1. LVPS HEC Overview and Development
MPI LVPS-HEC Meeting
13-Oct-2009
H. Oberlack
MPI für Physik, Munich

2. ATLAS Calorimeter System
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

3. ATLAS LAr End-Cap Calorimeter System
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

4. ATLAS End-Cap Calorimeter & Surroundings
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

5. LAr End-Cap Cryostat Open
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

6. LVPS-HEC Box between TILE fingers
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

7. LVPS-HEC POWER BOX
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

8. DC/DC Converter
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

9. Two LVPS-HEC Boards in Front-End Crate
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

10. LVPS Boundary Conditions
LV box serves 1 quadrant with 8 φ-wedges; each φ-wedge (HEC 1 and 2) has 3+2=5 PSB boards;
Each PSB board requires 3 voltages:+7.2, +3.2,-1.6;
Each FEB crate has 2 LV boards;
Each LV board has 2 connectors, each connector serves 2 φ-wedges;
Limitations:
Volume of LVPS box between Tilecal fingers
Power cables from electronic room (USA15) to LVPS-HEC boxes
One feed-through / LVPS box
# feed-through connectors
Power through individual feed-through lines
Water cooling circuit of LVPS box
Water cooling of FEC (which LVPS-HEC so far does not use)
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

11. Current Needs & Limitations
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

12. Connector at FEC LV board is symmetric:
60 lines out of 64 used, 4 spare lines (900 mA) per connector
Heat loss per connector: 2.21 W
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

13. HEC Cabling Schematic inside Cryostat
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

14. Improved LVPS-HEC Design
Granularity of DC/DC system is too coarse, loss of entire quadrant
(8 wedges) in case of failure.
 New DC/DC design with finer granularity (2 wedges)
Single point of failures observed:
Single point of failure in DC/DC converter
Single point of failure on monitor board
 New design without single point of failure
Access for exchange of LVPS box needs opening of ATLAS, i.e. EC system needs to be moved:
10 weeks needed for opening and closing, i.e. Access ones per year.
 New design of LVPS box for fast exchange within monthly acces of 3 days
CONCLUSION:
Need new LVPS system for present HEC cold Electronics for Phase I
Need new LVPS system for new HECPAS cold Electronics for Phase II
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009

15. Tentative Upgrade Scenario
LHC Operation: Inst. Luminosity up to 1*10**34 cm-2 s-1
2010 – 2013
Operate present HEC cold elecronics
Operate present LVPS-HEC
sLHC phase I: Inst. Luminosity up to 3*10**34 cm-2 s-1
2014 – 2017
Operate present HEC cold electronics, be prepared for change over to HECPAS
Fall 2013: Install new LVPS-Phase I
sLHC phase II: Inst. Luminosity up to 1*10**35 cm-2 s-1
2019 – 20xx
Fall 2017: Install new cold electronics HECPAS
Fall 2017: Install new LVPS-Phase II for HECPAS
H. Oberlack MPI LVPS-HEC Meeting 13-Oct-2009