Minutes of the ISOLDE Physics Group Meeting, November 16th 2016

There were no comments to the minutes of the previous physics group meeting.

Technical news

• GPS

• Last week the 66Ni run continued at Miniball.
• The problems at Linac 2 led to a break in operation of about 36 hours, after which the run was resumed (Wednesday afternoon).
• On Saturday a leak developed on the GPS target. This time the proton count was a bit higher (6.5e18) but of the same order as the previous target units which have developed leaks. The GPS target was also using the new batch of bases.
• The HRS target had been installed as a backup, but since the GPS problem occurred only on Saturday there was no time to set up the post-accelerated beam. With this, the Miniball run had to come to an end.
• The GPS target was exchanged on Monday for a bare unit with a VD5 ion source.

• HRS

• After the leak developed on the GPS target, the HRS target was used to produce (at LA1) a calibration 66Ga source for the Miniball run.
• Afterwards VITO performed further tests of their setup until Monday morning 6:00 AM, when the high-intensity proton beam was stopped.
• A low-intensity proton beam (5e12 ppp) was still delivered on Monday morning and used to irradiate Pb-Bi blocks for the LIEBE project (the MEDICIS Montrac was used). There were no issues with the irradiation, but a miscalculation led to a ten times higher than planned dose rate from the target. The samples are now being measured close to the ISOLDE tape station by a team from Kolkata.
• The first separator course started on Monday on HRS. The HRS target was exchanged for a bare unit with a surface ion source.

• HIE-ISOLDE
• Some energy tests have been performed by Alberto.
• Set-up for SPEDE tests will begin on Thursday.
• RILIS

• The 66Ni ionization went without major problems until the end.
• Because of the broken GPS target the actinium ionisation tests were replaced with molybdenum tests.

Physics and schedule

• The 66Ni users were happy with the physics outcome, despite the various delays and interruptions. The collected data look good in all channels, including particle-gamma coincidences. The calibrations with 66Ga went well and also revealed that one of the preamps of the LaBr3 detectors was saturated, but five others were functioning properly.
• VITO studied again 26,28Na on Sunday. After getting the laser polarization under control the beta asymmetry obtained on-line was similar to the one obtained at Collaps in the past (about 25% for 26Na and about 40% for 28Na).
• Thirteen 181Hf samples were received from Bonn by the SSP group, to be used for perturbed angular correlation measurements. This will ensure plenty of measurements for the upcoming months.
• Haraldur Pall Gunnlaugsson was at ISOLDE last week to oversee a series of collections which will be shipped to Bilbao for Mӧssbauer spectroscopy.
• The second separator course will take place next week.

Safety

• There were some reports about the hand-foot monitor near the ISOLDE stairs malfunctioning, but other users did not remember seeing a problem (as Maria explained some time ago it might be connected to the hand sensors which are not positioned optimally for people with small hands).
• The RP fundamentals e-course is no longer required for obtaining access to ISOLDE. What remains as compulsory for RP safety is the supervised area e-course and the classroom course.
• There was a meeting with safety officers concerning future improvements on the way collections are performed in the GLM/GHM area. A new working group was established to discuss and implement these improvements.

AOB

• The decisions for the next ISOLDE fellows, associates and corresponding associates have been communicated. ISOLDE fellows: André Welker and Stavroula Pallada, ISOLDE Associates: Angela Braco (6 months starting 1st February) and Andrei Andreyev (one year starting 1st April), ISOLDE Corresponding Associates: Olof Tengblad (4 months starting 1st February) and Nikolaos Patronis (2 months, might be dedicated to n_TOF).
• Users are asked not to forget to register for the ISOLDE Workshop and the also very attractive satellite workshop of the NUSPRASEN ENSAR network using the on-line application https://indico.cern.ch/event/561089/registrations/30813/ and from there the one to NUSPRASEN.
• Feed-back from the separator course was positive. Following the course some suggestions for the future operation of the facility are to establish a clear protocol for users to follow in case of problems and an updated/extended walk-through material available in the control room (the so-called ISOLDE baby-sitting guide).
• An end-of-the-year celebration is being planned for one of the following Fridays. To be announced.

Seminar

• The meeting was followed by a seminar of Martin Gonzalez-Alonso from Institut de Physique Nucléaire de Lyon on Precision measurements in nuclear beta decay in the LHC era.

The next PG meeting will be held Wednesday November 23rd at 14:00 followed by a seminar by Hanne Heylen from MPIK Heidelberg on Nuclear moments of the neutron-rich Al isotopes at the border of the island of inversion

Minutes taken by VM