The CNGS Horns
Electrical Systems
4th workshop on Neutrino Beams and Instrumentation
7 – 11 November 2003 at KEKGilles.Maire EP/TA31

Outline¾Introduction.
¾Electrical Circuit.
¾Components and Status.
¾Test of inner conductor Horn.
¾Controls.
¾Planning.
¾Conclusions.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

2

Introduction
Horn and Reflector (Load)
I

Every 6s

50mst

•7 m long (approx.)
Sandry Wallon IN2P3• 1.6 tonne (approx.)

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE3Introduction
General View
Charging
Power Supplyin surface

Horn and Reflector
In Target Chamber

Strip Lines fromTransformers toHorn & Reflector

Power cables(~1000m) along
Access Galleries
Pulse Transformer
In Service Gallery

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

4Introduction
Parameters
Load Peak current

Unit

HORN System

REFLECTOR System

kA150

180

1632

Transformer ratio
Primary current peak

A9375

5625

Load inductanceµH

2,7 X 16 X 16 = 691

1,5 X 32 X 32 = 1540

Total inductance with 4 cables

µH

1210

2046

Load resistancemΩ

0,6 X 16 X 16 = 154

0,21 X 32 X 32 = 215

Total resistance with 4 cables

mΩ328

495

Total capacitance for one pulseµF40804080

Pulse durationms

7,510Charging voltage

V7700

6300

Total stored energykJ

2 X 119 = 238

2 X 80 = 160

Load max. voltage

V

280

150

Mean power dissipated by current
only (2 pulses)

kW

16

10,5

Total power dissipated (with beam)

kW

26

16,5

Water flow for delta T=5Cl/min

70

70

Pressure

bar

1,2

1,2

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

5Electrical Circuit
DiagramCharging Unit
10kV - 20A
Thyristors
BridgeTRDischarge
Circuit 1

DiodesBridgeCapaI

Thyristors
Discharge

Pulse 1Start
Charging

StopCharging

Delay 50ms

Polarity Changer
Earthingt

PowerCables(~1000m)

Pulse 2Capa

Thyristors
Discharge

Experimental Area
TR

HORN

Discharge
Circuit 2

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

6Electrical Circuit
WANF Recuperation or NEW ?
Beginning of Project

NOW

WANF Recuperation
NEW
WANF Recuperation

WANF Recuperation
NEWNEW

Capacitors

WANF Recuperation

NEW

Discharge Switches

NEWNEW

Power Cables

NEWNEW

Pulse Transformers

NEW

WANF Recuperation

Power SupplyThy. Bridge
Transfo. LV/HVElectronics

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

7Components and Status
Charging Power Supply¾ Need to increase charging voltage to 10kV.

• Buy new transformer (LV/HV), first delivery in July 2003 andsecond for July2004.
• All other power components can work at 10kV.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

8Components and Status
Charging Power Supply¾ Electronic regulation and interlocks.

• Old and obsolete regulation (25 years old). We had spare cards

but electronic components didn’t exist on the market.
• The Power Group will take in charge this installation aftercommissioning. We will install a standard electronics of thisgroup. The study and installation will be done for the end of2003.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

9Components and Status
Charging Power Supply
Old Electronic
New Electronic

6U24U

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

10Components and Status
Capacitors Discharge¾ At the beginning of Project• We wanted to reuse WANF capacitors.
• For safety and infrastructure constraints, Safety Division ofCern forced to us to install this equipment in a new building. Theestimate cost of this new building was 650kCHF.

¾ Now• After new study, we will buy new capacitors (self healingtechnology) for a cost of 200kCHF.
• We will install equipment in an existing building.

¾ Call for Tender• Result of the Call for Tender was in June 2003, AVX-TPC (FR).
• Pre-Series in December 2003 and series in September 2004.
4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

11Components and Status
Capacitors Discharge
Capacitance

340µF +/-5%

Operating Voltage

10000Vdc

Reverse Voltage

50%

Maximum Peak Current

1300A

Energy17kJ

Repetition Rate

6sec

Life Time

2x107 pulses

Serial resistance<3.3 mΩCapacitor inductance<100 nH

Dielectric Stress

206 V/µm

Ignition temperature ofdielectric fluid

Rape seed oil: 344°C

Dielectric system

Rough polypropylene film
metallized

Dimensions

L=360mm
W=335mm
H=705mm

Weight102kg

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

12Components and Status
Capacitors Discharge

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

13

Components and StatusCapacitors Discharge¾ WANF capacitors• 36 racks with a total of 360 capacitors.

¾ New capacitors• 12 racks with a total of 48 capacitors.

¾ Results• Space saving. Number of racks dividedby 3.
• Important cost saving for infrastructureand cabling.
Rack with WANF capacitors
4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

14Components and Status
Thyristor Switches (20kV, 18kA)- All Th. Switches needed

have been bought anddelivered by ARCEL (FR).
- 3 thyristors in series,
sharing resistor, RCsnubber and impulsetransformer.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

15Components and Status
Thyristor Switches (20kV, 18kA)

2 Th. Switches are alreadyinstalled and tested inBA7.
•8,2kV, 170kA with ratio 32•6,5kV, 150kA with ratio 10

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

16

Components and Status
Power Cables¾ Important parameters for the choice of the power cables.
• Resistance and inductance cable must be much smaller than load

impedance (Transformer, Strip Lines and Horn).

9 To minimize the voltage drop in the cable.
9 Not to increase too much the duration of the pulse.

¾ Our choice.

• Four 18kV cables in parallel (each with 2 twisted 150 mm2 CUconductors) will be installed per system.
• For 4 cables in parallel, the resistance and inductance (Nexans datasheet) will be : R = 100mΩ, L = 160 µH.
• Measurements have been performed on the existing WANF cables.
The impedance of this cable was R = 110mΩ, L = 130µH.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

17Components and StatusPulse Transformers¾ At the beginning of the project• We wanted to buy 2 new transformers with ratio 14 for an

estimate cost of 580kCHF.

¾ Now, reusing of WANF transformers• A test program has been realized to validate the reusing of the2 Tesla pulse transformers of WANF.
• We can reuse this transformers in ration 32 or 16 (special
coupling in the secondary side.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

18

Components and Status
Pulse Transformers
Ratio 32

150000100000

Simulation

50000

0.002

0.004

0.006

0.008

0.01

0.012

-50000-100000

SL Current
Primary Current

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

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Components and Status
Pulse Transformers
Ratio 16150000100000

Simulation

50000

0.001

0.002

0.003

0.004

0.005

0.006

-50000-100000

SL Current

Primary Current

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

20

Test of inner conductor Horn
100.000 double pulses in Oct. 2003
I = 150kA
Water Flow = 50l/min at 1.5 bars
Ambient temp. = 20°C
Primary Water temp. = 20°C
Start

End

Neck Small diam.

20°C

32°C

Neck Big diam.

20°C

34°C

Water IN Horn

20°C

26°C

Water OUT Horn

20°C30°C

Transformer

20°C

50°C

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

21

Controls
Control Room supervision
CERN network

Card

Ethernet
CardLocal Supervision PC
Card

Applicom
Card

Industrial Ethernetd i g i t a l

PLC

DISCHARGE
CIRCUITPOWER
CONVERTER

Designed by Sylvain RAVAT EP/TA3

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

22

Controls

PLC Racks

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

23

Controls

GeneralView

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

24

Controls

HistoricalView4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

25

PlanningNov. 2003
4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE

26

Conclusions¾Electrical circuit•Good progress since the beginning of the project with thevalidation of the electrical circuit.

¾Cost Saving of 750kCHF since the beginning of project.
•Migration to an existing building with new capacitors.
•Reusing of the pulse transformers.

¾Test and Key date•Validation of the first Horn inner conductor with 100.000 double

pulses during October 2003.
•Test of the two Horns and Reflector before the end of 2004.
•Power cables will be installed at the beginning of 2005.
•Moving electrical circuit in BHA4 at the beginning of 2005.

4th NBI, 7 - 11 November 2003 at KEK by Gilles MAIRE27