KEK IR status Shuji Tanaka KEK DEPFET workshop 2011/2/7-9 1

Latest design of IP chamber Straight section Kohriki Very simple Be structure Cooling route is change (back) to feed forward type Worry for cooling dead region (end point of IP) Forward manifold is placed on crotch part Be part is only within “Physics window” . -> other region can add materials (ex 100um Au for SR) Be structure is simple barrel type -> very cheap 2

Narrow Space issue between PXD and IP At present, it seems that we can avoid space problem by optimizing beam pipe shape( still should pay attention) 3

Cooling test mockup Nakayama

Connection technology choice Brazing Be: 1M yen EBW or Brazing EBW Weak point by EBW HIP: Hot lsostatic Pressing HIP EBW: Electron Beam Welding Be: 34M yen Pros. : very simple structure and cheap Be part Cons. : Be-SUS region face with vacuum part 5

Tests before IP chamber production Mechanical analysis of beam pipe (KEK) Mockup production of crotch part by Al. To evaluate howto make sawtooth structure Ta-SUS HIP welding test production Brazing test EBW test -> to see thermal effects of pipe (deformation, vacuum sealing) Be part test production (NGK insulators Co. Lid.) Check the precision of structure -> cut into some pieces Be-SUS Connection test next year (before next summer) 6

Mechanical analysis Deformation by self weight Koike equivalent stress ：Max 22MPa 　　　　　　　(support point) Deformation：Max　0.0082mm Support point : End of flange and +/- 350 mm from IP 拡大 Near IP equivalent stress ：Max 1.2MPa

Mechanical analysis (cantilever) equivalent stress ：Max 176MPa Deformation ：Max　6.7mm equivalent stress Max

Mechanical analysis Self weight + coolant pressure 10atm IP region equivalent stress ：Max 93MPa 変位：Max　0.014mm Be Equivalent stress：Max42MPa Deformation：Max　～0.011mm

Ta-SUS HIP welding test production 1, make Ta-SUS HIP (diffusion bonding) test pieces 2, applying thermal stress by EBW 3, check the vacuum level and mechanical deformation (This procedure will be used on joining ,inner and outer pipes)

Mockup production of crotch part by Al In order to evaluate the production procedures how to cut inside(Saw tooth) of crotch part beam pipe. ->will be finish before the end of Mar.

IR design (top view:KEK) BPM move to QC side Japan group will take care and assemble SVD 3rd layer KEK: CDC design, Endflange, Beam pipe SVD endring, SVD 3rd

Immanuel Gfall (HEPHY Vienna) Space Requirement SVD Two types of design(Vienna and KEK) will be discussed on next B2GM 18 November 2010 Immanuel Gfall (HEPHY Vienna) 13

IR design (side view) We start discussion about bracket of beam pipe now.

Space allocation of inner tracker Heavy Metal support End flange (Ta?) End ring Some suspension Structure for beam pipe IP flange position CFRP 1mm Total weight will be ~100kg

End-Flange prototyping This bracket has a role of shielding Material: Heavy Metal (>1.5cm t) 16

SVD installation

SVD installation Kohriki

SVD installation (mechanics)

QCS-SVD-joint Pin（φ10） Main block Long pipe（M8） Clamp（ M8ナット） SVD could be kept by CDC by releasing Pin. (to be Independent with QC cryostat) 20101202 Kohriki 20

SVD Mechanical Analysis equivalent stress：Max 25MPa Deformation：Max　0.015mm Mechanical distortion is enough small ＝SVD can keep structure by sustain each end 最大主応力：Max 15MPa

SVD+IR installation procedure Find a solution for installing this IR structure. ~ Establish a reasonable procedure to connect vacuum chamber flanges. Belle II is fully equipped. IP chamber is supported by SVD frame. SVD is supported by CDC. QCS cryostats can move out. Connection flanges for vacuum chambers. Top view Little work space to access flanges. It is impossible to connect flanges in this configuration. Some work spaces to access flanges. It will be possible to make use of these spaces.

DISCUSSION ITEMS 23

Touschek BG estimation ( High energy neutron BG) http://kds. kek

Ohnishi

Nakayama

Photonuclear peak

BEAST Operation (idea) The baseline of BEAST II operation is no collision of beams, because of no Belle magnetic field. Preparing new solenoid magnet to study BG level.(just idea) Inner diameter ~60 cm setup some radiation monitors Need more cost ~ 1 Oku-en. Difficulty shaping outer magnetic field (need return yoke?) KEKB group prefer to use Belle detector because of easiness of operation-> schedule will delay 1~1.5 years

CO2 cooling We had meeting with KEK cryogenic group about CO2 cooling last month. They said: The cooling power of CO2 system should be less than 3 Reitou- tons( Japanese unit: it means pumping power should be less than 7.5 kW, and parallel ). If our system satisfy this requirement, there are no limitation for system production. If our system power will be higher than requirement, we need permission for each sub-parts. KEK group agree to maintain CO2 system on Belle II operation, then it is better to start discussing about our system outline and schedule (Next B2GM).

Summary The basic design of beam optics is finished Inner structure of beam pipe is almost fixed (on schedule). Still need Sawtooth optimization (beam test on next year) Space assignment with PXD and SVD should be discuss in detail (in particular near 3rd layer SVD) Mechanical analysis estimation and connection test (IP) (OK) Vacuum test on Be-SUS connection (within 1 year) Mockup production (crotch part) BEASTII and neutron simulation discussion are started There are still some open issues (cabling, cooling) 34

Schedule ~2011 Mar. Mechanical design and joint test Mockup production of crotch part 2011- Mechanical design fix (Ridge(Sawtooth), cooling…) Optimizing production procedure Service space allocation SR beam test (May and July:X-ray 5-50 keV) 2012 Beam pipe production 2013 IR Assembly 35

bkup 36

General IR design IR design based on Nano-beam scheme Beam energy was changed to 7x4 GeV (vertical beam size: 940 nm- >59nm) To save the short lifetime for LER(Touschek effect) Crossing angle 83 mrad To make QCS magnets closer to IP Separated final quadrupole magnets Use both of superconducting and permanent magnets Boundary conditions between accelerator and detector are same as the present Angle of 41.5 mrad between HER orbit and Belle To save vertical emittance increase by anti-solenoid fringe fields 37