MUCOOL meeting minutes, Friday July 17, 1998. ------------------------------------------------------- Agenda 1. Beamline studies Tom Kobilarchik 2. Beamline/Instumentation channel studies Steve Kahn 3. Bent solenoid status Al Bross 4. RF Status Al Moretti 5. Cooling Simulation update(s) Paul/Panagiotis Minutes 1) Tom has introduced a wedge in his beamline configuration in order to take out the dispersion seen in his initial design. Paul verifies that the new beam looks better. Tom wants to go back and systematically document all his studies. He has documentation; Steve G. asks for a MUCCOL TM on the design. Next week he will have to revisit the yield issue, and report on target selection. Tom wants to use a thick target. The questions are how well do we know production at low energies, effect of re-interactions, radiation problems (if any). Nikolai should get involved (Steve and Ray will obtain the info). 2) Steve has a GEANT model of the solenoid channel. His main concern at this stage is to understand the field, and validate his model. He has included detectors in his simulation (TPCs), but with no great detail (no windows, etc). For his field map he is using an elliptical integral for the straight section and the superposition of current loops for the bends. The transverse field has spikes in the transition region between straight and bend sections. Alvin suggests to optimize matching in the transition region by adding/subtracting current loops and look at the axial field. The particle loss is 50/200, it happens after the transition region. The beam size is within the acceptance, and Steve uses an uncorrelated beam at the input of his channel. He observes on x, x' correlation at the cavities, and a x, p correlation. 3) Al reports on the engineering studies on the solenoid operating parameters. They are starting with the high field (15T) solenoid for cooling and then they will continue with the exp. magnet (MUCOOL channel). There is a FNAL engineer working on the bend solenoid. He wants to obtain a realistic drawing, including detectors, etc. He needs more information on where do the components go. For the TPCs the issue is field uniformity. For this reason he would like to avoid breaks of the coil configuration in the "natural" geometric breaks (straight, bend, straight), since the size of the cryostats will compromise the field uniformity. The big issue seems to be the RF cavity. Where does it go? How big of a penetration does it need to feed the RF cables? How about vaccumm, nitrogen lines, etc. Al M. asks for a 6''-12'' gap for the wave guide. There is a discussion on how big of a wave guide we need. The issue is not resolved: how are we going to feed the cavity, how are we going to keep operating temperature. For the second issue a warm cavity seems to be a better option, but we would like to use the same cavities as for cooling. Alvin wants to know if we could break the field without loosing the beam, in order to avoid the problems of installing the RF in the solenoid. 4) Al discussed the status of taking over LabG and its equipment. This will be the location for the MUCOOL RF test facility. There is equipment there which might be useful, we have to negotiate with Bob Webber. We also need to make sure that the clean-up of the area happens in a timely fashion (it seems like this will be done before we want to move in). Al discussed the problem of keeping the Be window in the cavity without bowing after the cavity cools down to its operational temperature. The current designs call for the installation of a stiffener ring. This is a Be ring in the design; Alvin argues that we could use a lesser material with no implications to minimize cost (the issue here is not to magnetize the ring). Finally, the issue of what happens to the Be window if there is a spark was discussed. Could we install a protection system (the one used at FNAL is discussed as an example). Al will consider making a spark test for the first Be windows. 5) moved to next week Panagiotis Spentzouri