Minutes from REX meeting 2005-04-22

 

Present: Pierre Delahaye, Mats Lindroos (chair), Fredrik Wenander, Romain Savreux, Nikolai Trofimov, Thomas Sieber, Luis Fraile and Peter B

 

 

General issues

 

* Comments to last week’s minutes. Thomas will do the alignment of the mass slit in the beam diagnostics box himself as the integration of the alignment group has come to a halt.

 

* A PhD student from Jyväskylä is scheduled to come down for two periods; 4/7 to 8/8 and 28/8 to end Oct. He will work together with Fredrik and Pierre on REX and the ECRIS charge breeder.

 

* Thomas, Fredrik and Mats should look into the budget at the next meeting. Peter should verify if he can contribute with 25 or 50 kCHF from the Physics group account this year.

 

* Miniball has asked for x-ray shielding of the 9-gap resonator. It is still not evident if it contributes significantly to the background level. When the full setup of Miniball is operational a dedicated test with and without 9-gap on should be carried out. Meanwhile, Pierre promised to send Piet and Heiko a report from his summer student that made some background measurements. A temporary solution could be to add some of the flexible lead shielding sheets lying around.

 

* Mats has spoken to S. Myers about the support from the BD group. There will be fire brigade tactics for the hardware until 2008, with a very limited support. The Russian project associate will come and work full time on the software migration for two years.

 

* Both Thomas and Fredrik are astonished how long time it takes to order things with DAI. The absolutely quickest time to get a delivery from outside CERN is >1 week.

 

 

Controls system etc

 

* The beam diagnostics system is now running again. Some dll files were missing and networking problems with the FEC PC. It is still not running at the new XP machine at the TRAP but the control system experts are looking into it.

 

* Roman is continuing working on the interface to the new CS of REXTRAP.

 

* Nikolai has performed tests with the RF system, checking the frontends. Problems with the PLC software were encountered, and expert help is awaited. When this is solved the system is operational, except for missing application programmes. The new CS can run in parallel with the old OPC server, and will only be launched in case application programmes are available.

 

 

REXTRAP and REXEBIS

 

* B. Crepieux is taking over the coolant filling of the TRAP and the EBIS. Pierre will provide a translation in French of the cooling instructions.

 

* It is foreseen to start the trap next week to verify that a 40-50% efficiency can be achieved with the new control system. Thereafter the beam will transported through the beam transfer section (BTS). If the power supply to the emittance meter arrives the emittance measurements will be resumed. Possible also Li injection from the trap ion source into the trap will be tested and cooling with alternative buffer gases.

 

* An ISOLDE target with Al is prepared so AlF injection into the trap/EBIS can be tested by leaking some fluorine compound gas into the target. The test is foreseen for the 10/5 if the EBIS is up running.

 

* For the Xe run we are preparing the possibility of connecting isotopically enriched 130Xe to the EBIS. The bottle is available from the Physics group.

 

* Still not received the ordered NEG strips (see comments above about delay of orders). Fortunately some strips were found at CERN already on Monday. Installed and baking finished on coming Monday.

 

* Due to an air leak in the needle valve at the beginning we might have saturated the NEG strips during bakeout. If so, they can not be regenerated but has to be exchanged. We don't want to think about that scenario. We'll know on Monday when the system is cold.

 

* An offer to install a draining pump to lower the pressure after the EBIS has been provided by D. Gros. Overall cost incl installaion 4500 euros, 6 weeks from ordering. Drawbacks: expensive, noisy, long delay. Moreover, already at relatively low 2 bar return pressure for the cooling water the newly produced cooling tube from Stockholm gets excessively warm when the vacuum bore tube is baked out. Thus, a decrease of the return pressure might not be sufficient. It was concluded that the temperature on the in- and outside of the cooling mantle should be surveyed after the baking out has been finished. If necessary one has to come up with a different design for the cooling tube and meanwhile use heating bands to stabilise the temperature.

 

 

LINAC

 

* Berdermann from Bertronix is here. He is working on the cooling of the cavity in the 200 MHz amplifier, to reduce that from 80 to 40 deg C. A test run foreseen for the near future. Also Berdermann complained about the low quality of the installation of the new air cooling system.

 

* Thomas has asked for an improvement of the installation of the air cooling system.

 

* Still some tuning to be done as the nominal output power value is not reached.

 

* The electronics workshop in Munich has finished the modifications of the low level amplifier modules. They should arrive at CERN by next Wednesday.

 

* The alignment of the mass slit in the beam diagnostics box after the separator remains to be done. This is difficult due to the long viewing distance.

 

* The dust cleaning of the Linac is still to be done. Thomas will contact an external company.

 

 

Minutes taken by Fredrik Wenander