Presents: B. Allongue (CERN-ECP/ESS), J. Bohm (Prague, SCT), R. Chadelas
(Clermont, Tiles), G. Dumont (CERN, ECP/ESS), Ph. Farthouat, M&J Givoletti
(CAEN), Z. Hajduk (CERN, TRT), Piotr Malecki (Cracow, SCT), R. Richter
(CERN, Muons), Francois Vazeille (Tiles)
1. Organisational matters.
A working group on power supplies has been set-up with a representative
of each sub-system. They are:
The frequency of the meeting should be of the order of 4 per year and
should be organised during one of sub-system week.
The next one will be on Friday January 30, 1998.
2. Sub-systems presentations.
Most of the material is available in the FE electronics coordination
page.
In the cavern, the magnetic field may be between 300 and 1000 Gauss
and the radiation levels are (for 10 years of operation):
- 10 Gy and 5 10^11 to 10^12 N.cm^-2
A summary of the requirements are given in the following table:
|
|
|
|
PIXELS | 2600 | 1.5 V, 1.5 A | |
3V, 2A | |||
10 V, 0.01 mA | |||
500 V, 2 mA | |||
SCT | 4088 | 1 V, 6 mA | |
3.5 V, 1 A | |||
4 V, 250 mA | |||
7 V, 6 mA | |||
10 V, 0.01 mA | |||
300 V, 4 mA | For n-on-n detector. | ||
TRT | 1350 | 3.3V, 6A | |
- 3.3 V, 3 A | |||
5 V, 1 A | |||
HEC | 320 | -3 V, 100 mA | |
4 V, 500 mA | |||
8 V, 1 A | |||
TILES (1) | 256 | 5 V, 500 mA | High voltage distributors |
15 V, 500 mA | |||
- 15 V, 500 mA | |||
TILES (2) | 128 | 5 V, 20 A | Read-out Barrel |
-5 V, 10 A | |||
9 V, 400 mA | |||
TILES (3) | 128 | 5 V, 14 A | Read-out Extended Barrel |
- 5 V, 7 A | |||
9 V, 300 mA |
The SCT has already a fairly detailed block diagram of their power supplies and one has been irradiated with 1.3 10^10 N.cm^-2 and 2.5 Gy (gamma) without exhibiting any failure. They also consider the use of a shield (40 to 50 cm of polyurethylene) to decrease the radiation level of fast neutrons by two orders of magnitude.
ZH presented an evaluation of extra cost in cables which would be introduced if one has the PS of the TRT in USA15. This exercise should be repeated for other sub-systems.
3. Manufacturers presentations.
CAEN and DPS were present. Both of them are designing power supplies
(high and low voltages) and expressed their interest in collaborating with
us. A first step will be to try to understand with them what are the elements
in our requirements which are driving the cost.
4. Work.
- Someone has to write down irradiation test procedure. R. Richter
to look at it. Prague will continue an irradiation of existing LV prototypes
for SCT.
- Same for magnetic field. Ph. Farthouat to look at it with the CERN
electronics pool.
- Z. Hajduk to start compiling the requirements and to contact manufacturers.
- Sub-systems to evaluate the cost of extra cables if the PS are in
USA15.