Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: SQUID-based instrumentation for ultra-low-field MRI
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph