To do for the next K0 beam time Department of Physics, Tohoku University H. Kanda

18 Aug. 2006LNS Nuclear Physics Working Group2 “Next” what? The next beam times in September The next beam times in September Preparation status of the LD2 target and a vacuum gamma beam duct Preparation status of the LD2 target and a vacuum gamma beam duct The coming beam time already proposed and approved The coming beam time already proposed and approved Neutron detector for NKS2 Neutron detector for NKS2 Beam profile monitor Beam profile monitor The experimental plan to be proposed in the near future The experimental plan to be proposed in the near future Investigation of “ quasi-freedom ” of deuteron target Investigation of “ quasi-freedom ” of deuteron target

18 Aug. 2006LNS Nuclear Physics Working Group3 Preparation of the LD2 target We have modified our LD2 target We have modified our LD2 target elongation of the insertion part to fit the dimension of the 680 magnet elongation of the insertion part to fit the dimension of the 680 magnet new TMP port for speeding up the vacuum pumping new TMP port for speeding up the vacuum pumping Direct attachment of the TMP greatly worked to shorten the pumping period Old cryostat: Roughly 1 night to pump down to 1x10 -5 mbar for starting the refrigerator New cryostat: Only 1 hour to pump! Direct attachment of the TMP greatly worked to shorten the pumping period Old cryostat: Roughly 1 night to pump down to 1x10 -5 mbar for starting the refrigerator New cryostat: Only 1 hour to pump!

18 Aug. 2006LNS Nuclear Physics Working Group4 Preparation of the LD2 target Elongation should have changed the thermal condition inside the cryostat which will force modification of the liquefaction and vapor-suppressing method. Elongation should have changed the thermal condition inside the cryostat which will force modification of the liquefaction and vapor-suppressing method. Vapor-suppression is essential to reduce the ambiguity of the target density. However, vapor suppressed state is identified only by a phase diagram. Vapor-suppression is essential to reduce the ambiguity of the target density. However, vapor suppressed state is identified only by a phase diagram. We have to re-build the vapor-suppression method for the new cryostat and see the liquid without any vapor bubbles by our eyes. And the test of the long term (~ one week) stability is prefered. We have to re-build the vapor-suppression method for the new cryostat and see the liquid without any vapor bubbles by our eyes. And the test of the long term (~ one week) stability is prefered. These test should be finished until mid- September for the installation and the stable operation in the next next beam time. These test should be finished until mid- September for the installation and the stable operation in the next next beam time. Time course of the temperatures and phase diagram measured by the old cryostat. Operation point

18 Aug. 2006LNS Nuclear Physics Working Group5 What’s the trouble? The liquid deuterium is consisted of ICF34 flange, an aluminum shell (EB-welded), the polyimide film (adhered on the aluminum shell), and a flange for the liquid temperature monitor (sealed by an indium wire). The liquid deuterium is consisted of ICF34 flange, an aluminum shell (EB-welded), the polyimide film (adhered on the aluminum shell), and a flange for the liquid temperature monitor (sealed by an indium wire). Gas leak happened when the cell is refrigerated down to 150 ~ 200 K. Gas leak happened when the cell is refrigerated down to 150 ~ 200 K. REFINED: adhering method of polyimide film, tightening of ICF flange, tightening of indium seal REFINED: adhering method of polyimide film, tightening of ICF flange, tightening of indium seal LEAK TESTED (in LN2): an ICF flange, film surfaces, and adhered surfaces LEAK TESTED (in LN2): an ICF flange, film surfaces, and adhered surfaces TESTED but NOT ISOLATED: indium seal and flange for the thermometer (thermometer is adhered through the hole of the flange) TESTED but NOT ISOLATED: indium seal and flange for the thermometer (thermometer is adhered through the hole of the flange) The flange for the thermometer is now the most suspicious for the source of the leakage. The isolation of the seal and the flange itself is quit difficult... Blank flange is needed to be relieved that the seal is good. The flange for the thermometer is now the most suspicious for the source of the leakage. The isolation of the seal and the flange itself is quit difficult... Blank flange is needed to be relieved that the seal is good.

18 Aug. 2006LNS Nuclear Physics Working Group6 Preparation of the vacuum gamma beam duct Gamma beam travels through the air as long as 3.2 m (1.1x10 -2 X 0 ) after the collimator to the target. Gamma beam travels through the air as long as 3.2 m (1.1x10 -2 X 0 ) after the collimator to the target. A vacuum duct of 2 m long (4.4x10 -3 X 0 including film-windows: 50  m, and the remaining air) reduced the trigger rate by 30 % with  Tag=2MHz and 2mm thick acrylic target. A vacuum duct of 2 m long (4.4x10 -3 X 0 including film-windows: 50  m, and the remaining air) reduced the trigger rate by 30 % with  Tag=2MHz and 2mm thick acrylic target. A vacuum duct of 3 m long (9.9x10 -4 X 0 ) is now planned to replace the old one. Thinner film (25  m) will be used. The new one is estimated to reduce the trigger rate by 45 %. A vacuum duct of 3 m long (9.9x10 -4 X 0 ) is now planned to replace the old one. Thinner film (25  m) will be used. The new one is estimated to reduce the trigger rate by 45 %. Plan view of the pair magnet, the 680 magnet, and some elements for gamma beam line. gamma beam Pair magnet pump ~3.0m Pirani gauge

18 Aug. 2006LNS Nuclear Physics Working Group7 Neutron detector Multi-pion photoproduction experiment: LNS Exp#2551 was approved last year to run with the K0 photoproduction experiment: #2552. In the proposal, I commented to place the neutron detector at the forward of the NKS2.... No preparation is carried out so far. Multi-pion photoproduction experiment: LNS Exp#2551 was approved last year to run with the K0 photoproduction experiment: #2552. In the proposal, I commented to place the neutron detector at the forward of the NKS2.... No preparation is carried out so far. However, the neighbor of the NKS2 is too crowded now to place the large object as the neutron detector (a passage will be lost). However, the neighbor of the NKS2 is too crowded now to place the large object as the neutron detector (a passage will be lost).

18 Aug. 2006LNS Nuclear Physics Working Group8 Beam profile monitor The only solution to make room for the neutron detector is to remove the HSBPM by Ishikawa-san and Koutaku-san, which played the important role in the beam tuning period. The only solution to make room for the neutron detector is to remove the HSBPM by Ishikawa-san and Koutaku-san, which played the important role in the beam tuning period. X-ray imaging camera “ Remote RadEye ” might be one of the good replacements of the HSBPM and Polaroid films. Thanks to its small size, it will be easy to place it on the Lead glass counter. X-ray imaging camera “ Remote RadEye ” might be one of the good replacements of the HSBPM and Polaroid films. Thanks to its small size, it will be easy to place it on the Lead glass counter.

18 Aug. 2006LNS Nuclear Physics Working Group9 Investigation of “quasi-freedom” of the deuteron target In our result of pion photoproduction on proton and deuteron, interesting phenomena could be seen. In our result of pion photoproduction on proton and deuteron, interesting phenomena could be seen. The double pion photoproduction cross sections on free proton are consistent with the results from other experiments. The double pion photoproduction cross sections on free proton are consistent with the results from other experiments. The cross sections on quasi-free proton, namely proton in deuteron, are smaller than the results from other experiments. They resemble to the double pion photoproduction cross sections on quasi-free neutron. The cross sections on quasi-free proton, namely proton in deuteron, are smaller than the results from other experiments. They resemble to the double pion photoproduction cross sections on quasi-free neutron. The single pion photoproduction cross sections are in good agreement with the other results. The single pion photoproduction cross sections are in good agreement with the other results. Can deuteron be considered as the quasi-free target of nucleon? Which is the most likely view, in these words as quasi-, semi-, pseudo-, non-, and anti-? Can deuteron be considered as the quasi-free target of nucleon? Which is the most likely view, in these words as quasi-, semi-, pseudo-, non-, and anti-? Detailed analysis for final states will reveal more precise view of the “ quasi-freedom ” of the deuteron. (needs hermetic detector system and more statistics) Detailed analysis for final states will reveal more precise view of the “ quasi-freedom ” of the deuteron. (needs hermetic detector system and more statistics)

18 Aug. 2006LNS Nuclear Physics Working Group10 Cross sections for  p -> p  +  - and gp ->  ++  -

18 Aug. 2006LNS Nuclear Physics Working Group11 Cross sections for g”p” -> p  +  - compared with other results for “p” target and “n” target

18 Aug. 2006LNS Nuclear Physics Working Group12 Cross sections for  d -> pp  -

18 Aug. 2006LNS Nuclear Physics Working Group13 Summary I ’ m sorry for the delay of the preparation of the liquid deuterium target. I ’ m sorry for the delay of the preparation of the liquid deuterium target. I ’ m sorry for the delay of the preparation of a neutron detector. I ’ m sorry for the delay of the preparation of a neutron detector. Pion photoproduction experiment showed an interesting results. Detailed investigation will provide us of more interesting results. Pion photoproduction experiment showed an interesting results. Detailed investigation will provide us of more interesting results.