LEReC Instrumentation status and plans for Shutdown

Toby Miller9/27/18

Introduction

• Current & Charge• Profile Monitors

• New High Power PM’s• Existing PM’s

• Beam Positions Monitors (BPM)• Beam Loss Monitors (BLM)• Temperatures• Recombination Monitor• Magnetometers• Ion Clearing Electrode (ICE)

Current & Charge Measurement• FCT System

• Redundant FCT receiver Chassis – Critical MPS Element• New chassis fabrication & testing• Redundant Heliax cable installation

• Review & improve system performance • Firmware Improvements

• implement offset adjustments• faster differential measurements• fixing bugs in the integration windows so they can be adjusted.

• Hardware testing for performance evaluation & improvement• Alternative techniques for measuring the FCTs

• direct sampling • Down-conversion of the signal by mixing and then directly measuring it• These have the advantage of removing the logarithmic translation with a cost of dynamic range

• Spare FCT ordered for LEReC – includes 200C bakeout option

• ICT Scope Application for CW• update to use fewer resources • Possible integration directly into the Zynq as is done for CeC. • Investigation of conflicting readings with CW vs Pulse mode.

• Install DCCT in extraction line with new chamber for larger beam aperture• Provides calibrated current measurement – FC & FCT can be cross calibrated• Improvement being made to time stamp accuracy of logged data

High Power Profile Monitors• Beam Induced Fluorescence Monitor

• Design & build 2 chambers • Install in 1 transport line• Hold 1 for back-up installation into extraction line

• Buy one camera system to test (~$20k)

• Wire Scanner• Install in extraction line• Design & Build support• Pull cables • Test & install CERN electronics• Design & install Fast PMT digitizer

High Power PMs

BIF

WSH+VWIRE SCANNER• Motion Control

• VME based motion control cards loaned from CERN

• Signal Acquisition (BNL)• PMT + scintillator• Fast digitizer needed

• Large signle scintillator• or Fiber scintillator• Fast response

Black Plate(Ferite or anodized SS)

Light-tight Enclosures

Viewports

Cameras &Intensifiers

Beam Induced Fluorescence Mon• Motion Control

• Intinsified camera• Black background• Tilted windows cut down reflections• Must eliminate all light leaks into

beam line

Profile Monitors• Upgrade RF diagnostic line profile monitor

• Change 50 mm YAG crystals to 60 mm crystals• Turn around the YAG holder wheel so that the position indicating marks will

be visible by the camera• Install new BNNT screen• Change resolution target for improved contrast

• Rework tr.yag profile monitor • Replacement H-slit with V-slit

• laser exit table• Add laser profile camera• Install cover interlock switches• Possible reconfiguration of optics for better cathode imaging

• Camera Performance• Study reliability & failures of camera manager during the run• Study EPICS based camera manager software• Improve failure detection & mitigation routines

LEReC BPM Run-19 Enhancements• Relocation of inj.b1/b2 amplifiers to reduce noise• Diode limiters have prevented further amplifier failures • Libera BPM software revision

• Debug an issue which requires reboot after CW beam• Add reboot/reset capability for operations

• Auto Gain Control• For last 2 weeks of the run auto-gain was enabled for all BPMs

• Need to have limits on intensity ramp-up rate to avoid overflow• Alternate method - develop scripts for manual gain control

• 2 or 3 gain states are all that is necessary for ~30-200pC range

• Post-mortem MPS logging• Options for easier display of BPM data after trips

Beam Loss Monitors• Add new scintillating fiber to extraction line near dump

• Modify the PMT BLM cards

• Lower noise

• Faster response

• Collaborating with JLAB

• Dump Radiation Monitoring Array

• Graphical display of loss data implemented

• Libera masked BLM electronics – CANCELED • e-beam loss signal expected to be higher than RHIC loss signal.

• Can be a back-up plan ($4k/4ch => $16k cost)

• Diamond Detector

• Fast detector, insensitive to magnetic fields

• Tested in transport line

• Signal is too small to use without local amplification

• --> PMT + Scintillating fiber

• fast enough

• magnetic insensitive

• more sensitive

Temperatures• Install new sensors near dump entrance

• Build transmitter & receiver chassis• Need details of required locations

• Investigate noise issues• Possible beam induced noise in transmitter chassis

• Add shielding• Possible relocation

Recombination Monitors• Install 2nd upgraded PMT+scintillator

• Good sensitivity measured with RHIC ions spilled out

• Time Digitizer• Complete controls integration and set up of time

digitizer• Histogram Graphing & data logging set up

• Install 2 Paddle-style scintillators from PHENIX• Is this still necessary?• Build duplicate electronics setup• Full controls integration

Magnetometers• Current array of USB based magnetometers

• Unreliable communication method

• System no longer needed

• According to Alexei: “We need magnetometers only because

RHIC magnets were ramping to high-energy. For the next

few years, we would operate at or below present injection energy”

• Propose to remove all hardware

Ion Clearing Electrodes• Tested with higher voltage – no improvement• Do we need larger electrodes in G-t-B area?• Fast transient view on scope requested

• Design & install Fast HV Bias Tee• Couple to scope

• Can apply to Anode bias too…

Thank You!

Special thanks to

Dan Lehn and Tony Curcio and all of the technicians in the Accelerator Component & Instrumentation Group

for continuous efforts to help realize this aggressive project!

Back-up Slides

LEReC BPM Run-19 Enhancements- BPM Auto Gain

Max ADCCounts

AttenuationSetting

This rate of rampingintensity works wellwith the AGC loop.