18/6/03GS/ALICE Forum1 LVPS - Grounding Meeting of LVPS TF on Tuesday 17/6 Overview of TPC, TRD and...

18/6/03 GS/ALICE Forum 1

LVPS - Grounding

Meeting of LVPS TF on Tuesday 17/6

Overview of TPC, TRD and TOF subsystem with F. Szoncso/TIS-GS Review of subsystems SPD, SSD, HMPID, DiMuons (Tk & Trig) Grounding scheme of each subsystem

Wiener PL500 radiation testing, status and plans (ESS)

CAEN dc/dc converter radiation testing (ESS group & CMS team)

AREMpro radiation testing

Latest calculations of radiation levels


TPC Grounding


TRD Grounding


To DAQ

LowPower Supply

TOF ReadoutVME crate

To DAQ

48VBUS bar

TOF ReadoutVME crate

Optical link

Reference ground RG

½ TOF sector

LVDS

LVDS

FEA cards

Cabletray

2.5V

LVDS

Cabletray

TRM1

TRM2

TRM12

DRMGN

D

TRM1

TRM2

TRM12

DRM

Z

2.5 V VV VV

HVPower Supply

HV Distributionbox

SG

TOF Grounding


HV PS

LV PS

Subdetector Support - Safety Ground

Vessel (if any)

FEE

Screen (if any)

Equipment Rack - Safety Ground

Copper links (if any)

Grounding - (Over)simplified generic model

GS/210503

Mains

1M

Mains Ground

Tra

sf

Optical Links

Mains Ground


Status of Grounding

• Preliminary grounding plans shown– TPC, TRD, TOF, SPD, SSD, HMPID, DiMuons

• First overview of large systems by TIS does not reveal inconsistencies or violation of safety rules

• Plans comply with guidelines (isolation of subsystems, etc)– HMPID: problem of metallic pipes

• Not (yet) all mapped to generic template– Simplified functional scheme needed for operational verification

• Are guidelines an overkill ?– Follow established best practices in large detectors– Proof of principle: test with slice of real system (by end 2003)


Status of LV Power Supplies (I)

• Wiener (PL500 & variants)• Power & Radiation tolerance

– Joint effort in ESS to develop rad tolerant configuration for LHC experiments

– Power block validated for ATLAS & CMS radiation levels in exp. hall– Standard embedded microprocessor (controls all operations) sensitive to

very low levels– Recently tested new device may be more tolerant

• Controls– Modification required (switching of individual channels)– Control (OPC server) not yet finalized– Very slow response from supplier– Action: draft a common ALICE requirement document (L. Jirden) and get

help of ESS group to raise interest in supplier and expedite delivery


Status of LV Power Supplies (II)

• CAEN dc/dc converter (SASY, EASY)– Radiation test with ≈ 20MeV neutrons (CMS team)– Fluence up to >> 10 years LHC– 4 SEU observed, analysis under way– Radiation tolerance seems to be more than adequate for the levels

expected in ALICE– EMI of input power cables to be measured– Final validation of prototypes by ≈ end 2003

• AREMpro– Low power units for SDD (and possibly SSD)– Radiation tested with neutrons - spectrum up to ≈ 20MeV– No problems found for fluence >> 10 years LHC


Latest calculations of radiation levels(B. Pastircak)

• Charged hadrons contribution included in tables• Fluence includes normalization of NIEL to 1 MeV

neutrons• Higher fluence values for SPD inner layer (mainly)• Outside ITS

– TPC FE (inner radius) TID ≈ 0.65krad– fluence (1MeV n eq) ≈ 6.1011 cm-2 (p, > 20MeV) ≈ 6.1011 cm-2

– Other subdet locations with (p, > 20MeV) >> 108 cm-2

• Levels at rack locations are very low– TID ≈ 1 rad– fluence (1 MeV n eq.) << 108 cm-2

– ==> standard commercial equipment can be used


Status of LV Power Supplies (III)

• Some thoughts on Wiener LVPS• ALICE requires individual channel control as in PL500

F12– not requested by other LHC experiments (see eg ATLAS LVPS MS)– small number, relatively uninteresting business opportunity ?

• What if Wiener does not deliver “ALICE” PL500s ?– (Nearly) all subsystems have voltage regulators on FE load– Radiation levels in ALICE hall are expected to be so low that industry

standard products (wide range) may be used. Advantages and drawbacks:

• Estimated cost ≈ 1 Euro/W (< 3x lower than HEP units)• Outstanding reliability• Simpler functionality (remote setting, ramping, etc)• Developments needed: market survey, test, control s/w (OPC server etc)

– Should somebody look into this possibility ?


Conclusion

• Good progress in implementation of grounding plan• Progress in dc/dc converter testing• Questions on prototyping and availability of LVPS

– Essential controls not yet available– ALICE specific requirements may be niche market– Action: common ALICE requirements document

– Single source dependence

• Commercial “rad soft” equipment can be used at rack locations

18/6/03GS/ALICE Forum1 LVPS - Grounding Meeting of LVPS TF on Tuesday 17/6 Overview of TPC, TRD and...

Documents

Transcript of 18/6/03GS/ALICE Forum1 LVPS - Grounding Meeting of LVPS TF on Tuesday 17/6 Overview of TPC, TRD and...