PROGRESS REPORT FOR THE CRYRING FACILITY G. Andler, J. Axelsson, L. Bagge, M. Björkhage, P. Carlé, H. Danared, A. Källberg, L. Liljeby, K-G. Rensfelt, A. Paál, U. Rosengård, A. Simonsson, and M. af Ugglas, Manne Siegbahn Laboratory, Frescativägen 24, SE-104 05 Stockholm, Sweden Abstract The present status and upgrades planned in the near future for CRYRING are described. The topics include new residual gas ionisation beam profile monitors, a cur- rent transformer, an ECR source, and an upgrade of the vacuum system. 1 OVERVIEW OF CRYRING The CRYRING facility [1] has two ion sources, an EBIS source CRYSIS for highly charged ions [2] and an electron bombardment source MINIS for singly charged molecular and atomic ions. Both sources are placed on high voltage platforms (maximum 40 kV). If q/m>0.24 the ions are accelerated in an RFQ to 290 keV/u, other- wise they are only transported through the RFQ. The ring has 52 m circumference and maximum Bρ is 1.44 Tm [3]. The electron cooler has recently been equipped with a superconducting gun solenoid [4] to reduce the transverse temperature to 1 meV. CRYSIS is also used for low en- ergy collision experiments, surface physics and for the SMILE ion trap [5]. 2 IONS STORED IN THE RING 2.1 Presently Used Ions Three different groups of ions are used for experiments in the ring, highly charged ions, molecular ions, and heavy singly charged ions. So far around 60 different ions have been stored in the ring, and as examples those used hitherto this year are presented in table 1. Electron cool- ing has been used in all cases in the table except for Ca + and Sr + . 2.2 Future Ion Programme The ECR source will fill the gap between two other sources and produce ions with q>1 and q/m<0.24. We also plan to test a source for negative ions during the autumn. 3 DIAGNOSTICS Besides the two devices described below, more news about diagnostics can be found in references [6] and [7]. Table 1. Ions stored in the ring during spring 1998. Ion Current μA Energy MeV/u D + 20 24 F 6+ 1 8 N 4+ 2 6 Ar 13+ 1 5.6 Pb 53+, 54+ 0.1 4.2 HD + 5 0.3 CH 2 + 0.5 CN + 0.4 0.14 HCN + 2 0.13 Ca + 5 0.001 2 Sr + 6 1 0.0005 2 1 Limited by space charge tune shift. 2 Neither accelerated nor electron cooled. 3.1 Beam Profile Monitors One vertical and one horizontal beam profile monitor has been mounted in the ring [8]. The design is based on a detector developed by the atomic physics group [9]. The residual-gas ionisation beam profile monitors measure the horizontal and vertical profiles of stored ion beams with a spatial resolution of ±0.2-0.3 mm. Since the ion rates are relatively low a chevron assembly is used with a resistive anode as a detector head. A high-voltage system, maximum ±3 kV, generates a homogenous electric field over the active volume. Four charge sensitive pre-amplifiers integrate the charges at each corner of the resistive anode. A fifth pre- amplifier is used for the timing. After pulse shaping, am- plification, and stretching the spatial co-ordinates are computed from the ratio of the charge amplitudes with analogue dividers. The digitised position data are stored in a PC by a dedicated dual-port increment matrix memory card. The beam profile monitor without detector is shown in figure 1, and an example of read-out from the beam pro- file monitor is shown in figure 2. 3.2 AC Current Transformer To be able to measure low ion currents we have bought an AC current transformer from Bergoz [10]. Especially 526