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  Nuclear hyperfine mixing in 229Th89+ 2025  Not logged in ELOG logo
Message ID: 38     Entry time: Sat Jun 21 08:48:16 2025
Author: Arya, Julien, Wilfried 
Category: Accelerator 
Subject: Low 229Th particle numbers and 229Th lifetime in ring 
With reference to entry 37 Laser timing:

- at last 30 injections accumulation: 10k counts on particle detector (accumulated during manipulation until it saturates, e.g. no more Th in ESR)
- at first 70 injections accumulation: 7.6k counts
- at second 70 injections accumulation: 2.8k counts

did another 2 30 injections accumulations to confirm lower yield: 
- at first 30 injections accumulation: 3.7k counts
  SIS intensities look fine, around 1.2e9
- at second 30 injections accumulation:  6.9k counts
  saved to /data.local2/2025_229Th/2025_229ThDAQ1_0101.lmd with DAQ1
  SIS intensities look fine, around 1.2e9, only users during injection
  "late" contaminants on PD seem to quickly disappear after start of modulation 3 
  (attachment 1: full timing spectrum, attachment 2: timing spectrum at the end of the modulation)
- at second 60 injections accumulation:  0 counts, maybe scrapers overshot,did another one, still not accumulating

     -------------------   Some issue on accelerator side   -------------------
        FSR people had to go into cave, that's why we were the only users, 
        but since nothing got into ESR
        Connection to scrapers was lost, on call service had to do a reset

- at second 60 injections accumulation:  11.9k counts
  saved to /data.local2/2025_229Th/2025_229ThDAQ1_0102.lmd with DAQ1
  again observed that the late contaminant om the particle detector (see attachment 3) is more prominent in at the beginning.
  This also manifests in an early steep fall off on the counts/s, see attachment 4
Attachment 1: Bildschirmfoto_timing_full_2025-06-21_09-30-46.png  173 kB  Uploaded Sat Jun 21 12:24:46 2025  | Hide | Hide all | Show all
Bildschirmfoto_timing_full_2025-06-21_09-30-46.png
Attachment 2: Bildschirmfoto_timing_end_of_manipulation_2025-06-21_09-36-24.png  170 kB  Uploaded Sat Jun 21 12:25:03 2025  | Hide | Hide all | Show all
Bildschirmfoto_timing_end_of_manipulation_2025-06-21_09-36-24.png
Attachment 3: Bildschirmfoto_timing_full_60_2025-06-21_11-25-51.png  172 kB  Uploaded Sat Jun 21 12:29:53 2025  | Show | Hide all | Show all
Attachment 4: Bildschirmfoto_PDSouth_lifetimes_2025-06-21_11-26-43.png  173 kB  Uploaded Sat Jun 21 12:30:05 2025  | Show | Hide all | Show all
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