1. S.Burger BE-BI-PM HiRadMat Scientific Board 29th June 2017
HiRadMat New BTV
S.Burger BE-BI-PM HiRadMat Scientific Board 29th June 2017
Thanks to the colleagues:
M.Bergamaschi (BE-BI), Aymeric Bouvard (EN-EA), E.Bravin (BE-BI), V.Clerc (EN-EA), A.Fabich (EN-EA), A.Goldblatt (BE-BI), A.Guerrerro (BE-BI), JJ.Gras (BE-BI), F.Harden (EN-EA), L.Jensen (BE-BI), K.Kessi (BE-BI), S.Mazzoni (BE-BI), C.Rinaldi (BE-BI), F.Roncarolo (BE-BI), A.Sounas (BE-BI), T.Lefevre (BE-BI), G.Trad (BE-BI), etc...
& OP-SPS team !!

2. Content BTV description New BTV development Specifications Layout
Design/Installation
Measurements
Conclusion

3. BTV description Insertion device Radiator Lights Camera
Holding an
in-vacuum radiator
Radiator
Can be scintillating (Al2O3, ZrO2 etc…) or reflecting material (C, Ti, etc…) depending on the application and type of beam
Beam direction
Vacuum pipe
Lights
Mainly used for system calibration and beam steering
Glass window
Camera
Can be standard CCD or special Rad hard (CMOS, CID, Vidicon tube)
Optical density filters
Can be added in front of the camera to increase the dynamics of the system

4. New BTV development: Specifications
Give beam position and size for all HRM extractions
440 GeV beam
1-288 bunches / 5e9 to 1.7e11p per bunch ( 4.9e13p max)
0.1 < σ < 1.5 mm
Max density on screen > 1e15p/mm2 (material choice)
Experience gained with:
BTV/BPKG instrument
Screen test HRM32 experiment in 2016
BTV/BPKG instrument
 Robust material for screen  Sigradur G (Glassy Carbon)
 In vacuum to avoid parasitic light
Energy threshold for Cherenkov emission in air: 37.4GeV
 Vacuum < 7.07mbar
 Need to cut the forward OTR generated by the vacuum
entrance window  give ~30% larger beam size.
 Protect camera from backscattering particles  relocate camera in a safe area (optical line)
HRM32 experiment

5. New BTV development: Layout
Installation of camera in TT61 to move away from the irradiated zone
 Optical line up to TT61, behind shielding
Location for camera
TT61
TNC
New BTV

6. CATIA 3D drawing of the new BTV for HRM
New BTV development: Design/Installation
Image from V.Clerc
Beam
p BEAM
Photons
Photons
Installation of the new BTV HRM from Located end of experimental table A
CATIA 3D drawing of the new BTV for HRM

7. New BTV development: Design/Installation
Photons
Camera WATEC 902H3
2 filter wheels for high dynamics (up to OD7)
A single lens (Focal length 1m).
Magnification of ~0.2
Reference image for calibration
Resolution [um/px]
Horizontal 72
Vertical 79
Achromatic Lens Focal 1m
Diam: 80mm
Screen position IN
Beam
Mirror
Diameter 4”
Camera lens
Focal 75mm + 40mm ring
Camera
WATEC ULT902H3
~5m
~0.9m
~0.3m

8. New BTV development: Design/Installation
C foil (fixed)
75um
Beam
Screens IN
New screen setup
SiC
0.5mm Ti
0.1mm
Chromox
0.5mm
Sigradur G Glassy C
0.5mm
New screen setup

9. New BTV development: Measurements
Example of beam measurements with the new BTV HRM showing
All range of beams can be observed:
Up to 48 bunches with scintillation screens
Thickness of the screen plays a role on the measurements (as σ ~ thickness)
Measurements always larger than OTR
Up to 288 bunches with OTR screens (only single bunch (<E11p) with large sigma (>1.5mm) are difficult to observe with OTR)
‘Best results’ obtained so far with SiC screen (matching the theoretical HRM optics)
Unfortunately it does not sustain the full beam intensity (breaks the 3rd shots of 288 bunches/σ = 0.3mm)

10. New BTV development: Measurements
Beam:
Single bunch ~1e11p
FP_0.3mm
BTV setup
Fixed red filter in front of the camera
No OD filter needed for single bunch here
SiC (>50 measurements)
σH = 0.26mm
σV = 0.28mm
GlassyC - Sigradur G (>50 measurements)
σH = 0.30mm
σV = 0.36mm
Ti (a few measurments)
σH = 0.28mm
σV = 0.23mm
Measurements very reproductible / systematic
OTR measurements difference depending on material (SiC/GlassyC and Ti)
 Need some study to better understand (optical aberrations, artefacts, etc ?)

11. Conclusion
Challenging design (small beam + high intensity !)
Beam size measurements: we passed from unrealistic results (in air, in radiation area) to realistic ones (in vacuum, camera in a safe location) and we are now close to real ones (with ‘blocking foil’) !
Still some studies to better understand the OTR measurement discrepancy
 Need some accesses and beam time !
Thank you !

12. BACKUP SLIDES

13. Strips of the BPKG and BTV screen at the back
Combined instrumentation: BTV/BPKG: Design
BPKG gives a permanent non invasive beam position measurement for each extraction to be correlated with the HiRadMat experiment.
Dedicated BTV is used to define BPKG offsets (+ first tests for profile measurement)
Position resolution <0.1mm
Transvers and
Strips of the BPKG and BTV screen at the back
Al2O3:CrO2, SiC and Al2O3 (target) screens

14. BTV/BPKG performance (2)
Zoom
 Use of scintillating screens:
to delay the acquisition on the decay time of the scintillation
above a few E12p/mm2  non linearity
for low intensity beam
above 1E13p/mm2  damage
Single bunch (1E11p)
Al2O3 screen
12 bunches (1.2E12p)
Al2O3 screen
T 0.1%
Delay 60ms
 Use of OTR screens is limited as acquisition must be synchronized with beam (backscattering particles gives high background on camera !)
Zoom
Can not be used above 12 bunches (not made for anyway)
Works fine for BPKG offset setup up
24 bunches (2.4E12p)
Al2O3 screen
T 100%
Delay 280ms
12 bunches (1.2E12p)
SiC screen
T 0.001%
S.Burger BE-BI-PM 29th June BI Day - Best Western/Chavannes de Bogis (CH)

15. During experiment with R4550 jaw target !
Beam measurements (without blocking foil)
Screen: Alumina 1mm
Filter NO
Screen: Chromox 0.5mm
Filter OD4
Screen: Ti 0.1mm
Filter OD1
Screen: SiC 0.5mm
Filter OD3
Single bunch (~1E11p)
FP2_0.5mm
12bunch (~1.2E12p)
FP2_0.5mm
72bunch (~7.2E12p)
FP2_0.5mm
216bunch (~2.4E13p)
FP2_0.25mm
Screen: SiC 0.5mm
Filter OD4
During experiment with R4550 jaw target !
288bunch (~3.2E13p)
FP2_0.25mm
Screen to use VS beam type (intensity + optics)
BE-BI MSWG 2017_07_07

16. Beam measurements (without blocking foil)
Doubt on the beam sigma measured Always ~30% larger than the model (!?)
σH,V<0.3mm
Satellites
Tails
Measurements until Tuesday June 13th 18H27  give tails
From Tuesday June 13th 18H43  give satellites
If tails and satellites are not beam but ‘reflections’ or forward OTR from entrance vacuum window
(expected negligible from Zemax simulations):
work ongoing to define the source (mask, color filters, etc…)
Some post processing to derive the real beam size (optics used 0.25 & 0.3)
Plot from A.Fabich
Plot from A.Fabich
Satellites
Error on beam size could be >11%
Tails
Error on beam size could be >35%
[mm]
[mm]
BE-BI MSWG 2017_07_07

17. Viewport Vacuum window Air Vacuum Backward OTR from screen
Reflection of forward OTR
from vacuum entrance window
 Contributes to enlarge the measurement
Vacuum window
Air
Vacuum

18. Viewport Vacuum window Air Vacuum Backward OTR from screen
Reflection of forward OTR
from vacuum entrance window
Reflection of forward OTR
from ‘blocking’ foil
‘Superposed’ contribution
Air
Vacuum

19. Screens IN C foil (fixed) 75um Screen change in HRM BTV 2017_08_03
Beam
Screens IN
2017_08_03
Screen change in HRM BTV
Al2O3 replaced by new Glassy C Sigradur G
Keep amorphous SiC even if broken to compare quality/sensitivity
288 bunches 0.25mm sigma traces on the C foil.
Not holes yet but not far…
SiC broken…

20. To do
Need access to:
check the ‘blocking’ foil
Put a second camera (digital) with a beam splitter
Get rid of the red filter
Check focus
Need beam time to:
Measure with white light
Scan measurement with OD filter (camera artefact with different S/N?)
Scan the beam position on the screen (damage?)