ix семинар памяти В.П.Саранцева 1 project fama: modernization of channels...

IX семинар памяти В.П.Саранцева 1

Project FAMA:

Modernization of channels for surface modification of materials

V. Alexandrov, S. Bogomolov, N. Kazarinov, V. Shevtsov JINR, Dubna, 141980, Russia

P.Beličev, N. Nešković, A.Dobrosavljević Vinča Institute of Nuclear Sciences, P. O. Box 522,

11001 Belgrade, Serbia


Project FAMA is related to the construction of the low energy part of TESLA Accelerator Installation (TAI) in the Vinča Institute of Nuclear Sciences (Belgrade, Serbia) and is intended for modification and analysis of materials by ion beams. FAMA includes 3 machines and 6 experimental channels. The machines are: - 14.5 GHz ECR heavy ion source – the M1 machine, - a plasma source of light ions – the M2 machine, - a small isochronous cyclotron – the M3 machine.


M2

A scheme of the FAMA : C1 – the channel for analysis of ion beams and irradiation, C2 – the channel for surface modification of materials,

mVINIS14.5 GHz ECRIS

pVINISMulticusp ECRIS

C3 – the channel for ion implantation, and C4 – the channel for deeper modification of materials.


A three-dimensional view of the M1 machine

14.5 GHz ECRIS

extraction electrode(puller)


A schematic view of the M1 channel

202.

7

506.

5

165

1042

.5

166.

5

elementeff.lengthon В/Во

(mm)

Aperturewh(mm)

B(T)

GQL

(T/m)

M1-SL 165.0 7070 0.6 -

M1-QL 202.7 8989 - 0.874

M1-AM1*) 658.6 10662 0.207 -

*) Eff.radius – 419.3 mm, geometrical radius – 400 mm, bending angle 90о, entrance angle 0о, exit angle 26.6о, Rogowski type.

Geometry and maximum values of fields and gradient


A three-dimensional view of the C1 channel


A schematic view of the C1 channel

125.7282

C1-SMC1-SL

255180

M1-AM1

249 334300 479170

779C1

Channel

1425.7

target

elementeff.length,

mm

Inner diameter,

mm

Good field

region,mm

B,T

C1-SM 180 110 80 0.04

C1-SL 170 110 80 0.7

Geometry and maximum values of fields

C1-BS


Some of the ion beams produced with the M1 machine

for C1 & C2

Ionspecies

Ionenergy(keV)

Ioncurrent(eA)

4He+ 15760

20

4He2+ 30410

40

14N4+ 60230

80

40Ar2+ 3050

40

86Kr12+ 180130

240

136Xe19+ 28543

380

for C2

Ionspecies

Ionenergy(keV)

Ioncurrent(eA)

14N5+ 75

470100125

14N6+ 90

87120150

40Ar8+

120660160

200

40Ar12+180

36240300

for C2

Ionspecies

Ionenergy(keV)

Ioncurrent(eA)

136Xe23+

345

25460

575

207Pb16+

24030320

400

207Pb20+

300

10400

500

136Xe19+ 475 43


Some of the ion beams spectra

Kripton beam spectrum

Ar 2+, mVINIS 05.02.1998

00.10.20.30.40.50.6

2 3 4 5 6 7 8 9 10 11 12

charge state

cu

rre

nt,

mA

136 Xe 19+

136 Xe 23+


Initial beam parameters

Initial particle distribution - VK

emittance, mmmrad

250

α 0radius, mm 5

XX`-plane XY-plane


Particle trajectories and 14N4+ beam envelope (C1)

0 50 100 150 200 250 300 350 400 450 500

D istance, cm

- 5- 4- 3- 2- 1

012345

En

ve

lop

es

, cm

Bz,

T

Horizontal

Vertical

Aperture

Aperture

1.0

0.5

0

-0.5

-1.0

puller

М1-АМ1

М1-АМ1

C1-SLM1-SL

Particle trajectories and 14N4+ beam envelope (C1)


Beam envelopes (C1)

0 50 100 150 200 250 300 350 400 450 500

D istance, cm

- 5- 4- 3- 2- 1

012345

En

ve

lop

es

, cm

Bz,

T

Horizontal

Vertical

Aperture

Aperture

1.0

0.5

0

-0.5

-1.0

0 50 100 150 200 250 300 350 400 450 500

D istance, cm

- 5- 4- 3- 2- 1

012345

En

ve

lop

es

, cm

Bz,

T

Horizontal

Vertical

Aperture

Aperture

1.0

0.5

0

-0.5

-1.0

4He2+

40Ar2+


Xenon beam

q=19

q=18

q=18

q=19

q=20

On target

Inside C1-DC

XX`-planeBeam spot

Beams with А > 100 need in collimation


Efficiency of transportation (C1)

М1 exitParameters of

elementsOn target

Ionspecies

Ionenergy(keV)

Ioncurrent(eA)

BM1-SL

(T)

BC1-SL

(T)

GM1-QL(Т/m)

Ioncurrent(eA)

Effici-ency(%)

xMF / yMF

(mm)

4He+ 15 760 0.33 0.28 -0.32 494 65 10 / 1220 760 0.38 0.33 -0.57 692 91 14 / 14

4He2+ 30 410 0.25 0.20 -0.35 82 20 12 / 1640 410 0.28 0.22 -0.29 123 30 10 / 15

14N4+ 60 230 0.31 0.27 -0.13 110 48 10 / 2080 230 0.35 0.31 -0.15 161 70 10 / 20

40Ar2+ 30 50 0.60 0.70 -0.79 1.5 3 17 / 2440 50 0.60 0.70 -0.91 1.5 3 9. / 9.

86Kr12+ 180 130 0.46 0.41 -0.14 77 59 18 / 20240 130 0.54 0.43 -0.22 115 89 6 / 19

136Xe19+ 285 43 0.45 0.41 -0.19 35 82 21 / 26380 43 0.53 0.43 -0.28 43 100 7 / 20


CONCLUSION on M1-C1 channel

Losses in magnet A1-M1 and in channel C1 for all beams, except argon, possible avoid. Practically there are losses for all types of beams at the beginning of M1 channel (in region of solenoid M1-SL). At increase in current of beam and reduction of its energy these losses grow (helium and 14N4+ at energy 60 Kev) and there are losses in puller. For elements with A<100 there is only the main charged state near target, extraneous ones are lost on the channel aperture. For heavier elements, in particular for xenon, it is required to use the variable vertical ion beam slit (C1-BS).


M1-C2 channel (heavy ions)

C2-QT12

C2-QT13C2-SL

M1-AM1


M1-C2 channel (heavy ions)Analysing magnet C2-MA

Radius of deflection 600 mm

Pole face rotation angles 26.6о

Pole edge profile Rogowski type

Scanners

Leff,

mmAperturewh, mm

C2-CS1 160 74 250

C2-CS2 160 250 74

C2-SL solenoid

Length with screen, mm 196

Inner diameter, mm 110

External diameter with screen, mm 384

Thickness of screen, mm 20

Effective length (В/Во)2, mm 131

B, T 0.7

Electrostatic triplets

length(mm)

(mm)

VQ

(kV)

QT21 75.0 69.5 1.3

QT22 150.0 69.5 1.3

QT23 75.0 69.5 1.3

QT31 100.0 69.5 1.3

QT32 200.0 69.5 1.3

QT33 100.0 69.5 1.3

B,T

.0138

.0138


M1-C2 channel (heavy ions)

Particle trajectories of krypton beam and apertures.Interface of MCIB04 code


C2 channel (heavy ions)

RMS 86Kr12+, 240 keV beam envelopes. Interface of OPTIMA code


M1-C2 channel. Efficiency of transportation

АМ1 exit С2-МА entry С2-МА exit

Energy(keV)

Ion current(eA)

Eff-cy(%)

Ion current(eA)

Eff-cy(%)

Ion current(eA)

Eff-cy(%)

Ion current(eA)

14N4+ 60 230 49 113 47 108 47 10814N4+ 80 230 70 160 68 156 62 142

86Kr12+ 180 130 59 76 50 65 45 5886Kr12+ 240 130 89 115 88 114 84 109

4He+ 15760380

6575

494285

3262

243235

2859

213220

4He+ 20760380

8796

660365

4378

327296

3276

243290

4He2+ 30 410 20 82 20 82 20 824He2+ 40 410 28 116 28 116 28 116

136Xe23 345 25 72 18 70 17.5 63 16207Pb16 400 30 98 29 84 25 84 25


M1-C2 channel. CONCLUSION

The loss in the triplet QT1 will exist under any adjustment and any currents of bunch.

To reduce these losses it needs to replace the first quadrupole QT11 in the triplet QT1 on solenoid.

Efficiency of transportation in channel C2 is in interval 80 - 100%.

Main losses occur in channel M1.

On example of 4He+ it is shown that efficiency of transportation possible to enlarge for smaller initial beam currents.


M2-C2 channel. Light ions

Multicusp ECRIS pVINIS

Ionspecies

E[keV]

Itot

[mA]

(90%)[

mmmrad]

Ispice

[mA]

H− 30 3.30 22.5 3.30

H2+ 30 10.25 28.3 4.61

H3+ 30 10.28 28.2 7.71

D− 30 2.58 23.0 2.58

D2+ 30 7.91 32.5 3.95

D3+ 30 11.62 33.7 8.13

Itot

[mA]

Ispice

[mA]

1.16 1.16

1.03 0.46

1.03 0.77

0.77 0.77

0.79 0.40

0.58 0.41


M2-C2 channel. Light ions:gradients and voltages of elements of channel

IonsGQD1

(T/m)

GQD2

(T/m)

BMА

(T)

VQT21

(kV)

VQT22

(kV)

VQT23

(kV)

VQT31

(kV)

VQT32

(kV)

VQT33

(kV)

H− -0.0049 -0.1807 0.042 1.44 -0.69 -0.30 -0.56 0.32 0.15

H2+ 0.1174 0.1281 0.059 -1.73 1.52 -1.27 -0.16 -0.02 0.09

H3+ 0.1285 0.1842 0.072 -1.94 1.51 -0.99 -0.94 0.37 0.22

D− -0.0069 -0.2556 0.059 1.44 -0.69 -0.30 -0.56 0.32 0.15

D2+ 0.1484 0.2127 0.083 -1.32 1.38 -1.40 -0.58 0.36 -0.15

D3+ 0.0297 0.3918 0.102 -1.31 1.37 -1.39 -0.56 0.36 -0.15


M2-C2 channel. Light ions:phase space of 2H+ on target


M2-C2 channel. Light ions:passing of fractions along channel

0 100 200 300 400 500 600 700 800 900 1000d istance, cm

0.0

0.2

0.4

0.6

0.8

1.0C

urr

i / C

urr

oi

D3+

D2+

D1+


M2-C2 channel. Light ions: CONCLUSION

Possible provide 100% transportation through channel M2-C2 if initial beam current to reduce (in contrast with nominal) before values, provided in Table. For light ions it is required to raise the voltages on triplet QT2 before 2 kV.


CONCLUSION

Потерь в магните М1-АМ1 и в канале С1 для всех пучков можно избежать. Для всех типов пучков есть потери в начале канала M1. При увеличении тока пучка и уменьшении его энергии потери растут. Для элементов с А < 100 в районе мишени остается только основная зарядность, посторонние теряются. Для более тяжелых элементов требуется диафрагмирование пучка.Эффективность транспортировки в канале С2 находится в интервале 80 100%. Ее можно увеличить для меньших начальных токов пучка. В канале М2-С2 можно обеспечить 100% токопрохождение для уменьшенных начальных токов пучков. Для легких ионов требуется увеличить до 2 кВ напряжения на квадруполях C2-QT21 и C2-QT22.


THANK YOU

ix семинар памяти В.П.Саранцева 1 project fama: modernization of channels...

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