Time of Flight

SVN: ​http://gauss.bu.edu/svn/tof-system/

Two experiments:

• "Regular Helium Atom Scattering" (using microchannel plate) ​Diagram ​(diagram with box photos)
• "Metastable Helium Atom Scattering" (using channeltron) ​Diagram ​(diagram with box photos)

Meetings

• ToFPCBComments13Dec2019
• TofPCBComments05Dec2019
• TofPCBComments27Nov2019
• TofMeeting22Oct2019
• TofMeeting17Sep2019
• TofMeeting1Jun2020

Notes on testing

• ​HV Pusler RevA 1/16/20
• ​LV Mixer RevA 1/24/20
• ​Filament Supply RevA 1/31/20 Disregard this, the wrong transistor was used during testing.

Full Testing

• ​Filament Supply Full Test 2/6/20 Testing DC-Conditions
• ​Filament Supply Full Test 2/7/20 Testing Pulsing
• ​LV Mixer Full Test 2/13/20 Testing Mixing at Increasing Speeds
• ​HV Pulser Full Test 2/25/20 Testing Pulsing at Increasing Speeds
• ​PreAmp Full Test 2/27/20 Testing amplification and discrimination

RevB Testing

• ​HV RevB Testing ToF adapter RevB -> HV RevB -> Filament Supply RevB
• ​LV RevB Testing ToF adapter RevB -> LV RevB -> Filament Supply RevB

Setup

The following boards have components and features which may need to be tuned when first assembling the system. Below are descriptions of the adjustable features on each board and relevant equations for tuning the functions of the boards.

• ​PreAmp Setup
• ​HV Pulser Setup
• ​LV Mixer Setup

Other boards in this project should not need to be adjusted but relevant notes on the boards can be found below.

Notes on Revisions

• LV Mixer: ​RevB
• HV Pulser: ​RevB
• ToF Adapter: ​RevB checked, needs fixes ESH 3/2/20
• Filament Supply: ​RevB checked, ok ESH 3/2/20
• Pre-Amp: ELBAT_Preamp_RevA RevA
• Firmware: ​RevB

PCB Documentation

Rev A boards ordered Dec 2019:

• TOF box adapter
  • Schematic: ​http://gauss.bu.edu/svn/tof-system/Hardware/tof/tags/RevA/adapterBoard.pdf
  • SVN: ​http://gauss.bu.edu/svn/tof-system/Hardware/filament/tags/RevA/
• LV pulser/mixer
  • Schematic: ​http://gauss.bu.edu/svn/tof-system/Hardware/lv/tags/RevA/lvMixer.pdf
  • SVN: ​http://gauss.bu.edu/svn/tof-system/Hardware/lv/tags/RevA/
• HV pulser
  • Schematic: ​http://gauss.bu.edu/svn/tof-system/Hardware/hv/tags/RevA/hvPulser.pdf
  • SVN: ​http://gauss.bu.edu/svn/tof-system/Hardware/hv/tags/RevA/
• Filament supply
  • Schematic: ​http://gauss.bu.edu/svn/tof-system/Hardware/filament/tags/RevA/Fil.pdf
  • SVN: ​http://gauss.bu.edu/svn/tof-system/Hardware/filament/tags/RevA/

Wiring - WIP

• DB9 - Twisted pairs
• DB15 - Twisted pairs
• BNC - 1 BNC -> open wires, X BNC -> BNC
• Minifit Jr - 2x2, 2x1
• FPGA Header - look this up

The following boxes/instruments need to be constructed for Xuetao in 2019:

Regular Helium

• TOF box (pulse output and TDC input NewTOFBox
• Filament supply (same as BU) NewFilamentSupply
• Quad PS (commercial power supplies)
• LV pulser (same as BU) NewLVMixer
• Preamplifier (need input signal specs) NewMCPPreamp

Metastable Helium

• TOF box (pulse output only, no detector readout) NewTOFBox
  • Trigger signal out to TDC
• Filament PS for Exciter (? not sure) ~1A for indirectly heated cathode NewFilamentSupply (one fil. end is at Cathode potential)
  • Can be same supply as for regular helium e-gun, pulsed at 200V
• 200V bias supply for HV pulser
• HV pulser (Bill's design with transformers) NewHVPulser
  • Update design if needed ("high-side" FET drivers?)

Older version of list for BU

• TOF box
  • FPGA board with pseudo-random pulser and TDC; controlled via USB/serial I/F
  • Pulse input from detector preamp (also supplies preamp power)
  • 0..-25V manually adjustable supply for cathode offset (with panel meter)
• Filament supply
  • Isolated supply, 0-3A constant current (?)
• HV Pulser / Mixer
• LV Pulser / Mixer
• Preamp (MCP)
• Preamp (Channeltron)
• E-Gun power supply

On 5/30/19, Michael visited. He says only the first 4 boxes are needed. Xuetao will not use the Channeltron because he has a huge MCP.

For the "Regular" experiment, we use the MCP preamp and LV pulser

For the "Metastable" experiment, we use the Channeltron preamp and HV pulser

Photos (by board/box):

• ​http://ohm.bu.edu/~hazen/elbat_tof/Photos/

Photos (raw):

• ​http://gauss.bu.edu/svn/tof-system/Photos/