IMS Scientific Meeting

Tuesday May 28, 2024, 1:00 PM → 3:40 PM Europe/Berlin

General Discussion and Technology¶

Technologie

• IDA3:
  • rf-generator matching has to be done manually otherwise the matching is very unstable
  • the backup generator and matchbox should be tested at IDA3
  • the generator and matchbox currently used at IDA3 should be tested with a different sputter gun

Messtechnik

• PTC:
  • the PTC again reaches its old basetemperatures of less than 4K
  • the issue was mostlikely due to contaminated Helium inside the PTC due to a leak in the pressure controller during refilling or the rotation valve frequency was incorrectly set.
    • the controller of the rotationary valve will be marked to be always set to "30.0"
• New JJ-Dipstick:
  • dipstick is now operational and reaches temperatures below 3.8K
  • 12 channels for JJ measurements + 12 channels for other dc measurements
    • multiple people can measure during one cooldown
    • everyone should enter in the PTC calendar which channels they intend to use and which channels are still free
• SQUID measurements at PTC:
  • noise is reduced significantly when unplugging the thermometer from the dipstick "PTC-SQUID"
  • test whether noise is already removed when lakeshore bridge is turned off and how unplugging the thermometer inside the PTC affects the noise
  • does the noise improve when using the new advanced/highperformance lakeshore bridge?
• Bluefors:
  • next time the Bluefors cryostat is opened up Sebastian wants to take a look at it
  • the remaining copper parts of the dc-wiring will be installed on the MXC stage for the next run

Other topics

• clean up till the lab tour on 12.06.24 :
  • all labs must be tidied up for the lab tour
  • everyone should actively look for trash in the labs and offices
  • measurement data, laboratory journals, delivery notes, signed theses, etc. must be kept.
  • ask if you are unsure whether something can be thrown away
• KRYO contributions:
  • Posters: Lena, Friedrich, Nick, (Nahuel)
  • Talks: Michael, Martin, Juan Ma

MMCs¶

• etching SiO₂ results in sharper edges than a lift-off (Juan Ma. shows SEM images)
• how to proceed with Au:Er?
  • ITEP magnetometer measurement of foil or INT or Heidelberg
• who takes care of data analysis/evaluation?

 

SQUIDs¶

• Jodok: JJs of last batch didn't work
  • test at which fabrication stepp the error occured (Al or Trilayer or ...)
  • new batch: 80nm to much SiO₂ deposited
  • simulations with Chang
• Konstantin: critical currents of crossJJs larger by a factor of 2 than  expected
  • more statistics required
• Dennis: PTC measurement of Nb-arrays in preperation, RT-measurements are ok
• Saadia: besides fabrication of magnetometer SQUIDs, think of methods to improve the shielding inside the PTC additionally to the µ-metal shielding
• Mona: simulations require up to 50GB of RAM ⇒ ims13