224Ra run 29-30 August 2011

Target issues
* Target number #457 UC W-surf
* Beam on target (no converter)
* Mass markers: Na, Mn, Rb
* GPS separator
* Extraction electrode 69 mm (real distance)
* Uht(GPS, CCV)=30.20 kV, Uht(trap, CCV)=30000 V, Elec05=190 V

Yield measurements

Experimental issues
* Beam to Miniball
* IS475

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

ISOLDE
74% transmission from GPS.FC490 to TRAP injection plate for 238U, few pA

Low energy
Stable beam

Only a quick test with 238U

Linac transmission and energy: 
No stripper foils. WITCH magnets 0.1 and 3T.

Transmission from RFQ.FC20 to XL65.FC50

- 84% for A/q = 4 at 2.82 MeV/u

- 55% for 224Ra52+ (4.3077) at 2.82 MeV/u

Total transmission (radioactive beam)
HRS.FC490_to_trap x Trap_EBIS x Linac
0.71*0.023*0.55=0.9%

Delivered beams

224Ra52+

TRAP HT=30000 V, Trap gas=7.5 V

With T_period= 400 ms and T_breed=396 ms, I_coll 187 mA => trap+EBIS=2.3%

Prot.current: 1.8uA 2964ppp

Total cycles: 13/26

RA0.FC90 7.1 pA

On MB FC 6 epA -> 7E5 part/s

Setting summary
For GPS we used:

GPS_SEP_30kV_#457_2011-08-22-39K.csv

GPS_TAP_30kV_#457_2011-08-22-39K.csv

REX low energy settings saved as:

110829_1538_TRAP_GPS_224Ra

110829_1538_BTS_GPS_224Ra

EBIS_110829_1528_GPS_224Ra52+_1.4%_slow_extraction

REX separator and linac settings saved as:
110829_1536_SEP_Aq4.3077_224Ra52+_MB

110829_1536_Aq4.3077_224Ra52+_MB

Technical problems

* The target and line heated dropped at the beginning of the run due to a PLC problem.

Comments / Lessons learned
* Full set-up done in one day (GPS to MB), definitely too short to find optimum settings.
* The GPS mass factor for 238U was different from 23Na. Caused initial beam confusions.