liu sps beam scraping system preliminary studies of new design and materials

1

LIU SPS Beam Scraping SystemPreliminary studies of new design and materials

(Materials studies based on TED/TCDI conditions)

LIU-SPS, Beam Loss, Protection, Transfer Lines Working Group Meeting

Maciariello Fausto Lorenzo 15/01/2013

2

Scraper history

Maciariello Fausto Lorenzo (EN-STI-TCD)

• Two orientations, two axis scrapers in LSS 1 and LSS 5• Used during operations more intensively with LHC

beams• Fast mechanical movements with risk of failure• Limited lifetime of edge-welded bellows• Polluting the machine, additional shielding needed

(RP)

Device H count V countBSHV.51659 28042 28043BSHV.11759 665 630BSHV.11771 176036 173971

Cycles on 16/01/2012Device H count V countBSHV.51659 7663 7623BSHV.11759 219 193BSHV.11771 78332 77406

Cycles on 14/01/2013

3

Results Boron Nitride

Transient Thermal

0.00

E+00

1.81

E-01

3.63

E-01

5.44

E-01

7.25

E-01

9.06

E-01

1.09

E+00

1.27

E+00

1.45

E+00

1.63

E+00

1.81

E+00

1.99

E+00

2.18

E+00

2.36

E+00

2.54

E+00

2.72

E+00

2.90

E+000

200

400

600

800

1000

1200

1400

1600

1800

2000

T [˚C ]

[m]

• Below the Melting point 2270 ˚C

• Max temperature reached with graphite R4550 was around 1300˚C


4

Results Boron Nitride (free)

Transient Structural

• Stassi’s criterion:

o Limit in compression 512 Mpa – Maximum compression stress 700Mpa

o Limit in traction 29 Mpa – Maximum traction stress 105 Mpa


5

The density is the key

Graph

ite

Boron

Nitr

ide

Boron

Nitr

ide

(hot

pre

ssed

)

Boron

Car

bide

Alum

iniu

m

Silico

n Car

bide

(HIP

)

Silico

n Nitr

ide

(HIP

)

Alum

inum

nitr

ide

Alum

ina

(85)

(H88

0)

Alum

ina

(97.

6)0.00E+00

5.00E+02

1.00E+03

1.50E+03

2.00E+03

2.50E+03

3.00E+03

3.50E+03

4.00E+03

• Even if the limit stress of BN is five times higher than graphite the increasing in density makes the stresses much higher

• No material was founded in our list of best materials.

ρ [Kg/m3]


6

Results Cfc 1.4

Transient Thermal

• Max service temperature for Cfc around 2000 ˚C (under vacuum).

• Below the Max service temperature.


0.00

E+00

1.81

E-01

3.63

E-01

5.44

E-01

7.25

E-01

9.06

E-01

1.09

E+00

1.27

E+00

1.45

E+00

1.63

E+00

1.81

E+00

1.99

E+00

2.18

E+00

2.36

E+00

2.54

E+00

2.72

E+00

2.90

E+00

0

200

400

600

800

1000

1200

1400T [˚C ]

[m]

7

Results Cfc 1.4

Transient Structural (Compression)

• Maximum /Minimum stress’ criterion needed:

• Limit in Compression (along z) 82.4 Mpa – Maximum compression stress 45 Mpa (Safety factor=1.82)

o Remind !!!• We are not taking into account the Dynamic stresses.


8

Results Cfc 1.7

Transient Thermal (Compression)


• Max service temperature for Cfc around 2000 ˚C (under vacuum).

• Below the Max service temperature.

9

Results Cfc 1.7

Transient Structural (Compression)

• Maximum /Minimum stress’ criterion needed:

o Limit in Compression 132 Mpa – Maximum traction stress 31 Mpa (safety factor =4.25)


10

ReminderTraction S.F.t Compression S.F.c

Max. value[MPa]

Limit[MPa]

Max value[MPa]

Limit[MPa]

Graphite R4550 26 38 1.46 143 125

Boron Nitrite 105 29 700 512

CFC 1.4 5 3084

6 45 82 1.45

CFC 1.7 4.8 12.848

2.6 31 132 4.25

• Best material in terms of ratio σlim/ σmax is CFC1.7• BN from CESselector, Cfc RNFF-SG 1.4 and 1.7 g/cm3 have been

used for TCDS Collimator (Sintec)• Dimanyc effects and scraping conditions still to take into account.


11

Design options – passive scraper


• Low density materials, thermal extension small• Brazing techniques not adequate

Go for a clamped solution

• Collimator designo without cooling (TCDI type) or with cooling (TCS type)

12

Design options


• Depending on cooling needs a insert design is also an option

Courtesy K. Ilinov /M. Furtinger for Medaustron

13Maciariello Fausto Lorenzo (EN-STI-TCD)

Thank you for your attention

• Any questions ?

liu sps beam scraping system preliminary studies of new design and materials

Documents