1. Powering of the Stave modules in the GOAT-1 proposal. Vladimir Gromov, Ruud Kluit, Harry van der Graaf. NIKHEF, Amsterdam. EUDET Annual Meeting, Amsterdam, the Netherlands. October 6, 2008.

2. Outline V.Gromov2 EUDET-08 6/10/2008  The GOAT-1 proposal : Gossip in ATlas.  Cooling of the Stave module.  Parallel powering scheme.  Summary.

3. GOAT-1: GOssip in ATlas V.Gromov3 EUDET-08 6/10/2008 Ø60mm Beampipe Inner Layer: 7 double Goat strings CO 2 cooling channels P-string conductor G-string conductor Gossip detector unit (1.4cm x 1.4cm) ~ 1m 64 chips The ATLAS Pixel B-Layer Replacement Proposal.

4. Cooling of the Stave module. Gossip Read-out chip (100mW/cm 2 ) CO 2 cooling tube - diameter 0.5mm - mass flux 858kg/m 2 ● sec heat Evaluations done by Bart Verlaat (NIKHEF, Amsterdam) Power_per _stave = 1.4cm ● 1.4cm ● 128chips ● 100mW/cm 2 = 26W Aluminum block - total cross-section 8.6mm 2 0.3mm V.Gromov4 EUDET-08 6/10/2008

5. Goat 1 stave ΔTmax=2°C Heat transport to the cooling tube. Aluminum block - total cross-section 8.6mm 2 +10.1mm 2 V.Gromov5 EUDET-08 6/10/2008 Simulations done by Bart Verlaat (NIKHEF, Amsterdam) ` ` CO 2 cooling tubes

6. Parallel powering scheme. V.Gromov6 EUDET-08 6/10/2008 Consider the use of the available ALU block cross-section (S=8.6mm2). Chip #1 170mA Power Supply Source 1.2V 11A 1.4cm R= 26.5 ● 10 -9 Ω ● m ● 1.4 ● 10 -2 m / 8.6 ● 10 -6 m 2 = 4.3 ● 10 -5 Ω. ∆V = R ● 11A+ R ●( 11A-0.34A) + R ●( 11A-2 ● 0.34A)+…+ R ● 0.34A = 8mV 8.6mm 2 R 1.2V 0V 1.192V 8mV Power losses ≈ 0.9% Chip #2 170mA Chip #3 170mAChip #4 170mA R Chip #63 170mAChip #64 170mA R R R R 340mA Chip #65 170mAChip #66 170mA Chip #125 170mAChip #126 170mA Chip #127 170mAChip #128 170mA Power Supply Source 1.2V 11A 1.2V 0V R R R R R R R R

7. Powering scheme with non-regular ALU block. V.Gromov7 EUDET-08 6/10/2008 Chip #1 170mA Power Supply Source 1.2V 11A ∆V R 1.2V 0V 1.185V 15mV Power losses ≈ 1.3% Chip #2 170mA Chip #3 170mAChip #4 170mA R1 Chip #63 170mAChip #64 170mA R2 R1 R 340mA Chip #65 170mAChip #66 170mA Chip #125 170mAChip #126 170mA Chip #127 170mAChip #128 170mA Power Supply Source 1.2V 11A 1.2V 0V R2 R1 R2 R R31 R2 R31 R2 R1 ∆V R= 4.3 ● 10 -5 Ω ∆V = R ● 11A ● 32 = 15mV

8. Summary. V.Gromov8 EUDET-08 6/10/2008  The cooling system proposed for the GOAT-1 project requires an Aluminum stave for heat transportation to the CO 2 tube.  The Aluminum stave could also be used for the powering of the read-out electronics.  The presented analysis demonstrates that with the available amount of conductive material (aluminum) the parallel powering scheme could be successfully used.