II-9. Instrumentation

RIKEN Accel. Prog. Rep. 54 (2021)

RIKEN Accel. Prog. Rep. 54 (2021)

Development of auto-focusing and auto-centering system for theBigRIPS separator
Y. Shimizu,∗1 N. Fukuda,∗1 H. Takeda,∗1 H. Suzuki,∗1 T. Sumikama,∗1 T. Baba,∗1 and K. Yoshida∗1

p1 = +1.80

F340

p1 = -225.81

F320400−2020−400−40−20020−4040−2002040

p1 = +0.84

F53040x (mm)

θ (mrad)Countsx (mm)40p1 = -6.35

F520020−2010−400−40−20020−4040−20020Counts

p1 = +1.71

F74040x (mm)

θ (mrad)x (mm)

1. Start DAQ,
2. Start analysis,
3. Provide analyzed results,
4. Stop DAQ,
5. Evaluate new magnet currents,
6. Apply new magnet currents, and7. Output the stability of the magnets.

40

p1 = -60.34

F7

2030
020
−2010−40

The realtime analysis program is always running to convert raw data into analyzed data stored as a TTree object in root.7) Presently, when the step shifts from 5to 6, one of the choices “APPLY TO TUNE,” “NEXTFOCAL PLANE,” and “FINISH” must be selected on
the browser interface.
The system test of the auto-focusing and autocentering system was conducted online for the 82 Gebeam production required for HiCARI commissioning.
The auto-centering was performed for each focal planein the order of F2, F5, and F7. Subsequently, the autofocusing was performed for each focal plane in the orderof F1, F2, F3, F5, and F7. Figure 1 shows the positions
and phase spaces at each focal plane after the autofocusing and auto-centering. These auto-tunings weresuccessfully demonstrated. Furthermore, the operation
time became shorter than that of conventional manualtuning.
In future work, the simultaneous tuning of the STQs
∗160

θ (mrad)and dipole magnets will be continuously automated in
the order of F1 to F7.
CountsVarious radioactive isotope (RI) beams have been
produced by the superconducting in-ﬂight separator BigRIPS since 2007.1) We are developing the technologiesof the RI-beam separation2,3) and particle-identiﬁcation
analysis.4) We developed eﬃcient RI beam production,
including a control system for the magnetic ﬁeld witha feedback algorithm.5) In the case of a 132 Sn beam,
the production time was reduced by a factor of approximately 1/4 in the past decade. To further improvethe eﬃciency of RI beam production, we are developing a fully automatic RI beam production system basedon our technological developments and experiences. As
the ﬁrst step, auto-focusing and auto-centering systems
were developed to automatically tune the STQs anddipole magnets on the BigRIPS separator.
In the auto-focusing and auto-centering systems, weused the BYACO (BeYond Analysis, Control, or Operation alone) ecosystem developed for online operation of
the BigRIPS separator by connecting the comprehensive analyses seamlessly with others, such as devices
and data acquisition (DAQ) systems.6) The sequencer
programming of the auto-focusing and auto-centering
includes an automated loop, which consists of 7 steps

0−40−2002040x (mm)−40−2002040x (mm)Fig. 1. Positions (left column) and phase spaces (right column) at each focal plane (F3, F5, and F7) after theauto-focusing and auto-centering. The pink curves andlines show the fitted functions of the Gaussian and 1storder polynomial, respectively. The p1 values show thefitted results.

References

1) T. Kubo, Nucl. Instrum. Methods Phys. Res. B 204, 97(2003).
2) N. Fukuda et al., J. Phys. Soc. Jpn. 87, 014202 (2018).
3) T. Sumikama et al., Nucl. Instrum. Methods Phys. Res.
B 463, 237 (2020).
4) N. Fukuda et al., Nucl. Instrum. Methods Phys. Res. B
317, 323 (2013).
5) Y. Shimizu et al., RIKEN Accel. Prog. Rep. 50, 206 (2017).
6) T. Sumikama et al., in this report.
7) R. Brun, F. Rademakers, Nucl. Instrum. Methods Phys.
Res. A 389, 81 (1997).

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