  153Eu3+:Y2SiO5 is a very attractive candidate for a long lived, multimode
quantum memory due to the long spin coherence time (~15 ms), the relatively
large hyperfine splitting (100 MHz) and the narrow optical homogeneous
linewidth (~100 Hz). Here we show an atomic frequency comb memory with spin
wave storage in a promising material 153Eu3+:Y2SiO5, reaching storage times
slightly beyond 10 {\mu}s. We analyze the efficiency of the storage process and
discuss ways of improving it. We also measure the inhomogeneous spin linewidth
of 153Eu3+:Y2SiO5, which we find to be 69 \pm 3 kHz. These results represent a
further step towards realising a long lived multi mode solid state quantum
memory.
