29,30Na run September 2009

Target issues
* Target number #410 UC2C W-surface
* Beam on target (no converter)
* Mass markers: no mass marker (trace elements 23Na and 39K)
* HRS separator
* RFQ cooler operated in cw mode
* Extraction electrode 50 mm
* Uht(HRS,CCV)=30.34 kV, Uht(HRS, HT_target)=30.3371 kV, Uht(RFQ cooler)=30.20 kV, RFQ extraction=0 V, Uht(trap)=30.00kV, Elec05=165 V

Yield tests by target group. Measured 27Na and 26Na – wait for result from target group
Estimation 30Na and 29Na – wait for estimation from target group

Experimental issues
*  Beam to Miniball
* IS482

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

ISOLDE
133Cs

HRS.FC490=1.43 nA, HRS.FC748=1.20 nA , CA0.FC68=1.16 nA, Trap inj plate=1.14 nA

=> Overall transmission from HRS.FC490 to trap inj plate=80%
RFQ transmission could not be tested for light elements due to lack of mass marker.

Low energy
Stable beam 23Na
Tperiod=15 ms, Tbreeding=13 ms
Trap inj. plate=16 pA, RFQ.FC20(22+)=15 pA
Trap+EBIS efficiency=13%

Linac transmission and energy: 
85% RFQ.FC20 to XL65.FC50 for A/q=4, 2.85 MeV/u

Total estimated transmission for radioactive beam (best case)
HRS.FC490_to_trap x Trap_EBIS x Linac x MBcollimator
0.80*0.13*0.85*0.84=7.4%

Delivered beams
For both beams: Tperiod=20 ms, Tbreed=13 ms, no beam gate

Icoll=192 mA, optimised for Na7+

* 30Na7+

Contamination from Isolde: Al, Mg
Contamination from EBIS Z>=20 removed with separator 3mm slits

Beam composition of radioactive part (ignoring EBIS components): 12 % Na, 4 % Mg, 84 % Al
When running with 19 pulses out of 40 pulses, 1.8uA
Total beam intensity ~ 4E+4, Na intensity ~5E+3

* 29Na7+

When running with 17 out of 41 pulses, 1.6 uA proton beam

Possibly 0.05 to 0.1 epA on RFQ.FC20

Setting summary
For HRS we used:

* HRS-SEP-9-09-02-30340.csv

* RFQ-9-09-01-30340.csv

* RFQ-REX-9-09-01-30340.csv

REX low energy settings saved as:
* REX-30kV-2009-09-04_HRS_23Na.xml

* BTS-30kV-2009-09-04_HRS_23Na.xml

* EBIS_2009-09-04_HRS_23Na_normalextraction_last.csv

REX separator and linac base settings saved as:
* 090819_0900_SEP_Aq4_2.85MeVu_88%_L65.csv

* 090904_1641_30Na7+_2.85MeVu.csv

Technical problems
* XIHS.MQ50 interlock badly connected on the PS caused a few trips
* REXEBIS dsc (cfv-170-rxpow) stopped a few times. Didn’t affect the beam to the experiment.

Comments / Lessons learned
* We could change between light (29,30Na) and heavy beams 200Po with short notice. Some retuning of the trap injection was required to have an optimized transmission.
* 15 ms trap cooling was sufficient even if it wasn’t actually used.