SPSU05.08.2008

Progress on coatings and grooves

C.Yin-Vallgren, S.Calatroni, P.Chiggiato, P.Costa Pinto, M.Taborelli

-C based coatings: aging-Grooves

SPSU05.08.2008

Evolution of CNe9 over 1 month

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 500 1000 1500 2000

energy

SE

Y

CNe9_20080630_1

CNe9_20080702_4

CNe9_20080707_1

CNe9_20080714_1

CNe9_20080723_1

CNe9_top_20080714_

2h3d8d15d23d

Aging of C

Slight shift of Emax to lower E, is compatible with higher SEY for surface sensitive, low energy electrons. Same as for contamination coverage of air exposed surfaces of metals

SPSU05.08.2008

Aging for 2 nominally identical samples stored in the lab in air, in sample box

Measurements made repeatedly on the same sample: the air exposure occurs after the sample has received already a doseTypical dose per measurement: 10-7Clb/mm2

Aging of C

0.4

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0.6

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0.9

1

1.1

1.2

1.3

1.4

0 5 10 15 20 25 30 35Time[d]

SE

Y

C-Ne 8 bottom

C-Ne9 top

SPSU05.08.2008

Is there a difference between aging of irradiated and non-irradiated samples?

0.4

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0.9

1

1.1

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1.4

0 10 20 30 40

Time[d]

SE

Y

C-Ne 8 bottom

C-Ne9 top

CNe9_B

CNe9-bottom

One sample measured only once after 1 monthOne sample measured only twice (2h and 1 month)To be studied more in detail

Aging of C

SPSU05.08.2008

0.0

0.1

0.2

0.3

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0.5

0.6

0.7

0.8

0.9

1.0

0 500 1000 1500 2000

energy

SE

Y

CNe9_RoughZr_20080715_1

CNe9_RoughZr_20080724_1

CNe9_RoughZr_2008

Aging of C on rough Zr: 1 week air

SPSU05.08.2008 1

10

100

1000

104

105

0 5 10 15 20

Particles counted before and after coating3m > D

particles > 5mm

REF measure 1TUBE before coatingREF measure 2TUBE after coating

nu

mb

er

of

pa

rtic

les

run#

1

10

100

1000

104

0 5 10 15 20

Particles counted before and after coatingD

particles > 5m

REF measure 1TUBE before coatingREF measure 2TUBE after coating

nu

mb

er

of

pa

rtic

les

run#

Measure 1Two identical SS tubesMeasured in clean room

TUBE + REF

TUBE coated with carbon

REF remains in the coating lab. (closed with

plastic covers)

Measure 2TUBE + REF

measured again in the clean room

MEASUREMENT OF PARTICLES IN A CARBON COATED TUBE

SPSU05.08.2008

Grooves, calculation of L.Wang at SLAC on the geometryobtained on copper

Progress on grooves

2mm

100 200 300 400 500 600 7000.2

0.3

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0.5

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0.7

0.8

0.9

1

Energy (eV)

SE

Y

0=1.50,Height=1.0mm, =150, B=0

CERN workshop onCopper (S.Atieh, J.M.Geisser)

0 100 200 300 400 500 600 7000.2

0.3

0.4

0.5

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0.8

0.9

1

Energy (eV)

SE

Y

0=1.50,Height=1.0mm, =15o

B=0.2TeslaB=2 Tesla

B=0

Assuming delta-max=1.51mm

15º

Reduction also for B=0so that we can measure in the lab

B=0.2TB=2T

SPSU05.08.2008

0 200 400 600 8000

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1

1.2

1.4

Energy (eV)S

EY

Grooved SurfaceFlat Surface

0=1.20,B=2 Tesla,R

tip=0.13mm,H=1mm

Measurement on Cu grooves (scan on the sample)

Progress on grooves

Expected decrease (perfect shape: 15° aperture, B=0) : factor 2Expected decrease (20° aperture + radii 0.13 mm, B=2T) : factor 1.3Measured decrease (real shape: 20 °+ radii 0.03 mm, B=0): factor 1.2The difference is possibly due to imperfection of the machined shape

B=2T, 20°, 0.13 mm radii)

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1.0

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2.0

0 500 1000 1500 2000

Energy [eV]

SEY

GrCu_20080711_1

GrCu_20080711_2

GrCu_20080711_3

GrCu_20080711_4

GrCu_20080711_5

GrCu_20080711_6

SmCu_20080711_1

SmCu_20080711_2

flat

grooves

SPSU05.08.2008

Progress on grooves

On Stainless steel:- By manufacturing with a shaped cutting tool the bottom of

the valley is rounded and the tips bend- The entire piece bends

grooves

-release material tensions by thermal treatment before machining- Trials in progress with a milling tool, but for the moment is shows to much wear

millingshape tool

SPSU05.08.2008

Plans for SEY instrument

Done:- Retarding system up to -90V to measure low energy part of the SEY curve

Next:-Implement flood gun for conditioning with e-beam

SPSU05.08.2008

Next on coatings:-New SPS liner, aged 15 days (CNe13, starting δmax =1)-More measurements of aging with single measurement on aged sample-layer of CNx

-characterization by Raman (collaboration with the Uni of Cambridge)

Next on grooves:-Improved shape from workshop-Measurements to be done on Al grooves received from M.Pivi

Other-SPS sample to be extracted and measured on 11/8, possibly new C sample inserted on the same day