nuCARIBU Beams

The Californium Rare Isotope Breeder Upgrade (CARIBU) that was used previously to provide beam of neutron-rich isotopes far from stability has been upgraded to nuCARIBU. The fission products are now obtained from neutron-induced fission on uranium-235.

The facility allows for fast, efficient and essentially chemistry-free extraction of fission fragments. nuCARIBU, like its predecessor CARIBU, uses a gas catcher and various isotope separation techniques to provide low-energy beams for mass measurements, beta decay or laser manipulation, or for injection into the ATLAS accelerator following charge breeding.

For more information on what beams, energies, and intensities are available, please contact the ATLAS User Liaison. The 2025 PAC will consider beamtime for experiment staring in early 2026 and the neutron-rich radioactive beams will be provided by nuCARIBU with neutron-induced fission on ²³⁵U. Primary beam power will be intermediate between the initial 10% of full power available in the previous PAC and full power that is planned for the following PAC. As a result, the mass separated yields to be used for planning experiments for the 2025 PAC are roughly a factor above that available in the previous PAC and are given in the table below for low-energy and reaccelerated beams, respectively. Please note that the fission fragment distribution for neutron-induced fission of ²³⁵U is shifted somewhat from that from spontaneous fission of ²⁵²Cf so that some new isotopes are available, and some isotopes previously available no longer are.

A table of nuCARIBU beams

The rates, given in the last two columns for Low Energy and Reaccelerated beams, are in ions per second.

Nuclide	A	Z	N	t1/2	Low Energy	Reaccelerated
81Ge	81	32	49	7.6 s	5.6E+03	6.2E+02
82Ge	82	32	50	4.6 s	6.3E+03	6.9E+02
82As-m	82	33	49	13.7 s	7.7E+03	8.6E+02
82As	82	33	49	19 s	7.7E+03	8.6E+02
83Ge	83	32	51	1.9 s	2.4E+03	2.6E+02
83As	83	33	50	13.4 s	1.4E+04	1.6E+03
83Se	83	34	49	22.3 m	8.8E+03	9.7E+02
84As	84	33	51	5.5 s	9.8E+03	1.1E+03
84Se	84	34	50	3.3 m	3.1E+04	3.5E+03
85As	85	33	52	2.03 s	6.0E+03	6.7E+02
85Se-m	85	34	51	19 s	4.4E+04	4.9E+03
85Se	85	34	51	39 s	4.4E+04	4.9E+03
85Br	85	35	50	2.87 m	1.2E+04	1.3E+03
86As	86	33	53	0.9 s	9.9E+02	1.1E+02
86Se	86	34	52	15 s	4.2E+04	4.6E+03
86Br-m	86	35	51	4.5 s	2.3E+04	2.5E+03
86Br	86	35	51	55.5 s	2.3E+04	2.5E+03
87Se	87	34	53	5.6 s	3.6E+04	4.0E+03
87Br	87	35	52	55.9 s	6.3E+04	7.0E+03
87Kr	87	36	51	1.27 h	2.3E+04	2.5E+03
88Se	88	34	54	1.5 s	1.3E+04	1.5E+03
88Br	88	35	53	16.4 s	6.9E+04	7.6E+03
88Kr	88	36	52	2.84 h	8.6E+04	9.5E+03
89Se	89	34	55	0.41 s	2.4E+03	2.7E+02
89Br	89	35	54	4.37 s	5.2E+04	5.7E+03
89Kr	89	36	53	3.15 m	1.7E+05	1.9E+04
89Rb	89	37	52	15.4 m	1.0E+04	1.1E+03
90Br	90	35	55	1.9 s	2.7E+04	3.0E+03
90Kr	90	36	54	32.3 s	2.2E+05	2.4E+04
90Rb-m	90	37	53	4.3 m	4.2E+04	4.6E+03
90Rb	90	37	53	2.6 m	4.2E+04	4.6E+03
91Br	91	35	56	0.54 s	1.1E+04	1.2E+03
91Kr	91	36	55	8.6 s	1.6E+05	1.7E+04
91Rb	91	37	54	58 s	1.1E+05	1.2E+04
91Sr	91	38	53	9.5 h	1.2E+04	1.4E+03
92Br	92	35	57	0.34 s	1.3E+03	1.5E+02
92Kr	92	36	56	1.84 s	8.2E+04	9.1E+03
92Rb	92	37	55	4.48 s	1.6E+05	1.7E+04
92Sr	92	38	54	2.71 h	5.3E+04	5.9E+03
93Kr	93	36	57	1.29 s	2.4E+04	2.7E+03
93Rb	93	37	56	5.85 s	1.5E+05	1.7E+04
93Sr	93	38	55	7.4 m	1.3E+05	1.4E+04
93Y	93	39	54	10.2 h	5.4E+03	6.0E+02
94Kr	94	36	58	0.21 s	4.3E+03	4.8E+02
94Rb	94	37	57	2.73 s	7.8E+04	8.6E+03
94Sr	94	38	56	1.25 m	2.2E+05	2.5E+04
94Y	94	39	55	18.7 m	1.9E+04	2.1E+03
95Kr	95	36	59	0.78 s	3.6E+02	3.9E+01
95Rb	95	37	58	0.377 s	3.8E+04	4.2E+03
95Sr	95	38	57	25.1 s	2.3E+05	2.5E+04
95Y	95	39	56	10.3 m	5.5E+04	6.1E+03
96Rb	96	37	59	0.199 s	8.4E+03	9.2E+02
96Sr	96	38	58	1.06 s	1.8E+05	2.0E+04
96Y -m	96	39	57	9.6 s	1.1E+05	1.2E+04
96Y	96	39	57	6.2 s	1.1E+05	1.2E+04
97Rb	97	37	60	0.169 s	1.9E+03	2.1E+02
97Sr	97	38	59	0.42 s	8.5E+04	9.4E+03
97Y	97	39	58	3.76 s	1.6E+05	1.8E+04
97Zr	97	40	57	16.8 h	5.4E+04	6.0E+03
98Rb	98	37	61	0.107 s	1.2E+02	1.4E+01
98Sr	98	38	60	0.65 s	4.0E+04	4.4E+03
98Y -m	98	39	59	2.1 s	1.1E+05	1.2E+04
98Y	98	39	59	0.59 s	1.1E+05	1.2E+04
98Zr	98	40	58	30.7 s	1.3E+05	1.4E+04
98Nb	98	41	57	2.9 s	7.7E+03	8.5E+02
99Sr	99	38	61	0.269 s	6.6E+03	7.3E+02
99Y	99	39	60	1.47 s	9.7E+04	1.1E+04
99Zr	99	40	59	2.2 s	1.8E+05	2.0E+04
99Nb-m	99	41	58	2.6 m	2.2E+04	2.4E+03
99Nb	99	41	58	15 s	2.2E+04	2.4E+03
100Sr	100	38	62	0.201 s	4.0E+02	4.5E+01
100Y	100	39	61	0.73 s	4.3E+04	4.8E+03
100Zr	100	40	60	7.1 s	2.5E+05	2.7E+04
100Nb-m	100	41	59	3 s	3.2E+04	3.5E+03
100Nb	100	41	59	1.5 s	3.2E+04	3.5E+03
100Mo	100	42	58	stable	3.6E+03	4.0E+02
101Y	101	39	62	0.43 s	1.4E+04	1.5E+03
101Zr	101	40	61	2.1 s	1.4E+05	1.5E+04
101Nb	101	41	60	7.1 s	9.5E+04	1.1E+04
101Mo	101	42	59	14.6 m	9.2E+03	1.0E+03
102Y	102	39	63	0.36 s	8.2E+03	9.0E+02
102Zr	102	40	62	2.9 s	8.8E+04	9.8E+03
102Nb	102	41	61	1.3 s	7.8E+04	8.7E+03
102Mo	102	42	60	11.3 m	3.2E+04	3.6E+03
103Y	103	39	64	0.26 s	1.3E+02	1.4E+01
103Zr	103	40	63	1.3 s	2.5E+04	2.7E+03
103Nb	103	41	62	1.5 s	7.0E+04	7.7E+03
103Mo	103	42	61	1.13 m	5.1E+04	5.7E+03
103Tc	103	43	60	54 s	4.1E+03	4.5E+02
104Zr	104	40	64	1.2 s	4.1E+03	4.5E+02
104Nb	104	41	63	4.8 s	2.8E+04	3.1E+03
104Mo	104	42	62	60 s	5.6E+04	6.2E+03
104Tc	104	43	61	18.2 m	4.6E+03	5.1E+02
105Zr	105	40	65	0.493 s	5.8E+03	6.4E+02
105Nb	105	41	64	3 s	6.9E+03	7.6E+02
105Mo	105	42	63	36 s	3.3E+04	3.7E+03
105Tc	105	43	62	7.6 m	2.4E+03	2.7E+02
106Nb	106	41	65	1 s	7.8E+02	8.6E+01
106Mo	106	42	64	8.4 s	1.8E+04	2.0E+03
106Tc	106	43	63	36 s	1.3E+03	1.5E+02
107Nb	107	41	66	0.766 s	1.1E+02	1.3E+01
107Mo	107	42	65	3.5 s	6.0E+03	6.7E+02
107Tc	107	43	64	21.2 s	1.1E+03	1.2E+02
108Mo	108	42	66	1.5 s	1.5E+03	1.7E+02
108Tc	108	43	65	5.1 s	1.2E+03	1.3E+02
109Mo	109	42	67	1.41 s	7.7E+02	8.5E+01
109Tc	109	43	66	1.4 s	6.7E+02	7.4E+01
109Ru	109	44	65	34.5 s	8.5E+01	9.4E+00
110Mo	110	42	68	2.77 s	1.9E+02	2.1E+01
110Tc	110	43	67	0.83 s	5.8E+02	6.4E+01
110Ru	110	44	66	15 s	4.9E+02	5.4E+01
111Tc	111	43	68	1.98 s	2.2E+02	2.5E+01
111Ru	111	44	67	1.5 s	5.9E+02	6.5E+01
112Ru	112	44	68	4.5 s	4.9E+02	5.4E+01
112Rh	112	45	67	4 s	1.6E+02	1.7E+01
113Ru	113	44	69	2.7 s	2.8E+02	3.1E+01
113Rh	113	45	68	0.9 s	3.4E+02	3.8E+01
113Pd	113	46	67	1.64 m	5.6E+01	6.1E+00
114Ru	114	44	70	8.14 s	8.6E+01	9.5E+00
114Rh	114	45	69	1.8 s	2.9E+02	3.3E+01
114Pd	114	46	68	2.48 m	2.1E+02	2.3E+01
115Rh	115	45	70	0.99 s	1.8E+02	2.0E+01
115Pd	115	46	69	47 s	3.8E+02	4.2E+01
115Ag-m	115	47	68	18.7 s	7.8E+01	8.6E+00
115Ag	115	47	68	20 m	7.8E+01	8.6E+00
116Rh	116	45	71	0.7 s	8.3E+01	9.1E+00
116Pd	116	46	70	12.7 s	3.4E+02	3.7E+01
116Ag-m	116	47	69	10.5 s	2.4E+02	2.6E+01
116Ag	116	47	69	2.68 m	2.4E+02	2.6E+01
117Pd	117	46	71	5 s	3.8E+02	4.2E+01
117Ag-m	117	47	70	5.3 s	1.5E+02	1.7E+01
117Ag	117	47	70	1.22 m	1.5E+02	1.7E+01
118Pd	118	46	72	2.4 s	1.6E+02	1.7E+01
118Ag-m	118	47	71	2.4 s	3.2E+02	3.5E+01
118Ag	118	47	71	4 s	3.2E+02	3.5E+01
118Cd	118	48	70	50.3 m	8.5E+01	9.4E+00
119Ag	119	47	72	2.1 s	3.3E+02	3.6E+01
119Cd-m	119	48	71	2.2 m	2.3E+02	2.6E+01
119Cd	119	48	71	2.69 m	2.3E+02	2.6E+01
120Cd	120	48	72	50.8 s	4.2E+02	4.6E+01
121Ag	121	47	74	0.78 s	1.3E+02	1.4E+01
121Cd	121	48	73	13.5 s	3.6E+02	4.0E+01
122Cd	122	48	74	5.3 s	5.9E+02	6.5E+01
123Cd	123	48	75	2.09 s	2.7E+02	3.0E+01
124Cd	124	48	76	1.24 s	6.0E+02	6.7E+01
124In	124	49	75	3.18 s	1.7E+02	1.9E+01
126In	126	49	77	1.63 s	1.6E+02	1.8E+01
126Sn	126	50	76	100000 y	2.2E+03	2.4E+02
127Sn-m	127	50	77	4.15 m	4.7E+03	5.2E+02
127Sn	127	50	77	2.12 h	4.7E+03	5.2E+02
128Sn	128	50	78	59.1 m	1.5E+04	1.7E+03
128Sb-m	128	51	77	10.1 m	8.5E+02	9.3E+01
129Sn-m	129	50	79	6.9 m	2.1E+04	2.3E+03
129Sn	129	50	79	2.4 m	2.1E+04	2.3E+03
129Sb	129	51	78	4.4 h	3.2E+03	3.5E+02
130In	130	49	81	0.29 s	4.7E+02	5.2E+01
130Sn	130	50	80	3.7 m	5.4E+04	6.0E+03
130Sb-m	130	51	79	6.5 m	2.8E+04	3.1E+03
130Sb	130	51	79	38.4 m	2.8E+04	3.1E+03
130Te	130	52	78	stable	2.9E+03	3.2E+02
131Sn	131	50	81	39 s	4.4E+04	4.8E+03
131Sb	131	51	80	23 m	8.2E+04	9.1E+03
131Te-m	131	52	79	1.35 d	1.6E+04	1.8E+03
131Te	131	52	79	25 m	1.6E+04	1.8E+03
132Sn	132	50	82	40 s	2.9E+04	3.2E+03
132Sb-m	132	51	81	2.8 m	1.1E+05	1.2E+04
132Sb	132	51	81	4.2 m	1.1E+05	1.2E+04
132Te	132	52	80	3.26 d	7.6E+04	8.4E+03
132I	132	53	79	2.28 h	9.1E+02	1.0E+02
133Sn	133	50	83	1.44 s	6.8E+03	7.6E+02
133Sb	133	51	82	2.5 m	1.1E+05	1.2E+04
133Te-m	133	52	81	55.4 m	2.1E+05	2.3E+04
133Te	133	52	81	12.4 m	2.1E+05	2.3E+04
133I	133	53	80	20.8 h	8.2E+03	9.1E+02
134Sn	134	50	84	1.04 s	8.8E+02	9.7E+01
134Sb	134	51	83	0.8 s	3.6E+04	3.9E+03
134Te	134	52	82	42 m	3.1E+05	3.4E+04
134I -m	134	53	81	3.7 m	4.3E+04	4.7E+03
134I	134	53	81	52.6 m	4.3E+04	4.7E+03
134Xe-m	134	54	80	0.29 s	1.7E+03	1.9E+02
135Sb	135	51	84	1.71 s	7.2E+03	8.0E+02
135Te	135	52	83	19 s	1.6E+05	1.8E+04
135I	135	53	82	6.57 h	1.5E+05	1.6E+04
135Xe-m	135	54	81	15.3 m	1.3E+04	1.4E+03
135Xe	135	54	81	9.1 h	1.3E+04	1.4E+03
136Sb	136	51	85	0.82 s	5.7E+02	6.3E+01
136Te	136	52	84	17.5 s	6.5E+04	7.2E+03
136I -m	136	53	83	47 s	1.3E+05	1.4E+04
136I	136	53	83	1.39 m	1.3E+05	1.4E+04
137Te	137	52	85	2.5 s	1.9E+04	2.2E+03
137I	137	53	84	24.5 s	1.3E+05	1.4E+04
137Xe	137	54	83	3.82 m	1.6E+05	1.8E+04
137Cs	137	55	82	30.17 y	3.0E+03	3.3E+02
138Te	138	52	86	1.4 s	3.3E+03	3.6E+02
138I	138	53	85	6.5 s	7.1E+04	7.8E+03
138Xe	138	54	84	14.1 m	2.4E+05	2.6E+04
138Cs-m	138	55	83	2.9 m	2.3E+04	2.6E+03
138Cs	138	55	83	32.2 m	2.3E+04	2.6E+03
139Te	139	52	87	0.58 s	3.3E+02	3.7E+01
139I	139	53	86	2.3 s	3.8E+04	4.2E+03
139Xe	139	54	85	39.7 s	2.1E+05	2.4E+04
139Cs	139	55	84	9.3 m	6.5E+04	7.2E+03
139Ba	139	56	83	1.396 h	3.4E+03	3.8E+02
140I	140	53	87	0.86 s	6.8E+03	7.5E+02
140Xe	140	54	86	13.6 s	1.7E+05	1.9E+04
140Cs	140	55	85	1.06 m	1.0E+05	1.1E+04
140Ba	140	56	84	12.75 d	2.4E+04	2.7E+03
141I	141	53	88	0.45 s	2.0E+03	2.2E+02
141Xe	141	54	87	1.72 s	6.1E+04	6.7E+03
141Cs	141	55	86	24.9 s	1.4E+05	1.6E+04
141Ba	141	56	85	18.3 m	8.2E+04	9.1E+03
141La	141	57	84	3.9 h	9.2E+02	1.0E+02
142Xe	142	54	88	1.22 s	2.2E+04	2.4E+03
142Cs	142	55	87	1.8 s	1.1E+05	1.3E+04
142Ba	142	56	86	10.7 m	1.5E+05	1.7E+04
142La	142	57	85	1.54 h	4.8E+03	5.3E+02
143Xe	143	54	89	0.3 s	2.6E+03	2.9E+02
143Cs	143	55	88	1.78 s	7.0E+04	7.7E+03
143Ba	143	56	87	14.3 s	2.0E+05	2.3E+04
143La	143	57	86	14.1 m	1.9E+04	2.1E+03
143Ce	143	58	85	1.38 d	1.6E+03	1.7E+02
144Xe	144	54	90	1.2 s	3.0E+02	3.3E+01
144Cs	144	55	89	1.01 s	2.1E+04	2.3E+03
144Ba	144	56	88	11.4 s	2.0E+05	2.2E+04
144La	144	57	87	40.7 s	5.3E+04	5.9E+03
144Ce	144	58	86	284.6 d	1.7E+03	1.9E+02
145Cs	145	55	90	0.59 s	3.8E+03	4.2E+02
145Ba	145	56	89	4 s	9.3E+04	1.0E+04
145La	145	57	88	24 s	9.5E+04	1.1E+04
145Ce	145	58	87	3 m	4.2E+03	4.7E+02
146Cs	146	55	91	0.322 s	3.8E+02	4.2E+01
146Ba	146	56	90	2.2 s	4.5E+04	5.0E+03
146La	146	57	89	6.3 s	7.4E+04	8.2E+03
146Ce	146	58	88	13.5 m	2.9E+04	3.2E+03
146Pr	146	59	87	24.2 m	1.8E+02	2.0E+01
147Ba	147	56	91	0.892 s	1.2E+04	1.3E+03
147La	147	57	90	4.02 s	3.2E+04	3.5E+03
147Ce	147	58	89	56 s	5.0E+04	5.5E+03
147Pr	147	59	88	13.4 m	1.8E+04	2.0E+03
148Ba	148	56	92	0.64 s	1.1E+03	1.2E+02
148La	148	57	91	1.1 s	1.7E+04	1.8E+03
148Ce	148	58	90	56 s	6.1E+04	6.8E+03
148Pr	148	59	89	2.27 m	3.9E+03	4.3E+02
149La	149	57	92	1.1 s	4.0E+03	4.4E+02
149Ce	149	58	91	5.2 s	3.5E+04	3.8E+03
149Pr	149	59	90	2.3 m	1.5E+04	1.6E+03
149Nd	149	60	89	1.72 h	3.4E+02	3.7E+01
150La	150	57	93	0.608 s	5.2E+02	5.7E+01
150Ce	150	58	92	4.4 s	1.9E+04	2.2E+03
150Pr	150	59	91	6.2 s	1.1E+04	1.2E+03
150Nd	150	60	90	stable	1.6E+03	1.8E+02
151Ce	151	58	93	1 s	4.6E+03	5.1E+02
151Pr	151	59	92	22.4 s	1.2E+04	1.3E+03
151Nd	151	60	91	12.4 m	3.9E+03	4.4E+02
152Ce	152	58	94	3.1 s	1.0E+03	1.1E+02
152Pr	152	59	93	3.2 s	5.1E+03	5.6E+02
152Nd	152	60	92	11.4 m	7.0E+03	7.7E+02
152Pm-m	152	61	91	7.5 m	1.4E+02	1.5E+01
152Pm	152	61	91	4.1 m	1.4E+02	1.5E+01
153Ce	153	58	95	1.47 s	8.5E+01	9.4E+00
153Pr	153	59	94	4.3 s	1.8E+03	2.0E+02
153Nd	153	60	93	28.9 s	5.5E+03	6.1E+02
153Pm	153	61	92	5.4 m	4.4E+02	4.8E+01
154Pr	154	59	95	2.3 s	2.5E+02	2.8E+01
154Nd	154	60	94	25.9 s	2.9E+03	3.2E+02
154Pm-m	154	61	93	2.7 m	5.4E+02	5.9E+01
154Pm	154	61	93	1.7 m	5.4E+02	5.9E+01
155Nd	155	60	95	8.9 s	8.7E+02	9.6E+01
155Pm	155	61	94	48 s	6.3E+02	6.9E+01
155Sm	155	62	93	22.2 m	6.5E+01	7.2E+00
156Nd	156	60	96	5.5 s	2.3E+02	2.6E+01
156Pm	156	61	95	26.7 s	3.5E+02	3.9E+01
156Sm	156	62	94	9.4 h	1.5E+02	1.7E+01
157Pm	157	61	96	10.9 s	1.5E+02	1.6E+01
157Sm	157	62	95	8 m	1.3E+02	1.5E+01
158Sm	158	62	96	5.5 m	1.2E+02	1.3E+01