1. A NbTi split magnet directly cooled by a cryocooler;Masuyama;IEEE transactions on applied superconductivity,1993
2. A 7.7T NbTi superconducting magnet system cooled by 4 K GM refrigerator;Takahashi;Adv. Cryog. Eng.,1993
3. High efficient pulse tube refrigerator with linear-motor drive compressor;Ohtani;Adv. Cryog. Eng.,1993
4. Miniature pulse tube cooler;Chan,1993
5. Novel configuration of three-stage pulse tube refrigerator for temperatures below 4 K;Matsubara;Cryogenics,1994