Presents: B. Allongue (CERN-ECP/ESS), J. Bohm (Prague, SCT), G. Dumont (CERN, ECP/ESS), Ph. Farthouat (CERN), Guido Guidi (CAEN), Z. Hajduk (CERN, TRT), S. Kersten (Wuppertal, Pixels), E. Petrolo (CERN,Muons), R. Richter (CERN, Muons), J. Stastny (Prague, SCT), Francois Vazeille (Tiles), Brig Wiiliams (Penn)
 

1. Test Set-up for measurement in magnetic field. G. Dumont
A test set-up consisting in a magnet able to provide magnetic field up to 2 kGauss in a 200*500*500 mm^3 volume is being installed in the ESS group lab. It will allow to test power supplies or components in magnetic field.

2. Common specifications. Z. Hajduk
Zbyszek presented a table regrouping the specifications of the inner tracker power supplies. This table has to be updated with the last available data from the sub-detectors. Some manufacturers have been given these pre-specifications for comments.
This is a first step toward a possible single specification.

Action: Update the table (ZH with data from SK and JB).
Action: Check that the manufacturers can give feedback (ZH).
Action: Extract a single specification (ZH).

3. Power supplies in USA15.
The impact on the cost of locating the PS in USA15 has been evaluated by ZH for the TRT and JB for the SCT.
Assuming a 6 kW power loss in the cables for the TRT, ZH estimated an overcost of 250-360 kChF and an increase in the cross-section from 600 cm^2 to 750 cm^2. BW stated that the cost for cables cooling should be added as it is probably necessary to cool them.
For the SCT, JB computed a cost increase of 1750 kChF for a total power loss in the cables of 2.6 kW.

Action: Other sub-detectors to make the exercise.

4. Radiation damages. R. Richter
Robert showed the effect of radiations on components used in the power supplies. In particular he emphasised that the lateral PNP and vertical NPN and PNP devices are sensitive in particular to neutrons (no Beta after 10^12 N.cm^-2 in lateral PNP).
He encouraged everybody to look at the RD49 (Radtol) status report presented by P. Jarron at the last LEB.
He proposed to start looking at irradiation measurements of sensitive components in collaboration with CMS.
In parallel one could pursue the idea of shielding the power supplies against neutrons with polyethylen or polyethylen with Boron (see Atlas Technical note #028).
Francois Vazeille presented a neutron radiation facility available in Clermont-Ferrand.