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Although the survival rate of intraocular retinoblastoma (RB) is nearly 100%, the outcome of central nervous system (CNS) involvement or Trilateral retinoblastoma (TRb: very rare RB which associated with brain tumor) is dismal. We retrospectively reviewed our six cases of these rare tumors. Their ages at diagnosis are 0y3m-1y10m (median 1y3m) (Male 4, Female 2). Only one had RB family history. Their affected eyes were bilateral 2, unilateral 3 and no 1. Their CNS diseases were suprasellar tumor 3, pineal tumor 1 and cerebrospinal fluid (CSF) cytology positive 2. Two of the suprasellar tumor patients had spinal metastasis. Three of the six patients were TRb. One TRb patient was treated with chemotherapy and high-dose chemotherapy without radiotherapy. Although he suffered with secondary osteosarcoma seven years later, he got complete remission and alive 5 years more without any tumor recurrence. The second TRb patient was treated with chemotherapy and local radiotherapy but relapsed 20 months later. The third TRb patient was chemotherapy resistant. Two CSF positive patients had optic nerve invasion. One patient with chiasm invasion died 11 months later because of treatment resistance. The other patient with optic nerve invasion before optic canal had no CNS tumor nor CSF involvement at diagnosis. Chemotherapy before enucleation was given to avoid dissemination. However, CSF cytology became positive after enucleation and remained even with intensified chemotherapy. Finally, he got remission with radiotherapy and high-dose chemotherapy, and alive without disease for 3.8 years. The last patient had suprasellar genetically classified retinoblastoma tumor and cerebrospinal metastasis. This patient showed good chemotherapy response and is still under treatment. Even with &quotso called° fatal RB cases, some case could survive with intensified therapy. Data accumulation is necessary for better survival of these tumors.

The lateral electron‐photon technique (LEPT) and intensity‐modulated radiation therapy (IMRT) are commonly used for total scalp irradiation. However, the treatment planning and irradiation are laborious and time‐consuming. We herein present the multijaw‐size concave arc technique (MCAT) as a total scalp irradiation method that overcomes these problems. CT datasets for eight patients previously treated for angiosarcoma of the scalp were replanned using MCAT, LEPT, and IMRT. The MCAT was designed with a dynamic conformal arc for the total scalp, with a multileaf collimator to shield the brain. Two additional conformal arcs with a decreased upper‐jaw position of the first dynamic conformal arc were used to reduce the cranial hotspots. The prescribed dose was 40 Gy (2 Gy/fraction) to 95% of the planning target volume (PTV, defined as the total scalp plus a 4 mm margin). MCAT was compared with LEPT and IMRT with respect to the PTV dose homogeneity (D5%–95%), underdosage (V < 90%), overdosage (V > 110%), doses to the brain, and the delivery time and monitor units (MUs) for single irradiation. We were able to formulate treatment plans for all three techniques that could deliver the prescription dose in all patients. MCAT was significantly superior to LEPT with respect to PTV dose homogeneity, overdosage, and underdosage, although MCAT was inferior to IMRT with respect to dose homogeneity and overdosage. The mean brain dose and high‐dosage volume of all three techniques were low, but IMRT provided larger volume to the brain than did the other two techniques in the low dosage region. In MCAT, the mean delivery time could be reduced by approximately half or more, and the mean MUs could be reduced by at least 100 compared to the other two techniques. MCAT can achieve total scalp irradiation with substantially fewer MUs and a shorter delivery time than LEPT and IMRT. PACS number: 87.55.D‐

We investigated the relative biological effectiveness (RBE) of therapeutic proton beams at six proton facilities in Japan with respect to cell lethality of HSG cells. The RBE of treatments could be determined from experimental data. For this purpose, we used a cell survival assay to compare the cell-killing efficiency of proton beams. Among the five linear accelerator (LINAC) X-ray machines at 4 or 6 MeV that were used as reference beams, there was only a small variation (coefficient of variation CV = 3.1% at D10) in biological effectiveness. The averaged value of D10 for the proton beams at the middle position of the spread-out Bragg peak (SOBP) was 4.98. These values showed good agreement, with a CV of 4.3% among the facilities. Thus, the average RBE10 (RBE at the D10 level) at the middle position of the SOBP beam for six facilities in Japan was 1.05 with a CV of 2.8%.

Background: The aim of this study is to evaluate the cost-effectiveness of proton beam therapy with cochlear dose reduction compared with conventional X-ray radiotherapy for medulloblastoma in childhood. Methods: We developed a Markov model to describe health states of 6-year-old children with medulloblastoma after treatment with proton or X-ray radiotherapy. The risks of hearing loss were calculated on cochlear dose for each treatment. Three types of health-related quality of life (HRQOL) of EQ-5D, HUI3 and SF-6D were used for estimation of quality-adjusted life years (QALYs). The incremental cost-effectiveness ratio (ICER) for proton beam therapy compared with X-ray radiotherapy was calculated for each HRQOL. Sensitivity analyses were performed to model uncertainty in these parameters. Results: The ICER for EQ-5D, HUI3 and SF-6D were $21 716/QALY, $11 773/QALY, and $20 150/QALY, respectively. One-way sensitivity analyses found that the results were sensitive to discount rate, the risk of hearing loss after proton therapy, and costs of proton irradiation. Cost-effectiveness acceptability curve analysis revealed a 99% probability of proton therapy being cost effective at a societal willingness-to-pay value. Conclusions: Proton beam therapy with cochlear dose reduction improves health outcomes at a cost that is within the acceptable cost-effectiveness range from the payer's standpoint.

Periodic checks for proton machine quality assurance (QA) are significant for machine users safely and accurately to provide proton-beam treatment for cancer. Our aim in this study was to describe a revision to proton machine QA procedures for wobbled-proton-beam therapy at the Shizuoka Cancer Center (SCC) in Japan. The previous daily, monthly, and annual QA procedures were determined by reference to our past operational experience and to QA papers for medical accelerators. The revised QA procedures were initiated in May 2011 after preliminary measurements to decide baselines for the QA procedures. This paper presents the proton machine QA procedures and the results of representative QA measurements. Three action levels were decided on by reference to the American Association of Physicists in Medicine Task Group 142 report. Tolerances of inspection action were decided on based on the provisional operational results and actual fluctuations of the QA measurement for a year, and those of scheduled action and stop-treatment action were determined by reference to the machine QA papers and those of the inspection action. No deviation from the tolerance of the scheduled action has been observed so far. Although a few QA procedures exceeded the tolerance of the inspection action, these excesses were resolved by inspection and improvement of the respective measuring procedure within the designated QA time. Hereafter, the proton machine QA procedures proposed in this study will be performed continuously at the SCC to assure patient safety and accurate operation of proton therapy.

We have developed an ion-beam-assisted-deposition (IBAD) and a pulsed-laser-deposition (PLD) technique to produce REBa 2 Cu 3 O x (RE123, RE: rare earth) coated conductors with high performances. Distributions of critical currents ( I c ) in the longitudinal direction were improved in most wires routinely fabricated under optimized process. A typical wire showed I c of 460 A/cm at 77 K and self-field, about 200 A/cm at 65 K and 3 T and about 300 A/cm at 50 K and 5 T. In addition, further high I c values over 800 A/cm were also obtained in thick films. Finally, we succeeded in fabricating an 816.4 m long wire with end-to-end I c of 572 A/cm, corresponding to the new world record I c × L value of 466,981 Am/cm.

METHODS: Twenty-six patients with diffuse intrinsic pontine glioma (DIPG) were retrospectively analyzed at National Center for Child Health and Development, one of the largest pediatric brain tumor centers in Japan. The following information was collected from the electric medical record: clinical characteristics, surgery / pathology reports, treatments and outcomes. RESULTS: Between June, 2002 and April, 2016, 26 patients were diagnosed as DIPG and treated. Median age was 6 years (2–12). There were 19 boys and 7 girls. Common presenting symptoms included, cranial nerve palsies, ataxia, long-tract signs, vomiting, and altered consciousness. 20 patients (77%) were diagnosed within 40 days from symptom onset. 13 patients (50%) underwent biopsy. Patients who underwent biopsy tend to have atypical imaging and clinical features. Interval from diagnosis to radiation therapy was significantly longer in biopsy group than non-biopsy group (29 days and 8 days respectively, p=0.04). Histopathlogy diagnoses were: glioblastoma 4, anaplastic astrocytoma 5 and other glioma 4. H3 K27M mutations were detected in 5 patients among 8 patients tested (63%). CMV protein was not detected in all 4 patients tested. All but one patient underwent focal radiation therapy (RT) of 54Gy/30 fractions and one patient presented with dissemination underwent craniospinal RT. Fourteen patients (54%) did not receive any chemotherapy as an upfront treatment. Seven patients (27%) received temozolomide (TMZ)-based chemotherapy and the rest (19%) received other chemotherapy regimen. Mean overall survival (OS) of all 26 patients was 313 days. Mean progression-free survival (PFS) was 201 days. Biopsy, TMZ, any chemotherapy or H3 K27M mutation was not associated with survival outcomes. CONCLUSIONS: DIPG continues to be an incurable disease. Biopsy in DIPG is safe and feasible. H3 K27M mutation is a frequent event in DIPG. Chemotherapy is not a standard upfront treatment for DIPG.

Atypical teratoid rhabdoid tumors (AT/RTs) are highly aggressive embryonal CNS tumors. Up to one-third of AT/RTs are reported to have germline mutation and/or deletion of SMARCB1/hSNF5. In accordance with the increased understanding for pediatric cancer predisposition syndrome, the needs for genetic counseling and testing is expanding. And next generation suquencing technique is inevitable for these genotyping. So we start to prepare genetic testing system of AT/RT for future pediatric cancer predisposition program. Proior to the genetic testing, pretest counseling is performed for each patient/family. Informed consent was obtained according to the institutional ethical review board. Genomic DNA was isolated from the patient’s periphera blood, and somatic DNA was extracted from frozen tissues or FFPE samples. Genetic analysis of the SMARCB1 coding sequence was performed by Sanger method. Deletion of SMARCB1 is examined by quantitative analysis of each exon with droplet digital PCR (ddPCR). SNP array analysis is also tried if frozen sample is available. Three AT/RT patients and one rhabdoid tumor patient received genetic testing. None of them had germline mutation. In an infant ATRT, Sanger sequence analysis revealed frameshift mutation (c649-650delAT). Also, ddPCR showed uniparenteral heterodisomy (UPD). In another AT/RTs, copy number decrease and UPD over whole region of SMARCB1, or exon 3 deletion are recognized respectively. Rhabdoid tumor case had nonsense mutation (c610C>T). Although most of AT/RT should have biallelic mutation, false negative could happen due to less tumor cells obtained in those samples. Enlightenment for sampling and accumulation for testing would be important.

The prognosis of diffuse intrinsic pontine glioma (DIPG) remains dismal. The only effective treatment is radiation therapy so far. Nevertheless, the therapeutic effect of radiation therapy doesn’t last for long and almost all the patients experience relapse after several months. Recently, re-irradiation for relapsed DIPG was attempted and showed some benefit for those patients. We retrospective reviewed the efficacy and safety of re-irradiation therapy for five DIPG cases from April 2013 to December 2017. Five patients include three boys and two girls, their mean age was 7.2 years old (4–12). One case only did biopsy for diagnosis, others diagnosed clinically. One case underwent ventricular Ommaya reservoir insertion due to hydrocephalus. Radiation doses were from 19.8Gy to 50.4Gy(1.8–3.0Gy/Fr). The median duration between diagnosis and recurrence was 7.5 months (4–10 months), and the mean survival after the re-irradiation was 6.3 months (two of them still surviving). All five patients completed the treatment without acute toxicity, and four out of five patients demonstrated some improvement of their symptoms which occurred at the recurrence. It has been suggested that re-irradiation might be an effective and safe treatment for selected patients with recurrent DIPG.

To evaluate dose-volume histogram (DVH) parameters as predictors of radiation pneumonitis (RP) in esophageal cancer patients treated with definitive concurrent chemoradiotherapy.Thirty-seven esophageal cancer patients treated with radiotherapy with concomitant chemotherapy consisting of 5-fluorouracil and cisplatin were reviewed. Radiotherapy was delivered at 2 Gy per fraction to a total of 60 Gy. For most of the patients, two weeks of interruption was scheduled after 30 Gy. The percentage of lung volume receiving more than 5-50 Gy in increments of 5 Gy (V5-V50, respectively), and the mean lung dose (MLD) were analyzed.Ten (27%) patients developed RP of grade 2; 2 (5%), grade 3; 0 (0%), grade 4; and 1 (3%), grade 5. By univariate analysis, all DVH parameters (i.e., V5-V50 and MLD) were significantly associated with grade 2 RP (p0.01). The incidences of grade 2 RP were 13%, 33%, and 78% in patients with V20s of 24%, 25-36%, and 37%, respectively. The optimal V20 threshold to predict symptomatic RP was 30.5% according to the receiver operating characteristics curve analysis.DVH parameters were predictors of symptomatic RP and should be considered in the evaluation of treatment planning for esophageal cancer.

We have studied two types of heating systems to produce thick GdBa2Cu3O7−X (Gd123) films with high critical current (Ic) stably at a high speed by the PLD method. Material yields of both PLD systems reached about 50–60% by optimization of evaporation condition. Hot-wall heating type (type 2) could fabricate the thicker Gd123 film with the higher Ic compared to contact heating type (type 1) and maximum Ic reached 1040 A at about 6 μm thick. Furthermore, it was estimated that type 2 could fabricate Gd123 film with an Ic of about 700 A at about twice speed compared to type 1. Finally, it was considered that the hot-wall heating type was very advantageous to prepare thick Gd123 film with high Ic at a high speed from the system structure.

This paper describes a process for the fabrication of coated conductor (CC) wires, which is developed by Fujikura, and discusses their properties. These wires are composed of a buffer layer, which is formed by the ion beam assisted deposition (IBAD) technique, and a superconducting layer, which is formed by the pulsed laser deposition (PLD) process. In order to increase the I c × L which means the product of critical current ( I c ) and the length ( L ) of the CC wires the I c value and I c distribution along the length of CC wires have been improved by using a new PLD pilot plant. The I c value increases approximately linearly with the thickness of the superconducting layer, and it continues to increase up to a thickness of approximately 4 μm or 5 μm. The I c × L value of our fabricated CC wire is 176,023 Am. The I c value of a short sample is 972 A/cm. The process rate of IBAD is enhanced up to 100 m/h and that of PLD is enhanced up to 20 m/h. A 40-m long CC tape, which has an average I c of 300 A, is fabricated by the improved IBAD and PLD techniques.

Rectal volume variation has a crucial effect on prostate localization during external beam radiotherapy for prostate cancer. This study investigated the effect of rectal volume reduction by a rectum-emptying tube (RET) on prostate immobilization.The study group comprised 21 patients who underwent proton beam treatment for prostate cancer. Sigmoid-shaped flexible plastic RETs were used to drain gases from the rectum. Computed tomography (CT) was performed before and after RET placement at the treatment planning stage and at the beginning of treatment. Prostate displacement and changes in rectal volume were measured on the CT images. The feasibility of RET placement was evaluated during and after the procedure.All 21 patients tolerated the procedure. The rectal volume was significantly lower with a RET than without a RET. The differences in rectal volume between the treatment planning stage and the beginning of treatment were significantly lower with a RET than without. RET placement significantly decreased prostate displacement in the anteroposterior and superoinferior directions but not in the left-right direction.RET placement reduced both rectal volume and variation in rectal volume. The procedure reduced displacement of the prostate. RET placement thus appears to be an effective technique for immobilizing the prostate.

By an IBAD/PLD method, a 500 m-length high-performance GdBa2Cu3Ox (GdBCO) coated conductor with BaZrO3 (BZO) was fabricated. End-to-end Ic of the 503.5 m tape was 349.6 A/cm at 77 K, corresponding Ic times L value of 176,023 Am. New approaches to decrease the thickness of IBAD buffer layers were developed by combination of IBAD-MgO(111) and IBAD-Gd2Zr2O7 (GZO). The maximum Jc of the GdBCO on the buffer layer was 550 A/cm. We also started to investigate IBAD-MgO(OOl) by using a large IBAD system with a 110 cm times 15 cm ion source. A 50 m-length IBAD-MgO tape with DeltaPhi of 13deg was fabricated at a 100 m/h-1 pass. Insulated REBCO wires with Cu or Ni-Cr lamination were developed using 5 mm-wide conductors sliced from 10 mm-wide IBAD/PLD tapes. Practical long insulated wires were supplied for several prototypes of motors, transformers and fault current limiters in fiscal 2007.

We have developed long Gd-123 coated conductors by ion-beam-assisted deposition (IBAD) and pulsed-laser-deposition (PLD) method. Recently, large-scale reel-to-reel apparatus with the 110 cm × 15 cm assisting ion source was introduced to IBAD system. It was enable to produce 500 m-class IBAD–Gd 2 Zr 2 O 7 (GZO) tapes with Δ ϕ of below 15° and high throughputs of 3 m/h. Furthermore, apparatus with multi-lane and laser scanning was introduced to PLD system. As a result, end to end I c of 318 A were obtained for a 201.5 m long tape, and I c × L values were 64,077 Am. Furthermore, 500 m-class deposition was carried out by improving PLD conditions. As a result, I c × L values of 112,166 Am was obtained and it’s a world record on August 2007. In the short samples, I c of over 500 A was obtained with Gd-123 thickness of 2.0 μm and over 100 A was obtained in magnetic field of 3 T, perpendicular to c -axis.

Pinning effect induced by a grainlike structure on top of a TbFeCo recording layer with an Al or Ag underlayer is investigated. We confirm that the pinning effect depends on the surface structure of the recording layer as well as the underlayer. The Al-underlayered TbFeCo medium shows higher recording density during thermally assisted magnetic recording and higher coercivity than those of the Ag-underlayered one. We can observe that only the Al-underlayered TbFeCo medium has the grainlike structure on top of the TbFeCo recording layer, which reflects well a grainlike structure on the Al underlayer's surface. It indicates that the surface profile of not only the underlayer but also the TbFeCo recording layer laminated onto the underlayer is necessary for inducing the strong pinning effect in the TbFeCo magnetic recording media.

We have developed a long Y-123 coated conductors by ion-beam-assisted deposition (IBAD) and pulsed-laser-deposition (PLD) method. Now, we can routinely obtained 100 m class Y-123 tapes with over 100 A at 77 K. For power applications using Y-123 conductors, coiling and cooling techniques are important elements. From 2004, we have developed and demonstrated a solenoid type coil that is the most suitable for practical application because it has advantage such as (1) uniformity of magnetic field (2) no joint. In this paper, we describe the development of conduction-cooled HTS test coil that has 14 turn × 22 layers using 100 m Y-123 conductors. In order to use the conduction cooling system, the Y-123 conductors were stabilized for 0.1 mm thick Cu tapes and spacers between the layers consisted of aluminum nitride in the coils. In the demonstration of this coil at 30 K, 40 K, 50 K, 60 K and 77 K by cryo-cooling system, the good cooling and superconducting performances were observed. The central magnetic fields of over 1 T were successfully obtained with operating currents of over 400 A and under 40 K. Furthermore, this coil was operated on additional magnetic fields of 3 T by combination of LTS magnets. The central magnetic fields of 0.5 T were generated from the cooled HTS coils with operating current of 190 A on additional magnetic fields of 3 T by LTS magnets at 30 K. Total magnetic fields were exceeded 3.5 T at 30 K.

We report a case of locally recurrent anorectal cancer treated with proton beam therapy (PBT) alone that led to a clinically complete response. A 70-year-old woman with paraparesis due to infantile paralysis underwent abdominoperineal resection (APR) and D3 lymphadenectomy for anorectal cancer (PERb, type 2, 50×40 mm, muc-tub1, M1a[lung], Stage IV a]. Three months after APR, right middle and right lower lobectomies were performed for synchronous lung metastases. Adjuvant chemotherapy was not administered. One year and 8 months after APR, computed tomography (CT) showed local recurrence of the tumor (29×28 mm), which contacted the right ischial spine. Pelvic exenteration combined with sacral resection was not performed because of the patient's poor performance status. PBT (70 Gy [RBE]/25 F/5 week) was administered for treatment of the recurred tumor. CT revealed that the tumor disappeared 1 year after PBT, which was defined as complete response. The patient is alive and has not experienced recurrence for 7 years.

We have developed long tape processing for coated conductors by the advanced TFA-MOF method. In order to obtain uniform and high superconducting performance, a 25-m long tape with dummy tapes, which were connected at the both end of the 25-m long tape, was fabricated by the reel-to-reel (RTR) system with a relatively high gas flow rate. As a result, a uniform I c value over 100 A and a high end-to-end I c value of 100 A were obtained in the tape. It revealed the I c · L product of 2500 A m. For higher I c · L products in long tapes, the key process factors were investigated.

We have investigated the effects of a heating rate in the calcination process on microstructures of YBa 2 Cu 3 O 7− y (YBCO) precursor and final films. As a result, it was found CuO segregation in the YBCO precursor film, when the precursor was prepared at a rapid heating rate in the calcination. In the case of heating this precursor film in the crystallization process, many large pores and misoriented YBCO crystals tend to remain in the YBCO final film and its I C value deteriorates compared with the case of crystallizing the precursor, which is prepared at the slow heating rate in the calcination. It is important to control the heating rate in the calcination, in order to attain higher J C of the YBCO final films.

Recent progress in the research and development of the TFA-MOD processing for the coated conductors was reviewed. For the higher I c performance, crack generation in the thick films was a problem, which limits increasing I c values. It was found that both lower heating rate and low P H 2 O in the crystallization step are effective to improve the critical thickness for obtaining crack-free films. However, the high P H 2 O is preferable for a high production rate and high J c performance. Then, the new heat treatment profile, which could suppress crack formation even in thick films under the high P H 2 O , was developed. Consequently, the high I c value of 470 A at 77 K was realized in the film with 3 μm in thick. Concerning the long-tape processing, the key factors for high I c performance by TFA-MOD process were investigated. The highly textured substrate for high crystallinity of the YBCO layer, the thick film with maintaining reasonable high J c and full conversion reaction to form the YBCO layer are important to obtain high superconducting performance in long tapes. At present, a 25 m long tape with a reasonable high I c value of 100 A, and a high I c value of 250 A in a 4 m long tape were achieved. In order to realize a high production rate, the processes for both calcination and crystallization steps have to be developed. In the calcination step, the multi-turning continuous system was developed to maintain an effective travelling rate even in the multi-coating method. On the other hand, in the crystallization step, it was confirmed that optimization of the processing parameters such as a high water vapour partial pressure, a low total pressure, and a high gas flow rate could make the YBCO growth rate increase. The combination effect of these parameters is experimentally confirmed and the 5 times higher production rate was achieved in the crystallization step. Additionally, the equipment design of the multi-turning system with a new gas flow concept, which is a vertical gas flow system, was investigated by means of both numerically and experimentally, and the concept was confirmed at least. Consequently, a high production rate over 5 m/h could be expected by combining the above mentioned effects.

High quality YBa 2 Cu 3 O 7− δ coated conductors with a length of several hundred meters are available now. For practical applications of long tapes, non-destructive and efficient techniques for characterization are necessary. For that purpose, we installed a commercial machine. The measuring principle is that a tape is introduced into a space of an applied magnetic field and the induced current within the superconducting tape is evaluated by measuring the magnetic field distribution just above the tape surface using a Hall sensor array. The advantages of the technique are that the measurement speed is rather high, 15 mm/s at maximum, and tapes are absolutely safe from damages by excessive heating. On the other hand, the estimation of the critical current is not straightforward because the issue of the calibration is not trivial. A 2D computer simulation code was developed to calculate the distribution of the induced current within the tape. In the simulation, it was assumed that the current–voltage relation of the superconductor obeys a power law. It is shown that the critical current deduced from the measurement is strongly dependent on the n -value.

We have investigated influences of the H2O gas inlet temperature in the calcination process on both microstructures and superconducting properties of YBCO films fabricated by the advanced TFA-MOD process, from the viewpoint of the process control in the reel-to-reel system. Low Ic values were recognized in the films which were prepared by introducing the H2O gas from the lower temperature than 200 °C. XRD measurements and cross-sectional TEM observations suggest that the YBCO films calcined with the H2O inlet temperature below 200 °C revealed a random orientation without epitaxial growth. Consequently, it has been understood that control to keep low partial pressure of the H2O gas in a lower temperature region is important for fabrication of long-length YBCO tapes with high performance by the reel-to-reel system.

We fabricated Y 1− x Sm x Ba 2 Cu 3 O y and YSm x Ba 2 Cu 3 O y (YSmBCO) films on SrTiO 3 (STO) single crystalline substrates and IBAD buffered metallic tapes (PLD-CeO 2 /IBAD-GZO/Hastelloy) by the advanced TFA-MOD process by mixing TFA salts of Y, Sm, Ba and Cu naphthenate, and tried to improve the superconductivity properties compared with those of the pure YBa 2 Cu 3 O 7− δ (YBCO). As a result, J c values of Y 1− x Sm x Ba 2 Cu 3 O y films with x = 0.05 or 0.3, which were fabricated on STO substrates, were improved under the high magnetic fields compared with those of the YBCO without substitution. However, Sm segregation was detected near the STO substrate which was obtained by the TEM–EDS (transmission electron microscopy–energy-dispersive X-ray spectroscopy) analysis. On the other hand, Y 1− x Sm x Ba 2 Cu 3 O y films with x = 0.05 and YSm x Ba 2 Cu 3 O y films with x = 0.3, which were fabricated on IBAD buffered metallic substrates, also improved I c value under the high magnetic fields compared with those of the YBCO without substitution. Moreover, from the TEM-EDS analysis, Y or Sm segregation was not found. The difference in the Sm segregation behavior between the film on STO and CeO 2 buffered substrates could be explained by the difference in the ratios of the misfit parameters between YBCO/substrate and SmBCO/substrate. Additionally, it was considered that the above phenomenon might be unique in the MOD system and could not be observed in the PLD system, because of the difference in the crystal growth mechanism. In the film of YSm 0.3 Ba 2 Cu 3 O y , we observed the grains of (Y, Sm) 2 O 3 and (Y, Sm) 2 Cu 2 O 5 by TEM observation. We will further investigate the origin of pinning centers.

To realize a higher production rate is one of the important issues in the development of the long-tape processing for the YBCO coated conductors by the TFA-MOD process using the reel-to-reel system. Not only scale-up of the furnace and decrease of YBCO thickness with the higher Jc value, but higher YBCO growth rates could be effective to achieve a higher traveling rate in this system. It was confirmed that optimization of the process parameters such as high water vapor partial pressure, high diffusion constants due to a low applied total pressure, and a high gas flow rate affect the YBCO growth rate. Consequently, these higher growth rate conditions were simultaneously applied to the reel-to-reel system. As a result, the traveling rate of 1.2 m/h was achieved for fabricating YBCO films in the reel-to-reel system, which is about five times as fast as the previous traveling rate with maintaining high Ic value of higher than 200 A/cm-width by controlling above conditions.

Recent progress in the research and development of the TFA-MOD processing for the coated conductors is reviewed. For the higher Ic performance, process conditions such as heating rate and water vapor inlet temperature in the calcination step and heating rate and water vapor pressure in the crystallization step have been optimized to obtain YBCO films with good crystallinity. Consequently, a high Ic value of 431A/cm-w was achieved by the combination of the above optimized conditions with the use of highly textured CeO2 cap layered substrates. Forwards the effort for long tape fabrication with high production rate, the multi-turn system for coating and calcination step was developed. Additionally, the reel-to-reel system for the crystallization step was developed for the longer tape, and a 25m long YBCO tape with a reasonable end-to-end Ic value of 100A, which corresponds to 2500Am as a product of IcxL, was obtained by the above continuous system. For the higher production rate in the crystallization step, it was confirmed that optimization of the processing parameters such as high water partial pressure, high diffusion constants due to low total pressure, and a high gas flow rate affects the YBCO growth rate.

A multi-turning Reel-to-Reel tape conveyance system of the long YBCO coated conductors using TFA-MOD process is desired to be high production rate without large degradation between tape lines. The numerical simulation, which calculated the YBCO growth kinetics, gas element diffusion and gas flow, shown a possibility that the vertical gas flow onto the tape surface realized high production rate of YBCO conductor even on the wider tape. This possibility was also proved by experimental measurements.