, the decision to
> be made is how many signals go to each distribution box, what cables are
> used and what electronics is used to generate the trigger signals.
>
> I pass this on for people to start thinking about this. We can have a
> discussion at the Cal Working group meeting next Tuesday.
>
> Cheers, Elton.
>
>

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