1. E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo, M. Palm
LHC BSRT
system
G. Trad
On behalf of:
BSRT team
E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo, M. Palm
BI/TB 2014
11th December

2. The LHC BSRT systems, G. Trad – BI/TB 2014
Content
BSRT
Beam Synchrotron Radiation Telescope
For transverse and longitudinal beam diagnostics
SR extraction
Optical Systems
Detectors
Control
Light Source
Upgrades and new functionalities
To do list
The LHC BSRT systems, G. Trad – BI/TB 2014

3. The LHC BSRT systems, G. Trad – BI/TB 2014
Source Characteristics
SR extraction
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

4. The LHC BSRT systems, G. Trad – BI/TB 2014
Run 1 Problems
Proposed solutions
Adopted solution
However…
Monitoring
Extraction system
SR extraction
Optical Systems
RF Heating Issues
=> system’s failure
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

5. The LHC BSRT systems, G. Trad – BI/TB 2014
Run 1 Problems
Proposed solutions
Adopted solution
However…
Monitoring
Extraction system
SR extraction
Both options avoid the use of ferrites and aim at reducing the coupling impedance of the device to reduce the absorbed RF power from the beam
Both options studied using RF simulations codes (A. Nosich, M. Wendt) and the expected improvement was checked via the stretched wire technique
It was chose to avoid ceramic, not being comfortable with its behaviour to thermal cycles.
Replacing metallic parts seen by the beam with ceramic (MACOR)
Optical Systems
Detectors
Control
Avoiding
“cavity-like” gaps
The LHC BSRT systems, G. Trad – BI/TB 2014

6. The LHC BSRT systems, G. Trad – BI/TB 2014
Run 1 Problems
Proposed solutions
Adopted solution
However…
Monitoring
Extraction system
SR extraction
Optical Systems
Detectors
2800 bunches
N= ppb
Absorbed power in postLS1 design =1/3 preLS1
Meas : ~10W
Sim : ~2-3 W
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

7. The LHC BSRT systems, G. Trad – BI/TB 2014
Run 1 Problems
Proposed solutions
Adopted solution
However…
Monitoring
Extraction system
SR extraction
Optical Systems
Detectors
Control
Recent RF simulations carried
out by B. Salvant (BE/ABP)
Predicts a larger Q for the
800 MHz resonance that in
the worst case could hit line in the beam spectrum leading to “several hundred Watts”
The LHC BSRT systems, G. Trad – BI/TB 2014

8. The LHC BSRT systems, G. Trad – BI/TB 2014
Run 1 Problems
Proposed solutions
Adopted solution
However…
Monitoring
Extraction system
SR extraction
In-Vacuum temperature probes
Installed on both beams on the mirrors holder
Optical Systems
Hartmann-Mask for wave front distortion detection
Detectors
To be installed only on Beam 1:
Mask to be machined soon, hopefully installed before run II (first technical stop at the latest)
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

9. The LHC BSRT systems, G. Trad – BI/TB 2014
Calibration Line
Imaging System
Longitudinal Monitors
Interferometry system
Optical systems
SR extraction
Essential for the imaging system (beam size diagnostics) to calculate the calibration factors (mmobject/px)
Limitation: Initially, it was implemented on the optical table, not including all the optical components (Extraction and Steering mirrors)
Optical Systems
Alignment
(light reaches the camera)
Periscope
External laser
Detectors
Fix
Extraction mirror
Control
Optical System
Moving
The LHC BSRT systems, G. Trad – BI/TB 2014

10. Optical systems Calibration Line Imaging System Longitudinal Monitors
Interferometry system
Optical systems
SR extraction
Essential for the imaging system (beam size diagnostics) to calculate the calibration factors (mmobject/px)
Limitation: Initially, it was implemented on the optical table, not including all the optical components (Extraction and Steering mirrors)
Improvement: An external line was installed replacing the periscope with a modified BTV tank
Optical Systems
Detectors
Control
Installed and operational on beam 1
The LHC BSRT systems, G. Trad – BI/TB 2014

11. The LHC BSRT systems, G. Trad – BI/TB 2014
Calibration Line
Imaging System
Longitudinal Monitors
Interferometry system
Optical systems
SR extraction
Limitation:
Low resolution limited by diffraction with respect to the beam sizes to be measured
Proposal:
Lower the imaging wavelength
from VIS (400 nm)to NUV (250 nm)
Implications:
Change of all the optical elements (mirrors, lenses, detectors…)
Optical Systems
Detectors
Status:
Installed on both beams and being qualified
Will be ready for restart.
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

12. The LHC BSRT systems, G. Trad – BI/TB 2014
Calibration Line
Imaging System
Longitudinal Monitors
Interferometry system
Optical systems
AGAP and LDM placed as close as possible to the steering mirror
New optical systems more robust to eventual misalignments
Splitter longitudinal/transverse diagnostics placed before the imaging line such as eventual changes in the system (filters, tests) have no effects on the reliability of the longitudinal measurement
Small additional optical table installed and AGAP and LDM relocated. Will be available for the restart
SR extraction
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

13. The LHC BSRT systems, G. Trad – BI/TB 2014
Calibration Line
Imaging System
Longitudinal Monitors
Interferometry system
Optical systems
Alternative technique to measure beam size not limited by the light diffraction theoretically featuring high spatial resolution (tens of microns)
SR extraction
Detector
2 lenses Focusing
SLITS
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

14. The LHC BSRT systems, G. Trad – BI/TB 2014
Calibration Line
Imaging System
Longitudinal Monitors
Interferometry system
Optical systems
SR extraction
Motorized double slits still under construction, should be ready around February
Focusing system ready and installed, to be checked next week.
In absence of the slits, the optical line is used as an imaging line (at nm) and will be used to compare lenses short vs long focal lengths:
Line 1: f1=4800 mm f2=300 mm
Line 2: f1=1100 mm f2 =18mm
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

15. The LHC BSRT systems, G. Trad – BI/TB 2014
Optical systems
SR extraction
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

16. The LHC BSRT systems, G. Trad – BI/TB 2014
Transverse
Imaging
Interferometry
Longitudinal
Detectors
SR extraction
Proxicam type HL4 S NIR (cathode N)
Optical Systems
Detectors
New camera, with intensifier type T
to cope with the shift of imaging toward NUV
features lower sensitivity at 450 GeV (IR source), however gain is available to compensate for this loss
Status:
Installed and tested only in DC mode, still to be tested in gated mode
No implications for the software side since the interface is still the same
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

17. The LHC BSRT systems, G. Trad – BI/TB 2014
Transverse
Imaging
Interferometry
Longitudinal
Detectors
SR extraction
Digital camera was chosen instead of analog camera, since it features lower noise
Camera model: Andor Zyla, features high frame rate (max 1000fps) coupled to a high sensitivity third generator GaAsP intensifier
Communication via USB 3 extenders via OM3 multimode fibers limited to <100m.
=> New fibers were pulled from ua47 since fibers to us45 are about 150 m.
Dedicated computer (bought) will be installed in ua47 and camera stream will be saved locally since no possibility in the meanwhile to include digital cameras in the control system.
Status:
Camera received and being tested with the PC
Fibers pulled
Intensifier expected start of January
Acquisitions cannot be tested before
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

18. The LHC BSRT systems, G. Trad – BI/TB 2014
Transverse
Imaging
Interferometry
Longitudinal
Detectors
SR extraction
Optical Systems
Same Photomultiplier and photon counting detector for Abort Gap and LDM as for RUN I
Dedicated presentation will cover these detectors and an eventual update, will be given in January by Stefano.
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

19. The LHC BSRT systems, G. Trad – BI/TB 2014
Hardware
Software
Control
Tunnel
Old patch panels were removed and replaced by new ones (ie control and power supplies patch, motors patches) 
All cabling changed for more flexible one. 
BSRT imaging motors and LDM are operational 
Thermocouple amplification box installed on both beams but not tested yet in the tunnel (only lab tests) 
Intensified camera operational (gated mode not tested) 
12 OD3 fibres were pulled from RA43/47 to UA43/47 (racks BY06 and BY03 respectively): connection tested with usb2.0 and usb3.0 converters, ok. 
PC for fast digital camera acquisition ordered and in preparation 
Gallery  
MIDI crate reorganized and completed with cards (resolver removed) 
New motor patch panels were installed 
New ctrl and power supplies patches were installed (need to modify B1 for pneumatic ctrl and calibration lamp on/off) 
SR extraction
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

20. The LHC BSRT systems, G. Trad – BI/TB 2014
Hardware
Software
Control
SR extraction
Based on Run I experience, functional specifications are being upgraded.
In addition:
the control system has to cope with the “two wavelength” imaging system (switch of the lenses).
The control of the new pneumatic switches used for the lenses switch and the ND filters and colour filters need to be implemented
Future Implementation of the interferometer line (slit control, filters, lenses, and digital camera acquisition) should be taken into account.
Optical Systems
Detectors
Control
The LHC BSRT systems, G. Trad – BI/TB 2014

21. Summary BSRT extraction Optical system Detector Software
Longitudinal
separation
New mirror design
Intensifier type T
Functional
Specifications
NUV imaging
Digital camera
simulations
Pneumatic Controls
Hartmann Line
Lens &Coating change
Measurement
Imaging control
AGAP LDM
PMT
Monitoring
Imaging short focal
Interfer.
Control
T. Probes
Slits
Interfeometer
Hartmann
Optics

22. Summary BSRT extraction Optical system Detector Software
Longitudinal
separation
New mirror design
Intensifier type T
Functional
Specifications
NUV imaging
Digital camera
simulations
Pneumatic Controls
Hartmann Line
Lens &Coating change
Measurement
Imaging control
AGAP LDM
PMT
Monitoring
Imaging short focal
Interfer.
Control
T. Probes
Slits
Interfeometer
Hartmann
Optics

23. Thank you!

24. To Do list before the holidays:
Pneumatics: 
- Tests of pneumatic filters with electronics done in lab  - Sub-D15 M-F adapters needed for limit switch reading , in fabrication  - Modify B1 gallery patch for pneumatic ctrl (2 pneumatic ctrl boxes, ie 2 serial ports)