1 / 11

CLIC Transverse Profile Monitoring

CLIC Transverse Profile Monitoring. CLIC Requirements. CTC. Critical issue identified for the CDR: ‘1um resolution Laser Wire Scanner’ Foreseen at the end of the Main Linac and in the BDS: Studied by RHUL Damping ring & RTML would need as well high precision measurements DR’s and TA’s

jerry-ellison
Download Presentation

CLIC Transverse Profile Monitoring

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CLIC Transverse Profile Monitoring

  2. CLIC Requirements CTC • Critical issue identified for the CDR: ‘1um resolution Laser Wire Scanner’ • Foreseen at the end of the Main Linac and in the BDS: Studied by RHUL • Damping ring & RTML would need as well high precision measurements • DR’s and TA’s • Based on Synchrotron Radiation (SR) techniques (X-ray, interferometry,..) • LWS could be used as well but more expensive • Transfer lines: • Thermal limitations of OTR screen in the range of ….. • Development of Degradable OTR screen • Need for non-interceptive beam diagnostic in the Drive Beam Complex • 20-50um resolution but with very high charge beams • Strategy here in the used classical interceptive devices (OTR) up to the thermal limit for screen • Option for Optical Diffraction Radiation, Synchrotron Radiation, LWS: • ODR could be used in straight section • Simple and cheap • Single shot measurements but no beam profile • Compatible 3-4 screens method instead of Quad scans • SR and LWS would need in bending magnet and be based on quad scans (need a DUMP afterwards)

  3. CLIC Transverse Beam size Requirements CTC Main Beam Drive Beam 102 10 DB Decelerator DB Injectorcomplex 1 MB Injectorcomplex 10-1 Beam size (mm) PDR & DR RTML Main Linac BDS 10-2 10-3 10-4 10-3 10-2 10-1 1 10 102 103 Beam energy (GeV)

  4. CLIC Transverse Beam size Requirements CTC 102 DB Decelerator Zone Of Interest 10 DB Injectorcomplex 1 MB Injectorcomplex 10-1 Beam size (mm) PDR & DR n Linac & BDS 10-2 10-3 10-4 10-3 10-2 10-1 1 10 102 103 Beam energy (GeV)

  5. Available Techniques & limitations CTC ODR LWS SR Techniques OTR 102 DB Decelerator Optical Transition Radiation Limited by charge density Synchrotron Radiation Techniques Limit ? 10 DB Injectorcomplex 1 Optical Diffraction Radiation Limited by resolution ? MB Injectorcomplex 10-1 Beam size (mm) PDR & DR n Linac & BDS Laser Wire Scanner Ultimateresolution ? 10-2 10-3 10-4 10-3 10-2 10-1 1 10 102 103 Beam energy (GeV)

  6. Potential Test Facilities CTC ODR LWS SR Techniques OTR 102 Optical Transition Radiation Synchrotron Radiation Techniques 10 1 Optical Diffraction Radiation 10-1 Beam size (mm) Laser Wire Scanner 10-2 10-3 10-4 10-3 10-2 10-1 1 10 102 103 Beam energy (GeV)

  7. Thermal limitations of OTR screens CTC • Main Beam: 321 bunches with 3.72x109 electrons • Assuming a reduced repetition rate ~1Hz during the measurement: For quad scans: beam should be dumped afterwards • Limited for thermal resistant screen (~3000oC): Max ~ 250um2 size density • - For a single bunch ~ 10um2: Would work but close to the limit (DR & RTML) • Drive Beam: 70128 bunches with 5x1010 electrons • For the full beam, it only works if the beam density >10cm2 : Never the Case ! • at the limit with a single Drive Beam: (0.36mm2) • Can be foreseen for the DB Decelerator because the beam envelope is becoming larger

  8. Spatial resolution limitation of ODR CTC • Principle of operation: Observe the interference pattern of diffraction radiation form two slits ‘Position of the peak ~ 1/g’ • Impact parameter to produce visible photons depending on the beam energy - For DB Energy: a~600um

  9. Spatial resolution limitation of ODR CTC • Several machine have already observed ODR • Spatial resolution limitations still to be understood ! • Not an absolute measurement ! Method needs cross-calibration: Could be used to measure change in beam size - potentially a candidate for DB complex 7GeV Observed size: 200-1000um Signal distortion in near field: if the observer is at a distance L < lg2/2p 1.28GeV Low emittance Observed size: 10-70um

  10. Next Step for R&D CTC • Laser Wire Scanner: • Demonstrate the resolution: Followed up by RHUL in test facilities: • ATF2 (1um resolution: Main Beam system) • PETRA (~ Drive Beam system) • CESR-TA ? • Integrate the monitor in the different areas of the CLIC complex: ‘Simulation‘ • Design of the detection system – including bends if necessary • First study in the CLIC main tunnel by Greg Penn in 2003 • Estimate the level of background – Acceptable beam loss level • Develop the technology: ‘Lab’ • High power Optical fiber laser for simplicity and cost optimization (Studied by Oxford / JAI) • Optical system and distributed systems for cost optimization • Develop detector for very high energy scheme • Synchrotron Radiation: to be followed through DR collaboration • Point spread function techniques: (done in PSI) • X-ray optics (done in several places: DESY / ALBA ?) • LWS (done in ATF2/KEK – CESRA-TA ?) • Optical Transition Radiation: • Demonstrate a resolution of 1um: RHUL colleagues in ATF2-KEK • Develop degradable monitor • Optical Diffraction Radiation: (ATF2 – CESR-TA) • Used for beam sizes in DB complex in Linear section: Cost saving compared to LWS • Used for non interceptive beam energy monitoring along the CLIC Main Beam linac

  11. CLIC Transverse Beam size Requirements CTC 102 DB Decelerator 10 DB Injectorcomplex 1 MB Injectorcomplex 10-1 Beam size (mm) PDR & DR n Linac & BDS 10-2 10-3 10-4 10-3 10-2 10-1 1 10 102 103 Beam energy (GeV)

More Related