1. Progress on coatings and grooves
C.Yin-Vallgren,
S.Calatroni,
P.Chiggiato,
P.Costa Pinto,
M.Taborelli
C based coatings: aging
Grooves
SPSU

2. Evolution of CNe9 over 1 month
Aging of C
Evolution of CNe9 over 1 month 2h 3d 8d
15d
23d
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
SPSU

3. Typical dose per measurement: 10-7Clb/mm2
Aging of C
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 dose
Typical dose per measurement: 10-7Clb/mm2
SPSU

4. One sample measured only once after 1 month
Aging of C
Is there a difference between aging of irradiated and non-irradiated samples?
One sample measured only once after 1 month
One sample measured only twice (2h and 1 month)
To be studied more in detail
SPSU

5. Aging of C on rough Zr: 1 week air
SPSU

6. MEASUREMENT OF PARTICLES IN A CARBON COATED TUBE
TUBE coated with carbon
Measure 2
TUBE + REF measured again in the clean room
Measure 1
Two identical SS tubes
Measured in clean room
TUBE + REF
REF remains in the coating lab. (closed with plastic covers)
SPSU

7. Grooves, calculation of L.Wang at SLAC on the geometry
Progress on grooves
Grooves, calculation of L.Wang at SLAC on the geometry
obtained on copper
Reduction also for B=0
so that we can measure
in the lab
CERN workshop on
Copper (S.Atieh, J.M.Geisser)
1mm
15º
Assuming delta-max=1.5
2mm
B=0
B=0.2T
B=2T
SPSU

8. Measurement on Cu grooves (scan on the sample)
Progress on grooves
Measurement on Cu grooves (scan on the sample)
flat
grooves
B=2T, 20°, 0.13 mm radii)
Expected decrease (perfect shape: 15° aperture, B=0) : factor 2
Expected decrease (20° aperture + radii 0.13 mm, B=2T) : factor 1.3
Measured decrease (real shape: 20 °+ radii 0.03 mm, B=0): factor 1.2
The difference is possibly due to imperfection of the machined shape
SPSU

9. - The entire piece bends
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
milling
shape tool
SPSU

10. 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
SPSU

11. -New SPS liner, aged 15 days (CNe13, starting δmax =1)
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
SPSU