Injector
Beam extraction with H+ at 50 keV, 20 mA for Phase B+ H+ commissioning was completed on 21 July 2021. D+ plasma conditioning was conducted from 22 to 25 July and D+ beam extraction at 100 keV, 30 mA was started on 26 July. D+ beam injection into RFQ started on 27 July.
Radio Frequency (RF) System and RFQ cavity
A short maintenance was performed for solving the issues on driver tetrode anode PS in chain 4B on 26 July (completed on 27 July morning). The RF system is operated stably at 1 Hz repetition (for 1 ms pulse). The RFQ conditioning towards 10% duty cycle has been put on-hold to prioritize beam operation.
Beam Instrumentation
A remote session with Ciemat was conducted on 26 July to improve the HEBT SEM Grid control. BPMs were not available at the beginning of the operations: they are progressively back on line and further checks are ongoing (it is necessary to debug a recent software update).
Control System
The Cryoplant LCS (Local Control System, stand-alone system at present) is under integration into LIPAc control system. We were happy to welcome after a long time an EU expert that will support this activity on-site in July and August.
LIPAc beam operation: H+ and D+ beam operation
The first H+ beam campaign at low current and low duty cycle has been successfully completed end of last week, fulfilling all the objectives defined in the Experimental Program, namely:
- Injector test @20 mA extraction current (~10 mA at the exit of the LEBT)
- Chopper test (100 msec)
- LEBT (Low Energy Beam Transport) solenoid optimization (to maximize RFQ ACCT – AC Current Transformer- reading)
- Transport up to HEBT FC (High Energy Beam Transport Faraday Cup)
- Transport up to Beam Dump (monitor ACCTs) (~8 mA at the entrance)
- Optimization of the dipole field
- Beam dimension (by DPlate slits and HEBT SEM grid) and profile measurement (by HEBT SEM grids)
- Alignment checks (screening with quadrupoles magnets)
- Diagnostic checks
The D+ transport started beginning of this week. D+ extraction and transport up to the Beam Dump was successful with a good quality of the beam and excellent fraction of transported current (almost 80% from LEBT ACCT up to HEBT ACCT).
The following experimental program is being followed and target to be completed end of July:
- Injector test @30 mA extraction current (~20 mA at the exit of the LEBT)
- Chopper test (60 and 100 msec)
- Source current adjustment
- Transport up to HEBT FC
- Transport up to Beam Dump (~16 mA at the entrance)
- Optimization of the dipole field
- Beam dimension (by DPlate slits and HEBT SEM grid) and profile measurement (by HEBT SEM grids)
- Alignment checks (screening with quadrupoles magnets)
- Buncher 2 phasing for BPM measurements and checks
- Diagnostic checks as much as possible
- Check of the beam barycenter and tuning of steerers
Next week the summer maintenance period will start. LIPAc operation is scheduled to resume end of September.
Disclaimer: the information reported is not meant to be technically complete and doesn’t cover all the activities currently carried out on LIPAc.