Texas A and M 14.5 and 6.4 GHz electron cyclotron resonance ion sources

The plasma chamber of the Texas A and M 14.5 GHz electron cyclotron resonance (ECR) ion source ECR2 has been redesigned recently. Small-diameter (1.8 mm), water-carrying copper tubes are interposed between the Nb-Fe-B permanent magnets and the aluminum plasma-chamber wall. This design allows for more protection of the hexapole via water cooling than the previous design and also eliminates all of the troublesome water-to-vacuum seals of the previous design. Both ECR2 and the 6.4 GHz electron cyclotron resonance ion source ECR1 have similarly dimensioned aluminum plasma chambers, both incorporate biased disks, but the experience with each has been much different. The performance and the operation of the two sources are compared.