Status of the CLIC DR wiggler design and production at BINP

CLIC DR emittance requirements SC emittance PM emittance CLIC DR normalized emittance  as a function of the wiggler period and the field amplitude by M.Korostelev, IBS included PM SC N

Outline

• Wiggler parameter selection

• Magnetic and mechanical design

• Quench protection system

• Wiggler production status

• Wiggler production schedule

CLIC DR emittance requirements

SC emittance

PM emittance

CLIC DR normalized emittance 

as a function of the wiggler period

and the field amplitude

(by M.Korostelev, IBS included)

PM SC (NbTi) Period length cm 10 5

Aperture (beam) mm 12 12

Peak field T 1.7 2.5

Temperature K Room 4.2 K

Wiggler parameters selection IFor a sine-like wiggler model:

5 / 2 5 3

2 5

/

32min

/ 1

2 5 3

w w

w

L

I L

I h

The field amplitude depends on the wiggler gap and period length as:

The gap usually is defined by external conditions (SR passing)

PM technology vs SC technology

Facility Year Bm(T) g(mm

)  (mm) L (mm) Ay(mm) SC

CLIC DR

SC CLS (Canada) 200

DLS (UK) 200

CLS-2 (Canada) 200 7 4.0 14 48 1000 9.5 ALBA (Spain) 200

PM

PETRAIII

4-m-long PM damping wiggler for

Main principles

 Short period and high field amplitude

 Simple technology and easy production

 Easy in tuning

 Reliable (all coils are wound by a single wire  min of contacts)

 Magnetic forces are directed in the iron yoke 

no fixing mechanical band is needed

 Special quench protection system is proposed

Magnetic design IMagnetic flux

y

z Half period

End part

Air – blue

Iron – green

Coil - red

Magnetic design IIField amplitude in the wiggler parts (3D)

Magnetic design IIIField distribution (3D)

Longitudinal in central pole

Longitudinal in the end part

Transverse

dB/B = ±3.5x10-4

at X = ±1 cm

Mechanical design IGeneral view

Mechanical design IIYoke regular part

End coils to compensate the first

and the second integral

SC wire contacts

SC strand thickness – 30 um

For many years Bochvar Institute in Moscow produces special NbTi SC wire for BINP with the following parameters:

Critical current curve

In our case the current

density in the SC wire is

1250 A/mm2

Quench protection system I

A comparator measures the voltage difference between upper and low coils, which appears in case of quench If the difference appears, the heater (stainless steel strip mounded along all the coils) heats the

coils by the capacitor pulse discharge, providing uniform distribution

of the stored energy along the wiggler

Quench protection system II

Voltage distribution diagrams with and without the quench protection system

Magnetic measurements

 Hall probe array (5 probes placed horizontally with 10 mm distance)

700 A PS 

 Testing cryostat

Status

 Wiggler development and design is completed

 The wiggler manufacturing drawings passed the

technological department

 Parts of the spooling device are manufactured and its assembling will start in near future

 We have all materials including SC wire

 We have the testing cryostat, power supplies for the

main coil (700 A) and for the correction coils (2 PSs 10 A)

 We have all necessary equipment for magnetic

measurement

 The quench protection system is under development

now

Schedule

17.03.07 – 01.10.07: the wiggler design and starting the production of the coiler unit to test the winding technology

01.10.07 – 01.03.08: finalizing of the winding technology and starting of production of the wiggler prototype

15.11.07 – Status report including: magnetic field calculation, winding technology description, drawings of the wiggler prototype and winding tooling, description of the quench protection system

01.03.08 – 01.06.08: yoke and tooling production 01.06.08 – 15.07.08: coils production

15.07.08 – 01.08.08: wiggler installation in the cryostat

01.08.08 – 01.10.08: wiggler test and magnetic measurement

Conclusion

 The short prototype of the SC wiggler for the CLIC

DR is under production at BINP

 Main parameters of the wiggler are: Bmax = 2.5 T with the period length of 50 mm and the pole gap