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Message ID: 53     Entry time: Tue May 13 17:46:35 2025
Author: Carsten 
Category: Runs 
Subject: Start of DR measurements with 208Bi 
Same ramps as before, 8 repetitions.
ESR is set-up for breeding of 208Bi80+.
In order to reduce unwanted primary at injection to the ESR, in the transfer line scrapers are in use, presently GTE4DS5HL -5.0, GTE4DS5HR +7.0

The 208Bi80+ can be easily scraped since most unwanted species are lost during the deceleration ramp, and only 3 peaks remain. These 3 peaks are quite far away from the 208Bi80+.
Please note, that frequencies at decelerated beam is different than the ones in Yury's ID.

The detector DD1AG is not moving.

For scraping essentially DS3HG and DD1IG are used plus the particle detector.
DS3HG also shows the "overshooting behavior of DD2_G (particle detector, but not so strong).
Scraping of the 208Bi80+ with DS3HG at 0 but at -35 alreadz all other peaks are gone, thus the setting for the scraper DD3_DS3HG is -35.
With the DD1IG we cannot touch the 208Bi80+. Set to 26.
Particle detector presently is at -65 but this might be too far out.

I_el is 500mA, NOT bunched for the first tests.
stopped and restarted NTCAP: IQ_2025-05-13_17-39-30
run032.lmd (detector position not very good).
We had about 1e6 ions at the low energy.
First DR spectrum of 208Bi80+ but with moderate statistics. Going to different detector position as cross check.
18:05 closed run0032.lmd

Changed detector position to from -65 to -55.
Opened file from run0033.lmd
(At the moment 10 injections, 60 x 10s waiting - 10 min)

Intensity is about 1e6 ions at the beginning of the measurement.
After a few scans we see the first DR spectrum of 208Bi80+

Thus, we are sure to have the right beam.
Resolution is good.

The attached (online) spectrum is about 4 or 5 fully cycles (>1 h).

Please keep in mind that these are "small" DR resonances.

The lower spectrum is about 60% of the true counts during this time.
Attachment 1: DR_208Bi_500mA_unbunched(DC).png  17 kB  Uploaded Tue May 13 20:29:02 2025  | Hide | Hide all
DR_208Bi_500mA_unbunched(DC).png
Attachment 2: DR_208Bi_500mA_unbunched(DC)_true_counts.png  17 kB  Uploaded Tue May 13 20:35:07 2025  | Hide | Hide all
DR_208Bi_500mA_unbunched(DC)_true_counts.png
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