Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Development of rebunching cavities at IAP   A focus of work at IAP has been the development and optimization of spiral
loaded cavities since the 1970s [A. Schempp et al, NIM 135, 409 (1976)]. These
cavities feature a high efficiency, a compact design and a big variety of
possible fields of application. They find use both as bunchers and post
accelerators to vary the final energy of the beam. In comparison to other
available designs, the advantage of these structures lies in their small size.
Furthermore they can easily be tuned to the required resonance frequency by
varying the length of the spiral. Due to the small size of the cavities the
required budget can also be kept low. Here, two slightly different types of
spiral loaded cavities, which were built for the REX-ISOLDE project at CERN and
the intensity upgrade program at GSI are being discussed.

16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio