11Be run October 2009

Target issues
* Target number #414 Ta rolls, W surface, RILIS
* Beam on target (no converter)
* Mass markers: Cs, Be
* GPS separator
* Extraction electrode 65 mm
* Uht(GPS,CCV)=30.22 kV, Uht(HRS, HT_target)=30.2198 kV, Uht(trap)=30.00kV, Elec05=210 V
* Yield measurements by target group: 10Be 5E8 / uC (almost exactly database figure), 11Be 4.7E6 / uC

Experimental issues
* Beam to Miniball
* IS430

Tuning
* Normal extraction from EBIS
* REXTRAP timing free-running relative to protons pulses

* use isotopically pure 20Ne in REXTRAP

ISOLDE
27Al: GPS.FC490=413 pA (overestimated by ~20%?), GPS.FC558=296 pA, CA0.FC68=288 pA, trap inj plate=280 pA => 68% (80%?)

Low energy
Stable beam 9Be3+
Tperiod=50ms, Tbeamgate=open, Tbreeding=20ms, Icoll=58mA, Ugun=3300V
Trap inj. plate=35pA, RFQ.FC20(27+)=3pA
Trap+EBIS efficiency=2.9%

Radioactive beam 11Be3+
Tperiod=50ms, Tbeamgate=open, Tbreeding=20ms, Icoll=58mA, Ugun=3300V
Trap inj. plate=1.8pA, RFQ.FC20=0.15pA ?

Linac transmission and energy: 
9Be3+ at 2.86 MeV/u: RFQ.FC20=5pA, XL65.FC50=4.2pA -> 84%

XL65.FC50 to Miniball FC almost 100%

Use 25ug/cm2 C stripping foil: Be 3+ to 4+ 100% / 22Ne 6+ to 8+ <20% => factor 5 reduction

Total transmission (radioactive beam)
GPS_to_trap x Trap_EBIS x Linac x MB
0.80?*0.03*0.84*1.00=2%

Delivered beams
* 11Be4+ 10/33 pulses 1.28uA average => 6E4/s at secondary target

* small 11B contamination, larger contamination from heavier beam (most likely 22Ne)

Setting summary
For GPS we used:
* GPS_SEP_9-10-13-30210V.csv

* GPS_REX_9-10-13-30210V.csv

REX settings saved as:

* EBIS_2009-10-17_GPS_9Be3.csv

* REX-30kV-2009-10-17_GPS_9Be_soso.xml

* BTS-30kV-2009-10-17_GPS_9Be_soso.xml

* 091017_1559_SEP_Aq3.6666_84%_2.86MeVu_L65.csv

* 091017_1918_Aq3.6666_84%_2.86MeVu_MB+foil.csv

Technical problems

* Cathode failed on Monday 12/10.

* The beam did not go through the linac on Sat evening/Sun morning. Not sure what the problem was. Suspect something physically blocking the beam in DB3 (?)

* The FC and MCP of DB3 are not working.

Comments / Lessons learned
* It is possible to change the cathode, bake-out the EBIS, ramp-up the electron beam and have the machine set-up in less than a week. (Low energy part was running Saturday evening and Miniball had beam from Sunday18/10 afternoon).

* Difficult to diagnose a problem without beam diagnostics.

* Do not forget to scale the MQ behind the bender when using stripper foils.

* For the next run consider:
longer pumping time of natural abundance Be before the run
if 12be, try continuous injection into EBIS -> short breeding time, maintained/better yield?
if 12Be, run linac at 100 Hz