Status of the FETS Laserwire Scanner David Lee UKNFIC Meeting

David Lee 07/11/2008 Outline Introduction Vacuum Vessel Optics Detector > Field Map > Electronics Conclusion / Outlook Status of the FETS Laserwire Scanner 1

David Lee 07/11/2008 The Front End Test Stand Magnetic LEBT RFQ MEBT and chopper H − ion source Laser profile monitor Status of the FETS Laserwire Scanner 2

David Lee 07/11/2008 The Front End Test Stand Magnetic LEBT RFQ MEBT and chopper H − ion source Laser profile monitor Status of the FETS Laserwire Scanner 2

David Lee 07/11/2008 Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − −− − − − − − Laser-based Beam Diagnostics: Principle for H − Collect the detached electrons Status of the FETS Laserwire Scanner 3

David Lee 07/11/2008 Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − Collect the detached electrons −− − − − − − Laser-based Beam Diagnostics: Principle for H − Status of the FETS Laserwire Scanner 3

David Lee 07/11/2008 Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − Collect the detached electrons −− − − − − − Laser-based Beam Diagnostics: Principle for H − Status of the FETS Laserwire Scanner 3

David Lee 07/11/2008 Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − Collect the detached electrons −− − − − − − Laser-based Beam Diagnostics: Principle for H − Status of the FETS Laserwire Scanner 3

David Lee 07/11/2008 Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − Collect the detached electrons −− − − − − − Laser-based Beam Diagnostics: Principle for H − Status of the FETS Laserwire Scanner 3

David Lee 07/11/2008 Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − Collect the detached electrons −− − − − − − Laser-based Beam Diagnostics: Principle for H − Status of the FETS Laserwire Scanner 3

David Lee 07/11/2008 Steering the Laser Beam Status of the FETS Laserwire Scanner 4

David Lee 07/11/2008 Steering the Laser Beam Status of the FETS Laserwire Scanner 4

David Lee 07/11/2008 Vacuum Vessel Internals Installation Status of the FETS Laserwire Scanner 5

David Lee 07/11/2008 Optics Optical table constructed in R8 Simple optics design compete Gives reasonable performance in terms of laser diameter in the interaction region Reconstruction of overlapping measurements could overcome problems with laser performance Status of the FETS Laserwire Scanner 6

David Lee 07/11/2008 Vessel / Optics: To Do One of the plates from the tank internals needs modifying In the workshop today Re-installed next Wednesday Vacuum window to couple in the laser to be constructed Have some drawings showing how this could be done Complete laser safety requirements for RAL Interlocks / Screening Documentation Install laser and optics at RAL Alignment… Status of the FETS Laserwire Scanner 7

David Lee 07/11/2008 The Electron Detector (I) H −, H 0 Electrons Electron collector Magnet Copper accelerating sheath Status of the FETS Laserwire Scanner 8

David Lee 07/11/2008 The Electron Detector (II) Status of the FETS Laserwire Scanner 9

David Lee 07/11/2008 Detector Magnet Field Map (I) Status of the FETS Laserwire Scanner 10

David Lee 07/11/2008 Detector Magnet Field Map (II) Status of the FETS Laserwire Scanner 11 Magnet measured in opposite polarity to how it’s will be used & how it’s previously been tested  Discrepancy due to hysteresis

David Lee 07/11/2008 Detector Readout “Prototype”“Production” Status of the FETS Laserwire Scanner 12

David Lee 07/11/2008 Detector: To Do Test ‘production’ electronics Finish installation of detector Magnet Readout Power / data feed-thoughs Status of the FETS Laserwire Scanner 13

David Lee 07/11/2008 Reconstruction Software Test figure No overlap50 % (?) overlap Test figure Status of the FETS Laserwire Scanner 14

David Lee 07/11/2008 Conclusions and Outlook The FETS laserwire scanner is progressing (reasonably) well Installation should be complete by the end of the month Then *all* we need is a beam And then the fun really begins… Status of the FETS Laserwire Scanner 15

Backup Slides

David Lee 07/11/2008 H − Injection H − from Linac Circulating protons Stripping foil Status of the FETS Laserwire Scanner 16

David Lee 07/11/2008 The Need for Multiple (>2) Projections Status of the FETS Laserwire Scanner 17

David Lee 07/11/2008 The Need for Multiple (>2) Projections Status of the FETS Laserwire Scanner 17

David Lee 07/11/2008 The Need for Multiple (>2) Projections Status of the FETS Laserwire Scanner 17

David Lee 07/11/2008 The Need for Multiple (>2) Projections Status of the FETS Laserwire Scanner 17

David Lee 07/11/2008 Laser-based beam diagnostics principle for H − Photo-dissociate some of the H - ions Separate species using a dipole magnet − − − − − − −− −−− − − −− − − − − − − − − Collect the detached electrons −− − − − − − Rev. Sci. Instrum. 73, 998 (2002) Status of the FETS Laserwire Scanner 18

David Lee 07/11/2008 ADC Two channel, integrate and hold, 20-bit ADC Minimum sensitivity: −0.2–50 pC Expected signal size ~1 pC so in effect we have a ~ 14-bit ADC Status of the FETS Laserwire Scanner 19

David Lee 07/11/2008 ADC Protoboard DDC112 Clock In Atmel μprocessor RS232 to PC Input 1 Power in Range select jumpers Status of the FETS Laserwire Scanner 20

David Lee 07/11/2008 ADC Test Charge Resolution Status of the FETS Laserwire Scanner 21

David Lee 07/11/2008 The Need for Non-Destructive, Non-Interceptive Diagnostics Allows for online monitoring of the beam Status of the FETS Laserwire Scanner 22

David Lee 07/11/2008 The Need for Non-Destructive, Non-Interceptive Diagnostics Allows for online monitoring of the beam Prevents the beam damaging the instrument PlasticRuby P46 Status of the FETS Laserwire Scanner 22