Sn and In run summer 2005

Target issues:

* Target number #304. LaC, surface ioniser with C line

* To improve the Sn/In ratio 6 consecutive pulses with closed beam gate, thereafter 6 empty pulses with beam gate open.

* The frontend and target was vented just before beam delivery. Similar yield before and after the incident.

REX issues

isotopes run: 108Sn30+ with lasers and 108In30+ without lasers the last 24 h.

breeding time: 198 ms, peak charge at 30+

currents:

* For 12/12 pulses, 2E13 p/p with 108Sn we had:

TRAP inj plate = 30-45 pA; BTS.FC20 = 25 pA; RFQ.FC20 >40-50 pA for 30+; BEN.FC100~25 pA

efficiency:

* GPS.FC690 to REXTRAP:90% (checked with 139La beam)

* Trap 48% for stable 139La (500 us beam gate for 10 Hz);

Trap >50% for stable 112Sn (4.85 Hz, no beam gate);

* EBIS 8% for 139La30+ (98 ms breeding time)

EBIS 7% for 112Sn30+ (198 ms breeding time, no beam gate);

EBIS 6% for 108Sn30+ (198 ms breeding time, no beam gate);

* Linac transmission 60%

Linac energy:

* 2.83 MeV/u

comments:

* The low repetition rate (4.85 Hz) was imposed by low A/q (3.6)

* After the trap, at the EBIS-BTS bellow and at the mass separator slit around 100 uSv/h

* Timing to the Linac nicely stable when running at the pretrigger 1 ms before the EBIS pulse.

* Didier helped for the first time with beam tuning.

technical problems:

* The low energy part worked without any interventions; one reboot of BD FEC

* One of the consoles in the control room keeps hanging

* Last run before repair of 200 MHz amp

lessons learned:

* Sometimes it works really well!