372596168

RIKEN Accel. Próg. Rep. 24 (1990)

11-2. RILAC Operation

Y. Chiba, M. Hemmi, M. Yanokura, M. Kasę, E. Ikezawa, T. Aihara, ¹

T. Ohki, ¹ H. Hasebe, ¹ T. Chiba, and Y. Miyazawa

This year, the PIG ion source, which had been used for many years, of RILAC was replaced with a new ECR ion source. For the replacement, reg-ular RILAC operation was discontinued by the end of July. The remaining period of the year was devoted to the modification of the injector high voltage station and the installation of the ECR ion source on it. Tables 1 to 3 show the operation statistics for the calendar year 1990. The “overhaul and improvement” in Table 1 includes the ion source renewal. During regular operation, there arose no serious trouble except carelesslv mistak-ing ⁶⁶Zn⁵⁺ ions for ⁶⁴Zn⁵⁺ ions gave a loss in beam time to RIKEN Ring Cyclotron.

Table 1. Statistics of the operation for Jan. 1 - Dec. 31, 1990.

	Day	%
Beam time	123	33.7
Freąuency change	6	1.6
Overhaul and improvement	95	26.0
Periodic inspection and repair	21	5.8
Machinę trouble	0	0.0
Scheduled shut down	120	32.9
Total	365	100
Table 2. Beam time for individual research		groups.
	Day	%
Atomie physics	33	26.8
Solid-state physics	21	17.1
Nuclear chemistry	24	19.5
Radiation chemistry	7	5.7
Accelerator research	4	3.3
Beam transportation to RRC	34	27.6
Total	123	100

Table 3. List of ions used in this year.

Ion	Mass	Charge State	Day
N	14	2	3
Ne	20	2	7
Al	27	3	4
Si	28	3	5
Ar	40	3	19
Ar	40	4	45
Ti	48	3	8
Cr	52	5	2
Cu	63	4	9
Zn	64	3	1
Zn	64	5	6
Kr	84	5	5
Kr	84	8	2
Xe	132	6	5
Xe	132	9	2

The newly instałled ECR ion source, called NEOMAFIOS, developed and manufactured by C.E.N.-G., France, arrived at our facilities in Feb-ruary 1990. Performance tests¹⁵ and operation training for the new ion source were repeated on a test bench until the end of July. August through the middle of November, we successively carried out the removal of the old PIG ion source system from the injector high voltage station, the installation of the ECR ion source system, and the prepa-ration of peripheral eąuipments. Most of the instru-ments on the station were replaced with new ones designed for the ECR ion source system.

Adjustment of the ECR ion source combined with beam transport in the injector system was started in the middle of November and acceleration test of RILAC using an ⁴⁰Ar⁸⁺ beam in the end.

Beam acceleration will be reopened for users in the middle of January 1991.

References

1) E. Ikezawa et at.: This Report, p. 133.

Sumijyu Accelerator Service, Ltd.